Initial plugin version

.project

@@ -1,73 +0,0 @@
-<?xml version="1.0" encoding="UTF-8"?>
-<projectDescription>
-	<name>com.minres.scviewer.parent</name>
-	<comment></comment>
-	<projects>
-	</projects>
-	<buildSpec>
-		<buildCommand>
-			<name>org.eclipse.m2e.core.maven2Builder</name>
-			<arguments>
-			</arguments>
-		</buildCommand>
-	</buildSpec>
-	<natures>
-		<nature>org.eclipse.m2e.core.maven2Nature</nature>
-	</natures>
-	<filteredResources>
-		<filter>
-			<id>0</id>
-			<name></name>
-			<type>10</type>
-			<matcher>
-				<id>org.eclipse.ui.ide.multiFilter</id>
-				<arguments>1.0-name-matches-false-false-features</arguments>
-			</matcher>
-		</filter>
-		<filter>
-			<id>0</id>
-			<name></name>
-			<type>10</type>
-			<matcher>
-				<id>org.eclipse.ui.ide.multiFilter</id>
-				<arguments>1.0-name-matches-false-false-plugins</arguments>
-			</matcher>
-		</filter>
-		<filter>
-			<id>0</id>
-			<name></name>
-			<type>10</type>
-			<matcher>
-				<id>org.eclipse.ui.ide.multiFilter</id>
-				<arguments>1.0-name-matches-false-false-com.minres.*</arguments>
-			</matcher>
-		</filter>
-		<filter>
-			<id>0</id>
-			<name></name>
-			<type>10</type>
-			<matcher>
-				<id>org.eclipse.ui.ide.multiFilter</id>
-				<arguments>1.0-name-matches-false-false-product</arguments>
-			</matcher>
-		</filter>
-		<filter>
-			<id>0</id>
-			<name></name>
-			<type>10</type>
-			<matcher>
-				<id>org.eclipse.ui.ide.multiFilter</id>
-				<arguments>1.0-name-matches-false-false-tests</arguments>
-			</matcher>
-		</filter>
-		<filter>
-			<id>0</id>
-			<name></name>
-			<type>10</type>
-			<matcher>
-				<id>org.eclipse.ui.ide.multiFilter</id>
-				<arguments>1.0-name-matches-false-false-p2repositories</arguments>
-			</matcher>
-		</filter>
-	</filteredResources>
-</projectDescription>

README.md

@@ -6,18 +6,30 @@ created by the SystemC VCD trace implementation and the SystemC Verification Lib
 For further description of the SCV please refer to 
 http://www.accellera.org/activities/committees/systemc-verification.
 
-> If you encounter issue when running on Linux please try running as `SWT_GTK3=0 scviewer` as there exist issues wiht GTK3.
-
-The viewer has the following features
-- support of VCD files (compressed and uncompressed)
- - real numbers
- - showing vectors and real numbers as analog (step-wise & continuous)
- - various value representations of bit vectors
-- support of SCV transaction recordings in various formats
- - text log files (compressed and uncompressed)
- - sqlite based 
- - visualization of transaction relations
+The viewer is in early alpha stage and not yet ready for production use!
 
+The plugins are structured as follows:
+- com.minres.scviewer.database
+	the interface defining the API to access the database and the implementation for VCD
+- com.minres.scviewer.database.text
+	an implementation of the API to read the text files generated by the SCV
+	sc_tr_text database
+- com.minres.scviewer.database.sqlite
+	an implementation of the API to read the files generated by implementation in the
+	sc_tr_sqlite project using a SQLite based database
+- com.minres.scviewer.database.test
+	a some JUnit tests of the 3 back ends
+- com.minres.scviewer.ui
+	the viewer it self to diplay the transactions and associated views like the
+	outline of the DB and the properties of the transaction
+- com.minres.scviewer.feature
+	the feature combining the plugins above into a somhow usable form
+- scv_tr_sqlite
+	a C++ project containing the SQLite based SCV database implementation and the scv4tlm 
+	socket implementations.
+	A simple example (scv_tr_recording_example.cpp) for testig purposes of the database is
+	provided. 
+	
 To build the plugins the Eclipse SDK or PDE can be used. In both cases the Groovy
 eclipse plugin (http://groovy.codehaus.org/Eclipse+Plugin or Market) has to be
 installed.
@@ -27,5 +39,4 @@ TODO
 - add more tests
 - move to feature based product to allow automatic updates
 - improve graphics
-- catch-up e3 plugin to functionality of e4 product
-- add calculated traces
+- catch-up e3 plugin to functionality of e4 product

com.minres.scviewer.database.binary/.classpath

@@ -1,7 +1,5 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <classpath>
-	<classpathentry exported="true" kind="lib" path="json-20180813.jar" sourcepath="json-20180813-sources.jar"/>
-	<classpathentry exported="true" kind="lib" path="leveldb-0.11-SNAPSHOT-uber.jar" sourcepath="leveldb-0.11-SNAPSHOT-sources.jar"/>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
 	<classpathentry kind="con" path="org.eclipse.pde.core.requiredPlugins"/>
 	<classpathentry kind="src" path="src"/>

com.minres.scviewer.database.binary/.project

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
 <projectDescription>
-	<name>com.minres.scviewer.database.leveldb</name>
+	<name>com.minres.scviewer.database.binary</name>
 	<comment></comment>
 	<projects>
 	</projects>

com.minres.scviewer.database.binary/META-INF/MANIFEST.MF

@@ -0,0 +1,14 @@
+Manifest-Version: 1.0
+Bundle-ManifestVersion: 2
+Bundle-Name: Binary Database
+Bundle-SymbolicName: com.minres.scviewer.database.binary
+Bundle-Version: 1.0.0.qualifier
+Bundle-Vendor: MINRES Technologies GmbH
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Import-Package: org.eclipse.osgi.framework.console;version="1.0.0",
+ org.osgi.framework;version="1.3.0",
+ org.osgi.service.component.annotations;version="1.2.0";resolution:="optional",
+ org.osgi.util.tracker;version="1.3.1"
+Automatic-Module-Name: com.minres.scviewer.database.binary
+Service-Component: OSGI-INF/*.xml
+Require-Bundle: com.minres.scviewer.database

com.minres.scviewer.database.binary/OSGI-INF/component.xml

@@ -1,6 +1,6 @@
 <?xml version="1.0" encoding="UTF-8"?>
-<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="LevelDbLoader">
-   <implementation class="com.minres.scviewer.database.leveldb.LevelDBLoader"/>
+<scr:component xmlns:scr="http://www.osgi.org/xmlns/scr/v1.1.0" name="BinaryDbLoader">
+   <implementation class="com.minres.scviewer.database.binary.BinaryDbLoader"/>
    <service>
       <provide interface="com.minres.scviewer.database.IWaveformDbLoader"/>
    </service>

com.minres.scviewer.database.binary/build.properties

@@ -0,0 +1,5 @@
+source.. = src/
+output.. = bin/
+bin.includes = META-INF/,\
+               .,\
+               OSGI-INF/

com.minres.scviewer.database.binary/src/com/minres/scviewer/database/binary/BinaryDbLoader.java

@@ -0,0 +1,56 @@
+/*******************************************************************************
+ * Copyright (c) 2015 MINRES Technologies GmbH and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     MINRES Technologies GmbH - initial API and implementation
+ *******************************************************************************/
+package com.minres.scviewer.database.binary;
+
+import java.io.File;
+import java.util.ArrayList;
+import java.util.Collection;
+import java.util.List;
+
+import com.minres.scviewer.database.IWaveform;
+import com.minres.scviewer.database.IWaveformDb;
+import com.minres.scviewer.database.IWaveformDbLoader;
+import com.minres.scviewer.database.IWaveformEvent;
+import com.minres.scviewer.database.RelationType;
+
+public class BinaryDbLoader implements IWaveformDbLoader {
+
+	
+	private List<RelationType> usedRelationsList = new ArrayList<>();
+
+	private IWaveformDb db;
+	
+		
+	public BinaryDbLoader() {
+	}
+
+	@Override
+	public Long getMaxTime() {
+		return 0L;
+	}
+
+	@Override
+	public List<IWaveform<? extends IWaveformEvent>> getAllWaves() {
+		List<IWaveform<? extends IWaveformEvent>> streams=new ArrayList<IWaveform<? extends IWaveformEvent>>();
+		return streams;
+	}
+
+	@Override
+	public boolean load(IWaveformDb db, File file) throws Exception {
+		return false;
+	}
+	
+	@Override
+	public Collection<RelationType> getAllRelationTypes(){
+		return usedRelationsList;
+	}
+
+}

com.minres.scviewer.database.sqlite/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+encoding/<project>=UTF-8

com.minres.scviewer.database.sqlite/META-INF/MANIFEST.MF

@@ -5,11 +5,13 @@ Bundle-SymbolicName: com.minres.scviewer.database.sqlite
 Bundle-Version: 1.0.0.qualifier
 Bundle-Vendor: MINRES Technologies GmbH
 Bundle-RequiredExecutionEnvironment: JavaSE-1.8
-Require-Bundle: com.minres.scviewer.database;bundle-version="1.0.0"
+Require-Bundle: com.minres.scviewer.database;bundle-version="1.0.0",
+ org.eclipse.equinox.util;bundle-version="1.0.500",
+ org.eclipse.equinox.ds;bundle-version="1.4.200",
+ org.eclipse.osgi.services;bundle-version="3.4.0"
 Bundle-ClassPath: .,sqlite-jdbc-3.8.7.jar
 Service-Component: OSGI-INF/component.xml
 Bundle-ActivationPolicy: lazy
 Embed-Dependency: sqlite-jdbc
 Embedded-Artifacts: sqlite-jdbc-3.8.7.jar;g="org.xerial";
  a="sqlite-jdbc";v="3.8.7"
-Automatic-Module-Name: com.minres.scviewer.database.sqlite

com.minres.scviewer.database.sqlite/pom.xml

@@ -4,8 +4,8 @@
   <parent>
   	<groupId>com.minres.scviewer</groupId>
   	<artifactId>com.minres.scviewer.parent</artifactId>
-  	<version>2.0.0-SNAPSHOT</version>
-	<relativePath>../..</relativePath>
+  	<version>1.0.0-SNAPSHOT</version>
+  	<relativePath>../com.minres.scviewer.parent</relativePath>
   </parent>
   <packaging>eclipse-plugin</packaging>
   <dependencies>
@@ -15,5 +15,4 @@
   		<version>3.8.7</version>
   	</dependency>
   </dependencies>
-  <version>1.0.0-SNAPSHOT</version>
-</project>
+  </project>

com.minres.scviewer.database.sqlite/src/com/minres/scviewer/database/sqlite/SQLiteDbLoader.java

@@ -13,8 +13,6 @@ package com.minres.scviewer.database.sqlite;
 import java.beans.IntrospectionException;
 import java.io.File;
 import java.io.FileInputStream;
-import java.io.FileNotFoundException;
-import java.io.IOException;
 import java.lang.reflect.InvocationTargetException;
 import java.sql.SQLException;
 import java.util.ArrayList;
@@ -24,6 +22,7 @@ import java.util.List;
 import com.minres.scviewer.database.IWaveform;
 import com.minres.scviewer.database.IWaveformDb;
 import com.minres.scviewer.database.IWaveformDbLoader;
+import com.minres.scviewer.database.IWaveformEvent;
 import com.minres.scviewer.database.RelationType;
 import com.minres.scviewer.database.sqlite.db.IDatabase;
 import com.minres.scviewer.database.sqlite.db.SQLiteDatabase;
@@ -61,9 +60,9 @@ public class SQLiteDbLoader implements IWaveformDbLoader {
 	}
 
 	@Override
-	public Collection<IWaveform> getAllWaves() {
+	public List<IWaveform<? extends IWaveformEvent>> getAllWaves() {
 		SQLiteDatabaseSelectHandler<ScvStream> handler = new SQLiteDatabaseSelectHandler<ScvStream>(ScvStream.class, database);
-		List<IWaveform> streams=new ArrayList<IWaveform>();
+		List<IWaveform<? extends IWaveformEvent>> streams=new ArrayList<IWaveform<? extends IWaveformEvent>>();
 		try {
 			for(ScvStream scvStream:handler.selectObjects()){
 				TxStream stream = new TxStream(database, db, scvStream);
@@ -81,21 +80,15 @@ public class SQLiteDbLoader implements IWaveformDbLoader {
 
 	@Override
 	public boolean load(IWaveformDb db, File file) throws Exception {
-		if(file.isDirectory() || !file.exists()) return false;
 		this.db=db;
-		try {
-			FileInputStream fis = new FileInputStream(file);
-			byte[] buffer = new byte[x.length];
-			int read = fis.read(buffer, 0, x.length);
-			fis.close();
-			if (read == x.length)
-				for (int i = 0; i < x.length; i++)
-					if (buffer[i] != x[i])	return false;
-		} catch(FileNotFoundException e) {
-			return false;
-		} catch(IOException e) { //if an I/O error occurs
-			return false;
-		}
+		FileInputStream fis = new FileInputStream(file);
+		byte[] buffer = new byte[x.length];
+		int read = fis.read(buffer, 0, x.length);
+		fis.close();
+		if (read == x.length)
+			for (int i = 0; i < x.length; i++)
+				if (buffer[i] != x[i])	return false;
+
 		database=new SQLiteDatabase(file.getAbsolutePath());
 		database.setData("TIMERESOLUTION", 1L);
 		SQLiteDatabaseSelectHandler<ScvSimProps> handler = new SQLiteDatabaseSelectHandler<ScvSimProps>(ScvSimProps.class, database);

com.minres.scviewer.database.sqlite/src/com/minres/scviewer/database/sqlite/TxStream.java

@@ -29,6 +29,7 @@ import com.minres.scviewer.database.ITxGenerator;
 import com.minres.scviewer.database.ITxStream;
 import com.minres.scviewer.database.IWaveform;
 import com.minres.scviewer.database.IWaveformDb;
+import com.minres.scviewer.database.IWaveformEvent;
 import com.minres.scviewer.database.RelationType;
 import com.minres.scviewer.database.sqlite.db.IDatabase;
 import com.minres.scviewer.database.sqlite.db.SQLiteDatabaseSelectHandler;
@@ -116,7 +117,6 @@ public class TxStream extends HierNode implements ITxStream<ITxEvent> {
 				sb.append(scvStream.getId());
 				resultSet = statement.executeQuery(sb.toString());
 				while (resultSet.next()) {
-					if(maxConcurrency==null) maxConcurrency=0;
 					Object value = resultSet.getObject("concurrencyLevel");
 					if(value!=null)
 						maxConcurrency=(Integer) value;
@@ -192,8 +192,8 @@ public class TxStream extends HierNode implements ITxStream<ITxEvent> {
 	}
 
 	@Override
-	public Boolean equals(IWaveform other) {
-		return(other instanceof TxStream && this.getId().equals(other.getId()));
+	public Boolean equals(IWaveform<? extends IWaveformEvent> other) {
+		return(other instanceof TxStream && this.getId()==other.getId());
 	}
 
 }

com.minres.scviewer.database.test/.settings/org.eclipse.core.resources.prefs

@@ -0,0 +1,3 @@
+eclipse.preferences.version=1
+encoding//src/com/minres/scviewer/database/test/DatabaseServicesTest.java=UTF-8
+encoding/<project>=UTF-8

com.minres.scviewer.database.test/DatabaseServicesTest.launch

@@ -0,0 +1,46 @@
+<?xml version="1.0" encoding="UTF-8" standalone="no"?>
+<launchConfiguration type="org.eclipse.pde.ui.JunitLaunchConfig">
+<booleanAttribute key="append.args" value="true"/>
+<stringAttribute key="application" value="org.eclipse.pde.junit.runtime.coretestapplication"/>
+<booleanAttribute key="askclear" value="false"/>
+<booleanAttribute key="automaticAdd" value="true"/>
+<booleanAttribute key="automaticValidate" value="false"/>
+<stringAttribute key="bootstrap" value=""/>
+<stringAttribute key="checked" value="[NONE]"/>
+<booleanAttribute key="clearConfig" value="true"/>
+<booleanAttribute key="clearws" value="true"/>
+<booleanAttribute key="clearwslog" value="false"/>
+<stringAttribute key="configLocation" value="${workspace_loc}/.metadata/.plugins/org.eclipse.pde.core/pde-junit"/>
+<booleanAttribute key="default" value="false"/>
+<stringAttribute key="deselected_workspace_plugins" value="com.minres.scviewer.e4.application,com.minres.scviewer.ui"/>
+<booleanAttribute key="includeOptional" value="true"/>
+<stringAttribute key="location" value="${workspace_loc}/../junit-workspace"/>
+<listAttribute key="org.eclipse.debug.core.MAPPED_RESOURCE_PATHS">
+<listEntry value="/com.minres.scviewer.database.test"/>
+</listAttribute>
+<listAttribute key="org.eclipse.debug.core.MAPPED_RESOURCE_TYPES">
+<listEntry value="4"/>
+</listAttribute>
+<stringAttribute key="org.eclipse.jdt.junit.CONTAINER" value="=com.minres.scviewer.database.test"/>
+<booleanAttribute key="org.eclipse.jdt.junit.KEEPRUNNING_ATTR" value="false"/>
+<stringAttribute key="org.eclipse.jdt.junit.TESTNAME" value=""/>
+<stringAttribute key="org.eclipse.jdt.junit.TEST_KIND" value="org.eclipse.jdt.junit.loader.junit4"/>
+<booleanAttribute key="org.eclipse.jdt.launching.ATTR_USE_START_ON_FIRST_THREAD" value="true"/>
+<stringAttribute key="org.eclipse.jdt.launching.JRE_CONTAINER" value="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
+<stringAttribute key="org.eclipse.jdt.launching.MAIN_TYPE" value=""/>
+<stringAttribute key="org.eclipse.jdt.launching.PROGRAM_ARGUMENTS" value="-os ${target.os} -ws ${target.ws} -arch ${target.arch} -nl ${target.nl} -consoleLog"/>
+<stringAttribute key="org.eclipse.jdt.launching.PROJECT_ATTR" value="com.minres.scviewer.database.test"/>
+<stringAttribute key="org.eclipse.jdt.launching.SOURCE_PATH_PROVIDER" value="org.eclipse.pde.ui.workbenchClasspathProvider"/>
+<stringAttribute key="org.eclipse.jdt.launching.VM_ARGUMENTS" value="-Xms40m -Xmx512m"/>
+<stringAttribute key="pde.version" value="3.3"/>
+<stringAttribute key="product" value="com.minres.scviewer.e4.product"/>
+<booleanAttribute key="run_in_ui_thread" value="true"/>
+<stringAttribute key="selected_target_plugins" value="com.google.guava@default:default,javax.annotation@default:default,javax.inject@default:default,javax.servlet@default:default,javax.xml@default:default,org.apache.ant@default:default,org.apache.commons.jxpath@default:default,org.apache.felix.gogo.command@default:default,org.apache.felix.gogo.runtime@default:default,org.codehaus.groovy@default:default,org.eclipse.ant.core@default:default,org.eclipse.core.commands@default:default,org.eclipse.core.contenttype@default:default,org.eclipse.core.expressions@default:default,org.eclipse.core.filesystem@default:default,org.eclipse.core.jobs@default:default,org.eclipse.core.resources@default:default,org.eclipse.core.runtime@default:true,org.eclipse.core.variables@default:default,org.eclipse.e4.core.contexts@default:default,org.eclipse.e4.core.di.annotations@default:default,org.eclipse.e4.core.di.extensions@default:default,org.eclipse.e4.core.di@default:default,org.eclipse.e4.core.services@default:default,org.eclipse.e4.emf.xpath@default:default,org.eclipse.e4.ui.di@default:default,org.eclipse.e4.ui.model.workbench@default:default,org.eclipse.e4.ui.services@default:default,org.eclipse.emf.common@default:default,org.eclipse.emf.ecore@default:default,org.eclipse.equinox.app@default:default,org.eclipse.equinox.bidi@default:default,org.eclipse.equinox.common@2:true,org.eclipse.equinox.ds@1:true,org.eclipse.equinox.preferences@default:default,org.eclipse.equinox.registry@default:default,org.eclipse.equinox.util@default:default,org.eclipse.jface@default:default,org.eclipse.osgi.compatibility.state@default:false,org.eclipse.osgi.services@default:default,org.eclipse.osgi@-1:true,org.eclipse.swt@default:default,org.hamcrest.core@default:default,org.junit@default:default"/>
+<stringAttribute key="selected_workspace_plugins" value="com.minres.scviewer.database.binary@default:default,com.minres.scviewer.database.sqlite@default:true,com.minres.scviewer.database.test@default:default,com.minres.scviewer.database.text@default:true,com.minres.scviewer.database.ui.swt@default:default,com.minres.scviewer.database.ui@default:default,com.minres.scviewer.database.vcd@default:default,com.minres.scviewer.database@default:true,com.opcoach.e4.preferences@default:default"/>
+<booleanAttribute key="show_selected_only" value="false"/>
+<booleanAttribute key="tracing" value="false"/>
+<booleanAttribute key="useCustomFeatures" value="false"/>
+<booleanAttribute key="useDefaultConfig" value="true"/>
+<booleanAttribute key="useDefaultConfigArea" value="false"/>
+<booleanAttribute key="useProduct" value="false"/>
+</launchConfiguration>

com.minres.scviewer.database.test/META-INF/MANIFEST.MF

@@ -2,7 +2,7 @@ Manifest-Version: 1.0
 Bundle-ManifestVersion: 2
 Bundle-Name: SCViewer database tests
 Bundle-SymbolicName: com.minres.scviewer.database.test
-Bundle-Version: 1.0.1.qualifier
+Bundle-Version: 1.0.0.qualifier
 Bundle-Vendor: MINRES Technologies GnbH
 Bundle-RequiredExecutionEnvironment: JavaSE-1.8
 Require-Bundle: org.junit,
@@ -12,4 +12,3 @@ Require-Bundle: org.junit,
  com.minres.scviewer.database.vcd;bundle-version="1.0.0"
 Bundle-ActivationPolicy: lazy
 Service-Component: OSGI-INF/component.xml
-Automatic-Module-Name: com.minres.scviewer.database.test

com.minres.scviewer.database.test/inputs/.gitignore

@@ -0,0 +1,2 @@
+/.scviewer.*
+/.my_db.txlog*

com.minres.scviewer.database.test/pom.xml

@@ -2,12 +2,11 @@
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>com.minres.scviewer.database.test</artifactId>
-	<version>1.0.1-SNAPSHOT</version>
 	<parent>
 		<groupId>com.minres.scviewer</groupId>
 		<artifactId>com.minres.scviewer.parent</artifactId>
-		<version>2.0.0-SNAPSHOT</version>
-		<relativePath>../..</relativePath>
+		<version>1.0.0-SNAPSHOT</version>
+		<relativePath>../com.minres.scviewer.parent</relativePath>
 	</parent>
 	<packaging>eclipse-test-plugin</packaging>
 	<build>
@@ -15,8 +14,17 @@
 			<plugin>
 				<groupId>org.eclipse.tycho</groupId>
 				<artifactId>tycho-surefire-plugin</artifactId>
-				<version>${tycho-version}</version>
+				<version>0.23.1</version>
+				<configuration>
+<!-- 					<bundleStartLevel /> -->
+					<dependencies>
+						<dependency>
+							<type>p2-installable-unit</type>
+							<artifactId>org.eclipse.equinox.ds</artifactId>
+						</dependency>
+					</dependencies>
+				</configuration>
 			</plugin>
 		</plugins>
 	</build>
-</project>
+	</project>

com.minres.scviewer.database.test/src/com/minres/scviewer/database/test/DatabaseServicesTest.java

@@ -0,0 +1,90 @@
+/*******************************************************************************
+ * Copyright (c) 2015 MINRES Technologies GmbH and others.
+ * All rights reserved. This program and the accompanying materials
+ * are made available under the terms of the Eclipse Public License v1.0
+ * which accompanies this distribution, and is available at
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     MINRES Technologies GmbH - initial API and implementation
+ *******************************************************************************/
+package com.minres.scviewer.database.test;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotNull;
+import static org.junit.Assert.assertTrue;
+
+import java.io.File;
+
+import org.junit.After;
+import org.junit.Before;
+import org.junit.Test;
+
+import com.minres.scviewer.database.IWaveformDb;
+import com.minres.scviewer.database.IWaveformDbFactory;
+
+public class DatabaseServicesTest {
+
+
+	private static IWaveformDbFactory waveformDbFactory;
+
+	private IWaveformDb waveformDb;
+	
+	public synchronized void setFactory(IWaveformDbFactory service) {
+		waveformDbFactory = service;
+	}
+
+	public synchronized void unsetFactory(IWaveformDbFactory service) {
+		if (waveformDbFactory == service) {
+			waveformDbFactory = null;
+		}
+	}
+	
+	@Before
+	public void setUp() throws Exception {
+		waveformDb=waveformDbFactory.getDatabase();
+		// Wait for OSGi dependencies
+//		for (int i = 0; i < 10; i++) {
+//			if (waveformDb.size() == 3) // Dependencies fulfilled
+//				return;
+//			Thread.sleep(1000);
+//		}
+//		assertEquals("OSGi dependencies unfulfilled", 3, WaveformDb.getLoaders().size());
+	}
+
+	@After
+	public void tearDown() throws Exception {
+	}
+
+	@Test
+	public void testVCD() throws Exception {
+		File f = new File("inputs/my_db.vcd").getAbsoluteFile();
+		assertTrue(f.exists());
+		waveformDb.load(f);
+		assertNotNull(waveformDb);
+		assertEquals(14,  waveformDb.getAllWaves().size());
+		assertEquals(2,  waveformDb.getChildNodes().size());
+	}
+
+	@Test
+	public void testTxSQLite() throws Exception {
+		File f = new File("inputs/my_db.txdb").getAbsoluteFile();
+		assertTrue(f.exists());
+		waveformDb.load(f);
+		assertNotNull(waveformDb);
+		assertEquals(3,  waveformDb.getAllWaves().size());
+		assertEquals(1,  waveformDb.getChildNodes().size());
+	}
+
+	@Test
+	public void testTxText() throws Exception {
+		File f = new File("inputs/my_db.txlog").getAbsoluteFile();
+		assertTrue(f.exists());
+		waveformDb.load(f);
+		assertNotNull(waveformDb);
+		assertEquals(3,  waveformDb.getAllWaves().size());
+		assertEquals(1,  waveformDb.getChildNodes().size());
+	}
+
+
+}

com.minres.scviewer.database.text/.classpath

@@ -2,6 +2,7 @@
 <classpath>
 	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
 	<classpathentry kind="con" path="org.eclipse.pde.core.requiredPlugins"/>
-	<classpathentry kind="src" path="src/"/>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry exported="true" kind="con" path="GROOVY_DSL_SUPPORT"/>
 	<classpathentry kind="output" path="target/classes"/>
 </classpath>

com.minres.scviewer.database.text/.settings/org.eclipse.jdt.groovy.core.prefs

@@ -0,0 +1,2 @@
+eclipse.preferences.version=1
+groovy.compiler.level=23

com.minres.scviewer.database.text/META-INF/MANIFEST.MF

@@ -0,0 +1,17 @@
+Manifest-Version: 1.0
+Bundle-ManifestVersion: 2
+Bundle-Name: Textual transaction database
+Bundle-SymbolicName: com.minres.scviewer.database.text
+Bundle-Version: 1.0.0.qualifier
+Bundle-Vendor: MINRES Technologies GmbH
+Bundle-RequiredExecutionEnvironment: JavaSE-1.8
+Import-Package: com.minres.scviewer.database,
+ org.osgi.framework;version="1.3.0"
+Require-Bundle: com.minres.scviewer.database;bundle-version="1.0.0",
+ org.codehaus.groovy;bundle-version="1.8.6",
+ org.eclipse.equinox.util;bundle-version="1.0.500",
+ org.eclipse.equinox.ds;bundle-version="1.4.200",
+ org.eclipse.osgi.services;bundle-version="3.4.0",
+ com.google.guava;bundle-version="15.0.0"
+Service-Component: OSGI-INF/component.xml
+Bundle-ActivationPolicy: lazy

com.minres.scviewer.database.text/build.properties

@@ -10,16 +10,6 @@
 ###############################################################################
 bin.includes = META-INF/,\
                .,\
-               OSGI-INF/,\
-               lib/,\
-               lib/mapdb-3.0.7.jar,\
-               lib/eclipse-collections-9.2.0.jar,\
-               lib/eclipse-collections-api-9.2.0.jar,\
-               lib/eclipse-collections-forkjoin-9.2.0.jar,\
-               lib/kotlin-stdlib-1.2.42.jar,\
-               lib/lz4-1.3.0.jar,\
-               lib/elsa-3.0.0-M5.jar
-bin.excludes = **/*.groovy,\
-               lib/mapdb-3.0.7-sources.jar,\
-               lib/mapdb-3.0.7-javadoc.jar
+               OSGI-INF/
+bin.excludes = **/*.groovy
 source.. = src/

com.minres.scviewer.database.text/pom.xml

@@ -2,30 +2,25 @@
 	xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd">
 	<modelVersion>4.0.0</modelVersion>
 	<artifactId>com.minres.scviewer.database.text</artifactId>
-	<version>2.0.2-SNAPSHOT</version>
 	<parent>
 		<groupId>com.minres.scviewer</groupId>
 		<artifactId>com.minres.scviewer.parent</artifactId>
-		<version>2.0.0-SNAPSHOT</version>
-		<relativePath>../..</relativePath>
+		<version>1.0.0-SNAPSHOT</version>
+		<relativePath>../com.minres.scviewer.parent</relativePath>
 	</parent>
 	<packaging>eclipse-plugin</packaging>
-	
 	<build>
-		<plugins>
-			<plugin>
+	<plugins>
+				<plugin>
 				<groupId>org.eclipse.tycho</groupId>
-				<artifactId>maven-compiler-plugin</artifactId>
-				<version>3.8.0</version>
+				<artifactId>tycho-compiler-plugin</artifactId>
+        		<version>0.23.1</version>
 				<configuration>
 					<compilerId>groovy-eclipse-compiler</compilerId>
-			        <compilerArguments>
-			            <indy/><!-- optional; supported by batch 2.4.12-04+ -->
-			        </compilerArguments>
 					<!-- set verbose to be true if you want lots of uninteresting messages -->
 					<!-- <verbose>true</verbose> -->
-					<source>1.8</source>
-					<target>1.8</target>
+					<source>1.7</source>
+					<target>1.7</target>
 				</configuration>
 				<dependencies>
 					<dependency>
@@ -37,9 +32,11 @@
 						<groupId>org.codehaus.groovy</groupId>
 						<artifactId>groovy-eclipse-batch</artifactId>
 						<version>${groovy-eclipse-batch-version}</version>
+						<!-- or choose a different compiler version -->
+						<!-- <version>2.1.8-01</version> -->
 					</dependency>
 				</dependencies>
 			</plugin>
-		</plugins>
+	</plugins>
 	</build>
-</project>
+	</project>

com.minres.scviewer.database.text/src/com/minres/scviewer/database/text/TextDbLoader.groovy

@@ -13,11 +13,8 @@ package com.minres.scviewer.database.text;
 import java.nio.charset.CharsetDecoder;
 import java.util.Collection;
 import java.util.zip.GZIPInputStream
-
-import org.codehaus.groovy.ast.stmt.CatchStatement
-import org.mapdb.DB
-import org.mapdb.DBMaker
-
+import org.apache.jdbm.DB
+import org.apache.jdbm.DBMaker
 import groovy.io.FileType
 
 import com.minres.scviewer.database.AssociationType
@@ -35,12 +32,12 @@ public class TextDbLoader implements IWaveformDbLoader{
 
 	IWaveformDb db;
 
+	DB backingDb;
+
 	def streams = []
 
 	def relationTypes=[:]
 
-	DB mapDb
-	
 	public TextDbLoader() {
 	}
 
@@ -50,8 +47,8 @@ public class TextDbLoader implements IWaveformDbLoader{
 	}
 
 	@Override
-	public Collection<IWaveform> getAllWaves() {
-		return streams;
+	public List<IWaveform> getAllWaves() {
+		return new LinkedList<IWaveform>(streams);
 	}
 
 	public Map<Long, ITxGenerator> getGeneratorsById() {
@@ -64,40 +61,27 @@ public class TextDbLoader implements IWaveformDbLoader{
 
 	@Override
 	boolean load(IWaveformDb db, File file) throws Exception {
-		if(file.isDirectory() || !file.exists()) return false;
 		this.db=db
 		this.streams=[]
-		try {
-			def gzipped = isGzipped(file)
-			if(isTxfile(gzipped?new GZIPInputStream(new FileInputStream(file)):new FileInputStream(file))){
-				def mapDbFile = File.createTempFile("."+file.name, null /*"tmp"*/, null /*file.parentFile*/)
-				mapDbFile.delete()
-				mapDbFile.deleteOnExit()
-				this.mapDb = DBMaker
-				.fileDB(mapDbFile)
-				.fileMmapEnableIfSupported()
-				.fileMmapPreclearDisable()
-				.cleanerHackEnable()
-				.allocateStartSize(64*1024*1024)
-				.allocateIncrement(64*1024*1024)
-				.make()
-				// NPE here --->
-				parseInput(gzipped?new GZIPInputStream(new FileInputStream(file)):new FileInputStream(file))
-				streams.each{ TxStream  stream -> stream.getMaxConcurrency() }
-				return true
+		def gzipped = isGzipped(file)
+		if(isTxfile(gzipped?new GZIPInputStream(new FileInputStream(file)):new FileInputStream(file))){
+			if(true) {
+				def parentDir=file.absoluteFile.parent
+				def filename=file.name
+				new File(parentDir).eachFileRecurse (FileType.FILES) { f -> if(f.name=~/^\.${filename}/) f.delete() }
+				this.backingDb = DBMaker.openFile(parentDir+File.separator+"."+filename+"_bdb")
+						.deleteFilesAfterClose()
+						.useRandomAccessFile()
+						.setMRUCacheSize(4096) 
+						//.disableTransactions()
+						.disableLocking()
+						.make();
+			} else {
+				this.backingDb = DBMaker.openMemory().disableLocking().make()
 			}
-		} catch (IndexOutOfBoundsException e) {
-			return false
-		} catch (IllegalArgumentException e) {
-			return false
-		} catch (NumberFormatException e) {
-			return false
-		} catch(EOFException e) {
-			return true;
-		} catch(Exception e) {
-			System.out.println("---->>> Exception "+e.toString()+" caught while loading database");
-			//System.out.println("---->>> Exception "+e.toString()+" caught while loading database. StackTrace following... ");
-			//e.printStackTrace()
+			parseInput(gzipped?new GZIPInputStream(new FileInputStream(file)):new FileInputStream(file))
+			calculateConcurrencyIndicees()
+			return true
 		}
 		return false;
 	}
@@ -123,7 +107,7 @@ public class TextDbLoader implements IWaveformDbLoader{
 		} catch (IOException e) {
 			return false;
 		} finally {
-			if(is!=null) is.close()
+			is.close()
 		}
 	}
 
@@ -136,9 +120,7 @@ public class TextDbLoader implements IWaveformDbLoader{
 			case "ms":return 1000000000000L
 			case "s": return 1000000000000000L
 		}
-		return 1L
 	}
-	
 	private def parseInput(InputStream inputStream){
 		def streamsById = [:]
 		def generatorsById = [:]
@@ -150,32 +132,26 @@ public class TextDbLoader implements IWaveformDbLoader{
 		BufferedReader reader = new BufferedReader(new InputStreamReader(inputStream, "UTF-8"));
 		long lineCnt=0;
 		reader.eachLine { line ->
-			def tokens = line.split(/\s+/) as ArrayList
+			def tokens = line.split(/\s+/)
 			switch(tokens[0]){
 				case "scv_tr_stream":
+				case "scv_tr_generator":
+				case "begin_attribute":
+				case "end_attribute":
 					if ((matcher = line =~ /^scv_tr_stream\s+\(ID (\d+),\s+name\s+"([^"]+)",\s+kind\s+"([^"]+)"\)$/)) {
 						def id = Integer.parseInt(matcher[0][1])
-						def stream = new TxStream(this, id, matcher[0][2], matcher[0][3])
+						def stream = new TxStream(db, id, matcher[0][2], matcher[0][3], backingDb)
 						streams<<stream
 						streamsById[id]=stream
-					}
-					break;
-				case "scv_tr_generator":
-					if ((matcher = line =~ /^scv_tr_generator\s+\(ID\s+(\d+),\s+name\s+"([^"]+)",\s+scv_tr_stream\s+(\d+),$/)) {
+					} else if ((matcher = line =~ /^scv_tr_generator\s+\(ID\s+(\d+),\s+name\s+"([^"]+)",\s+scv_tr_stream\s+(\d+),$/)) {
 						def id = Integer.parseInt(matcher[0][1])
 						ITxStream stream=streamsById[Integer.parseInt(matcher[0][3])]
 						generator=new TxGenerator(id, stream, matcher[0][2])
 						stream.generators<<generator
 						generatorsById[id]=generator
-					}
-					break;
-				case "begin_attribute":
-					if ((matcher = line =~ /^begin_attribute \(ID (\d+), name "([^"]+)", type "([^"]+)"\)$/)) {
+					} else if ((matcher = line =~ /^begin_attribute \(ID (\d+), name "([^"]+)", type "([^"]+)"\)$/)) {
 						generator.begin_attrs << TxAttributeType.getAttrType(matcher[0][2], DataType.valueOf(matcher[0][3]), AssociationType.BEGIN)
-					}
-					break;
-				case "end_attribute":
-					if ((matcher = line =~ /^end_attribute \(ID (\d+), name "([^"]+)", type "([^"]+)"\)$/)) {
+					} else if ((matcher = line =~ /^end_attribute \(ID (\d+), name "([^"]+)", type "([^"]+)"\)$/)) {
 						generator.end_attrs << TxAttributeType.getAttrType(matcher[0][2], DataType.valueOf(matcher[0][3]), AssociationType.END)
 					}
 					break;
@@ -203,18 +179,13 @@ public class TextDbLoader implements IWaveformDbLoader{
 					break
 				case "tx_record_attribute"://matcher = line =~ /^tx_record_attribute\s+(\d+)\s+"([^"]+)"\s+(\S+)\s*=\s*(.+)$/
 					def id = Integer.parseInt(tokens[1])
-					def name = tokens[2][1..-2]
-					def type = tokens[3] as DataType
-					def remaining = tokens.size()>5?tokens[5..-1].join(' '):""
-					transactionsById[id].attributes<<new TxAttribute(name, type, AssociationType.RECORD, remaining)
+					transactionsById[id].attributes<<new TxAttribute(tokens[2][1..-2], DataType.valueOf(tokens[3]), AssociationType.RECORD, tokens[5..-1].join(' '))
 					break
 				case "a"://matcher = line =~ /^a\s+(.+)$/
 					if(endTransaction){
-						transaction.attributes << new TxAttribute(transaction.generator.end_attrs[transaction.generator.end_attrs_idx], tokens[1])
-						transaction.generator.end_attrs_idx++
+						transaction.attributes << new TxAttribute(transaction.generator.end_attrs[0], tokens[1])
 					} else {
-						transaction.attributes << new TxAttribute(transaction.generator.begin_attrs[transaction.generator.begin_attrs_idx], tokens[1])
-						transaction.generator.begin_attrs_idx++
+						transaction.attributes << new TxAttribute(transaction.generator.begin_attrs[0], tokens[1])
 					}
 					break
 				case "tx_relation"://matcher = line =~ /^tx_relation\s+\"(\S+)\"\s+(\d+)\s+(\d+)$/
@@ -231,9 +202,17 @@ public class TextDbLoader implements IWaveformDbLoader{
 
 			}
 			lineCnt++
+			if((lineCnt%1000) == 0) {
+				backingDb.commit()
+			}
 		}
 	}
 
+	private def calculateConcurrencyIndicees(){
+		streams.each{ TxStream  stream -> stream.getMaxConcurrency() }
+	}
+
+
 	public Collection<RelationType> getAllRelationTypes(){
 		return relationTypes.values();
 	}

com.minres.scviewer.database.text/src/com/minres/scviewer/database/text/TxStream.groovy

@@ -16,9 +16,7 @@ import java.util.Comparator;
 import java.util.List;
 import java.util.Map;
 import java.util.NavigableMap;
-
-import org.mapdb.Serializer
-
+import org.apache.jdbm.DB
 import com.minres.scviewer.database.ITxEvent;
 import com.minres.scviewer.database.IWaveform;
 import com.minres.scviewer.database.IWaveformDb
@@ -45,15 +43,15 @@ class TxStream extends HierNode implements ITxStream {
 	
 	private TreeMap<Long, List<ITxEvent>> events
 	
-	TxStream(TextDbLoader loader, int id, String name, String kind){
+	TxStream(IWaveformDb db, int id, String name, String kind, DB backingStore){
 		super(name)
 		this.id=id
-		this.database=loader.db
+		this.database=db
 		this.fullName=name
 		this.kind=kind
 		this.maxConcurrency=0
 		//events = new TreeMap<Long, List<ITxEvent>>()
-		events = loader.mapDb.treeMap(name).keySerializer(Serializer.LONG).createOrOpen();
+		events=backingStore.createTreeMap("stream-"+name)
 	}
 
 	List<ITxGenerator> getGenerators(){
@@ -112,7 +110,7 @@ class TxStream extends HierNode implements ITxStream {
 	}
 	
 	@Override
-	public Boolean equals(IWaveform other) {
+	public Boolean equals(IWaveform<? extends IWaveformEvent> other) {
 		return(other instanceof TxStream && this.getId()==other.getId());
 	}
 

com.minres.scviewer.database.text/src/org/apache/jdbm/BTree.java

@@ -0,0 +1,706 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+package org.apache.jdbm;
+
+import java.io.*;
+import java.util.Arrays;
+import java.util.Comparator;
+import java.util.List;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+/**
+ * B+Tree persistent indexing data structure.  B+Trees are optimized for
+ * block-based, random I/O storage because they store multiple keys on
+ * one tree node (called <code>BTreeNode</code>).  In addition, the leaf nodes
+ * directly contain (inline) small values associated with the keys, allowing a
+ * single (or sequential) disk read of all the values on the node.
+ * <p/>
+ * B+Trees are n-airy, yeilding log(N) search cost.  They are self-balancing,
+ * preventing search performance degradation when the size of the tree grows.
+ * <p/>
+ * BTree stores its keys sorted. By default JDBM expects key to implement
+ * <code>Comparable</code> interface but user may supply its own <code>Comparator</code>
+ * at BTree creation time. Comparator is serialized and stored as part of BTree.
+ * <p/>
+ * The B+Tree allows traversing the keys in forward and reverse order using a
+ * TupleBrowser obtained from the browse() methods. But it is better to use
+ * <code>BTreeMap</code> wrapper which implements <code>SortedMap</code> interface
+ * <p/>
+ * This implementation does not directly support duplicate keys. It is
+ * possible to handle duplicates by grouping values using an ArrayList as value.
+ * This scenario is supported by JDBM serialization so there is no big performance penalty.
+ * <p/>
+ * There is no limit on key size or value size, but it is recommended to keep
+ * keys as small as possible to reduce disk I/O. If serialized value exceeds 32 bytes,
+ * it is stored in separate record and tree contains only recid reference to it.
+ * BTree uses delta compression for its keys.
+ *
+ *
+ * @author Alex Boisvert
+ * @author Jan Kotek
+ */
+class BTree<K, V> {
+
+
+    private static final boolean DEBUG = false;
+
+
+    /**
+     * Default node size (number of entries per node)
+     */
+    public static final int DEFAULT_SIZE = 32; //TODO test optimal size, it has serious impact on sequencial write and read
+
+
+    /**
+     * Record manager used to persist changes in BTreeNodes
+     */
+    protected transient DBAbstract _db;
+
+
+    /**
+     * This BTree's record ID in the DB.
+     */
+    private transient long _recid;
+
+
+    /**
+     * Comparator used to index entries (optional)
+     */
+    protected Comparator<K> _comparator;
+
+
+    /**
+     * Serializer used to serialize index keys (optional)
+     */
+    protected Serializer<K> keySerializer;
+
+
+    /**
+     * Serializer used to serialize index values (optional)
+     */
+    protected Serializer<V> valueSerializer;
+
+    /**
+     * indicates if values should be loaded during deserialization, set to false during defragmentation
+     */
+    boolean loadValues = true;
+
+    /** if false map contains only keys, used for set*/
+    boolean hasValues = true;
+
+    /**
+     * The number of structural modifications to the tree for fail fast iterators. This value is just for runtime, it is not persisted
+     */
+    transient int modCount = 0;
+
+    /**
+     * cached instance of an insert result, so we do not have to allocate new object on each insert
+     */
+    protected BTreeNode.InsertResult<K, V> insertResultReuse; //TODO investigate performance impact of removing this
+
+
+    public Serializer<K> getKeySerializer() {
+        return keySerializer;
+    }
+
+
+
+
+    public Serializer<V> getValueSerializer() {
+        return valueSerializer;
+    }
+
+
+    /**
+     * Height of the B+Tree.  This is the number of BTreeNodes you have to traverse
+     * to get to a leaf BTreeNode, starting from the root.
+     */
+    private int _height;
+
+
+    /**
+     * Recid of the root BTreeNode
+     */
+    private transient long _root;
+
+
+    /**
+     * Total number of entries in the BTree
+     */
+    protected volatile long _entries;
+
+
+    /**
+     * Serializer used for BTreeNodes of this tree
+     */
+    private transient BTreeNode<K, V> _nodeSerializer = new BTreeNode();
+    {
+        _nodeSerializer._btree = this;
+    }
+
+
+    /**
+     * Listeners which are notified about changes in records
+     */
+    protected RecordListener[] recordListeners = new RecordListener[0];
+
+    final protected ReadWriteLock lock = new ReentrantReadWriteLock();
+
+    /**
+     * No-argument constructor used by serialization.
+     */
+    public BTree() {
+        // empty
+    }
+
+
+
+
+    /**
+     * Create a new persistent BTree
+     */
+    @SuppressWarnings("unchecked")
+    public static <K extends Comparable, V> BTree<K, V> createInstance(DBAbstract db)
+            throws IOException {
+        return createInstance(db, null, null, null,true);
+    }
+
+
+    /**
+     * Create a new persistent BTree
+     */
+    public static <K, V> BTree<K, V> createInstance(DBAbstract db,
+                                                    Comparator<K> comparator,
+                                                    Serializer<K> keySerializer,
+                                                    Serializer<V> valueSerializer,
+                                                    boolean hasValues)
+            throws IOException {
+        BTree<K, V> btree;
+
+        if (db == null) {
+            throw new IllegalArgumentException("Argument 'db' is null");
+        }
+
+        btree = new BTree<K, V>();
+        btree._db = db;
+        btree._comparator = comparator;
+        btree.keySerializer = keySerializer;
+        btree.valueSerializer = valueSerializer;
+        btree.hasValues = hasValues;
+        btree._recid = db.insert(btree, btree.getRecordManager().defaultSerializer(),false);
+
+        return btree;
+    }
+
+
+    /**
+     * Load a persistent BTree.
+     *
+     * @param db    DB used to store the persistent btree
+     * @param recid Record id of the BTree
+     */
+    @SuppressWarnings("unchecked")
+    public static <K, V> BTree<K, V> load(DBAbstract db, long recid)
+            throws IOException {
+        BTree<K, V> btree = (BTree<K, V>) db.fetch(recid);
+        btree._recid = recid;
+        btree._db = db;
+        btree._nodeSerializer = new BTreeNode<K, V>();
+        btree._nodeSerializer._btree = btree;
+        return btree;
+    }
+
+    /**
+     * Get the {@link ReadWriteLock} associated with this BTree.
+     * This should be used with browsing operations to ensure
+     * consistency.
+     *
+     * @return
+     */
+    public ReadWriteLock getLock() {
+        return lock;
+    }
+
+    /**
+     * Insert an entry in the BTree.
+     * <p/>
+     * The BTree cannot store duplicate entries.  An existing entry can be
+     * replaced using the <code>replace</code> flag.   If an entry with the
+     * same key already exists in the BTree, its value is returned.
+     *
+     * @param key     Insert key
+     * @param value   Insert value
+     * @param replace Set to true to replace an existing key-value pair.
+     * @return Existing value, if any.
+     */
+    public V insert(final K key, final V value,
+                    final boolean replace)
+            throws IOException {
+        if (key == null) {
+            throw new IllegalArgumentException("Argument 'key' is null");
+        }
+        if (value == null) {
+            throw new IllegalArgumentException("Argument 'value' is null");
+        }
+        try {
+            lock.writeLock().lock();
+            BTreeNode<K, V> rootNode = getRoot();
+
+            if (rootNode == null) {
+                // BTree is currently empty, create a new root BTreeNode
+                if (DEBUG) {
+                    System.out.println("BTree.insert() new root BTreeNode");
+                }
+                rootNode = new BTreeNode<K, V>(this, key, value);
+                _root = rootNode._recid;
+                _height = 1;
+                _entries = 1;
+                _db.update(_recid, this);
+                modCount++;
+                //notifi listeners
+                for (RecordListener<K, V> l : recordListeners) {
+                    l.recordInserted(key, value);
+                }
+                return null;
+            } else {
+                BTreeNode.InsertResult<K, V> insert = rootNode.insert(_height, key, value, replace);
+                boolean dirty = false;
+                if (insert._overflow != null) {
+                    // current root node overflowed, we replace with a new root node
+                    if (DEBUG) {
+                        System.out.println("BTreeNode.insert() replace root BTreeNode due to overflow");
+                    }
+                    rootNode = new BTreeNode<K, V>(this, rootNode, insert._overflow);
+                    _root = rootNode._recid;
+                    _height += 1;
+                    dirty = true;
+                }
+                if (insert._existing == null) {
+                    _entries++;
+                    modCount++;
+                    dirty = true;
+                }
+                if (dirty) {
+                    _db.update(_recid, this);
+                }
+                //notify listeners
+                for (RecordListener<K, V> l : recordListeners) {
+                    if (insert._existing == null)
+                        l.recordInserted(key, value);
+                    else
+                        l.recordUpdated(key, insert._existing, value);
+                }
+
+                // insert might have returned an existing value
+                V ret = insert._existing;
+                //zero out tuple and put it for reuse
+                insert._existing = null;
+                insert._overflow = null;
+                this.insertResultReuse = insert;
+                return ret;
+            }
+        } finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+
+    /**
+     * Remove an entry with the given key from the BTree.
+     *
+     * @param key Removal key
+     * @return Value associated with the key, or null if no entry with given
+     *         key existed in the BTree.
+     */
+    public V remove(K key)
+            throws IOException {
+        if (key == null) {
+            throw new IllegalArgumentException("Argument 'key' is null");
+        }
+        try {
+            lock.writeLock().lock();
+            BTreeNode<K, V> rootNode = getRoot();
+            if (rootNode == null) {
+                return null;
+            }
+            boolean dirty = false;
+            BTreeNode.RemoveResult<K, V> remove = rootNode.remove(_height, key);
+            if (remove._underflow && rootNode.isEmpty()) {
+                _height -= 1;
+                dirty = true;
+
+                _db.delete(_root);
+                if (_height == 0) {
+                    _root = 0;
+                } else {
+                    _root = rootNode.loadLastChildNode()._recid;
+                }
+            }
+            if (remove._value != null) {
+                _entries--;
+                modCount++;
+                dirty = true;
+            }
+            if (dirty) {
+                _db.update(_recid, this);
+            }
+            if (remove._value != null)
+                for (RecordListener<K, V> l : recordListeners)
+                    l.recordRemoved(key, remove._value);
+            return remove._value;
+        } finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+
+    /**
+     * Find the value associated with the given key.
+     *
+     * @param key Lookup key.
+     * @return Value associated with the key, or null if not found.
+     */
+    public V get(K key)
+            throws IOException {
+        if (key == null) {
+            throw new IllegalArgumentException("Argument 'key' is null");
+        }
+        try {
+            lock.readLock().lock();
+            BTreeNode<K, V> rootNode = getRoot();
+            if (rootNode == null) {
+                return null;
+            }
+
+            return rootNode.findValue(_height, key);
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
+
+    /**
+     * Find the value associated with the given key, or the entry immediately
+     * following this key in the ordered BTree.
+     *
+     * @param key Lookup key.
+     * @return Value associated with the key, or a greater entry, or null if no
+     *         greater entry was found.
+     */
+    public BTreeTuple<K, V> findGreaterOrEqual(K key)
+            throws IOException {
+        BTreeTuple<K, V> tuple;
+        BTreeTupleBrowser<K, V> browser;
+
+        if (key == null) {
+            // there can't be a key greater than or equal to "null"
+            // because null is considered an infinite key.
+            return null;
+        }
+
+        tuple = new BTreeTuple<K, V>(null, null);
+        browser = browse(key,true);
+        if (browser.getNext(tuple)) {
+            return tuple;
+        } else {
+            return null;
+        }
+    }
+
+
+    /**
+     * Get a browser initially positioned at the beginning of the BTree.
+     * <p><b>
+     * WARNING: If you make structural modifications to the BTree during
+     * browsing, you will get inconsistent browing results.
+     * </b>
+     *
+     * @return Browser positionned at the beginning of the BTree.
+     */
+    @SuppressWarnings("unchecked")
+    public BTreeTupleBrowser<K, V> browse()
+            throws IOException {
+        try {
+            lock.readLock().lock();
+            BTreeNode<K, V> rootNode = getRoot();
+            if (rootNode == null) {
+                return EMPTY_BROWSER;
+            }
+            return rootNode.findFirst();
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
+
+    /**
+     * Get a browser initially positioned just before the given key.
+     * <p><b>
+     * WARNING: <20>If you make structural modifications to the BTree during
+     * browsing, you will get inconsistent browing results.
+     * </b>
+     *
+     * @param key Key used to position the browser.  If null, the browser
+     *            will be positionned after the last entry of the BTree.
+     *            (Null is considered to be an "infinite" key)
+     * @return Browser positionned just before the given key.
+     */
+    @SuppressWarnings("unchecked")
+    public BTreeTupleBrowser<K, V> browse(final K key, final boolean inclusive)
+            throws IOException {
+        try {
+            lock.readLock().lock();
+            BTreeNode<K, V> rootNode = getRoot();
+            if (rootNode == null) {
+                return EMPTY_BROWSER;
+            }
+            BTreeTupleBrowser<K, V> browser = rootNode.find(_height, key, inclusive);
+            return browser;
+        } finally {
+            lock.readLock().unlock();
+        }
+    }
+
+
+    /**
+     * Return the persistent record identifier of the BTree.
+     */
+    public long getRecid() {
+        return _recid;
+    }
+
+
+    /**
+     * Return the root BTreeNode, or null if it doesn't exist.
+     */
+    BTreeNode<K, V> getRoot()
+            throws IOException {
+        if (_root == 0) {
+            return null;
+        }
+        BTreeNode<K, V> root = _db.fetch(_root, _nodeSerializer);
+        if (root != null) {
+            root._recid = _root;
+            root._btree = this;
+        }
+        return root;
+    }
+
+
+    static BTree readExternal(DataInput in, Serialization ser)
+            throws IOException, ClassNotFoundException {
+        BTree tree = new BTree();
+        tree._db = ser.db;
+        tree._height = in.readInt();
+        tree._recid = in.readLong();
+        tree._root = in.readLong();
+        tree._entries = in.readLong();
+        tree.hasValues = in.readBoolean();
+        tree._comparator = (Comparator) ser.deserialize(in);
+        tree.keySerializer = (Serializer) ser.deserialize(in);
+        tree.valueSerializer = (Serializer) ser.deserialize(in);
+        return tree;
+    }
+
+
+    public void writeExternal(DataOutput out)
+            throws IOException {
+        out.writeInt(_height);
+        out.writeLong(_recid);
+        out.writeLong(_root);
+        out.writeLong(_entries);
+        out.writeBoolean(hasValues);
+        _db.defaultSerializer().serialize(out, _comparator);
+        _db.defaultSerializer().serialize(out, keySerializer);
+        _db.defaultSerializer().serialize(out, valueSerializer);
+    }
+
+    /**
+     * Copyes tree from one db to other, defragmenting it allong the way
+     * @param recid
+     * @param r1
+     * @param r2
+     * @throws IOException
+     */
+    public static void defrag(long recid, DBStore r1, DBStore r2) throws IOException {
+        try {
+            byte[] data = r1.fetchRaw(recid);
+            r2.forceInsert(recid, data);
+            DataInput in = new DataInputOutput(data);
+            BTree t = (BTree) r1.defaultSerializer().deserialize(in);
+            t.loadValues = false;
+            t._db = r1;
+            t._nodeSerializer = new BTreeNode(t, false);
+
+
+            BTreeNode p = t.getRoot();
+            if (p != null) {
+                r2.forceInsert(t._root, r1.fetchRaw(t._root));
+                p.defrag(r1, r2);
+            }
+
+        } catch (ClassNotFoundException e) {
+            throw new IOError(e);
+        }
+    }
+
+
+    /**
+     * Browser returning no element.
+     */
+    private static final BTreeTupleBrowser EMPTY_BROWSER = new BTreeTupleBrowser() {
+
+        public boolean getNext(BTreeTuple tuple) {
+            return false;
+        }
+
+        public boolean getPrevious(BTreeTuple tuple) {
+            return false;
+        }
+
+        public void remove(Object key) {
+            throw new IndexOutOfBoundsException();
+        }
+    };
+
+
+    /**
+     * add RecordListener which is notified about record changes
+     *
+     * @param listener
+     */
+    public void addRecordListener(RecordListener<K, V> listener) {
+        recordListeners = Arrays.copyOf(recordListeners, recordListeners.length + 1);
+        recordListeners[recordListeners.length - 1] = listener;
+    }
+
+    /**
+     * remove RecordListener which is notified about record changes
+     *
+     * @param listener
+     */
+    public void removeRecordListener(RecordListener<K, V> listener) {
+        List l = Arrays.asList(recordListeners);
+        l.remove(listener);
+        recordListeners = (RecordListener[]) l.toArray(new RecordListener[1]);
+    }
+
+
+    public DBAbstract getRecordManager() {
+        return _db;
+    }
+
+
+    public Comparator<K> getComparator() {
+        return _comparator;
+    }
+
+    /**
+     * Deletes all BTreeNodes in this BTree
+     */
+    public void clear()
+            throws IOException {
+        try {
+            lock.writeLock().lock();
+            BTreeNode<K, V> rootNode = getRoot();
+            if (rootNode != null)
+                rootNode.delete();
+            _entries = 0;
+            modCount++;
+        } finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+    /**
+     * Used for debugging and testing only.  Populates the 'out' list with
+     * the recids of all child nodes in the BTree.
+     *
+     * @param out
+     * @throws IOException
+     */
+    void dumpChildNodeRecIDs(List<Long> out) throws IOException {
+        BTreeNode<K, V> root = getRoot();
+        if (root != null) {
+            out.add(root._recid);
+            root.dumpChildNodeRecIDs(out, _height);
+        }
+    }
+
+    public boolean hasValues() {
+        return hasValues;
+    }
+
+    /**
+     * Browser to traverse a collection of tuples.  The browser allows for
+     * forward and reverse order traversal.
+     *
+     *
+     */
+    static interface BTreeTupleBrowser<K, V> {
+
+        /**
+         * Get the next tuple.
+         *
+         * @param tuple Tuple into which values are copied.
+         * @return True if values have been copied in tuple, or false if there is no next tuple.
+         */
+        boolean getNext(BTree.BTreeTuple<K, V> tuple) throws IOException;
+
+        /**
+         * Get the previous tuple.
+         *
+         * @param tuple Tuple into which values are copied.
+         * @return True if values have been copied in tuple, or false if there is no previous tuple.
+         */
+        boolean getPrevious(BTree.BTreeTuple<K, V> tuple) throws IOException;
+
+        /**
+         * Remove an entry with given key, and increases browsers expectedModCount
+         * This method is here to support 'ConcurrentModificationException' on Map interface.
+         *
+         * @param key
+         */
+        void remove(K key) throws IOException;
+
+    }
+
+    /**
+     * Tuple consisting of a key-value pair.
+     */
+    static final class BTreeTuple<K, V> {
+
+        K key;
+
+        V value;
+
+        BTreeTuple() {
+            // empty
+        }
+
+        BTreeTuple(K key, V value) {
+            this.key = key;
+            this.value = value;
+        }
+
+    }
+
+
+
+}
+

com.minres.scviewer.database.text/src/org/apache/jdbm/BTreeLazyRecord.java

@@ -0,0 +1,97 @@
+package org.apache.jdbm;
+
+import java.io.*;
+
+/**
+ * An record lazily loaded from store.
+ * This is used in BTree/HTree to store big records outside of index tree
+ *
+ * @author Jan Kotek
+ */
+class BTreeLazyRecord<E> {
+
+    private E value = null;
+    private DBAbstract db;
+    private Serializer<E> serializer;
+    final long recid;
+
+    BTreeLazyRecord(DBAbstract db, long recid, Serializer<E> serializer) {
+        this.db = db;
+        this.recid = recid;
+        this.serializer = serializer;
+    }
+
+
+    E get() {
+        if (value != null) return value;
+        try {
+            value = db.fetch(recid, serializer);
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+        return value;
+    }
+
+    void delete() {
+        try {
+            db.delete(recid);
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+        value = null;
+        serializer = null;
+        db = null;
+    }
+
+    /**
+     * Serialier used to insert already serialized data into store
+     */
+    static final Serializer FAKE_SERIALIZER = new Serializer() {
+
+        public void serialize(DataOutput out, Object obj) throws IOException {
+            byte[] data = (byte[]) obj;
+            out.write(data);
+        }
+
+        public Object deserialize(DataInput in) throws IOException, ClassNotFoundException {
+            throw new UnsupportedOperationException();
+        }
+    };
+
+
+    static Object fastDeser(DataInputOutput in, Serializer serializer, int expectedSize) throws IOException, ClassNotFoundException {
+        //we should propably copy data for deserialization into separate buffer and pass it to Serializer
+        //but to make it faster, Serializer will operate directly on top of buffer.
+        //and we check that it readed correct number of bytes.
+        int origAvail = in.available();
+        if (origAvail == 0)
+            throw new InternalError(); //is backed up by byte[] buffer, so there should be always avail bytes
+        Object ret = serializer.deserialize(in);
+        //check than valueSerializer did not read more bytes, if yes it readed bytes from next record
+        int readed = origAvail - in.available();
+        if (readed > expectedSize)
+            throw new IOException("Serializer readed more bytes than is record size.");
+        else if (readed != expectedSize) {
+            //deserializer did not readed all bytes, unussual but valid.
+            //Skip some to get into correct position
+            for (int ii = 0; ii < expectedSize - readed; ii++)
+                in.readUnsignedByte();
+        }
+        return ret;
+    }
+
+
+    /**
+     * if value in tree is serialized in more bytes, it is stored as separate record outside of tree
+     * This value must be always smaller than 250
+     */
+    static final int MAX_INTREE_RECORD_SIZE = 32;
+
+    static {
+        if (MAX_INTREE_RECORD_SIZE > 250) throw new Error();
+    }
+
+    static final int NULL = 255;
+    static final int LAZY_RECORD = 254;
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/BTreeMap.java

@@ -0,0 +1,611 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+package org.apache.jdbm;
+
+import java.io.IOError;
+import java.io.IOException;
+import java.util.*;
+import java.util.concurrent.ConcurrentNavigableMap;
+
+
+/**
+ * Wrapper for <code>BTree</code> which implements <code>ConcurrentNavigableMap</code> interface
+ *
+ * @param <K> key type
+ * @param <V> value type
+ *
+ * @author Jan Kotek
+ */
+class BTreeMap<K, V> extends AbstractMap<K, V> implements ConcurrentNavigableMap<K, V> {
+
+    protected BTree<K, V> tree;
+
+    protected final K fromKey;
+
+    protected final K toKey;
+
+    protected final boolean readonly;
+
+    protected NavigableSet<K> keySet2;
+    private final boolean toInclusive;
+    private final boolean fromInclusive;
+
+    public BTreeMap(BTree<K, V> tree, boolean readonly) {
+        this(tree, readonly, null, false, null, false);
+    }
+
+    protected BTreeMap(BTree<K, V> tree, boolean readonly, K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
+        this.tree = tree;
+        this.fromKey = fromKey;
+        this.fromInclusive = fromInclusive;
+        this.toKey = toKey;
+        this.toInclusive = toInclusive;
+        this.readonly = readonly;
+    }
+
+    @Override
+    public Set<Entry<K, V>> entrySet() {
+        return _entrySet;
+    }
+
+
+
+    private final Set<java.util.Map.Entry<K, V>> _entrySet = new AbstractSet<Entry<K, V>>() {
+
+        protected Entry<K, V> newEntry(K k, V v) {
+            return new SimpleEntry<K, V>(k, v) {
+                private static final long serialVersionUID = 978651696969194154L;
+
+                public V setValue(V arg0) {
+                    BTreeMap.this.put(getKey(), arg0);
+                    return super.setValue(arg0);
+                }
+
+            };
+        }
+
+        public boolean add(java.util.Map.Entry<K, V> e) {
+            if (readonly)
+                throw new UnsupportedOperationException("readonly");
+
+            try {
+                if (e.getKey() == null)
+                    throw new NullPointerException("Can not add null key");
+                if (!inBounds(e.getKey()))
+                    throw new IllegalArgumentException("key outside of bounds");
+                return tree.insert(e.getKey(), e.getValue(), true) == null;
+            } catch (IOException e1) {
+                throw new IOError(e1);
+            }
+        }
+
+        @SuppressWarnings("unchecked")
+        public boolean contains(Object o) {
+
+            if (o instanceof Entry) {
+                Entry<K, V> e = (java.util.Map.Entry<K, V>) o;
+                try {
+                    if (!inBounds(e.getKey()))
+                        return false;
+                    if (e.getKey() != null && tree.get(e.getKey()) != null)
+                        return true;
+                } catch (IOException e1) {
+                    throw new IOError(e1);
+                }
+            }
+            return false;
+        }
+
+
+        public Iterator<java.util.Map.Entry<K, V>> iterator() {
+            try {
+                final BTree.BTreeTupleBrowser<K, V> br = fromKey == null ?
+                        tree.browse() : tree.browse(fromKey, fromInclusive);
+                return new Iterator<Entry<K, V>>() {
+
+                    private Entry<K, V> next;
+                    private K lastKey;
+
+                    void ensureNext() {
+                        try {
+                            BTree.BTreeTuple<K, V> t = new BTree.BTreeTuple<K, V>();
+                            if (br.getNext(t) && inBounds(t.key))
+                                next = newEntry(t.key, t.value);
+                            else
+                                next = null;
+                        } catch (IOException e1) {
+                            throw new IOError(e1);
+                        }
+                    }
+
+                    {
+                        ensureNext();
+                    }
+
+
+                    public boolean hasNext() {
+                        return next != null;
+                    }
+
+                    public java.util.Map.Entry<K, V> next() {
+                        if (next == null)
+                            throw new NoSuchElementException();
+                        Entry<K, V> ret = next;
+                        lastKey = ret.getKey();
+                        //move to next position
+                        ensureNext();
+                        return ret;
+                    }
+
+                    public void remove() {
+                        if (readonly)
+                            throw new UnsupportedOperationException("readonly");
+
+                        if (lastKey == null)
+                            throw new IllegalStateException();
+                        try {
+                            br.remove(lastKey);
+                            lastKey = null;
+                        } catch (IOException e1) {
+                            throw new IOError(e1);
+                        }
+
+                    }
+                };
+
+            } catch (IOException e) {
+                throw new IOError(e);
+            }
+
+        }
+
+        @SuppressWarnings("unchecked")
+        public boolean remove(Object o) {
+            if (readonly)
+                throw new UnsupportedOperationException("readonly");
+
+            if (o instanceof Entry) {
+                Entry<K, V> e = (java.util.Map.Entry<K, V>) o;
+                try {
+                    //check for nulls
+                    if (e.getKey() == null || e.getValue() == null)
+                        return false;
+                    if (!inBounds(e.getKey()))
+                        throw new IllegalArgumentException("out of bounds");
+                    //get old value, must be same as item in entry
+                    V v = get(e.getKey());
+                    if (v == null || !e.getValue().equals(v))
+                        return false;
+                    V v2 = tree.remove(e.getKey());
+                    return v2 != null;
+                } catch (IOException e1) {
+                    throw new IOError(e1);
+                }
+            }
+            return false;
+
+        }
+
+        public int size() {
+            return BTreeMap.this.size();
+        }
+
+        public void clear(){
+            if(fromKey!=null || toKey!=null)
+                super.clear();
+            else
+                try {
+                    tree.clear();
+                } catch (IOException e) {
+                    throw new IOError(e);
+                }
+        }
+
+    };
+
+
+    public boolean inBounds(K e) {
+        if(fromKey == null && toKey == null)
+            return true;
+
+        Comparator comp = comparator();
+        if (comp == null) comp = Utils.COMPARABLE_COMPARATOR;
+        
+        if(fromKey!=null){
+            final int compare = comp.compare(e, fromKey);
+            if(compare<0) return false;
+            if(!fromInclusive && compare == 0) return false;
+        }
+        if(toKey!=null){
+            final int compare = comp.compare(e, toKey);
+            if(compare>0)return false;
+            if(!toInclusive && compare == 0) return false;
+        }
+        return true;
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public V get(Object key) {
+        try {
+            if (key == null)
+                return null;
+            if (!inBounds((K) key))
+                return null;
+            return tree.get((K) key);
+        } catch (ClassCastException e) {
+            return null;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public V remove(Object key) {
+        if (readonly)
+            throw new UnsupportedOperationException("readonly");
+
+        try {
+            if (key == null || tree.get((K) key) == null)
+                return null;
+            if (!inBounds((K) key))
+                throw new IllegalArgumentException("out of bounds");
+
+            return tree.remove((K) key);
+        } catch (ClassCastException e) {
+            return null;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public V put(K key, V value) {
+        if (readonly)
+            throw new UnsupportedOperationException("readonly");
+
+        try {
+            if (key == null || value == null)
+                throw new NullPointerException("Null key or value");
+            if (!inBounds(key))
+                throw new IllegalArgumentException("out of bounds");
+            return tree.insert(key, value, true);
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public void clear(){
+        entrySet().clear();
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    public boolean containsKey(Object key) {
+        if (key == null)
+            return false;
+        try {
+            if (!inBounds((K) key))
+                return false;
+            V v = tree.get((K) key);
+            return v != null;
+        } catch (IOException e) {
+            throw new IOError(e);
+        } catch (ClassCastException e) {
+            return false;
+        }
+    }
+
+    public Comparator<? super K> comparator() {
+        return tree._comparator;
+    }
+
+    public K firstKey() {
+        if (isEmpty())
+            return null;
+        try {
+
+            BTree.BTreeTupleBrowser<K, V> b = fromKey == null ? tree.browse() : tree.browse(fromKey,fromInclusive);
+            BTree.BTreeTuple<K, V> t = new BTree.BTreeTuple<K, V>();
+            b.getNext(t);
+            return t.key;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public K lastKey() {
+        if (isEmpty())
+            return null;
+        try {
+            BTree.BTreeTupleBrowser<K, V> b = toKey == null ? tree.browse(null,true) : tree.browse(toKey,false);
+            BTree.BTreeTuple<K, V> t = new BTree.BTreeTuple<K, V>();            
+            b.getPrevious(t);            
+            if(!toInclusive && toKey!=null){
+                //make sure we wont return last key
+                Comparator c = comparator();
+                if(c==null) c=Utils.COMPARABLE_COMPARATOR;
+                if(c.compare(t.key,toKey)==0)
+                    b.getPrevious(t);
+            }
+            return t.key;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public ConcurrentNavigableMap<K, V> headMap(K toKey2, boolean inclusive) {
+        K toKey3 = Utils.min(this.toKey,toKey2,comparator());
+        boolean inclusive2 = toKey3 == toKey? toInclusive : inclusive;
+        return new BTreeMap<K, V>(tree, readonly, this.fromKey, this.fromInclusive, toKey3, inclusive2);
+    }
+
+
+    public ConcurrentNavigableMap<K, V> headMap(K toKey) {
+        return headMap(toKey,false);
+    }
+
+
+    public Entry<K, V> lowerEntry(K key) {
+        K k = lowerKey(key);
+        return k==null? null : new SimpleEntry<K, V>(k,get(k));
+    }
+
+    public K lowerKey(K key) {
+        if (isEmpty())
+            return null;
+        K key2 = Utils.min(key,toKey,comparator());
+        try {
+            BTree.BTreeTupleBrowser<K, V> b  = tree.browse(key2,true) ;
+            BTree.BTreeTuple<K, V> t = new BTree.BTreeTuple<K, V>();
+            b.getPrevious(t);
+
+            return t.key;
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+
+    }
+
+    public Entry<K, V> floorEntry(K key) {
+        K k = floorKey(key);
+        return k==null? null : new SimpleEntry<K, V>(k,get(k));
+
+    }
+
+    public K floorKey(K key) {
+        if (isEmpty())
+            return null;
+
+        K key2 = Utils.max(key,fromKey,comparator());
+        try {
+            BTree.BTreeTupleBrowser<K, V> b  = tree.browse(key2,true) ;
+            BTree.BTreeTuple<K, V> t = new BTree.BTreeTuple<K, V>();
+            b.getNext(t);
+            Comparator comp = comparator();
+            if (comp == null) comp = Utils.COMPARABLE_COMPARATOR;
+            if(comp.compare(t.key,key2) == 0)
+                return t.key;
+
+            b.getPrevious(t);
+            b.getPrevious(t);
+            return t.key;
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public Entry<K, V> ceilingEntry(K key) {
+        K k = ceilingKey(key);
+        return k==null? null : new SimpleEntry<K, V>(k,get(k));
+    }
+
+    public K ceilingKey(K key) {
+        if (isEmpty())
+            return null;
+        K key2 = Utils.min(key,toKey,comparator());
+
+        try {
+            BTree.BTreeTupleBrowser<K, V> b  = tree.browse(key2,true) ;
+            BTree.BTreeTuple<K, V> t = new BTree.BTreeTuple<K, V>();
+            b.getNext(t);
+            return t.key;
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public Entry<K, V> higherEntry(K key) {
+        K k = higherKey(key);
+        return k==null? null : new SimpleEntry<K, V>(k,get(k));
+    }
+
+    public K higherKey(K key) {
+        if (isEmpty())
+            return null;
+
+        K key2 = Utils.max(key,fromKey,comparator());
+
+        try {
+            BTree.BTreeTupleBrowser<K, V> b  = tree.browse(key2,false) ;
+            BTree.BTreeTuple<K, V> t = new BTree.BTreeTuple<K, V>();
+            b.getNext(t);
+            return t.key;
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public Entry<K, V> firstEntry() {
+        K k = firstKey();
+        return k==null? null : new SimpleEntry<K, V>(k,get(k));
+    }
+
+    public Entry<K, V> lastEntry() {
+        K k = lastKey();
+        return k==null? null : new SimpleEntry<K, V>(k,get(k));
+    }
+
+    public Entry<K, V> pollFirstEntry() {
+        Entry<K,V> first = firstEntry();
+        if(first!=null)
+            remove(first.getKey());
+        return first;
+    }
+
+    public Entry<K, V> pollLastEntry() {
+        Entry<K,V> last = lastEntry();
+        if(last!=null)
+            remove(last.getKey());
+        return last;
+    }
+
+    public ConcurrentNavigableMap<K, V> descendingMap() {
+        throw new  UnsupportedOperationException("not implemented yet");
+        //TODO implement descending (reverse order) map
+    }
+
+
+    public NavigableSet<K> keySet() {
+        return navigableKeySet();
+    }
+
+    public NavigableSet<K> navigableKeySet() {
+        if(keySet2 == null)
+            keySet2 = new BTreeSet<K>((BTreeMap<K,Object>) this);
+        return keySet2;
+    }
+
+    public NavigableSet<K> descendingKeySet() {
+        return descendingMap().navigableKeySet();
+    }
+
+
+
+    public ConcurrentNavigableMap<K, V> tailMap(K fromKey) {
+        return tailMap(fromKey,true);
+    }
+
+
+    public ConcurrentNavigableMap<K, V> tailMap(K fromKey2, boolean inclusive) {
+        K fromKey3 = Utils.max(this.fromKey,fromKey2,comparator());
+        boolean inclusive2 = fromKey3 == toKey? toInclusive : inclusive;
+
+        return new BTreeMap<K, V>(tree, readonly, fromKey3, inclusive2, toKey, toInclusive);
+    }
+
+    public ConcurrentNavigableMap<K, V> subMap(K fromKey, boolean fromInclusive, K toKey, boolean toInclusive) {
+        Comparator comp = comparator();
+        if (comp == null) comp = Utils.COMPARABLE_COMPARATOR;
+        if (comp.compare(fromKey, toKey) > 0)
+            throw new IllegalArgumentException("fromKey is bigger then toKey");
+        return new BTreeMap<K, V>(tree, readonly, fromKey, fromInclusive, toKey, toInclusive);
+    }
+
+    public ConcurrentNavigableMap<K, V> subMap(K fromKey, K toKey) {
+        return subMap(fromKey,true,toKey,false);
+    }
+
+
+    public BTree<K, V> getTree() {
+        return tree;
+    }
+
+
+    public void addRecordListener(RecordListener<K, V> listener) {
+        tree.addRecordListener(listener);
+    }
+
+    public DBAbstract getRecordManager() {
+        return tree.getRecordManager();
+    }
+
+    public void removeRecordListener(RecordListener<K, V> listener) {
+        tree.removeRecordListener(listener);
+    }
+
+
+    public int size() {
+        if (fromKey == null && toKey == null)
+            return (int) tree._entries; //use fast counter on tree if Map has no bounds
+        else {
+            //had to count items in iterator
+            Iterator iter = keySet().iterator();
+            int counter = 0;
+            while (iter.hasNext()) {
+                iter.next();
+                counter++;
+            }
+            return counter;
+        }
+
+    }
+
+
+    public V putIfAbsent(K key, V value) {
+        tree.lock.writeLock().lock();
+        try{
+            if (!containsKey(key))
+                 return put(key, value);
+            else
+                 return get(key);
+        }finally {
+            tree.lock.writeLock().unlock();
+        }
+    }
+
+    public boolean remove(Object key, Object value) {
+        tree.lock.writeLock().lock();
+        try{
+            if (containsKey(key) && get(key).equals(value)) {
+                remove(key);
+                return true;
+            } else return false;
+        }finally {
+            tree.lock.writeLock().unlock();
+        }
+
+
+    }
+
+    public boolean replace(K key, V oldValue, V newValue) {
+        tree.lock.writeLock().lock();
+        try{
+            if (containsKey(key) && get(key).equals(oldValue)) {
+                put(key, newValue);
+                return true;
+            } else return false;
+        }finally {
+            tree.lock.writeLock().unlock();
+        }
+
+    }
+
+    public V replace(K key, V value) {
+        tree.lock.writeLock().lock();
+        try{
+            if (containsKey(key)) {
+                return put(key, value);
+             } else return null;
+        }finally {
+            tree.lock.writeLock().unlock();
+        }
+    }
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/BTreeSet.java

@@ -0,0 +1,187 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package org.apache.jdbm;
+
+import java.util.*;
+
+/**
+ * Wrapper class for <code>>SortedMap</code> to implement <code>>NavigableSet</code>
+ * <p/>
+ * This code originally comes from Apache Harmony, was adapted by Jan Kotek for JDBM
+ */
+class BTreeSet<E> extends AbstractSet<E> implements NavigableSet<E> {
+
+
+    /**
+     * use keyset from this map
+     */
+    final BTreeMap<E, Object> map;
+
+    BTreeSet(BTreeMap<E, Object> map) {
+        this.map = map;
+    }
+
+    public boolean add(E object) {
+        return map.put(object, Utils.EMPTY_STRING) == null;
+    }
+
+
+    public boolean addAll(Collection<? extends E> collection) {
+        return super.addAll(collection);
+    }
+
+
+    public void clear() {
+        map.clear();
+    }
+
+    public Comparator<? super E> comparator() {
+        return map.comparator();
+    }
+
+
+    public boolean contains(Object object) {
+        return map.containsKey(object);
+    }
+
+
+    public boolean isEmpty() {
+        return map.isEmpty();
+    }
+
+
+    public E lower(E e) {
+        return map.lowerKey(e);
+    }
+
+    public E floor(E e) {
+        return map.floorKey(e);
+    }
+
+    public E ceiling(E e) {
+        return map.ceilingKey(e);
+    }
+
+    public E higher(E e) {
+        return map.higherKey(e);
+    }
+
+    public E pollFirst() {
+        Map.Entry<E,Object> e = map.pollFirstEntry();
+        return e!=null? e.getKey():null;
+    }
+
+    public E pollLast() {
+        Map.Entry<E,Object> e = map.pollLastEntry();
+        return e!=null? e.getKey():null;
+    }
+
+    public Iterator<E> iterator() {
+        final Iterator<Map.Entry<E,Object>> iter = map.entrySet().iterator();
+        return new Iterator<E>() {
+            public boolean hasNext() {
+                return iter.hasNext();
+            }
+
+            public E next() {
+                Map.Entry<E,Object> e = iter.next();
+                return e!=null?e.getKey():null;
+            }
+
+            public void remove() {
+                iter.remove();
+            }
+        };
+    }
+
+    public NavigableSet<E> descendingSet() {
+        return map.descendingKeySet();
+    }
+
+    public Iterator<E> descendingIterator() {
+        return map.descendingKeySet().iterator();
+    }
+
+    public NavigableSet<E> subSet(E fromElement, boolean fromInclusive, E toElement, boolean toInclusive) {
+        return map.subMap(fromElement,fromInclusive,toElement,toInclusive).navigableKeySet();
+    }
+
+    public NavigableSet<E> headSet(E toElement, boolean inclusive) {
+        return map.headMap(toElement,inclusive).navigableKeySet();
+    }
+
+    public NavigableSet<E> tailSet(E fromElement, boolean inclusive) {
+        return map.tailMap(fromElement,inclusive).navigableKeySet();
+    }
+
+
+    public boolean remove(Object object) {
+        return map.remove(object) != null;
+    }
+
+    public int size() {
+        return map.size();
+    }
+
+
+    public E first() {
+        return map.firstKey();
+    }
+
+
+    public E last() {
+        return map.lastKey();
+    }
+
+
+    public SortedSet<E> subSet(E start, E end) {
+        Comparator<? super E> c = map.comparator();
+        int compare = (c == null) ? ((Comparable<E>) start).compareTo(end) : c
+                .compare(start, end);
+        if (compare <= 0) {
+            return new BTreeSet<E>((BTreeMap<E,Object>) map.subMap(start, true,end,false));
+        }
+        throw new IllegalArgumentException();
+    }
+
+
+    public SortedSet<E> headSet(E end) {
+        // Check for errors
+        Comparator<? super E> c = map.comparator();
+        if (c == null) {
+            ((Comparable<E>) end).compareTo(end);
+        } else {
+            c.compare(end, end);
+        }
+        return new BTreeSet<E>((BTreeMap<E,Object>) map.headMap(end,false));
+    }
+
+
+    public SortedSet<E> tailSet(E start) {
+        // Check for errors
+        Comparator<? super E> c = map.comparator();
+        if (c == null) {
+            ((Comparable<E>) start).compareTo(start);
+        } else {
+            c.compare(start, start);
+        }
+        return new BTreeSet<E>((BTreeMap<E,Object>) map.tailMap(start,true));
+    }
+
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/DB.java

@@ -0,0 +1,173 @@
+package org.apache.jdbm;
+
+import java.util.*;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.ConcurrentNavigableMap;
+
+/**
+ * Database is root class for creating and loading persistent collections. It also contains
+ * transaction operations.
+ * //TODO just write some readme
+ * <p/>
+ *
+ * @author Jan Kotek
+ * @author Alex Boisvert
+ * @author Cees de Groot
+ */
+public interface DB {
+
+    /**
+     * Closes the DB and release resources.
+     * DB can not be used after it was closed
+     */
+    void close();
+
+    /** @return true if db was already closed */
+    boolean isClosed();
+
+    /**
+     * Clear cache and remove all entries it contains.
+     * This may be useful for some Garbage Collection when reference cache is used.
+     */
+    void clearCache();
+
+    /**
+     * Defragments storage so it consumes less space.
+     * It basically copyes all records into different store and then renames it, replacing original store.
+     * <p/>
+     * Defrag has two steps: In first collections are rearranged, so records in collection are close to each other,
+     * and read speed is improved. In second step all records are sequentially transferred, reclaiming all unused space.
+     * First step is optinal and may slow down defragmentation significantly as ut requires many random-access reads.
+     * Second step reads and writes data sequentially and is very fast, comparable to copying files to new location.
+     *
+     * <p/>
+     * This commits any uncommited data. Defrag also requires free space, as store is basically recreated at new location.
+     *
+     * @param sortCollections if collection records should be rearranged during defragment, this takes some extra time
+     */
+    void defrag(boolean sortCollections);
+
+    /**
+     * Commit (make persistent) all changes since beginning of transaction.
+     * JDBM supports only single transaction.
+     */
+    void commit();
+
+    /**
+     * Rollback (cancel) all changes since beginning of transaction.
+     * JDBM supports only single transaction.
+     * This operations affects all maps created or loaded by this DB.
+     */
+    void rollback();
+
+    /**
+     * This calculates some database statistics such as collection sizes and record distributions.
+     * Can be useful for performance optimalisations and trouble shuting.
+     * This method can run for very long time.
+     *
+     * @return statistics contained in string
+     */
+    String calculateStatistics();
+
+
+    /**
+     * Copy database content into ZIP file
+     * @param zipFile
+     */
+    void copyToZip(String zipFile);
+
+
+
+    /**
+     * Get a <code>Map</code> which was already created and saved in DB.
+     * This map uses disk based H*Tree and should have similar performance
+     * as <code>HashMap</code>.
+     *
+     * @param name of hash map
+     *
+     * @return map
+     */
+    <K, V> ConcurrentMap<K, V> getHashMap(String name);
+
+    /**
+     * Creates Map which persists data into DB.
+     *
+     * @param name record name
+     * @return
+     */
+    <K, V> ConcurrentMap<K, V> createHashMap(String name);
+
+
+    /**
+     * Creates  Hash Map which persists data into DB.
+     * Map will use custom serializers for Keys and Values.
+     * Leave keySerializer null to use default serializer for keys
+     *
+     * @param <K>             Key type
+     * @param <V>             Value type
+     * @param name            record name
+     * @param keySerializer   serializer to be used for Keys, leave null to use default serializer
+     * @param valueSerializer serializer to be used for Values
+     * @return
+     */
+    <K, V> ConcurrentMap<K, V> createHashMap(String name, Serializer<K> keySerializer, Serializer<V> valueSerializer);
+
+    <K> Set<K> createHashSet(String name);
+
+    <K> Set<K> getHashSet(String name);
+
+    <K> Set<K> createHashSet(String name, Serializer<K> keySerializer);
+
+    <K, V> ConcurrentNavigableMap<K, V> getTreeMap(String name);
+
+    /**
+     * Create  TreeMap which persists data into DB.
+     *
+     * @param <K>  Key type
+     * @param <V>  Value type
+     * @param name record name
+     * @return
+     */
+    <K extends Comparable, V> NavigableMap<K, V> createTreeMap(String name);
+
+    /**
+     * Creates TreeMap which persists data into DB.
+     *
+     * @param <K>             Key type
+     * @param <V>             Value type
+     * @param name            record name
+     * @param keyComparator   Comparator used to sort keys
+     * @param keySerializer   Serializer used for keys. This may reduce disk space usage     *
+     * @param valueSerializer Serializer used for values. This may reduce disk space usage
+     * @return
+     */
+    <K, V> ConcurrentNavigableMap<K, V> createTreeMap(String name,
+                                         Comparator<K> keyComparator, Serializer<K> keySerializer, Serializer<V> valueSerializer);
+
+    <K> NavigableSet<K> getTreeSet(String name);
+
+    <K> NavigableSet<K> createTreeSet(String name);
+
+    <K> NavigableSet<K> createTreeSet(String name, Comparator<K> keyComparator, Serializer<K> keySerializer);
+
+    <K> List<K> createLinkedList(String name);
+
+    <K> List<K> createLinkedList(String name, Serializer<K> serializer);
+
+    <K> List<K> getLinkedList(String name);
+
+    /** returns unmodifiable map which contains all collection names and collections thenselfs*/
+    Map<String,Object> getCollections();
+
+    /** completely remove collection from store*/
+    void deleteCollection(String name);
+
+    /** Java Collections returns their size as int. This may not be enought for JDBM collections.
+     * This method returns number of elements in JDBM collection as long.
+     *
+     * @param collection created by JDBM
+     * @return number of elements in collection as long
+     */
+    long collectionSize(Object collection);
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/DBAbstract.java

@@ -0,0 +1,590 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+package org.apache.jdbm;
+
+import java.io.DataInput;
+import java.io.DataOutput;
+import java.io.IOError;
+import java.io.IOException;
+import java.lang.ref.WeakReference;
+import java.util.*;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.ConcurrentNavigableMap;
+
+/**
+ * An abstract class implementing most of DB.
+ * It also has some JDBM package protected stuff (getNamedRecord)
+ */
+abstract class DBAbstract implements DB {
+
+
+    /**
+     * Reserved slot for name directory recid.
+     */
+    static final byte NAME_DIRECTORY_ROOT = 0;
+
+
+    /**
+     * Reserved slot for version number
+     */
+    static final byte STORE_VERSION_NUMBER_ROOT = 1;
+
+    /**
+     * Reserved slot for recid where Serial class info is stored
+     *
+     * NOTE when introducing more roots, do not forget to update defrag
+     */
+    static final byte SERIAL_CLASS_INFO_RECID_ROOT = 2;
+
+    /** to prevent double instances of the same collection, we use weak value map
+     *
+     * //TODO what to do when there is rollback?
+     * //TODO clear on close
+     */
+    final private Map<String,WeakReference<Object>> collections = new HashMap<String,WeakReference<Object>>();
+
+
+
+    /**
+     * Inserts a new record using a custom serializer.
+     *
+     * @param obj        the object for the new record.
+     * @param serializer a custom serializer
+     * @return the rowid for the new record.
+     * @throws java.io.IOException when one of the underlying I/O operations fails.
+     */
+    abstract <A> long insert(A obj, Serializer<A> serializer,boolean disableCache) throws IOException;
+
+    /**
+     * Deletes a record.
+     *
+     * @param recid the rowid for the record that should be deleted.
+     * @throws java.io.IOException when one of the underlying I/O operations fails.
+     */
+    abstract void delete(long recid) throws IOException;
+
+
+    /**
+     * Updates a record using a custom serializer.
+     * If given recid does not exist, IOException will be thrown before/during commit (cache).
+     *
+     * @param recid      the recid for the record that is to be updated.
+     * @param obj        the new object for the record.
+     * @param serializer a custom serializer
+     * @throws java.io.IOException when one of the underlying I/O operations fails
+     */
+    abstract <A> void update(long recid, A obj, Serializer<A> serializer)
+            throws IOException;
+
+
+    /**
+     * Fetches a record using a custom serializer.
+     *
+     * @param recid      the recid for the record that must be fetched.
+     * @param serializer a custom serializer
+     * @return the object contained in the record, null if given recid does not exist
+     * @throws java.io.IOException when one of the underlying I/O operations fails.
+     */
+    abstract <A> A fetch(long recid, Serializer<A> serializer)
+            throws IOException;
+
+    /**
+     * Fetches a record using a custom serializer and optionaly disabled cache
+     *
+     * @param recid        the recid for the record that must be fetched.
+     * @param serializer   a custom serializer
+     * @param disableCache true to disable any caching mechanism
+     * @return the object contained in the record, null if given recid does not exist
+     * @throws java.io.IOException when one of the underlying I/O operations fails.
+     */
+    abstract <A> A fetch(long recid, Serializer<A> serializer, boolean disableCache)
+            throws IOException;
+
+
+    public long insert(Object obj) throws IOException {
+        return insert(obj, defaultSerializer(),false);
+    }
+
+
+    public void update(long recid, Object obj) throws IOException {
+        update(recid, obj, defaultSerializer());
+    }
+
+
+    synchronized public <A> A fetch(long recid) throws IOException {
+        return (A) fetch(recid, defaultSerializer());
+    }
+
+    synchronized public <K, V> ConcurrentMap<K, V> getHashMap(String name) {
+        Object o = getCollectionInstance(name);
+        if(o!=null)
+            return (ConcurrentMap<K, V>) o;
+
+        try {
+            long recid = getNamedObject(name);
+            if(recid == 0) return null;
+
+            HTree tree = fetch(recid);
+            tree.setPersistenceContext(this);
+            if(!tree.hasValues()){
+                throw new ClassCastException("HashSet is not HashMap");
+            }
+            collections.put(name,new WeakReference<Object>(tree));
+            return tree;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    synchronized public <K, V> ConcurrentMap<K, V> createHashMap(String name) {
+        return createHashMap(name, null, null);
+    }
+
+
+    public synchronized <K, V> ConcurrentMap<K, V> createHashMap(String name, Serializer<K> keySerializer, Serializer<V> valueSerializer) {
+        try {
+            assertNameNotExist(name);
+
+            HTree<K, V> tree = new HTree(this, keySerializer, valueSerializer,true);
+            long recid = insert(tree);
+            setNamedObject(name, recid);
+            collections.put(name,new WeakReference<Object>(tree));
+            return tree;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public synchronized <K> Set<K> getHashSet(String name) {
+        Object o = getCollectionInstance(name);
+        if(o!=null)
+            return (Set<K>) o;
+
+        try {
+            long recid = getNamedObject(name);
+            if(recid == 0) return null;
+
+            HTree tree = fetch(recid);
+            tree.setPersistenceContext(this);
+            if(tree.hasValues()){
+                throw new ClassCastException("HashMap is not HashSet");
+            }
+            Set<K> ret  =  new HTreeSet(tree);
+            collections.put(name,new WeakReference<Object>(ret));
+            return ret;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public synchronized <K> Set<K> createHashSet(String name) {
+        return createHashSet(name, null);
+    }
+
+    public synchronized <K> Set<K> createHashSet(String name, Serializer<K> keySerializer) {
+        try {
+            assertNameNotExist(name);
+
+            HTree<K, Object> tree = new HTree(this, keySerializer, null,false);
+            long recid = insert(tree);
+            setNamedObject(name, recid);
+
+            Set<K> ret =  new HTreeSet<K>(tree);
+            collections.put(name,new WeakReference<Object>(ret));
+            return ret;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    synchronized public <K, V> ConcurrentNavigableMap<K, V> getTreeMap(String name) {
+        Object o = getCollectionInstance(name);
+        if(o!=null)
+            return (ConcurrentNavigableMap<K, V> ) o;
+
+        try {
+            long recid = getNamedObject(name);
+            if(recid == 0) return null;
+
+            BTree t =  BTree.<K, V>load(this, recid);
+            if(!t.hasValues())
+                throw new ClassCastException("TreeSet is not TreeMap");
+            ConcurrentNavigableMap<K,V> ret = new BTreeMap<K, V>(t,false); //TODO put readonly flag here
+            collections.put(name,new WeakReference<Object>(ret));
+            return ret;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    synchronized public <K extends Comparable, V> ConcurrentNavigableMap<K, V> createTreeMap(String name) {
+        return createTreeMap(name, null, null, null);
+    }
+
+
+    public synchronized <K, V> ConcurrentNavigableMap<K, V> createTreeMap(String name,
+                                                                          Comparator<K> keyComparator,
+                                                                          Serializer<K> keySerializer,
+                                                                          Serializer<V> valueSerializer) {
+        try {
+            assertNameNotExist(name);
+            BTree<K, V> tree = BTree.createInstance(this, keyComparator, keySerializer, valueSerializer,true);
+            setNamedObject(name, tree.getRecid());
+            ConcurrentNavigableMap<K,V> ret = new BTreeMap<K, V>(tree,false); //TODO put readonly flag here
+            collections.put(name,new WeakReference<Object>(ret));
+            return ret;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+
+    public synchronized <K> NavigableSet<K> getTreeSet(String name) {
+        Object o = getCollectionInstance(name);
+        if(o!=null)
+            return (NavigableSet<K> ) o;
+
+        try {
+            long recid = getNamedObject(name);
+            if(recid == 0) return null;
+
+            BTree t =  BTree.<K, Object>load(this, recid);
+            if(t.hasValues())
+                throw new ClassCastException("TreeMap is not TreeSet");
+            BTreeSet<K> ret =  new BTreeSet<K>(new BTreeMap(t,false));
+            collections.put(name,new WeakReference<Object>(ret));
+            return ret;
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public synchronized <K> NavigableSet<K> createTreeSet(String name) {
+        return createTreeSet(name, null, null);
+    }
+
+
+    public synchronized <K> NavigableSet<K> createTreeSet(String name, Comparator<K> keyComparator, Serializer<K> keySerializer) {
+        try {
+            assertNameNotExist(name);
+            BTree<K, Object> tree = BTree.createInstance(this, keyComparator, keySerializer, null,false);
+            setNamedObject(name, tree.getRecid());
+            BTreeSet<K> ret =  new BTreeSet<K>(new BTreeMap(tree,false));
+            collections.put(name,new WeakReference<Object>(ret));
+            return ret;
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+
+    }
+
+
+    synchronized public <K> List<K> createLinkedList(String name) {
+        return createLinkedList(name, null);
+    }
+
+    synchronized public <K> List<K> createLinkedList(String name, Serializer<K> serializer) {
+        try {
+            assertNameNotExist(name);
+
+            //allocate record and overwrite it
+
+            LinkedList2<K> list = new LinkedList2<K>(this, serializer);
+            long recid = insert(list);
+            setNamedObject(name, recid);
+
+            collections.put(name,new WeakReference<Object>(list));
+
+            return list;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    synchronized public <K> List<K> getLinkedList(String name) {
+        Object o = getCollectionInstance(name);
+        if(o!=null)
+            return (List<K> ) o;
+
+        try {
+            long recid = getNamedObject(name);
+            if(recid == 0) return null;
+            LinkedList2<K> list = (LinkedList2<K>) fetch(recid);
+            list.setPersistenceContext(this);
+            collections.put(name,new WeakReference<Object>(list));
+            return list;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    private synchronized  Object getCollectionInstance(String name){
+        WeakReference ref = collections.get(name);
+        if(ref==null)return null;
+        Object o = ref.get();
+        if(o != null) return o;
+        //already GCed
+        collections.remove(name);
+        return null;
+    }
+
+
+    private void assertNameNotExist(String name) throws IOException {
+        if (getNamedObject(name) != 0)
+            throw new IllegalArgumentException("Object with name '" + name + "' already exists");
+    }
+
+
+
+    /**
+     * Obtain the record id of a named object. Returns 0 if named object
+     * doesn't exist.
+     * Named objects are used to store Map views and other well known objects.
+     */
+    synchronized protected long getNamedObject(String name) throws IOException{
+        long nameDirectory_recid = getRoot(NAME_DIRECTORY_ROOT);
+        if(nameDirectory_recid == 0){
+            return 0;
+        }
+        HTree<String,Long> m = fetch(nameDirectory_recid);
+        Long res = m.get(name);
+        if(res == null)
+            return 0;
+        return res;
+    }
+
+
+    /**
+     * Set the record id of a named object.
+     * Named objects are used to store Map views and other well known objects.
+     */
+    synchronized protected void setNamedObject(String name, long recid) throws IOException{
+        long nameDirectory_recid = getRoot(NAME_DIRECTORY_ROOT);
+        HTree<String,Long> m = null;
+        if(nameDirectory_recid == 0){
+            //does not exists, create it
+            m = new HTree<String, Long>(this,null,null,true);
+            nameDirectory_recid = insert(m);
+            setRoot(NAME_DIRECTORY_ROOT,nameDirectory_recid);
+        }else{
+            //fetch it
+            m = fetch(nameDirectory_recid);
+        }
+        m.put(name,recid);
+    }
+
+
+
+
+    synchronized public Map<String,Object> getCollections(){
+        try{
+            Map<String,Object> ret = new LinkedHashMap<String, Object>();
+            long nameDirectory_recid = getRoot(NAME_DIRECTORY_ROOT);
+            if(nameDirectory_recid==0)
+                return ret;
+            HTree<String,Long> m = fetch(nameDirectory_recid);
+
+            for(Map.Entry<String,Long> e:m.entrySet()){
+                Object o = fetch(e.getValue());
+                if(o instanceof BTree){
+                    if(((BTree) o).hasValues)
+                        o = getTreeMap(e.getKey());
+                    else
+                        o = getTreeSet(e.getKey());
+                }
+                else if( o instanceof  HTree){
+                    if(((HTree) o).hasValues)
+                        o = getHashMap(e.getKey());
+                    else
+                        o = getHashSet(e.getKey());
+                }
+
+                ret.put(e.getKey(), o);
+            }
+            return Collections.unmodifiableMap(ret);
+        }catch(IOException e){
+            throw new IOError(e);
+        }
+
+    }
+
+
+    synchronized public void deleteCollection(String name){
+        try{
+            long nameDirectory_recid = getRoot(NAME_DIRECTORY_ROOT);
+            if(nameDirectory_recid==0)
+                throw new IOException("Collection not found");
+            HTree<String,Long> dir = fetch(nameDirectory_recid);
+
+            Long recid = dir.get(name);
+            if(recid == null) throw new IOException("Collection not found");
+
+            Object o = fetch(recid);
+            //we can not use O instance since it is not correctly initialized
+            if(o instanceof LinkedList2){
+                LinkedList2 l = (LinkedList2) o;
+                l.clear();
+                delete(l.rootRecid);
+            }else if(o instanceof BTree){
+                ((BTree) o).clear();
+            } else if( o instanceof  HTree){
+                HTree t = (HTree) o;
+                t.clear();
+                HTreeDirectory n = (HTreeDirectory) fetch(t.rootRecid,t.SERIALIZER);
+                n.deleteAllChildren();
+                delete(t.rootRecid);
+            }else{
+                throw new InternalError("unknown collection type: "+(o==null?null:o.getClass()));
+            }
+            delete(recid);
+            collections.remove(name);
+
+
+            dir.remove(name);
+
+        }catch(IOException e){
+            throw new IOError(e);
+        }
+
+    }
+
+
+    /** we need to set reference to this DB instance, so serializer needs to be here*/
+    final Serializer<Serialization> defaultSerializationSerializer = new Serializer<Serialization>(){
+
+        public void serialize(DataOutput out, Serialization obj) throws IOException {
+            LongPacker.packLong(out,obj.serialClassInfoRecid);
+            SerialClassInfo.serializer.serialize(out,obj.registered);
+        }
+
+        public Serialization deserialize(DataInput in) throws IOException, ClassNotFoundException {
+            final long recid = LongPacker.unpackLong(in);
+            final ArrayList<SerialClassInfo.ClassInfo> classes = SerialClassInfo.serializer.deserialize(in);
+            return new Serialization(DBAbstract.this,recid,classes);
+        }
+    };
+
+    public synchronized Serializer defaultSerializer() {
+
+        try{
+            long serialClassInfoRecid = getRoot(SERIAL_CLASS_INFO_RECID_ROOT);
+            if (serialClassInfoRecid == 0) {
+                //allocate new recid 
+                serialClassInfoRecid = insert(null,Utils.NULL_SERIALIZER,false);
+                //and insert new serializer
+                Serialization ser = new Serialization(this,serialClassInfoRecid,new ArrayList<SerialClassInfo.ClassInfo>());
+
+                update(serialClassInfoRecid,ser, defaultSerializationSerializer);
+                setRoot(SERIAL_CLASS_INFO_RECID_ROOT, serialClassInfoRecid);
+                return ser;
+            }else{
+                return fetch(serialClassInfoRecid,defaultSerializationSerializer);
+            }
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+
+    }
+
+
+    final protected void checkNotClosed(){
+        if(isClosed()) throw new IllegalStateException("db was closed");
+    }
+
+    protected abstract void setRoot(byte root, long recid);
+    protected abstract long getRoot(byte root);
+
+
+    synchronized public long collectionSize(Object collection){
+        if(collection instanceof BTreeMap){
+            BTreeMap t = (BTreeMap) collection;
+            if(t.fromKey!=null|| t.toKey!=null) throw new IllegalArgumentException("collectionSize does not work on BTree submap");
+            return t.tree._entries;
+        }else if(collection instanceof  HTree){
+            return ((HTree)collection).getRoot().size;
+        }else if(collection instanceof  HTreeSet){
+            return collectionSize(((HTreeSet) collection).map);
+        }else if(collection instanceof  BTreeSet){
+            return collectionSize(((BTreeSet) collection).map);
+        }else if(collection instanceof LinkedList2){
+            return ((LinkedList2)collection).getRoot().size;
+        }else{
+            throw new IllegalArgumentException("Not JDBM collection");
+        }
+    }
+
+
+    void addShutdownHook(){
+        if(shutdownCloseThread!=null){
+            shutdownCloseThread = new ShutdownCloseThread();
+            Runtime.getRuntime().addShutdownHook(shutdownCloseThread);
+        }
+    }
+
+    public void close(){
+        if(shutdownCloseThread!=null){
+            Runtime.getRuntime().removeShutdownHook(shutdownCloseThread);
+            shutdownCloseThread.dbToClose = null;
+            shutdownCloseThread = null;
+        }
+    }
+
+
+    ShutdownCloseThread shutdownCloseThread = null;
+
+    private static class ShutdownCloseThread extends Thread{
+
+        DBAbstract dbToClose = null;
+
+        ShutdownCloseThread(){
+            super("JDBM shutdown");
+        }
+
+        public void run(){
+            if(dbToClose!=null && !dbToClose.isClosed()){
+                dbToClose.shutdownCloseThread = null;
+                dbToClose.close();
+            }
+        }
+
+    }
+
+    synchronized public void   rollback() {
+        try {
+        for(WeakReference<Object> o:collections.values()){
+            Object c =  o.get();
+            if(c != null && c instanceof BTreeMap){
+                //reload tree
+                BTreeMap m = (BTreeMap) c;
+                m.tree = fetch(m.tree.getRecid());
+            }
+            if(c != null && c instanceof BTreeSet){
+                //reload tree
+                BTreeSet m = (BTreeSet) c;
+                m.map.tree = fetch(m.map.tree.getRecid());
+            }
+
+
+        }
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+
+    }
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/DBCache.java

@@ -0,0 +1,162 @@
+package org.apache.jdbm;
+
+import javax.crypto.Cipher;
+import java.io.IOError;
+import java.io.IOException;
+import java.util.Comparator;
+import java.util.Iterator;
+
+/**
+ * Abstract class with common cache functionality
+ */
+abstract class DBCache extends DBStore{
+
+    static final int NUM_OF_DIRTY_RECORDS_BEFORE_AUTOCOMIT = 1024;
+
+    static final byte NONE = 1;
+    static final byte MRU = 2;
+    static final byte WEAK = 3;
+    static final byte SOFT = 4;
+    static final byte HARD = 5;
+
+    static final class DirtyCacheEntry {
+        long _recid; //TODO recid is already part of _hashDirties, so this field could be removed to save memory
+        Object _obj;
+        Serializer _serializer;
+    }
+
+
+    /**
+     * Dirty status of _hash CacheEntry Values
+     */
+    final protected LongHashMap<DirtyCacheEntry> _hashDirties = new LongHashMap<DirtyCacheEntry>();
+
+    private Serializer cachedDefaultSerializer = null;
+
+
+    /**
+     * Construct a CacheRecordManager wrapping another DB and
+     * using a given cache policy.
+     */
+    public DBCache(String filename, boolean readonly, boolean transactionDisabled,
+                      Cipher cipherIn, Cipher cipherOut, boolean useRandomAccessFile,
+                     boolean deleteFilesAfterClose,boolean lockingDisabled){
+
+        super(filename, readonly, transactionDisabled,
+                cipherIn, cipherOut, useRandomAccessFile,
+                deleteFilesAfterClose,lockingDisabled);
+
+    }
+
+
+    @Override
+    public synchronized  Serializer defaultSerializer(){
+        if(cachedDefaultSerializer==null)
+            cachedDefaultSerializer = super.defaultSerializer();
+        return cachedDefaultSerializer;
+    }
+
+    @Override
+    boolean needsAutoCommit() {
+        return super.needsAutoCommit()||
+                (transactionsDisabled &&  !commitInProgress && _hashDirties.size() > NUM_OF_DIRTY_RECORDS_BEFORE_AUTOCOMIT);
+    }
+
+
+
+    public synchronized <A> long insert(final A obj, final Serializer<A> serializer, final boolean disableCache)
+            throws IOException {
+        checkNotClosed();
+
+        if(super.needsAutoCommit())
+            commit();
+
+        if(disableCache)
+            return super.insert(obj, serializer, disableCache);
+
+
+        //prealocate recid so we have something to return
+        final long recid = super.insert(PREALOCATE_OBJ, null, disableCache);
+
+//        super.update(recid, obj,serializer);
+
+//        return super.insert(obj,serializer,disableCache);
+
+        //and create new dirty record for future update
+        final DirtyCacheEntry e = new DirtyCacheEntry();
+        e._recid = recid;
+        e._obj = obj;
+        e._serializer = serializer;
+        _hashDirties.put(recid,e);
+
+        return recid;
+    }
+
+
+
+    public synchronized void commit() {
+        try{
+            commitInProgress = true;
+            updateCacheEntries();
+            super.commit();
+        }finally {
+            commitInProgress = false;
+        }
+    }
+
+    public synchronized  void rollback(){
+        cachedDefaultSerializer = null;
+        _hashDirties.clear();
+        super.rollback();
+    }
+
+    
+    private static final Comparator<DirtyCacheEntry> DIRTY_COMPARATOR = new Comparator<DirtyCacheEntry>() {
+        final public int compare(DirtyCacheEntry o1, DirtyCacheEntry o2) {
+            return (int) (o1._recid - o2._recid);
+
+        }
+    };
+    
+
+    /**
+     * Update all dirty cache objects to the underlying DB.
+     */
+    protected void updateCacheEntries() {
+        try {
+            synchronized(_hashDirties){
+
+                while(!_hashDirties.isEmpty()){
+                    //make defensive copy of values as _db.update() may trigger changes in db
+                    //and this would modify dirties again
+                    DirtyCacheEntry[] vals = new DirtyCacheEntry[_hashDirties.size()];
+                    Iterator<DirtyCacheEntry> iter = _hashDirties.valuesIterator();
+
+                    for(int i = 0;i<vals.length;i++){
+                        vals[i] = iter.next();
+                    }
+                    iter = null;
+
+                    java.util.Arrays.sort(vals,DIRTY_COMPARATOR);
+
+                    
+                    for(int i = 0;i<vals.length;i++){
+                        final DirtyCacheEntry entry = vals[i];
+                        vals[i] = null;
+                        super.update(entry._recid, entry._obj, entry._serializer);
+                        _hashDirties.remove(entry._recid);
+
+                    }
+
+                    //update may have triggered more records to be added into dirties, so repeat until all records are written.
+                }
+            }
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+
+    }
+
+
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/DBCacheMRU.java

@@ -0,0 +1,350 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+package org.apache.jdbm;
+
+import javax.crypto.Cipher;
+import java.io.IOException;
+
+/**
+ * A DB wrapping and caching another DB.
+ *
+ * @author Jan Kotek
+ * @author Alex Boisvert
+ * @author Cees de Groot
+ *
+ * TODO add 'cache miss' statistics
+ */
+class DBCacheMRU
+        extends DBCache {
+
+
+    private static final boolean debug = false;
+
+
+
+    /**
+     * Cached object hashtable
+     */
+    protected LongHashMap<CacheEntry> _hash;
+
+
+
+    /**
+     * Maximum number of objects in the cache.
+     */
+    protected int _max;
+
+
+
+    /**
+     * Beginning of linked-list of cache elements.  First entry is element
+     * which has been used least recently.
+     */
+    protected CacheEntry _first;
+
+    /**
+     * End of linked-list of cache elements.  Last entry is element
+     * which has been used most recently.
+     */
+    protected CacheEntry _last;
+
+
+    /**
+     * Construct a CacheRecordManager wrapping another DB and
+     * using a given cache policy.
+     */
+    public DBCacheMRU(String filename, boolean readonly, boolean transactionDisabled,
+                      Cipher cipherIn, Cipher cipherOut, boolean useRandomAccessFile,
+                     boolean deleteFilesAfterClose, int cacheMaxRecords, boolean lockingDisabled)  {
+        super(filename, readonly, transactionDisabled,
+            cipherIn, cipherOut, useRandomAccessFile,
+            deleteFilesAfterClose,lockingDisabled);
+
+        _hash = new LongHashMap<CacheEntry>(cacheMaxRecords);
+        _max = cacheMaxRecords;
+
+    }
+
+
+
+    public synchronized <A> A fetch(long recid, Serializer<A> serializer, boolean disableCache) throws IOException {
+
+        if (disableCache)
+            return super.fetch(recid, serializer, disableCache);
+        else
+            return fetch(recid, serializer);
+    }
+
+
+    public synchronized void delete(long recid)
+            throws IOException {
+        checkNotClosed();
+
+        super.delete(recid);
+        synchronized (_hash){
+            CacheEntry entry = _hash.get(recid);
+            if (entry != null) {
+                removeEntry(entry);
+                _hash.remove(entry._recid);
+            }
+            _hashDirties.remove(recid);
+        }
+
+        if(super.needsAutoCommit())
+            commit();
+
+    }
+
+    public synchronized <A> void update(final long recid, final A obj, final Serializer<A> serializer) throws IOException {
+        checkNotClosed();
+
+        synchronized (_hash){
+
+            //remove entry if it already exists
+            CacheEntry entry = cacheGet(recid);
+            if (entry != null) {
+                _hash.remove(recid);
+                removeEntry(entry);
+            }
+
+            //check if entry is in dirties, in this case just update its object
+            DirtyCacheEntry e = _hashDirties.get(recid);
+            if(e!=null){
+                if(recid!=e._recid) throw new Error();
+                e._obj = obj;
+                e._serializer = serializer;
+                return;
+            }
+            
+            //create new dirty entry
+            e = new DirtyCacheEntry();
+            e._recid = recid;
+            e._obj = obj;
+            e._serializer = serializer;
+            _hashDirties.put(recid,e);
+        }
+
+        if(super.needsAutoCommit())
+            commit();
+
+    }
+
+
+    public synchronized <A> A fetch(long recid, Serializer<A> serializer)
+            throws IOException {
+
+        checkNotClosed();
+
+        final CacheEntry entry = cacheGet(recid);
+        if (entry != null) {
+            return (A) entry._obj;
+        }
+
+        //check dirties
+        final DirtyCacheEntry entry2 = _hashDirties.get(recid);
+        if(entry2!=null){
+            return (A) entry2._obj;
+        }
+
+
+
+        A value = super.fetch(recid, serializer);
+
+        if(super.needsAutoCommit())
+            commit();
+
+
+        //put record into MRU cache
+        cachePut(recid, value);
+
+        return value;
+    }
+
+
+    public synchronized void close() {
+
+        if(isClosed())
+            return;
+
+        updateCacheEntries();
+        super.close();
+        _hash = null;
+    }
+
+
+
+    public synchronized void rollback() {
+
+        // discard all cache entries since we don't know which entries
+        // where part of the transaction
+        synchronized (_hash){
+            _hash.clear();
+            _first = null;
+            _last = null;
+        }
+
+        super.rollback();
+    }
+
+
+    /**
+     * Obtain an object in the cache
+     */
+    protected CacheEntry cacheGet(long key) {
+        synchronized (_hash){
+            CacheEntry entry = _hash.get(key);
+            if ( entry != null && _last != entry) {
+                //touch entry
+                removeEntry(entry);
+                addEntry(entry);
+            }
+            return entry;
+        }
+    }
+
+
+    /**
+     * Place an object in the cache.
+     *
+     * @throws IOException
+     */
+    protected void cachePut(final long recid, final Object value) throws IOException {
+        synchronized (_hash){
+            CacheEntry entry = _hash.get(recid);
+            if (entry != null) {
+                entry._obj = value;
+                //touch entry
+                if (_last != entry) {
+                    removeEntry(entry);
+                    addEntry(entry);
+                }
+            } else {
+
+                if (_hash.size() >= _max) {
+                    // purge and recycle entry
+                    entry = purgeEntry();
+                    entry._recid = recid;
+                    entry._obj = value;
+                } else {
+                    entry = new CacheEntry(recid, value);
+                }
+                addEntry(entry);
+                _hash.put(entry._recid, entry);
+            }
+        }
+    }
+
+    /**
+     * Add a CacheEntry.  Entry goes at the end of the list.
+     */
+    protected void addEntry(CacheEntry entry) {
+        synchronized (_hash){
+            if (_first == null) {
+                _first = entry;
+                _last = entry;
+            } else {
+                _last._next = entry;
+                entry._previous = _last;
+                _last = entry;
+            }
+        }
+    }
+
+
+    /**
+     * Remove a CacheEntry from linked list
+     */
+    protected void removeEntry(CacheEntry entry) {
+        synchronized (_hash){
+            if (entry == _first) {
+                _first = entry._next;
+            }
+            if (_last == entry) {
+                _last = entry._previous;
+            }
+            CacheEntry previous = entry._previous;
+            CacheEntry next = entry._next;
+            if (previous != null) {
+                previous._next = next;
+            }
+            if (next != null) {
+                next._previous = previous;
+            }
+            entry._previous = null;
+            entry._next = null;
+        }
+    }
+
+    /**
+     * Purge least recently used object from the cache
+     *
+     * @return recyclable CacheEntry
+     */
+    protected CacheEntry purgeEntry() {
+        synchronized (_hash){
+            CacheEntry entry = _first;
+            if (entry == null)
+                return new CacheEntry(-1, null);
+
+            removeEntry(entry);
+            _hash.remove(entry._recid);
+            entry._obj = null;
+            return entry;
+        }
+    }
+
+
+
+
+    @SuppressWarnings("unchecked")
+    static final class CacheEntry {
+
+        protected long _recid;
+        protected Object _obj;
+
+
+        protected CacheEntry _previous;
+        protected CacheEntry _next;
+
+
+        CacheEntry(long recid, Object obj) {
+            _recid = recid;
+            _obj = obj;
+        }
+
+    }
+
+
+    public void clearCache() {
+        if(debug)
+            System.err.println("DBCache: Clear cache");
+
+        // discard all cache entries since we don't know which entries
+        // where part of the transaction
+        synchronized (_hash){
+            _hash.clear();
+            _first = null;
+            _last = null;
+
+            //clear dirties
+            updateCacheEntries();
+
+        }
+    }
+
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/DBCacheRef.java

@@ -0,0 +1,401 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+package org.apache.jdbm;
+
+import javax.crypto.Cipher;
+import java.io.IOException;
+import java.lang.ref.ReferenceQueue;
+import java.lang.ref.SoftReference;
+import java.lang.ref.WeakReference;
+import java.util.Iterator;
+import java.util.concurrent.atomic.AtomicInteger;
+
+/**
+ * A DB wrapping and caching another DB.
+ *
+ * @author Jan Kotek
+ * @author Alex Boisvert
+ * @author Cees de Groot
+ *
+ * TODO add 'cache miss' statistics
+ */
+public class DBCacheRef
+        extends DBCache {
+
+
+
+    private static final boolean debug = false;
+
+
+
+    /**
+     * If Soft Cache is enabled, this contains softly referenced clean entries.
+     * If entry became dirty, it is moved to _hash with limited size.
+     * This map is accessed from SoftCache Disposer thread, so all access must be
+     * synchronized
+     */
+    protected LongHashMap _softHash;
+
+    /**
+     * Reference queue used to collect Soft Cache entries
+     */
+    protected ReferenceQueue<ReferenceCacheEntry> _refQueue;
+
+
+
+    /**
+     * Thread in which Soft Cache references are disposed
+     */
+    protected Thread _softRefThread;
+
+    protected static AtomicInteger threadCounter = new AtomicInteger(0);
+
+
+    /** counter which counts number of insert since last 'action'*/
+    protected int insertCounter = 0;
+
+    private final boolean _autoClearReferenceCacheOnLowMem;
+    private final byte _cacheType;
+
+
+    /**
+     * Construct a CacheRecordManager wrapping another DB and
+     * using a given cache policy.
+     */
+    public DBCacheRef(String filename, boolean readonly, boolean transactionDisabled,
+                      Cipher cipherIn, Cipher cipherOut, boolean useRandomAccessFile,
+                      boolean deleteFilesAfterClose,
+                      byte cacheType, boolean cacheAutoClearOnLowMem, boolean lockingDisabled) {
+
+        super(filename, readonly, transactionDisabled,
+                cipherIn, cipherOut, useRandomAccessFile,
+                deleteFilesAfterClose, lockingDisabled);
+
+
+        this._cacheType = cacheType;
+        _autoClearReferenceCacheOnLowMem = cacheAutoClearOnLowMem;
+
+
+        _softHash = new LongHashMap<ReferenceCacheEntry>();
+        _refQueue = new ReferenceQueue<ReferenceCacheEntry>();
+        _softRefThread = new Thread(
+                    new SoftRunnable(this, _refQueue),
+                    "JDBM Soft Cache Disposer " + (threadCounter.incrementAndGet()));
+        _softRefThread.setDaemon(true);
+        _softRefThread.start();
+
+    }
+
+
+    void clearCacheIfLowOnMem() {
+
+        insertCounter = 0;
+
+        if(!_autoClearReferenceCacheOnLowMem)
+            return;
+
+        Runtime r = Runtime.getRuntime();
+        long max = r.maxMemory();
+        if(max == Long.MAX_VALUE)
+            return;
+
+        double free = r.freeMemory();
+        double total = r.totalMemory();
+        //We believe that free refers to total not max.
+        //Increasing heap size to max would increase to max
+        free = free + (max-total);
+
+        if(debug)
+            System.err.println("DBCache: freemem = " +free + " = "+(free/max)+"%");
+
+        if(free<1e7 || free*4 <max)
+            clearCache();
+
+
+    }
+
+    public synchronized <A> A fetch(long recid, Serializer<A> serializer, boolean disableCache) throws IOException {
+
+        if (disableCache)
+            return super.fetch(recid, serializer, disableCache);
+        else
+            return fetch(recid, serializer);
+    }
+
+
+    public synchronized void delete(long recid)
+            throws IOException {
+        checkNotClosed();
+
+        super.delete(recid);
+        synchronized (_hashDirties){
+            _hashDirties.remove(recid);
+        }
+        synchronized (_softHash) {
+            Object e = _softHash.remove(recid);
+            if (e != null && e instanceof ReferenceCacheEntry) {
+                ((ReferenceCacheEntry)e).clear();
+            }
+        }
+
+        if(needsAutoCommit())
+            commit();
+
+    }
+
+    public synchronized <A> void update(final long recid, A obj, Serializer<A> serializer) throws IOException {
+        checkNotClosed();
+
+
+        synchronized (_softHash) {
+            //soft cache can not contain dirty objects
+            Object e = _softHash.remove(recid);
+            if (e != null && e instanceof ReferenceCacheEntry) {
+                ((ReferenceCacheEntry)e).clear();
+            }
+        }
+        synchronized (_hashDirties){
+            //put into dirty cache
+            final DirtyCacheEntry e = new DirtyCacheEntry();
+            e._recid = recid;
+            e._obj = obj;
+            e._serializer = serializer;
+            _hashDirties.put(recid,e);
+        }
+
+        if(needsAutoCommit())
+            commit();
+
+    }
+
+
+    public synchronized <A> A fetch(long recid, Serializer<A> serializer)
+            throws IOException {
+        checkNotClosed();
+
+        synchronized (_softHash) {
+            Object e = _softHash.get(recid);
+            if (e != null) {
+
+                if(e instanceof ReferenceCacheEntry)
+                    e = ((ReferenceCacheEntry)e).get();
+                if (e != null) {
+                    return (A) e;
+                }
+            }
+        }
+
+
+        synchronized (_hashDirties){
+            DirtyCacheEntry e2 = _hashDirties.get(recid);
+            if(e2!=null){
+                return (A) e2._obj;
+            }
+        }
+
+
+
+
+        A value = super.fetch(recid, serializer);
+
+        if(needsAutoCommit())
+            commit();
+
+           synchronized (_softHash) {
+
+                    if (_cacheType == SOFT)
+                        _softHash.put(recid, new SoftCacheEntry(recid, value, _refQueue));
+                    else if (_cacheType == WEAK)
+                        _softHash.put(recid, new WeakCacheEntry(recid, value, _refQueue));
+                    else
+                        _softHash.put(recid,value);
+           }
+
+
+        return value;
+    }
+
+
+    public synchronized void close() {
+        checkNotClosed();
+
+        updateCacheEntries();
+        super.close();
+        _softHash = null;
+        _softRefThread.interrupt();
+    }
+
+
+
+
+    public synchronized void rollback() {
+        checkNotClosed();
+
+
+        // discard all cache entries since we don't know which entries
+        // where part of the transaction
+        synchronized (_softHash) {
+            Iterator<ReferenceCacheEntry> iter = _softHash.valuesIterator();
+            while (iter.hasNext()) {
+                ReferenceCacheEntry e = iter.next();
+                e.clear();
+            }
+            _softHash.clear();
+        }
+
+        super.rollback();
+    }
+
+
+
+
+    
+	protected boolean isCacheEntryDirty(DirtyCacheEntry entry) {
+		return _hashDirties.get(entry._recid) != null;
+	}
+
+	protected void setCacheEntryDirty(DirtyCacheEntry entry, boolean dirty) {
+		if (dirty) {
+			_hashDirties.put(entry._recid, entry);
+		} else {
+			_hashDirties.remove(entry._recid);
+		}
+	}
+
+
+
+    interface ReferenceCacheEntry {
+        long getRecid();
+
+        void clear();
+
+        Object get();
+    }
+
+    @SuppressWarnings("unchecked")
+    static final class SoftCacheEntry extends SoftReference implements ReferenceCacheEntry {
+        protected final long _recid;
+
+        public long getRecid() {
+            return _recid;
+        }
+
+        SoftCacheEntry(long recid, Object obj, ReferenceQueue queue) {
+            super(obj, queue);
+            _recid = recid;
+        }
+    }
+
+    @SuppressWarnings("unchecked")
+    static final class WeakCacheEntry extends WeakReference implements ReferenceCacheEntry {
+        protected final long _recid;
+
+        public long getRecid() {
+            return _recid;
+        }
+
+        WeakCacheEntry(long recid, Object obj, ReferenceQueue queue) {
+            super(obj, queue);
+            _recid = recid;
+        }
+
+
+    }
+
+
+    /**
+     * Runs in separate thread and cleans SoftCache.
+     * Runnable auto exists when CacheRecordManager is GCed
+     *
+     * @author Jan Kotek
+     */
+    static final class SoftRunnable implements Runnable {
+
+        private ReferenceQueue<ReferenceCacheEntry> entryQueue;
+        private WeakReference<DBCacheRef> db2;
+
+        public SoftRunnable(DBCacheRef db,
+                            ReferenceQueue<ReferenceCacheEntry> entryQueue) {
+            this.db2 = new WeakReference<DBCacheRef>(db);
+            this.entryQueue = entryQueue;
+        }
+
+        public void run() {
+            while (true) try {
+
+                //collect next item from cache,
+                //limit 10000 ms is to keep periodically checking if db was GCed
+                ReferenceCacheEntry e = (ReferenceCacheEntry) entryQueue.remove(10000);
+
+                //check if  db was GCed, cancel in that case
+                DBCacheRef db = db2.get();
+                if (db == null)
+                    return;
+
+                if (e != null) {
+
+                    synchronized (db._softHash) {
+                        int counter = 0;
+                        while (e != null) {
+                            db._softHash.remove(e.getRecid());
+                            e = (SoftCacheEntry) entryQueue.poll();
+                            if(debug)
+                                counter++;
+                        }
+                        if(debug)
+                            System.err.println("DBCache: "+counter+" objects released from ref cache.");
+                    }
+                }else{
+                    //check memory consumption every 10 seconds
+                    db.clearCacheIfLowOnMem();
+
+                }
+
+
+            } catch (InterruptedException e) {
+                return;
+            } catch (Throwable e) {
+                //this thread must keep spinning,
+                //otherwise SoftCacheEntries would not be disposed
+                e.printStackTrace();
+            }
+        }
+
+    }
+
+
+    public void clearCache() {
+        if(debug)
+            System.err.println("DBCache: Clear cache");
+
+
+        synchronized (_softHash) {
+            if(_cacheType!=HARD){
+                Iterator<ReferenceCacheEntry> iter = _softHash.valuesIterator();
+                while (iter.hasNext()) {
+                    ReferenceCacheEntry e = iter.next();
+                    e.clear();
+                }
+            }
+            _softHash.clear();
+        }
+
+    }
+
+
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/DBMaker.java

@@ -0,0 +1,351 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+package org.apache.jdbm;
+
+import javax.crypto.Cipher;
+import javax.crypto.SecretKey;
+import javax.crypto.SecretKeyFactory;
+import javax.crypto.spec.IvParameterSpec;
+import javax.crypto.spec.PBEKeySpec;
+import javax.crypto.spec.SecretKeySpec;
+import java.io.IOError;
+import java.security.spec.KeySpec;
+
+/**
+ * Class used to configure and create DB. It uses builder pattern.
+ */
+public class DBMaker {
+
+    private byte cacheType = DBCacheRef.MRU;
+    private int mruCacheSize = 2048;
+
+    private String location = null;
+
+    private boolean disableTransactions = false;
+    private boolean lockingDisabled = false;
+    private boolean readonly = false;
+    private String password = null;
+    private boolean useAES256Bit = true;
+    private boolean useRandomAccessFile = false;
+    private boolean autoClearRefCacheOnLowMem = true;
+    private  boolean closeOnJVMExit = false;
+    private  boolean deleteFilesAfterCloseFlag = false;
+
+
+    private DBMaker(){}
+
+    /**
+     * Creates new DBMaker and sets file to load data from.
+     * @param file to load data from
+     * @return new DBMaker
+     */
+    public static DBMaker openFile(String file){
+        DBMaker m = new DBMaker();
+        m.location = file;
+        return m;
+    }
+
+    /**
+     * Creates new DBMaker which uses in memory store. Data will be lost after JVM exits.
+     * @return new DBMaker
+     */
+    public static DBMaker openMemory(){
+        return new DBMaker();
+    }
+
+    /**
+     * Open store in zip file
+     *
+     * @param zip file
+     * @return new DBMaker
+     */
+    public static DBMaker openZip(String zip) {
+        DBMaker m = new DBMaker();
+        m.location = "$$ZIP$$://"+zip;
+        return m;
+    }
+
+     static String  isZipFileLocation(String location){
+         String match = "$$ZIP$$://";
+         if( location.startsWith(match)){
+             return location.substring(match.length());
+         }
+         return null;
+     }
+
+    /**
+     * Use WeakReference for cache.
+     * This cache does not improve performance much,
+     * but prevents JDBM from creating multiple instances of the same object.
+     *
+     * @return this builder
+     */
+    public DBMaker enableWeakCache() {
+        cacheType = DBCacheRef.WEAK;
+        return this;
+    }
+
+    /**
+     * Use SoftReference for cache.
+     * This cache greatly improves performance if you have enoguth memory.
+     * Instances in cache are Garbage Collected when memory gets low
+     *
+     * @return this builder
+     */
+    public DBMaker enableSoftCache() {
+        cacheType = DBCacheRef.SOFT;
+        return this;
+    }
+
+    /**
+     * Use hard reference for cache.
+     * This greatly improves performance if there is enought memory
+     * Hard cache has smaller memory overhead then Soft or Weak, because
+     * reference objects and queue does not have to be maintained
+     *
+     * @return this builder
+     */
+    public DBMaker enableHardCache() {
+        cacheType = DBCacheRef.SOFT;
+        return this;
+    }
+
+
+    /**
+     * Use 'Most Recently Used' cache with limited size.
+     * Oldest instances are released from cache when new instances are fetched.
+     * This cache is not cleared by GC. Is good for systems with limited memory.
+     * <p/>
+     * Default size for MRU cache is 2048 records.
+     *
+     * @return this builder
+     */
+    public DBMaker enableMRUCache() {
+        cacheType = DBCacheRef.MRU;
+        return this;
+    }
+
+    /**
+     *
+     * Sets 'Most Recently Used' cache size. This cache is activated by default with size 2048
+     *
+     * @param cacheSize number of instances which will be kept in cache.
+     * @return this builder
+     */
+    public DBMaker setMRUCacheSize(int cacheSize) {
+        if (cacheSize < 0) throw new IllegalArgumentException("Cache size is smaller than zero");
+        cacheType = DBCacheRef.MRU;
+        mruCacheSize = cacheSize;
+        return this;
+    }
+
+    /**
+     * If reference (soft,weak or hard) cache is enabled,
+     * GC may not release references fast enough (or not at all in case of hard cache).
+     * So JDBM periodically checks amount of free heap memory.
+     * If free memory is less than 25% or 10MB,
+     * JDBM completely clears its reference cache to prevent possible memory issues.
+     * <p>
+     * Calling this method disables auto cache clearing when mem is low.
+     * And of course it can cause some out of memory exceptions.
+     *
+     * @return this builder
+     */
+    public DBMaker disableCacheAutoClear(){
+        this.autoClearRefCacheOnLowMem = false;
+        return this;
+    }
+
+
+    /**
+     * Enabled storage encryption using AES cipher. JDBM supports both 128 bit and 256 bit encryption if JRE provides it.
+     * There are some restrictions on AES 256 bit and not all JREs have it  by default.
+     * <p/>
+     * Storage can not be read (decrypted), unless the key is provided next time it is opened
+     *
+     * @param password used to encrypt store
+     * @param useAES256Bit if true strong AES 256 bit encryption is used. Otherwise more usual AES 128 bit is used.
+     * @return this builder
+     */
+    public DBMaker enableEncryption(String password, boolean useAES256Bit) {
+        this.password = password;
+        this.useAES256Bit = useAES256Bit;
+        return this;
+    }
+
+
+
+
+    /**
+     * Make DB readonly.
+     * Update/delete/insert operation will throw 'UnsupportedOperationException'
+     *
+     * @return this builder
+     */
+    public DBMaker readonly() {
+        readonly = true;
+        return this;
+    }
+
+
+    /**
+     * Disable cache completely
+     *
+     * @return this builder
+     */
+    public DBMaker disableCache() {
+        cacheType = DBCacheRef.NONE;
+        return this;
+    }
+
+
+    /**
+     * Option to disable transaction (to increase performance at the cost of potential data loss).
+     * Transactions are enabled by default
+     * <p/>
+     * Switches off transactioning for the record manager. This means
+     * that a) a transaction log is not kept, and b) writes aren't
+     * synch'ed after every update. Writes are cached in memory and then flushed
+     * to disk every N writes. You may also flush writes manually by calling commit().
+     * This is useful when batch inserting into a new database.
+     * <p/>
+     * When using this, database must be properly closed before JVM shutdown.
+     * Failing to do so may and WILL corrupt store.
+     *
+     * @return this builder
+     */
+    public DBMaker disableTransactions() {
+        this.disableTransactions = true;
+        return this;
+    }
+    
+    /**
+     * Disable file system based locking (for file systems that do not support it).
+     * 
+     * Locking is not supported by many remote or distributed file systems; such
+     * as Lustre and NFS. Attempts to perform locks will result in an 
+     * IOException with the message "Function not implemented".
+     * 
+     * Disabling locking will avoid this issue, though of course it comes with
+     * all the issues of uncontrolled file access.
+     * 
+     * @return this builder
+     */
+    public DBMaker disableLocking(){
+        this.lockingDisabled = true;
+        return this;
+    }
+    
+    /**
+     * By default JDBM uses mapped memory buffers to read from files.
+     * But this may behave strangely on some platforms.
+     * Safe alternative is to use old RandomAccessFile rather then mapped ByteBuffer.
+     * There is typically slower (pages needs to be copyed into memory on every write).
+     *
+     * @return this builder
+     */
+    public DBMaker useRandomAccessFile(){
+        this.useRandomAccessFile = true;
+        return this;
+    }
+
+
+    /**
+     * Registers shutdown hook and close database on JVM exit, if it was not already closed; 
+     * 
+     * @return this builder
+     */
+    public DBMaker closeOnExit(){
+        this.closeOnJVMExit = true;
+        return this;
+    }
+
+    /**
+     * Delete all storage files after DB is closed
+     *
+     * @return this builder
+     */
+    public DBMaker deleteFilesAfterClose(){
+        this.deleteFilesAfterCloseFlag = true;
+        return this;
+    }
+
+    /**
+     * Opens database with settings earlier specified in this builder.
+     *
+     * @return new DB
+     * @throws java.io.IOError if db could not be opened
+     */
+    public DB make() {
+
+        Cipher cipherIn = null;
+        Cipher cipherOut = null;
+        if (password != null) try {
+            //initialize ciphers
+            //this code comes from stack owerflow
+            //http://stackoverflow.com/questions/992019/java-256bit-aes-encryption/992413#992413
+            byte[] salt = new byte[]{3, -34, 123, 53, 78, 121, -12, -1, 45, -12, -48, 89, 11, 100, 99, 8};
+
+            SecretKeyFactory factory = SecretKeyFactory.getInstance("PBKDF2WithHmacSHA1");
+            KeySpec spec = new PBEKeySpec(password.toCharArray(), salt, 1024, useAES256Bit?256:128);
+            SecretKey tmp = factory.generateSecret(spec);
+            SecretKey secret = new SecretKeySpec(tmp.getEncoded(), "AES");
+
+            String transform = "AES/CBC/NoPadding";
+            IvParameterSpec params = new IvParameterSpec(salt);
+
+            cipherIn = Cipher.getInstance(transform);
+            cipherIn.init(Cipher.ENCRYPT_MODE, secret, params);
+
+            cipherOut = Cipher.getInstance(transform);
+            cipherOut.init(Cipher.DECRYPT_MODE, secret, params);
+
+            //sanity check, try with page size
+            byte[] data = new byte[Storage.PAGE_SIZE];
+            byte[] encData = cipherIn.doFinal(data);
+            if (encData.length != Storage.PAGE_SIZE)
+                throw new Error("Page size changed after encryption, make sure you use '/NoPadding'");
+            byte[] data2 = cipherOut.doFinal(encData);
+            for (int i = 0; i < data.length; i++) {
+                if (data[i] != data2[i]) throw new Error("Encryption provided by JRE does not work");
+            }
+
+        } catch (Exception e) {
+            throw new IOError(e);
+        }
+
+        DBAbstract db = null;
+
+
+        if (cacheType == DBCacheRef.MRU){
+          db = new DBCacheMRU(location, readonly, disableTransactions, cipherIn, cipherOut,useRandomAccessFile,deleteFilesAfterCloseFlag, mruCacheSize,lockingDisabled);
+        }else if( cacheType == DBCacheRef.SOFT || cacheType == DBCacheRef.HARD || cacheType == DBCacheRef.WEAK) {
+            db = new DBCacheRef(location, readonly, disableTransactions, cipherIn, cipherOut,useRandomAccessFile,deleteFilesAfterCloseFlag, cacheType,autoClearRefCacheOnLowMem,lockingDisabled);
+        } else if (cacheType == DBCacheRef.NONE) {
+            db = new DBStore(location, readonly, disableTransactions, cipherIn, cipherOut,useRandomAccessFile,deleteFilesAfterCloseFlag,lockingDisabled);
+        } else {
+            throw new IllegalArgumentException("Unknown cache type: " + cacheType);
+        }
+        
+        if(closeOnJVMExit){
+            db.addShutdownHook();
+        }
+
+        return db;
+    }
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/DBStore.java

@@ -0,0 +1,928 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+package org.apache.jdbm;
+
+
+import javax.crypto.Cipher;
+import java.io.*;
+import java.util.*;
+import java.util.zip.ZipEntry;
+import java.util.zip.ZipOutputStream;
+
+/**
+ * This class manages records, which are uninterpreted blobs of data. The
+ * set of operations is simple and straightforward: you communicate with
+ * the class using long "rowids" and byte[] data blocks. Rowids are returned
+ * on inserts and you can stash them away someplace safe to be able to get
+ * back to them. Data blocks can be as long as you wish, and may have
+ * lengths different from the original when updating.
+ * <p/>
+ * Operations are synchronized, so that only one of them will happen
+ * concurrently even if you hammer away from multiple threads. Operations
+ * are made atomic by keeping a transaction log which is recovered after
+ * a crash, so the operations specified by this interface all have ACID
+ * properties.
+ * <p/>
+ * You identify a file by just the name. The package attaches <tt>.db</tt>
+ * for the database file, and <tt>.lg</tt> for the transaction log. The
+ * transaction log is synchronized regularly and then restarted, so don't
+ * worry if you see the size going up and down.
+ *
+ * @author Alex Boisvert
+ * @author Cees de Groot
+ */
+class DBStore
+        extends DBAbstract {
+
+
+    /**
+     * Version of storage. It should be safe to open lower versions, but engine should throw exception
+     * while opening new versions (as it contains unsupported features or serialization)
+     */
+    static final long STORE_FORMAT_VERSION = 1L;
+
+    /**
+     * Underlying file for store records.
+     */
+    private PageFile _file;
+
+    /**
+     * Page manager for physical manager.
+     */
+    private PageManager _pageman;
+
+    /**
+     * Physical row identifier manager.
+     */
+    private PhysicalRowIdManager _physMgr;
+
+    /**
+     * Indicated that store is opened for readonly operations
+     * If true, store will throw UnsupportedOperationException when update/insert/delete operation is called
+     */
+    private final boolean readonly;
+    final boolean transactionsDisabled;
+    private final boolean deleteFilesAfterClose;
+
+    private static final int AUTOCOMMIT_AFTER_N_PAGES = 1024 * 5;
+
+
+    boolean commitInProgress = false;
+
+
+    /**
+     * cipher used for decryption, may be null
+     */
+    private Cipher cipherOut;
+    /**
+     * cipher used for encryption, may be null
+     */
+    private Cipher cipherIn;
+    private boolean useRandomAccessFile;
+    private boolean lockingDisabled;
+
+    void checkCanWrite() {
+        if (readonly)
+            throw new UnsupportedOperationException("Could not write, store is opened as read-only");
+    }
+
+
+
+
+    /**
+     * Logigal to Physical row identifier manager.
+     */
+    private LogicalRowIdManager _logicMgr;
+
+
+    /**
+     * Static debugging flag
+     */
+    public static final boolean DEBUG = false;
+
+
+    
+    static final long PREALOCATE_PHYS_RECID = Short.MIN_VALUE;
+    
+    static final Object PREALOCATE_OBJ = new Object();
+
+
+
+
+    private final DataInputOutput buffer = new DataInputOutput();
+    private boolean bufferInUse = false;
+
+
+    private final String _filename;
+
+    public DBStore(String filename, boolean readonly, boolean transactionDisabled, boolean lockingDisabled) throws IOException {
+        this(filename, readonly, transactionDisabled, null, null, false,false,false);
+    }
+
+
+    /**
+     * Creates a record manager for the indicated file
+     *
+     * @throws IOException when the file cannot be opened or is not
+     *                     a valid file content-wise.
+     */
+    public DBStore(String filename, boolean readonly, boolean transactionDisabled,
+                   Cipher cipherIn, Cipher cipherOut, boolean useRandomAccessFile,
+                   boolean deleteFilesAfterClose, boolean lockingDisabled){
+        _filename = filename;
+        this.readonly = readonly;
+        this.transactionsDisabled = transactionDisabled;
+        this.cipherIn = cipherIn;
+        this.cipherOut = cipherOut;
+        this.useRandomAccessFile = useRandomAccessFile;
+        this.deleteFilesAfterClose = deleteFilesAfterClose;
+        this.lockingDisabled = lockingDisabled;
+        reopen();
+    }
+
+
+    private void reopen()  {
+        try{
+        _file = new PageFile(_filename, readonly, transactionsDisabled, cipherIn, cipherOut,useRandomAccessFile,lockingDisabled);
+        _pageman = new PageManager(_file);
+        _physMgr = new PhysicalRowIdManager(_file, _pageman);
+
+        _logicMgr = new LogicalRowIdManager(_file, _pageman);
+
+        long versionNumber = getRoot(STORE_VERSION_NUMBER_ROOT);
+        if (versionNumber > STORE_FORMAT_VERSION)
+            throw new IOException("Unsupported version of store. Please update JDBM. Minimal supported ver:" + STORE_FORMAT_VERSION + ", store ver:" + versionNumber);
+        if (!readonly)
+            setRoot(STORE_VERSION_NUMBER_ROOT, STORE_FORMAT_VERSION);
+        }catch(IOException e){
+            throw new IOError(e);
+        }
+    }
+
+
+    /**
+     * Closes the record manager.
+     *
+     * @throws IOException when one of the underlying I/O operations fails.
+     */
+    public synchronized void close() {
+        checkNotClosed();
+        try {
+            super.close();
+            _pageman.close();
+            _file.close();
+            if(deleteFilesAfterClose)
+                _file.storage.deleteAllFiles();
+            
+            _pageman = null;
+
+            
+            _file = null;
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public boolean isClosed() {
+        return _pageman==null;
+    }
+
+
+    public synchronized <A> long insert(final A obj, final Serializer<A> serializer, final boolean disableCache)
+            throws IOException {
+        checkNotClosed();
+        checkCanWrite();
+
+        if (needsAutoCommit()) {
+            commit();
+        }
+
+
+        if (bufferInUse) {
+            //current reusable buffer is in use, have to fallback into creating new instances
+            DataInputOutput buffer2 = new DataInputOutput();
+            return insert2(obj, serializer, buffer2);
+        }
+
+        try {
+
+            bufferInUse = true;
+            return insert2(obj, serializer, buffer);
+        } finally {
+            bufferInUse = false;
+        }
+
+
+    }
+
+    boolean needsAutoCommit() {
+        return  transactionsDisabled && !commitInProgress &&
+                (_file.getDirtyPageCount() >= AUTOCOMMIT_AFTER_N_PAGES );
+    }
+
+
+    private <A> long insert2(A obj, Serializer<A> serializer, DataInputOutput buf)
+            throws IOException {
+        buf.reset();
+
+
+        long physRowId;
+        if(obj==PREALOCATE_OBJ){
+            //if inserted record is  PREALOCATE_OBJ , it gets special handling.
+            //it is inserted only into _logicMgr with special value to indicate null
+            //this is used to preallocate recid for lazy inserts in cache
+            physRowId = PREALOCATE_PHYS_RECID;
+        }else{
+            serializer.serialize(buf, obj);
+            if(buf.getPos()>RecordHeader.MAX_RECORD_SIZE){
+                throw new IllegalArgumentException("Too big record. JDBM only supports record size up to: "+RecordHeader.MAX_RECORD_SIZE+" bytes. Record size was: "+buf.getPos());
+            }
+            physRowId = _physMgr.insert(buf.getBuf(), 0, buf.getPos());
+        }
+        final long recid = _logicMgr.insert(physRowId);
+
+        if (DEBUG) {
+            System.out.println("BaseRecordManager.insert() recid " + recid + " length " + buf.getPos());
+        }
+
+        return compressRecid(recid);
+    }
+
+
+    public synchronized void delete(long logRowId)
+            throws IOException {
+
+        checkNotClosed();
+        checkCanWrite();
+        if (logRowId <= 0) {
+            throw new IllegalArgumentException("Argument 'recid' is invalid: "
+                    + logRowId);
+        }
+
+        if (needsAutoCommit()) {
+            commit();
+        }
+
+        if (DEBUG) {
+            System.out.println("BaseRecordManager.delete() recid " + logRowId);
+        }
+
+        logRowId =  decompressRecid(logRowId);
+
+        long physRowId = _logicMgr.fetch(logRowId);
+        _logicMgr.delete(logRowId);
+        if(physRowId!=PREALOCATE_PHYS_RECID){
+            _physMgr.free(physRowId);
+        }
+    }
+
+
+    public synchronized <A> void update(long recid, A obj, Serializer<A> serializer)
+            throws IOException {
+        checkNotClosed();
+        checkCanWrite();
+        if (recid <= 0) {
+            throw new IllegalArgumentException("Argument 'recid' is invalid: "
+                    + recid);
+        }
+
+        if (needsAutoCommit()) {
+            commit();
+        }
+
+        if (bufferInUse) {
+            //current reusable buffer is in use, have to create new instances
+            DataInputOutput buffer2 = new DataInputOutput();
+            update2(recid, obj, serializer, buffer2);
+            return;
+        }
+
+        try {
+            bufferInUse = true;
+            update2(recid, obj, serializer, buffer);
+        } finally {
+            bufferInUse = false;
+        }
+    }
+
+
+    private <A> void update2(long logRecid, final A obj, final Serializer<A> serializer, final DataInputOutput buf)
+            throws IOException {
+
+        logRecid =  decompressRecid(logRecid);
+
+        long physRecid = _logicMgr.fetch(logRecid);
+        if (physRecid == 0)
+            throw new IOException("Can not update, recid does not exist: " + logRecid);
+        buf.reset();
+        serializer.serialize(buf, obj);
+
+
+        if (DEBUG) {
+            System.out.println("BaseRecordManager.update() recid " + logRecid + " length " + buf.getPos());
+        }
+
+        long newRecid =
+            physRecid!=PREALOCATE_PHYS_RECID?
+            _physMgr.update(physRecid, buf.getBuf(), 0, buf.getPos()):
+            //previous record was only virtual and does not actually exist, so make new insert
+            _physMgr.insert(buf.getBuf(),0,buf.getPos());
+
+        _logicMgr.update(logRecid, newRecid);
+
+    }
+
+
+    public synchronized <A> A fetch(final long recid, final Serializer<A> serializer)
+            throws IOException {
+
+        checkNotClosed();
+        if (recid <= 0) {
+            throw new IllegalArgumentException("Argument 'recid' is invalid: "  + recid);
+        }
+
+        if (bufferInUse) {
+            //current reusable buffer is in use, have to create new instances
+            DataInputOutput buffer2 = new DataInputOutput();
+            return fetch2(recid, serializer, buffer2);
+        }
+        try {
+            bufferInUse = true;
+            return fetch2(recid, serializer, buffer);
+        } finally {
+            bufferInUse = false;
+        }
+    }
+
+    public synchronized <A> A fetch(long recid, Serializer<A> serializer, boolean disableCache) throws IOException {
+        //we dont have any cache, so can ignore disableCache parameter
+        return fetch(recid, serializer);
+    }
+
+
+    private <A> A fetch2(long recid, final Serializer<A> serializer, final DataInputOutput buf)
+            throws IOException {
+
+        recid =  decompressRecid(recid);
+
+        buf.reset();
+        long physLocation = _logicMgr.fetch(recid);
+        if (physLocation == 0) {
+            //throw new IOException("Record not found, recid: "+recid);
+            return null;
+        }
+        if(physLocation == PREALOCATE_PHYS_RECID){
+            throw new InternalError("cache should prevent this!");
+        }
+
+        _physMgr.fetch(buf, physLocation);
+
+        if (DEBUG) {
+            System.out.println("BaseRecordManager.fetch() recid " + recid + " length " + buf.getPos());
+        }
+        buf.resetForReading();
+        try {
+            return serializer.deserialize(buf); //TODO there should be write limit to throw EOFException
+        } catch (ClassNotFoundException e) {
+            throw new IOError(e);
+        }
+    }
+
+    byte[] fetchRaw(long recid) throws IOException {
+        recid =  decompressRecid(recid);
+        long physLocation = _logicMgr.fetch(recid);
+        if (physLocation == 0) {
+            //throw new IOException("Record not found, recid: "+recid);
+            return null;
+        }
+        DataInputOutput i = new DataInputOutput();
+        _physMgr.fetch(i, physLocation);
+        return i.toByteArray();
+    }
+
+
+    public synchronized long getRoot(final byte id){
+        checkNotClosed();
+
+        return _pageman.getFileHeader().fileHeaderGetRoot(id);
+    }
+
+
+    public synchronized void setRoot(final byte id, final long rowid){
+        checkNotClosed();
+        checkCanWrite();
+
+        _pageman.getFileHeader().fileHeaderSetRoot(id, rowid);
+    }
+
+
+
+
+    public synchronized void commit() {
+        try {
+            commitInProgress = true;
+            checkNotClosed();
+            checkCanWrite();
+            /** flush free phys rows into pages*/
+            _physMgr.commit();
+            _logicMgr.commit();
+
+            /**commit pages */
+            _pageman.commit();
+
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }finally {
+            commitInProgress= false;
+        }
+    }
+
+
+    public synchronized void rollback() {
+        if (transactionsDisabled)
+            throw new IllegalAccessError("Transactions are disabled, can not rollback");
+
+        try {
+            checkNotClosed();
+            _physMgr.rollback();
+            _logicMgr.rollback();
+            _pageman.rollback();
+
+            super.rollback();
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+
+    }
+
+    public void copyToZip(String zipFile) {
+        try {
+            String zip = zipFile;
+            String zip2 = "db";
+            ZipOutputStream z = new ZipOutputStream(new FileOutputStream(zip));
+
+            //copy zero pages
+            {
+                String file = zip2 +  0;
+                z.putNextEntry(new ZipEntry(file));
+                z.write(Utils.encrypt(cipherIn, _pageman.getHeaderBufData()));
+                z.closeEntry();
+            }
+
+            //iterate over pages and create new file for each
+            for (long pageid = _pageman.getFirst(Magic.TRANSLATION_PAGE);
+                 pageid != 0;
+                 pageid = _pageman.getNext(pageid)
+                    ) {
+                PageIo page = _file.get(pageid);
+                String file = zip2 +  pageid;
+                z.putNextEntry(new ZipEntry(file));
+                z.write(Utils.encrypt(cipherIn, page.getData()));
+                z.closeEntry();
+                _file.release(page);
+            }
+            for (long pageid = _pageman.getFirst(Magic.FREELOGIDS_PAGE);
+                 pageid != 0;
+                 pageid = _pageman.getNext(pageid)
+                    ) {
+                PageIo page = _file.get(pageid);
+                String file = zip2 + pageid;
+                z.putNextEntry(new ZipEntry(file));
+                z.write(Utils.encrypt(cipherIn, page.getData()));
+                z.closeEntry();
+                _file.release(page);
+            }
+
+            for (long pageid = _pageman.getFirst(Magic.USED_PAGE);
+                 pageid != 0;
+                 pageid = _pageman.getNext(pageid)
+                    ) {
+                PageIo page = _file.get(pageid);
+                String file = zip2 + pageid;
+                z.putNextEntry(new ZipEntry(file));
+                z.write(Utils.encrypt(cipherIn, page.getData()));
+                z.closeEntry();
+                _file.release(page);
+            }
+            for (long pageid = _pageman.getFirst(Magic.FREEPHYSIDS_PAGE);
+                 pageid != 0;
+                 pageid = _pageman.getNext(pageid)
+                    ) {
+                PageIo page = _file.get(pageid);
+                String file = zip2 + pageid;
+                z.putNextEntry(new ZipEntry(file));
+                z.write(Utils.encrypt(cipherIn, page.getData()));
+                z.closeEntry();
+                _file.release(page);
+            }
+            for (long pageid = _pageman.getFirst(Magic.FREEPHYSIDS_ROOT_PAGE);
+                 pageid != 0;
+                 pageid = _pageman.getNext(pageid)
+                    ) {
+                PageIo page = _file.get(pageid);
+                String file = zip2 + pageid;
+                z.putNextEntry(new ZipEntry(file));
+                z.write(Utils.encrypt(cipherIn, page.getData()));
+                z.closeEntry();
+                _file.release(page);
+            }
+
+            z.close();
+
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+
+
+
+    public synchronized void clearCache() {
+        //no cache
+    }
+
+
+    private long statisticsCountPages(short pageType) throws IOException {
+        long pageCounter = 0;
+
+        for (long pageid = _pageman.getFirst(pageType);
+             pageid != 0;
+             pageid = _pageman.getNext(pageid)
+                ) {
+            pageCounter++;
+        }
+
+
+        return pageCounter;
+
+    }
+
+    public synchronized String calculateStatistics() {
+        checkNotClosed();
+
+        try {
+
+            final StringBuilder b = new StringBuilder();
+
+            //count pages
+            {
+
+                b.append("PAGES:\n");
+                long total = 0;
+                long pages = statisticsCountPages(Magic.USED_PAGE);
+                total += pages;
+                b.append("  " + pages + " used pages with size " + Utils.formatSpaceUsage(pages * Storage.PAGE_SIZE) + "\n");
+                pages = statisticsCountPages(Magic.TRANSLATION_PAGE);
+                total += pages;
+                b.append("  " + pages + " record translation pages with size " + Utils.formatSpaceUsage(pages * Storage.PAGE_SIZE) + "\n");
+                pages = statisticsCountPages(Magic.FREE_PAGE);
+                total += pages;
+                b.append("  " + pages + " free (unused) pages with size " + Utils.formatSpaceUsage(pages * Storage.PAGE_SIZE) + "\n");
+                pages = statisticsCountPages(Magic.FREEPHYSIDS_PAGE);
+                total += pages;
+                b.append("  " + pages + " free (phys) pages with size " + Utils.formatSpaceUsage(pages * Storage.PAGE_SIZE) + "\n");
+                pages = statisticsCountPages(Magic.FREELOGIDS_PAGE);
+                total += pages;
+                b.append("  " + pages + " free (logical) pages with size " + Utils.formatSpaceUsage(pages * Storage.PAGE_SIZE) + "\n");
+                b.append("  Total number of pages is " + total + " with size " + Utils.formatSpaceUsage(total * Storage.PAGE_SIZE) + "\n");
+
+            }
+            {
+                b.append("RECORDS:\n");
+
+                long recordCount = 0;
+                long freeRecordCount = 0;
+                long maximalRecordSize = 0;
+                long maximalAvailSizeDiff = 0;
+                long totalRecordSize = 0;
+                long totalAvailDiff = 0;
+
+                //count records
+                for (long pageid = _pageman.getFirst(Magic.TRANSLATION_PAGE);
+                     pageid != 0;
+                     pageid = _pageman.getNext(pageid)
+                        ) {
+                    PageIo io = _file.get(pageid);
+
+                    for (int i = 0; i < _logicMgr.ELEMS_PER_PAGE; i += 1) {
+                        final int pos = Magic.PAGE_HEADER_SIZE + i * Magic.PhysicalRowId_SIZE;
+                        final long physLoc = io.pageHeaderGetLocation((short) pos);
+
+                        if (physLoc == 0) {
+                            freeRecordCount++;
+                            continue;
+                        }
+
+                        if(physLoc == PREALOCATE_PHYS_RECID){
+                            continue;
+                        }
+
+                        recordCount++;
+
+                        //get size
+                        PageIo page = _file.get(physLoc>>> Storage.PAGE_SIZE_SHIFT);
+                        final short physOffset =(short) (physLoc & Storage.OFFSET_MASK);
+                        int availSize = RecordHeader.getAvailableSize(page, physOffset);
+                        int currentSize = RecordHeader.getCurrentSize(page, physOffset);
+                        _file.release(page);
+
+                        maximalAvailSizeDiff = Math.max(maximalAvailSizeDiff, availSize - currentSize);
+                        maximalRecordSize = Math.max(maximalRecordSize, currentSize);
+                        totalAvailDiff += availSize - currentSize;
+                        totalRecordSize += currentSize;
+
+                    }
+                    _file.release(io);
+                }
+
+                b.append("  Contains " + recordCount + " records and " + freeRecordCount + " free slots.\n");
+                b.append("  Total space occupied by data is " + Utils.formatSpaceUsage(totalRecordSize) + "\n");
+                b.append("  Average data size in record is " + Utils.formatSpaceUsage(Math.round(1D * totalRecordSize / recordCount)) + "\n");
+                b.append("  Maximal data size in record is " + Utils.formatSpaceUsage(maximalRecordSize) + "\n");
+                b.append("  Space wasted in record fragmentation is " + Utils.formatSpaceUsage(totalAvailDiff) + "\n");
+                b.append("  Maximal space wasted in single record fragmentation is " + Utils.formatSpaceUsage(maximalAvailSizeDiff) + "\n");
+            }
+
+            return b.toString();
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public synchronized void defrag(boolean sortCollections) {
+
+        try {
+            checkNotClosed();
+            checkCanWrite();
+            commit();
+            final String filename2 = _filename + "_defrag" + System.currentTimeMillis();
+            final String filename1 = _filename;
+            DBStore db2 = new DBStore(filename2, false, true, cipherIn, cipherOut, false,false,false);
+
+            //recreate logical file with original page layout
+            {
+                //find minimal logical pageid (logical pageids are negative)
+                LongHashMap<String> logicalPages = new LongHashMap<String>();
+                long minpageid = 0;
+                for (long pageid = _pageman.getFirst(Magic.TRANSLATION_PAGE);
+                     pageid != 0;
+                     pageid = _pageman.getNext(pageid)
+                        ) {
+                    minpageid = Math.min(minpageid, pageid);
+                    logicalPages.put(pageid, Utils.EMPTY_STRING);
+                }
+
+                //fill second db with logical pages
+                long pageCounter = 0;
+                for (
+                        long pageid = db2._pageman.allocate(Magic.TRANSLATION_PAGE);
+                        pageid >= minpageid;
+                        pageid = db2._pageman.allocate(Magic.TRANSLATION_PAGE)
+                        ) {
+                    pageCounter++;
+                    if (pageCounter % 1000 == 0)
+                        db2.commit();
+                }
+
+                logicalPages = null;
+            }
+
+
+            //reinsert collections so physical records are located near each other
+            //iterate over named object recids, it is sorted with TreeSet
+            if(sortCollections){
+                long nameRecid = getRoot(NAME_DIRECTORY_ROOT);
+                Collection<Long> recids = new TreeSet<Long>();
+                if(nameRecid!=0){
+                    HTree<String,Long> m = fetch(nameRecid);
+                    recids.addAll(m.values());
+                }
+
+                for (Long namedRecid : recids) {
+                    Object obj = fetch(namedRecid);
+                    if (obj instanceof LinkedList) {
+                        LinkedList2.defrag(namedRecid, this, db2);
+                    } else if (obj instanceof HTree) {
+                        HTree.defrag(namedRecid, this, db2);
+                    } else if (obj instanceof BTree) {
+                        BTree.defrag(namedRecid, this, db2);
+                    }
+                }
+            }
+
+
+            for (long pageid = _pageman.getFirst(Magic.TRANSLATION_PAGE);
+                 pageid != 0;
+                 pageid = _pageman.getNext(pageid)
+                    ) {
+                PageIo io = _file.get(pageid);
+
+                for (int i = 0; i < _logicMgr.ELEMS_PER_PAGE; i += 1) {
+                    final int pos = Magic.PAGE_HEADER_SIZE + i * Magic.PhysicalRowId_SIZE;
+                    if (pos > Short.MAX_VALUE)
+                        throw new Error();
+
+                    //write to new file
+                    final long logicalRowId =  ((-pageid) << Storage.PAGE_SIZE_SHIFT) + (long) pos;
+
+                    //read from logical location in second db,
+                    //check if record was already inserted as part of collections
+                    if (db2._pageman.getLast(Magic.TRANSLATION_PAGE) <= pageid &&
+                            db2._logicMgr.fetch(logicalRowId) != 0) {
+                        //yes, this record already exists in second db
+                        continue;
+                    }
+
+                    //get physical location in this db
+                    final long physRowId =  io.pageHeaderGetLocation((short) pos);
+
+                    if (physRowId == 0)
+                        continue;
+
+
+                    if (physRowId == PREALOCATE_PHYS_RECID){
+                        db2._logicMgr.forceInsert(logicalRowId, physRowId);
+                        continue;
+                    }
+
+
+
+                    //read from physical location at this db
+                    DataInputOutput b = new DataInputOutput();
+                    _physMgr.fetch(b, physRowId);
+                    byte[] bb = b.toByteArray();
+
+                    //force insert into other file, without decompressing logical id to external form
+                    long physLoc = db2._physMgr.insert(bb, 0, bb.length);
+                    db2._logicMgr.forceInsert(logicalRowId, physLoc);
+
+                }
+                _file.release(io);
+                db2.commit();
+            }
+            for(byte b = 0;b<Magic.FILE_HEADER_NROOTS;b++){
+                db2.setRoot(b, getRoot(b));
+            }
+
+            db2.close();
+            _pageman.close();
+            _file.close();
+
+
+            List<File> filesToDelete = new ArrayList<File>();
+            //now rename old files
+            String[] exts = {StorageDiskMapped.IDR, StorageDiskMapped.DBR};
+            for (String ext : exts) {
+                String f1 = filename1 + ext;
+                String f2 = filename2 + "_OLD" + ext;
+
+                //first rename transaction log
+                File f1t = new File(f1 + StorageDisk.transaction_log_file_extension);
+                File f2t = new File(f2 + StorageDisk.transaction_log_file_extension);
+                f1t.renameTo(f2t);
+                filesToDelete.add(f2t);
+
+                //rename data files, iterate until file exist
+                for (int i = 0; ; i++) {
+                    File f1d = new File(f1 + "." + i);
+                    if (!f1d.exists()) break;
+                    File f2d = new File(f2 + "." + i);
+                    f1d.renameTo(f2d);
+                    filesToDelete.add(f2d);
+                }
+            }
+
+            //rename new files
+            for (String ext : exts) {
+                String f1 = filename2 + ext;
+                String f2 = filename1 + ext;
+
+                //first rename transaction log
+                File f1t = new File(f1 + StorageDisk.transaction_log_file_extension);
+                File f2t = new File(f2 + StorageDisk.transaction_log_file_extension);
+                f1t.renameTo(f2t);
+
+                //rename data files, iterate until file exist
+                for (int i = 0; ; i++) {
+                    File f1d = new File(f1 + "." + i);
+                    if (!f1d.exists()) break;
+                    File f2d = new File(f2 + "." + i);
+                    f1d.renameTo(f2d);
+                }
+            }
+
+            for (File d : filesToDelete) {
+                d.delete();
+            }
+
+
+            reopen();
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+
+    }
+
+    /**
+     * Insert data at forced logicalRowId, use only for defragmentation !!
+     *
+     * @param logicalRowId
+     * @param data
+     * @throws IOException
+     */
+    void forceInsert(long logicalRowId, byte[] data) throws IOException {
+        logicalRowId = decompressRecid(logicalRowId);
+
+        if (needsAutoCommit()) {
+            commit();
+        }
+
+        long physLoc = _physMgr.insert(data, 0, data.length);
+        _logicMgr.forceInsert(logicalRowId, physLoc);
+    }
+
+
+
+    /**
+     * Returns number of records stored in database.
+     * Is used for unit tests
+     */
+    long countRecords() throws IOException {
+        long counter = 0;
+
+        long page = _pageman.getFirst(Magic.TRANSLATION_PAGE);
+        while (page != 0) {
+            PageIo io = _file.get(page);
+            for (int i = 0; i < _logicMgr.ELEMS_PER_PAGE; i += 1) {
+                int pos = Magic.PAGE_HEADER_SIZE + i * Magic.PhysicalRowId_SIZE;
+                if (pos > Short.MAX_VALUE)
+                    throw new Error();
+
+                //get physical location
+                long physRowId = io.pageHeaderGetLocation((short) pos);
+
+                if (physRowId != 0)
+                    counter += 1;
+            }
+            _file.release(io);
+            page = _pageman.getNext(page);
+        }
+        return counter;
+    }
+
+
+    private  static int COMPRESS_RECID_PAGE_SHIFT = Integer.MIN_VALUE;
+    static{
+        int shift = 1;
+        while((1<<shift) <LogicalRowIdManager.ELEMS_PER_PAGE )
+        shift++;
+        COMPRESS_RECID_PAGE_SHIFT = shift;
+    }
+
+
+    private final static long COMPRESS_RECID_OFFSET_MASK =  0xFFFFFFFFFFFFFFFFL >>> (64- COMPRESS_RECID_PAGE_SHIFT);
+
+
+    /**
+     * Compress recid from physical form (block - offset) to (block - slot).
+     * This way resulting number is smaller and can be easier packed with LongPacker
+     */
+    static long compressRecid(final long recid) {
+        final long page = recid>>> Storage.PAGE_SIZE_SHIFT;
+        short offset =  (short) (recid & Storage.OFFSET_MASK);
+
+        offset = (short) (offset - Magic.PAGE_HEADER_SIZE);
+        if (offset % Magic.PhysicalRowId_SIZE != 0)
+            throw new InternalError("recid not dividable "+Magic.PhysicalRowId_SIZE);
+        long slot = offset / Magic.PhysicalRowId_SIZE;
+
+        return (page << COMPRESS_RECID_PAGE_SHIFT) + slot;
+
+    }
+
+    static long decompressRecid(final long recid) {
+
+        final long page = recid >>> COMPRESS_RECID_PAGE_SHIFT;
+        final short offset = (short) ((recid & COMPRESS_RECID_OFFSET_MASK) * Magic.PhysicalRowId_SIZE + Magic.PAGE_HEADER_SIZE);
+        return  (page << Storage.PAGE_SIZE_SHIFT) + (long) offset;
+    }
+
+
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/DataInputOutput.java

@@ -0,0 +1,297 @@
+package org.apache.jdbm;
+
+import java.io.*;
+import java.nio.ByteBuffer;
+import java.util.Arrays;
+
+/**
+ * Utility class which implements DataInput and DataOutput on top of byte[] buffer
+ * with minimal overhead
+ *
+ * @author Jan Kotek
+ */
+class DataInputOutput implements DataInput, DataOutput, ObjectInput, ObjectOutput {
+
+    private int pos = 0;
+    private int count = 0;
+    private byte[] buf;
+
+
+    public DataInputOutput() {
+        buf = new byte[8];
+    }
+
+    public DataInputOutput(byte[] data) {
+        buf = data;
+        count = data.length;
+    }
+
+    public byte[] getBuf() {
+        return buf;
+    }
+
+    public int getPos() {
+        return pos;
+    }
+
+
+    public void reset() {
+        pos = 0;
+        count = 0;
+    }
+
+
+    public void resetForReading() {
+        count = pos;
+        pos = 0;
+    }
+
+    public void reset(byte[] b) {
+        pos = 0;
+        buf = b;
+        count = b.length;
+    }
+
+    public byte[] toByteArray() {
+        byte[] d = new byte[pos];
+        System.arraycopy(buf, 0, d, 0, pos);
+        return d;
+    }
+
+    public int available() {
+        return count - pos;
+    }
+
+
+    public void readFully(byte[] b) throws IOException {
+        readFully(b, 0, b.length);
+    }
+
+    public void readFully(byte[] b, int off, int len) throws IOException {
+        System.arraycopy(buf, pos, b, off, len);
+        pos += len;
+    }
+
+    public int skipBytes(int n) throws IOException {
+        pos += n;
+        return n;
+    }
+
+    public boolean readBoolean() throws IOException {
+        return buf[pos++] == 1;
+    }
+
+    public byte readByte() throws IOException {
+        return buf[pos++];
+    }
+
+    public int readUnsignedByte() throws IOException {
+        return buf[pos++] & 0xff;
+    }
+
+    public short readShort() throws IOException {
+        return (short)
+                (((short) (buf[pos++] & 0xff) << 8) |
+                        ((short) (buf[pos++] & 0xff) << 0));
+
+    }
+
+    public int readUnsignedShort() throws IOException {
+        return (((int) (buf[pos++] & 0xff) << 8) |
+                ((int) (buf[pos++] & 0xff) << 0));
+    }
+
+    public char readChar() throws IOException {
+        return (char) readInt();
+    }
+
+    public int readInt() throws IOException {
+        return
+                (((buf[pos++] & 0xff) << 24) |
+                        ((buf[pos++] & 0xff) << 16) |
+                        ((buf[pos++] & 0xff) << 8) |
+                        ((buf[pos++] & 0xff) << 0));
+
+    }
+
+    public long readLong() throws IOException {
+        return
+                (((long) (buf[pos++] & 0xff) << 56) |
+                        ((long) (buf[pos++] & 0xff) << 48) |
+                        ((long) (buf[pos++] & 0xff) << 40) |
+                        ((long) (buf[pos++] & 0xff) << 32) |
+                        ((long) (buf[pos++] & 0xff) << 24) |
+                        ((long) (buf[pos++] & 0xff) << 16) |
+                        ((long) (buf[pos++] & 0xff) << 8) |
+                        ((long) (buf[pos++] & 0xff) << 0));
+
+    }
+
+    public float readFloat() throws IOException {
+        return Float.intBitsToFloat(readInt());
+    }
+
+    public double readDouble() throws IOException {
+        return Double.longBitsToDouble(readLong());
+    }
+
+    public String readLine() throws IOException {
+        return readUTF();
+    }
+
+    public String readUTF() throws IOException {
+        return Serialization.deserializeString(this);
+    }
+
+    /**
+     * make sure there will be enought space in buffer to write N bytes
+     */
+    private void ensureAvail(int n) {
+        if (pos + n >= buf.length) {
+            int newSize = Math.max(pos + n, buf.length * 2);
+            buf = Arrays.copyOf(buf, newSize);
+        }
+    }
+
+
+
+    public void write(int b) throws IOException {
+        ensureAvail(1);
+        buf[pos++] = (byte) b;
+    }
+
+    public void write(byte[] b) throws IOException {
+        write(b, 0, b.length);
+    }
+
+    public void write(byte[] b, int off, int len) throws IOException {
+        ensureAvail(len);
+        System.arraycopy(b, off, buf, pos, len);
+        pos += len;
+    }
+
+    public void writeBoolean(boolean v) throws IOException {
+        ensureAvail(1);
+        buf[pos++] = (byte) (v ? 1 : 0);
+    }
+
+    public void writeByte(int v) throws IOException {
+        ensureAvail(1);
+        buf[pos++] = (byte) (v);
+    }
+
+    public void writeShort(int v) throws IOException {
+        ensureAvail(2);
+        buf[pos++] = (byte) (0xff & (v >> 8));
+        buf[pos++] = (byte) (0xff & (v >> 0));
+
+    }
+
+    public void writeChar(int v) throws IOException {
+        writeInt(v);
+    }
+
+    public void writeInt(int v) throws IOException {
+        ensureAvail(4);
+        buf[pos++] = (byte) (0xff & (v >> 24));
+        buf[pos++] = (byte) (0xff & (v >> 16));
+        buf[pos++] = (byte) (0xff & (v >> 8));
+        buf[pos++] = (byte) (0xff & (v >> 0));
+
+    }
+
+    public void writeLong(long v) throws IOException {
+        ensureAvail(8);
+        buf[pos++] = (byte) (0xff & (v >> 56));
+        buf[pos++] = (byte) (0xff & (v >> 48));
+        buf[pos++] = (byte) (0xff & (v >> 40));
+        buf[pos++] = (byte) (0xff & (v >> 32));
+        buf[pos++] = (byte) (0xff & (v >> 24));
+        buf[pos++] = (byte) (0xff & (v >> 16));
+        buf[pos++] = (byte) (0xff & (v >> 8));
+        buf[pos++] = (byte) (0xff & (v >> 0));
+    }
+
+    public void writeFloat(float v) throws IOException {
+        ensureAvail(4);
+        writeInt(Float.floatToIntBits(v));
+    }
+
+    public void writeDouble(double v) throws IOException {
+        ensureAvail(8);
+        writeLong(Double.doubleToLongBits(v));
+    }
+
+    public void writeBytes(String s) throws IOException {
+        writeUTF(s);
+    }
+
+    public void writeChars(String s) throws IOException {
+        writeUTF(s);
+    }
+
+    public void writeUTF(String s) throws IOException {
+        Serialization.serializeString(this, s);
+    }
+
+    /** helper method to write data directly from PageIo*/
+    public void writeFromByteBuffer(ByteBuffer b, int offset, int length) {
+        ensureAvail(length);
+        b.position(offset);
+        b.get(buf,pos,length);
+        pos+=length;
+    }
+
+
+    //temp var used for Externalizable
+    SerialClassInfo serializer;
+    //temp var used for Externalizable
+    Serialization.FastArrayList objectStack;
+
+    public Object readObject() throws ClassNotFoundException, IOException {
+        //is here just to implement ObjectInput
+        //Fake method which reads data from serializer.
+        //We could probably implement separate wrapper for this, but I want to safe class space
+        return serializer.deserialize(this, objectStack);
+    }
+
+    public int read() throws IOException {
+        //is here just to implement ObjectInput
+        return readUnsignedByte();
+    }
+
+    public int read(byte[] b) throws IOException {
+        //is here just to implement ObjectInput
+        readFully(b);
+        return b.length;
+    }
+
+    public int read(byte[] b, int off, int len) throws IOException {
+        //is here just to implement ObjectInput
+        readFully(b,off,len);
+        return len;
+    }
+
+    public long skip(long n) throws IOException {
+        //is here just to implement ObjectInput
+        pos += n;
+        return n;
+    }
+
+    public void close() throws IOException {
+        //is here just to implement ObjectInput
+        //do nothing
+    }
+
+    public void writeObject(Object obj) throws IOException {
+        //is here just to implement ObjectOutput
+        serializer.serialize(this,obj,objectStack);
+    }
+
+
+    public void flush() throws IOException {
+        //is here just to implement ObjectOutput
+        //do nothing
+    }
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/DataInputOutput2.java

@@ -0,0 +1,215 @@
+///*
+//package org.apache.jdbm;
+//
+//import java.io.DataInput;
+//import java.io.DataOutput;
+//import java.io.IOException;
+//import java.nio.Buffer;
+//import java.nio.ByteBuffer;
+//import java.util.Arrays;
+//
+//*/
+///**
+// * Utility class which implements DataInput and DataOutput on top of ByteBuffer
+// * with minimal overhead
+// * This class is not used, is left here in case we would ever need it.
+// *
+// * @author Jan Kotek
+// *//*
+//
+//class DataInputOutput2 implements DataInput, DataOutput {
+//
+//    private ByteBuffer buf;
+//
+//
+//    public DataInputOutput2() {
+//        buf = ByteBuffer.allocate(8);
+//    }
+//
+//    public DataInputOutput2(ByteBuffer data) {
+//        buf = data;
+//    }
+//
+//    public DataInputOutput2(byte[] data) {
+//        buf = ByteBuffer.wrap(data);
+//    }
+//
+//
+//    public int getPos() {
+//        return buf.position();
+//    }
+//
+//
+//    public void reset() {
+//        buf.rewind();
+//    }
+//
+//
+//    public void reset(byte[] b) {
+//        buf = ByteBuffer.wrap(b);
+//    }
+//
+//    public void resetForReading() {
+//        buf.flip();
+//    }
+//
+//
+//    public byte[] toByteArray() {
+//        byte[] d = new byte[buf.position()];
+//        buf.position(0);
+//        buf.get(d); //reading N bytes restores to current position
+//
+//        return d;
+//    }
+//
+//    public int available() {
+//        return buf.remaining();
+//    }
+//
+//
+//    public void readFully(byte[] b) throws IOException {
+//        readFully(b, 0, b.length);
+//    }
+//
+//    public void readFully(byte[] b, int off, int len) throws IOException {
+//        buf.get(b,off,len);
+//    }
+//
+//    public int skipBytes(int n) throws IOException {
+//        buf.position(buf.position()+n);
+//        return n;
+//    }
+//
+//    public boolean readBoolean() throws IOException {
+//        return buf.get()==1;
+//    }
+//
+//    public byte readByte() throws IOException {
+//        return buf.get();
+//    }
+//
+//    public int readUnsignedByte() throws IOException {
+//        return buf.get() & 0xff;
+//    }
+//
+//    public short readShort() throws IOException {
+//        return buf.getShort();
+//    }
+//
+//    public int readUnsignedShort() throws IOException {
+//        return (((int) (buf.get() & 0xff) << 8) |
+//                ((int) (buf.get() & 0xff) << 0));
+//    }
+//
+//    public char readChar() throws IOException {
+//        return (char) readInt();
+//    }
+//
+//    public int readInt() throws IOException {
+//        return buf.getInt();
+//    }
+//
+//    public long readLong() throws IOException {
+//        return buf.getLong();
+//    }
+//
+//    public float readFloat() throws IOException {
+//        return buf.getFloat();
+//    }
+//
+//    public double readDouble() throws IOException {
+//        return buf.getDouble();
+//    }
+//
+//    public String readLine() throws IOException {
+//        return readUTF();
+//    }
+//
+//    public String readUTF() throws IOException {
+//        return Serialization.deserializeString(this);
+//    }
+//
+//    */
+///**
+//     * make sure there will be enough space in buffer to write N bytes
+//     *//*
+//
+//    private void ensureAvail(int n) {
+//        int pos = buf.position();
+//        if (pos + n >= buf.limit()) {
+//            int newSize = Math.max(pos + n, buf.limit() * 2);
+//            byte[] b = new byte[newSize];
+//            buf.get(b);
+//            buf = ByteBuffer.wrap(b);
+//            buf.position(pos);
+//        }
+//    }
+//
+//
+//    public void write(final int b) throws IOException {
+//        ensureAvail(1);
+//        buf.put((byte) b);
+//    }
+//
+//    public void write(final byte[] b) throws IOException {
+//        write(b, 0, b.length);
+//    }
+//
+//    public void write(final byte[] b, final int off, final int len) throws IOException {
+//        ensureAvail(len);
+//        buf.put(b,off,len);
+//    }
+//
+//    public void writeBoolean(final boolean v) throws IOException {
+//        ensureAvail(1);
+//        buf.put((byte) (v?1:0));
+//    }
+//
+//    public void writeByte(final int v) throws IOException {
+//        ensureAvail(1);
+//        buf.put((byte) v);
+//    }
+//
+//    public void writeShort(final short v) throws IOException {
+//        ensureAvail(2);
+//        buf.putShort(v);
+//    }
+//
+//    public void writeChar(final int v) throws IOException {
+//        writeInt(v);
+//    }
+//
+//    public void writeInt(final int v) throws IOException {
+//        ensureAvail(4);
+//        buf.putInt(v);
+//    }
+//
+//    public void writeLong(final long v) throws IOException {
+//        ensureAvail(8);
+//        buf.putLong(v);
+//    }
+//
+//    public void writeFloat(final float v) throws IOException {
+//        ensureAvail(4);
+//        buf.putFloat(v);
+//    }
+//
+//    public void writeDouble(final double v) throws IOException {
+//        ensureAvail(8);
+//        buf.putDouble(v);
+//    }
+//
+//    public void writeBytes(String s) throws IOException {
+//        writeUTF(s);
+//    }
+//
+//    public void writeChars(String s) throws IOException {
+//        writeUTF(s);
+//    }
+//
+//    public void writeUTF(String s) throws IOException {
+//        Serialization.serializeString(this, s);
+//    }
+//
+//}
+//*/

com.minres.scviewer.database.text/src/org/apache/jdbm/HTree.java

@@ -0,0 +1,542 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+package org.apache.jdbm;
+
+import java.io.*;
+import java.util.*;
+import java.util.concurrent.ConcurrentMap;
+import java.util.concurrent.atomic.AtomicReference;
+import java.util.concurrent.locks.ReadWriteLock;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+/**
+ * Persistent HashMap implementation for DB.
+ * Implemented as an H*Tree structure.
+ *
+ * @author Alex Boisvert
+ * @author Jan Kotek
+ */
+class HTree<K, V> extends AbstractMap<K, V> implements ConcurrentMap<K, V> {
+
+    final Serializer SERIALIZER = new Serializer<Object>() {
+
+        public Object deserialize(DataInput ds2) throws IOException {
+            DataInputOutput ds = (DataInputOutput) ds2;
+            try {
+                int i = ds.readUnsignedByte();
+                if (i == SerializationHeader.HTREE_BUCKET) { //is HashBucket?
+                    HTreeBucket ret = new HTreeBucket(HTree.this);
+                    if (loadValues)
+                        ret.readExternal(ds);
+
+                    if (loadValues && ds.available() != 0)
+                        throw new InternalError("bytes left: " + ds.available());
+                    return ret;
+                } else if (i == SerializationHeader.HTREE_DIRECTORY) {
+                    HTreeDirectory ret = new HTreeDirectory(HTree.this);
+                    ret.readExternal(ds);
+                    if (loadValues && ds.available() != 0)
+                        throw new InternalError("bytes left: " + ds.available());
+                    return ret;
+                } else {
+                    throw new InternalError("Wrong HTree header: " + i);
+                }
+            } catch (ClassNotFoundException e) {
+                throw new IOException(e);
+            }
+
+        }
+
+        public void serialize(DataOutput out, Object obj) throws IOException {
+            if (obj instanceof HTreeBucket) {
+                out.write(SerializationHeader.HTREE_BUCKET);
+                HTreeBucket b = (HTreeBucket) obj;
+                b.writeExternal(out);
+            } else {
+                out.write(SerializationHeader.HTREE_DIRECTORY);
+                HTreeDirectory n = (HTreeDirectory) obj;
+                n.writeExternal(out);
+            }
+        }
+    };
+
+    final protected ReadWriteLock lock = new ReentrantReadWriteLock();
+
+    /**
+     * Listeners which are notified about changes in records
+     */
+    protected RecordListener[] recordListeners = new RecordListener[0];
+
+    /**
+     * Serializer used to serialize index keys (optional)
+     */
+    protected Serializer<K> keySerializer;
+
+
+    /**
+     * Serializer used to serialize index values (optional)
+     */
+    protected Serializer<V> valueSerializer;
+    protected boolean readonly = false;
+    final long rootRecid;
+    DBAbstract db;
+    /** if false map contains only keys, used for set*/
+    boolean hasValues = true;
+
+    /**
+     * counts structural changes in tree at runtume. Is here to support fail-fast behaviour.
+     */
+    int modCount;
+
+    /**
+     * indicates if values should be loaded during deserialization, set to true during defragmentation
+     */
+    private boolean loadValues = true;
+
+    public Serializer<K> getKeySerializer() {
+        return keySerializer;
+    }
+
+    public Serializer<V> getValueSerializer() {
+        return valueSerializer;
+    }
+
+
+    /**
+     * cache writing buffer, so it does not have to be allocated on each write
+     */
+    AtomicReference<DataInputOutput> writeBufferCache = new AtomicReference<DataInputOutput>();
+
+
+    /**
+     * Create a persistent hashtable.
+     */
+    public HTree(DBAbstract db, Serializer<K> keySerializer, Serializer<V> valueSerializer, boolean hasValues)
+            throws IOException {
+        this.keySerializer = keySerializer;
+        this.valueSerializer = valueSerializer;
+        this.db = db;
+        this.hasValues = hasValues;
+
+        HTreeDirectory<K, V> root = new HTreeDirectory<K, V>(this, (byte) 0);
+        root.setPersistenceContext(0);
+        this.rootRecid = db.insert(root, this.SERIALIZER,false);
+    }
+
+
+    /**
+     * Load a persistent hashtable
+     */
+    public HTree(DBAbstract db,long rootRecid, Serializer<K> keySerializer, Serializer<V> valueSerializer, boolean hasValues)
+            throws IOException {
+        this.db = db;
+        this.rootRecid = rootRecid;
+        this.keySerializer = keySerializer;
+        this.valueSerializer = valueSerializer;
+        this.hasValues = hasValues;
+    }
+
+    void setPersistenceContext(DBAbstract db) {
+        this.db = db;
+    }
+
+
+    public V put(K key, V value) {
+        if (readonly)
+            throw new UnsupportedOperationException("readonly");
+        lock.writeLock().lock();
+
+        try {
+            if (key == null || value == null)
+                throw new NullPointerException("Null key or value");
+
+            V oldVal = (V) getRoot().put(key, value);
+            if (oldVal == null) {
+                modCount++;
+
+                //increase size
+                HTreeDirectory root = getRoot();
+                root.size++;
+                db.update(rootRecid,root,SERIALIZER);
+
+                for (RecordListener<K, V> r : recordListeners)
+                    r.recordInserted(key, value);
+            } else {
+
+                //notify listeners
+                for (RecordListener<K, V> r : recordListeners)
+                    r.recordUpdated(key, oldVal, value);
+            }
+
+            return oldVal;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+
+    public V get(Object key) {
+        if (key == null)
+            return null;
+        lock.readLock().lock();
+        try {
+            return getRoot().get((K) key);
+        } catch (ClassCastException e) {
+            return null;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }finally {
+            lock.readLock().unlock();
+        }
+    }
+
+
+    public V remove(Object key) {
+        if (readonly)
+            throw new UnsupportedOperationException("readonly");
+
+        lock.writeLock().lock();
+        try {
+            if (key == null)
+                return null;
+
+            V val = (V) getRoot().remove(key);
+             modCount++;
+
+
+            if (val != null){
+                //decrease size
+                HTreeDirectory root = getRoot();
+                root.size--;
+                db.update(rootRecid,root,SERIALIZER);
+
+
+                  for (RecordListener r : recordListeners)
+                        r.recordRemoved(key, val);
+            }
+
+            return val;
+        } catch (ClassCastException e) {
+            return null;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+    public boolean containsKey(Object key) {
+        if (key == null)
+            return false;
+        //no need for locking, get is already locked
+        V v = get((K) key);
+        return v != null;
+    }
+
+    public void clear() {
+        lock.writeLock().lock();
+        try {
+            Iterator<K> keyIter = keys();
+            while (keyIter.hasNext()) {
+                keyIter.next();
+                keyIter.remove();
+            }
+        } catch (IOException e) {
+            throw new IOError(e);
+        }finally {
+            lock.writeLock().unlock();
+        }
+
+    }
+
+
+    /**
+     * Returns an enumeration of the keys contained in this
+     */
+    public Iterator<K> keys()
+            throws IOException {
+        lock.readLock().lock();
+        try{
+            return getRoot().keys();
+        }finally {
+            lock.readLock().unlock();
+        }
+    }
+
+
+    public DBAbstract getRecordManager() {
+        return db;
+    }
+
+    /**
+     * add RecordListener which is notified about record changes
+     *
+     * @param listener
+     */
+    public void addRecordListener(RecordListener<K, V> listener) {
+        recordListeners = Arrays.copyOf(recordListeners, recordListeners.length + 1);
+        recordListeners[recordListeners.length - 1] = listener;
+    }
+
+    /**
+     * remove RecordListener which is notified about record changes
+     *
+     * @param listener
+     */
+    public void removeRecordListener(RecordListener<K, V> listener) {
+        List l = Arrays.asList(recordListeners);
+        l.remove(listener);
+        recordListeners = (RecordListener[]) l.toArray(new RecordListener[1]);
+    }
+
+
+    public Set<Entry<K, V>> entrySet() {
+        return _entrySet;
+    }
+
+    private Set<Entry<K, V>> _entrySet = new AbstractSet<Entry<K, V>>() {
+
+        protected Entry<K, V> newEntry(K k, V v) {
+            return new SimpleEntry<K, V>(k, v) {
+                private static final long serialVersionUID = 978651696969194154L;
+
+                public V setValue(V arg0) {
+                    //put is already locked
+                    HTree.this.put(getKey(), arg0);
+                    return super.setValue(arg0);
+                }
+
+            };
+        }
+
+        public boolean add(java.util.Map.Entry<K, V> e) {
+            if (readonly)
+                throw new UnsupportedOperationException("readonly");
+            if (e.getKey() == null)
+                throw new NullPointerException("Can not add null key");
+            lock.writeLock().lock();
+            try{
+                if (e.getValue().equals(get(e.getKey())))
+                    return false;
+                HTree.this.put(e.getKey(), e.getValue());
+                return true;
+            }finally {
+                lock.writeLock().unlock();
+            }
+        }
+
+        @SuppressWarnings("unchecked")
+        public boolean contains(Object o) {
+            if (o instanceof Entry) {
+                Entry<K, V> e = (java.util.Map.Entry<K, V>) o;
+
+                //get is already locked
+                if (e.getKey() != null && HTree.this.get(e.getKey()) != null)
+                    return true;
+            }
+            return false;
+        }
+
+
+        public Iterator<java.util.Map.Entry<K, V>> iterator() {
+            try {
+                final Iterator<K> br = keys();
+                return new Iterator<Entry<K, V>>() {
+
+                    public boolean hasNext() {
+                        return br.hasNext();
+                    }
+
+                    public java.util.Map.Entry<K, V> next() {
+                        K k = br.next();
+                        return newEntry(k, get(k));
+                    }
+
+                    public void remove() {
+                        if (readonly)
+                            throw new UnsupportedOperationException("readonly");
+                        br.remove();
+                    }
+                };
+
+            } catch (IOException e) {
+                throw new IOError(e);
+            }
+
+        }
+
+        @SuppressWarnings("unchecked")
+        public boolean remove(Object o) {
+            if (readonly)
+                throw new UnsupportedOperationException("readonly");
+
+            if (o instanceof Entry) {
+                Entry<K, V> e = (java.util.Map.Entry<K, V>) o;
+
+                //check for nulls
+                if (e.getKey() == null || e.getValue() == null)
+                    return false;
+                lock.writeLock().lock();
+                try{
+                    //get old value, must be same as item in entry
+                    V v = get(e.getKey());
+                    if (v == null || !e.getValue().equals(v))
+                        return false;
+                    HTree.this.remove(e.getKey());
+                    return true;
+                }finally{
+                    lock.writeLock().unlock();
+                }
+            }
+            return false;
+
+        }
+
+        @Override
+        public int size() {
+            lock.readLock().lock();
+            try {
+                int counter = 0;
+                Iterator<K> it = keys();
+                while (it.hasNext()) {
+                    it.next();
+                    counter++;
+                }
+                return counter;
+            } catch (IOException e) {
+                throw new IOError(e);
+            }finally {
+                lock.readLock().unlock();
+            }
+
+        }
+
+    };
+
+
+    HTreeDirectory<K, V> getRoot() {
+        //assumes that caller already holds read or write lock
+        try {
+            HTreeDirectory<K, V> root = (HTreeDirectory<K, V>) db.fetch(rootRecid, this.SERIALIZER);
+            root.setPersistenceContext(rootRecid);
+            return root;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+    public static HTree deserialize(DataInput is, Serialization ser) throws IOException, ClassNotFoundException {
+        long rootRecid = LongPacker.unpackLong(is);
+        boolean hasValues = is.readBoolean();
+        Serializer keySerializer = (Serializer) ser.deserialize(is);
+        Serializer valueSerializer = (Serializer)  ser.deserialize(is);
+
+        return new HTree(ser.db,rootRecid, keySerializer, valueSerializer, hasValues);
+    }
+
+    void serialize(DataOutput out) throws IOException {
+        LongPacker.packLong(out, rootRecid);
+        out.writeBoolean(hasValues);;
+        db.defaultSerializer().serialize(out, keySerializer);
+        db.defaultSerializer().serialize(out, valueSerializer);
+    }
+
+
+    static void defrag(Long recid, DBStore r1, DBStore r2) throws IOException {
+        //TODO should modCount be increased after defrag, revert or commit?
+        try {
+            byte[] data = r1.fetchRaw(recid);
+            r2.forceInsert(recid, data);
+            DataInput in = new DataInputStream(new ByteArrayInputStream(data));
+            HTree t = (HTree) r1.defaultSerializer().deserialize(in);
+            t.db = r1;
+            t.loadValues = false;
+
+            HTreeDirectory d = t.getRoot();
+            if (d != null) {
+                r2.forceInsert(t.rootRecid, r1.fetchRaw(t.rootRecid));
+                d.defrag(r1, r2);
+            }
+
+        } catch (ClassNotFoundException e) {
+            throw new IOError(e);
+        }
+
+    }
+
+    public int size(){
+        return (int) getRoot().size;
+    }
+
+    public boolean hasValues() {
+        return hasValues;
+    }
+
+    public V putIfAbsent(K key, V value) {
+        lock.writeLock().lock();
+        try{
+            if (!containsKey(key))
+                return put(key, value);
+            else
+                return get(key);
+        }finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+    public boolean remove(Object key, Object value) {
+        lock.writeLock().lock();
+        try{
+            if (containsKey(key) && get(key).equals(value)) {
+                remove(key);
+                return true;
+            } else return false;
+        }finally {
+            lock.writeLock().unlock();
+        }
+
+
+    }
+
+    public boolean replace(K key, V oldValue, V newValue) {
+        lock.writeLock().lock();
+        try{
+            if (containsKey(key) && get(key).equals(oldValue)) {
+                put(key, newValue);
+                return true;
+            } else return false;
+        }finally {
+            lock.writeLock().unlock();
+        }
+
+    }
+
+    public V replace(K key, V value) {
+        lock.writeLock().lock();
+        try{
+            if (containsKey(key)) {
+                return put(key, value);
+            } else return null;
+        }finally {
+            lock.writeLock().unlock();
+        }
+    }
+
+}
+

com.minres.scviewer.database.text/src/org/apache/jdbm/HTreeBucket.java

@@ -0,0 +1,352 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+package org.apache.jdbm;
+
+import java.io.*;
+import java.util.ArrayList;
+
+/**
+ * A bucket is a placeholder for multiple (key, value) pairs.  Buckets
+ * are used to store collisions (same hash value) at all levels of an
+ * H*tree.
+ * <p/>
+ * There are two types of buckets: leaf and non-leaf.
+ * <p/>
+ * Non-leaf buckets are buckets which hold collisions which happen
+ * when the H*tree is not fully expanded.   Keys in a non-leaf buckets
+ * can have different hash codes.  Non-leaf buckets are limited to an
+ * arbitrary size.  When this limit is reached, the H*tree should create
+ * a new HTreeDirectory node and distribute keys of the non-leaf buckets into
+ * the newly created HTreeDirectory.
+ * <p/>
+ * A leaf bucket is a bucket which contains keys which all have
+ * the same <code>hashCode()</code>.  Leaf buckets stand at the
+ * bottom of an H*tree because the hashing algorithm cannot further
+ * discriminate between different keys based on their hash code.
+ *
+ * @author Alex Boisvert
+ */
+final class HTreeBucket<K, V> {
+
+    /**
+     * The maximum number of elements (key, value) a non-leaf bucket
+     * can contain.
+     */
+    public static final int OVERFLOW_SIZE = 16;
+
+
+    /**
+     * Depth of this bucket.
+     */
+    private byte _depth;
+
+
+    /**
+     * Keys and values in this bucket.  Keys are followed by values at KEYPOS+OVERFLOW_SIZE
+     */
+    private Object[] _keysAndValues;
+
+    private byte size = 0;
+
+
+    private final HTree<K, V> tree;
+
+
+    /**
+     * Public constructor for serialization.
+     */
+    public HTreeBucket(HTree<K, V> tree) {
+        this.tree = tree;
+    }
+
+
+    /**
+     * Construct a bucket with a given depth level.  Depth level is the
+     * number of <code>HashDirectory</code> above this bucket.
+     */
+    public HTreeBucket(HTree<K, V> tree, byte level) {
+        this.tree = tree;
+        if (level > HTreeDirectory.MAX_DEPTH + 1) {
+            throw new IllegalArgumentException(
+                    "Cannot create bucket with depth > MAX_DEPTH+1. "
+                            + "Depth=" + level);
+        }
+        _depth = level;
+        _keysAndValues = new Object[OVERFLOW_SIZE * 2];
+    }
+
+
+    /**
+     * Returns the number of elements contained in this bucket.
+     */
+    public int getElementCount() {
+        return size;
+    }
+
+
+    /**
+     * Returns whether or not this bucket is a "leaf bucket".
+     */
+    public boolean isLeaf() {
+        return (_depth > HTreeDirectory.MAX_DEPTH);
+    }
+
+
+    /**
+     * Returns true if bucket can accept at least one more element.
+     */
+    public boolean hasRoom() {
+        if (isLeaf()) {
+            return true;  // leaf buckets are never full
+        } else {
+            // non-leaf bucket
+            return (size < OVERFLOW_SIZE);
+        }
+    }
+
+
+    /**
+     * Add an element (key, value) to this bucket.  If an existing element
+     * has the same key, it is replaced silently.
+     *
+     * @return Object which was previously associated with the given key
+     *         or <code>null</code> if no association existed.
+     */
+    public V addElement(K key, V value) {
+        //find entry
+        byte existing = -1;
+        for (byte i = 0; i < size; i++) {
+            if (key.equals(_keysAndValues[i])) {
+                existing = i;
+                break;
+            }
+        }
+
+        if (existing != -1) {
+            // replace existing element
+            Object before = _keysAndValues[existing + OVERFLOW_SIZE];
+            if (before instanceof BTreeLazyRecord) {
+                BTreeLazyRecord<V> rec = (BTreeLazyRecord<V>) before;
+                before = rec.get();
+                rec.delete();
+            }
+            _keysAndValues[existing + OVERFLOW_SIZE] = value;
+            return (V) before;
+        } else {
+            // add new (key, value) pair
+            _keysAndValues[size] = key;
+            _keysAndValues[size + OVERFLOW_SIZE] = value;
+            size++;
+            return null;
+        }
+    }
+
+
+    /**
+     * Remove an element, given a specific key.
+     *
+     * @param key Key of the element to remove
+     * @return Removed element value, or <code>null</code> if not found
+     */
+    public V removeElement(K key) {
+        //find entry
+        byte existing = -1;
+        for (byte i = 0; i < size; i++) {
+            if (key.equals(_keysAndValues[i])) {
+                existing = i;
+                break;
+            }
+        }
+
+        if (existing != -1) {
+            Object o = _keysAndValues[existing + OVERFLOW_SIZE];
+            if (o instanceof BTreeLazyRecord) {
+                BTreeLazyRecord<V> rec = (BTreeLazyRecord<V>) o;
+                o = rec.get();
+                rec.delete();
+            }
+
+
+            //move last element to existing
+            size--;
+            _keysAndValues[existing] = _keysAndValues[size];
+            _keysAndValues[existing + OVERFLOW_SIZE] = _keysAndValues[size + OVERFLOW_SIZE];
+
+            //and unset last element
+            _keysAndValues[size] = null;
+            _keysAndValues[size + OVERFLOW_SIZE] = null;
+
+
+            return (V) o;
+        } else {
+            // not found
+            return null;
+        }
+    }
+
+
+    /**
+     * Returns the value associated with a given key.  If the given key
+     * is not found in this bucket, returns <code>null</code>.
+     */
+    public V getValue(K key) {
+        //find entry
+        byte existing = -1;
+        for (byte i = 0; i < size; i++) {
+            if (key.equals(_keysAndValues[i])) {
+                existing = i;
+                break;
+            }
+        }
+
+        if (existing != -1) {
+            Object o = _keysAndValues[existing + OVERFLOW_SIZE];
+            if (o instanceof BTreeLazyRecord)
+                return ((BTreeLazyRecord<V>) o).get();
+            else
+                return (V) o;
+        } else {
+            // key not found
+            return null;
+        }
+    }
+
+
+    /**
+     * Obtain keys contained in this buckets.  Keys are ordered to match
+     * their values, which be be obtained by calling <code>getValues()</code>.
+     * <p/>
+     * As an optimization, the Vector returned is the instance member
+     * of this class.  Please don't modify outside the scope of this class.
+     */
+    ArrayList<K> getKeys() {
+        ArrayList<K> ret = new ArrayList<K>();
+        for (byte i = 0; i < size; i++) {
+            ret.add((K) _keysAndValues[i]);
+        }
+        return ret;
+    }
+
+
+    /**
+     * Obtain values contained in this buckets.  Values are ordered to match
+     * their keys, which be be obtained by calling <code>getKeys()</code>.
+     * <p/>
+     * As an optimization, the Vector returned is the instance member
+     * of this class.  Please don't modify outside the scope of this class.
+     */
+    ArrayList<V> getValues() {
+        ArrayList<V> ret = new ArrayList<V>();
+        for (byte i = 0; i < size; i++) {
+            ret.add((V) _keysAndValues[i + OVERFLOW_SIZE]);
+        }
+        return ret;
+
+    }
+
+
+    public void writeExternal(DataOutput out)
+            throws IOException {
+        out.write(_depth);
+        out.write(size);
+
+
+        DataInputOutput out3 = tree.writeBufferCache.getAndSet(null);
+        if (out3 == null)
+            out3 = new DataInputOutput();
+        else
+            out3.reset();
+
+        Serializer keySerializer = tree.keySerializer != null ? tree.keySerializer : tree.getRecordManager().defaultSerializer();
+        for (byte i = 0; i < size; i++) {
+            out3.reset();
+            keySerializer.serialize(out3, _keysAndValues[i]);
+            LongPacker.packInt(out, out3.getPos());
+            out.write(out3.getBuf(), 0, out3.getPos());
+
+        }
+
+        //write values
+        if(tree.hasValues()){
+            Serializer valSerializer = tree.valueSerializer != null ? tree.valueSerializer : tree.getRecordManager().defaultSerializer();
+
+            for (byte i = 0; i < size; i++) {
+                Object value = _keysAndValues[i + OVERFLOW_SIZE];
+                if (value == null) {
+                    out.write(BTreeLazyRecord.NULL);
+                } else if (value instanceof BTreeLazyRecord) {
+                    out.write(BTreeLazyRecord.LAZY_RECORD);
+                    LongPacker.packLong(out, ((BTreeLazyRecord) value).recid);
+                } else {
+                    //transform to byte array
+                    out3.reset();
+                    valSerializer.serialize(out3, value);
+
+                    if (out3.getPos() > BTreeLazyRecord.MAX_INTREE_RECORD_SIZE) {
+                        //store as separate record
+                        long recid = tree.getRecordManager().insert(out3.toByteArray(), BTreeLazyRecord.FAKE_SERIALIZER,true);
+                        out.write(BTreeLazyRecord.LAZY_RECORD);
+                        LongPacker.packLong(out, recid);
+                    } else {
+                        out.write(out3.getPos());
+                        out.write(out3.getBuf(), 0, out3.getPos());
+                    }
+                }
+            }
+        }
+        tree.writeBufferCache.set(out3);
+
+    }
+
+
+    public void readExternal(DataInputOutput in) throws IOException, ClassNotFoundException {
+        _depth = in.readByte();
+        size = in.readByte();
+
+        //read keys
+        Serializer keySerializer = tree.keySerializer != null ? tree.keySerializer : tree.getRecordManager().defaultSerializer();
+        _keysAndValues = (K[]) new Object[OVERFLOW_SIZE * 2];
+        for (byte i = 0; i < size; i++) {
+            int expectedSize = LongPacker.unpackInt(in);
+            K key = (K) BTreeLazyRecord.fastDeser(in, keySerializer, expectedSize);
+            _keysAndValues[i] = key;
+        }
+
+        //read values
+        if(tree.hasValues()){
+            Serializer<V> valSerializer = tree.valueSerializer != null ? tree.valueSerializer : (Serializer<V>) tree.getRecordManager().defaultSerializer();
+            for (byte i = 0; i < size; i++) {
+                int header = in.readUnsignedByte();
+                if (header == BTreeLazyRecord.NULL) {
+                    _keysAndValues[i + OVERFLOW_SIZE] = null;
+                } else if (header == BTreeLazyRecord.LAZY_RECORD) {
+                    long recid = LongPacker.unpackLong(in);
+                    _keysAndValues[i + OVERFLOW_SIZE] = (new BTreeLazyRecord(tree.getRecordManager(), recid, valSerializer));
+                } else {
+                    _keysAndValues[i + OVERFLOW_SIZE] = BTreeLazyRecord.fastDeser(in, valSerializer, header);
+                }
+            }
+        }else{
+            for (byte i = 0; i < size; i++) {
+                if(_keysAndValues[i]!=null)
+                    _keysAndValues[i+OVERFLOW_SIZE] = Utils.EMPTY_STRING;
+            }
+        }
+    }
+}
+
+

com.minres.scviewer.database.text/src/org/apache/jdbm/HTreeDirectory.java

@@ -0,0 +1,618 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+package org.apache.jdbm;
+
+import java.io.*;
+import java.util.*;
+
+/**
+ * Hashtable directory page.
+ *
+ * @author Alex Boisvert
+ */
+final class HTreeDirectory<K, V> {
+
+    /**
+     * Maximum number of children in a directory.
+     * <p/>
+     * (Must be a power of 2 -- if you update this value, you must also
+     * update BIT_SIZE and MAX_DEPTH.)
+     * <p/>
+     * !!!! do not change this, it affects storage format, there are also magic numbers which relies on 255 !!!
+     */
+    static final int MAX_CHILDREN = 256;
+
+
+
+
+    /**
+     * Number of significant bits per directory level.
+     */
+    static final int BIT_SIZE = 8; // log2(256) = 8
+
+
+    /**
+     * Maximum number of levels (zero-based)
+     * <p/>
+     * (4 * 8 bits = 32 bits, which is the size of an "int", and as
+     * you know, hashcodes in Java are "ints")
+     */
+    static final int MAX_DEPTH = 3; // 4 levels
+
+
+    /**
+     * Record ids of children nodes.
+     * It is saved in matrix to save memory, some subarrays may be null.
+     */
+    private long[][] _children;
+
+
+    /**
+     * Depth of this directory page, zero-based
+     */
+    private byte _depth;
+
+    /**
+     * This directory's record ID in the DB.  (transient)
+     */
+    private long _recid;
+
+    /** if this is root (depth=0), it contains size, otherwise -1*/
+    long size;
+
+    protected final HTree<K, V> tree;
+
+    /**
+     * Public constructor used by serialization
+     */
+    public HTreeDirectory(HTree<K, V> tree) {
+        this.tree = tree;
+    }
+
+    /**
+     * Construct a HashDirectory
+     *
+     * @param depth Depth of this directory node.
+     */
+    HTreeDirectory(HTree<K, V> tree, byte depth) {
+        this.tree = tree;
+        _depth = depth;
+        _children = new long[32][];
+    }
+
+
+    /**
+     * Sets persistence context.  This method must be called before any
+     * persistence-related operation.
+     *
+     * @param recid Record id of this directory.
+     */
+    void setPersistenceContext(long recid) {
+        this._recid = recid;
+    }
+
+
+    /**
+     * Get the record identifier used to load this hashtable.
+     */
+    long getRecid() {
+        return _recid;
+    }
+
+
+    /**
+     * Returns whether or not this directory is empty.  A directory
+     * is empty when it no longer contains buckets or sub-directories.
+     */
+    boolean isEmpty() {
+        for (int i = 0; i < _children.length; i++) {
+            long[] sub = _children[i];
+            if (sub!=null){
+                for (int j = 0; j < 8; j++) {
+                    if(sub[j] != 0) {
+                        return false;
+                    }
+                }
+            }
+        }
+        return true;
+    }
+
+    /**
+     * Returns the value which is associated with the given key. Returns
+     * <code>null</code> if there is not association for this key.
+     *
+     * @param key key whose associated value is to be returned
+     */
+    V get(K key)
+            throws IOException {
+        int hash = hashCode(key);
+        long child_recid = getRecid(hash);
+        if (child_recid == 0) {
+            // not bucket/node --> not found
+            return null;
+        } else {
+            Object node = tree.db.fetch(child_recid, tree.SERIALIZER);
+            // System.out.println("HashDirectory.get() child is : "+node);
+
+            if (node instanceof HTreeDirectory) {
+                // recurse into next directory level
+                HTreeDirectory<K, V> dir = (HTreeDirectory<K, V>) node;
+                dir.setPersistenceContext(child_recid);
+                return dir.get(key);
+            } else {
+                // node is a bucket
+                HTreeBucket<K, V> bucket = (HTreeBucket) node;
+                return bucket.getValue(key);
+            }
+        }
+    }
+
+    private long getRecid(int hash) {
+        long[] sub = _children[hash>>>3];
+        return sub==null? 0 : sub[hash%8];
+    }
+
+    private void putRecid(int hash, long recid) {
+        long[] sub = _children[hash>>>3];
+        if(sub == null){
+            sub = new long[8];
+            _children[hash>>>3] = sub;
+        }
+        sub[hash%8] = recid;
+    }
+
+
+
+    /**
+     * Associates the specified value with the specified key.
+     *
+     * @param key   key with which the specified value is to be assocated.
+     * @param value value to be associated with the specified key.
+     * @return object which was previously associated with the given key,
+     *         or <code>null</code> if no association existed.
+     */
+    Object put(final Object key, final Object value)
+            throws IOException {
+        if (value == null) {
+            return remove(key);
+        }
+        int hash = hashCode(key);
+        long child_recid = getRecid(hash);
+        if (child_recid == 0) {
+            // no bucket/node here yet, let's create a bucket
+            HTreeBucket bucket = new HTreeBucket(tree, (byte) (_depth + 1));
+
+            // insert (key,value) pair in bucket
+            Object existing = bucket.addElement(key, value);
+
+            long b_recid = tree.db.insert(bucket, tree.SERIALIZER,false);
+            putRecid(hash, b_recid);
+
+            tree.db.update(_recid, this, tree.SERIALIZER);
+
+            // System.out.println("Added: "+bucket);
+            return existing;
+        } else {
+            Object node = tree.db.fetch(child_recid, tree.SERIALIZER);
+
+            if (node instanceof HTreeDirectory) {
+                // recursive insert in next directory level
+                HTreeDirectory dir = (HTreeDirectory) node;
+                dir.setPersistenceContext(child_recid);
+                return dir.put(key, value);
+            } else {
+                // node is a bucket
+                HTreeBucket bucket = (HTreeBucket) node;
+                if (bucket.hasRoom()) {
+                    Object existing = bucket.addElement(key, value);
+                    tree.db.update(child_recid, bucket, tree.SERIALIZER);
+                    // System.out.println("Added: "+bucket);
+                    return existing;
+                } else {
+                    // overflow, so create a new directory
+                    if (_depth == MAX_DEPTH) {
+                        throw new RuntimeException("Cannot create deeper directory. "
+                                + "Depth=" + _depth);
+                    }
+                    HTreeDirectory dir = new HTreeDirectory(tree, (byte) (_depth + 1));
+                    long dir_recid = tree.db.insert(dir, tree.SERIALIZER,false);
+                    dir.setPersistenceContext(dir_recid);
+
+                    putRecid(hash, dir_recid);
+                    tree.db.update(_recid, this, tree.SERIALIZER);
+
+                    // discard overflown bucket
+                    tree.db.delete(child_recid);
+
+                    // migrate existing bucket elements
+                    ArrayList keys = bucket.getKeys();
+                    ArrayList values = bucket.getValues();
+                    int entries = keys.size();
+                    for (int i = 0; i < entries; i++) {
+                        dir.put(keys.get(i), values.get(i));
+                    }
+
+                    // (finally!) insert new element
+                    return dir.put(key, value);
+                }
+            }
+        }
+    }
+
+
+
+    /**
+     * Remove the value which is associated with the given key.  If the
+     * key does not exist, this method simply ignores the operation.
+     *
+     * @param key key whose associated value is to be removed
+     * @return object which was associated with the given key, or
+     *         <code>null</code> if no association existed with given key.
+     */
+    Object remove(Object key) throws IOException {
+        int hash = hashCode(key);
+        long child_recid = getRecid(hash);
+        if (child_recid == 0) {
+            // not bucket/node --> not found
+            return null;
+        } else {
+            Object node = tree.db.fetch(child_recid, tree.SERIALIZER);
+            // System.out.println("HashDirectory.remove() child is : "+node);
+
+            if (node instanceof HTreeDirectory) {
+                // recurse into next directory level
+                HTreeDirectory dir = (HTreeDirectory) node;
+                dir.setPersistenceContext(child_recid);
+                Object existing = dir.remove(key);
+                if (existing != null) {
+                    if (dir.isEmpty()) {
+                        // delete empty directory
+                        tree.db.delete(child_recid);
+                        putRecid(hash, 0);
+                        tree.db.update(_recid, this, tree.SERIALIZER);
+                    }
+                }
+                return existing;
+            } else {
+                // node is a bucket
+                HTreeBucket bucket = (HTreeBucket) node;
+                Object existing = bucket.removeElement(key);
+                if (existing != null) {
+                    if (bucket.getElementCount() >= 1) {
+                        tree.db.update(child_recid, bucket, tree.SERIALIZER);
+                    } else {
+                        // delete bucket, it's empty
+                        tree.db.delete(child_recid);
+                        putRecid(hash, 0);
+                        tree.db.update(_recid, this, tree.SERIALIZER);
+                    }
+                }
+                return existing;
+            }
+        }
+    }
+
+    /**
+     * Calculates the hashcode of a key, based on the current directory
+     * depth.
+     */
+    private int hashCode(Object key) {
+        int hashMask = hashMask();
+        int hash = key.hashCode();
+        hash = hash & hashMask;
+        hash = hash >>> ((MAX_DEPTH - _depth) * BIT_SIZE);
+        hash = hash % MAX_CHILDREN;
+        /*
+        System.out.println("HashDirectory.hashCode() is: 0x"
+                           +Integer.toHexString(hash)
+                           +" for object hashCode() 0x"
+                           +Integer.toHexString(key.hashCode()));
+        */
+        return hash;
+    }
+
+    /**
+     * Calculates the hashmask of this directory.  The hashmask is the
+     * bit mask applied to a hashcode to retain only bits that are
+     * relevant to this directory level.
+     */
+    int hashMask() {
+        int bits = MAX_CHILDREN - 1;
+        int hashMask = bits << ((MAX_DEPTH - _depth) * BIT_SIZE);
+        /*
+        System.out.println("HashDirectory.hashMask() is: 0x"
+                           +Integer.toHexString(hashMask));
+        */
+        return hashMask;
+    }
+
+    /**
+     * Returns an enumeration of the keys contained in this
+     */
+    Iterator<K> keys()
+            throws IOException {
+        return new HDIterator(true);
+    }
+
+    /**
+     * Returns an enumeration of the values contained in this
+     */
+    Iterator<V> values()
+            throws IOException {
+        return new HDIterator(false);
+    }
+
+
+    public void writeExternal(DataOutput out)
+            throws IOException {
+        out.writeByte(_depth);
+        if(_depth==0){
+            LongPacker.packLong(out,size);
+        }
+
+        int zeroStart = 0;
+        for (int i = 0; i < MAX_CHILDREN; i++) {
+            if (getRecid(i) != 0) {
+                zeroStart = i;
+                break;
+            }
+        }
+
+        out.write(zeroStart);
+        if (zeroStart == MAX_CHILDREN)
+            return;
+
+        int zeroEnd = 0;
+        for (int i = MAX_CHILDREN - 1; i >= 0; i--) {
+            if (getRecid(i) != 0) {
+                zeroEnd = i;
+                break;
+            }
+        }
+        out.write(zeroEnd);
+
+        for (int i = zeroStart; i <= zeroEnd; i++) {
+            LongPacker.packLong(out, getRecid(i));
+        }
+    }
+
+
+    public void readExternal(DataInputOutput in)
+            throws IOException, ClassNotFoundException {
+        _depth = in.readByte();
+        if(_depth==0)
+            size = LongPacker.unpackLong(in);
+        else
+           size = -1;
+
+        _children = new long[32][];
+        int zeroStart = in.readUnsignedByte();
+        int zeroEnd = in.readUnsignedByte();
+
+        for (int i = zeroStart; i <= zeroEnd; i++) {
+            long recid = LongPacker.unpackLong(in);
+            if(recid!=0)
+                putRecid(i,recid);
+        }
+
+    }
+
+    public void defrag(DBStore r1, DBStore r2) throws IOException, ClassNotFoundException {
+        for (long[] sub: _children) {
+            if(sub==null) continue;
+            for (long child : sub) {
+                if (child == 0) continue;
+                byte[] data = r1.fetchRaw(child);
+                r2.forceInsert(child, data);
+                Object t = tree.SERIALIZER.deserialize(new DataInputOutput(data));
+                if (t instanceof HTreeDirectory) {
+                    ((HTreeDirectory) t).defrag(r1, r2);
+                }
+            }
+        }
+    }
+
+    void deleteAllChildren() throws IOException {
+        for(long[] ll : _children){
+            if(ll!=null){
+                for(long l:ll ){
+                    if(l!=0){
+                      tree.db.delete(l);
+                    }
+                }
+            }
+        }
+
+    }
+
+
+    ////////////////////////////////////////////////////////////////////////
+    // INNER CLASS
+    ////////////////////////////////////////////////////////////////////////
+
+    /**
+     * Utility class to enumerate keys/values in a HTree
+     */
+    class HDIterator<A> implements Iterator<A> {
+
+        /**
+         * True if we're iterating on keys, False if enumerating on values.
+         */
+        private boolean _iterateKeys;
+
+        /**
+         * Stacks of directories & last enumerated child position
+         */
+        private ArrayList _dirStack;
+        private ArrayList _childStack;
+
+        /**
+         * Current HashDirectory in the hierarchy
+         */
+        private HTreeDirectory _dir;
+
+        /**
+         * Current child position
+         */
+        private int _child;
+
+        /**
+         * Current bucket iterator
+         */
+        private Iterator<A> _iter;
+
+        private A next;
+
+        /**
+         * last item returned in next(), is used to remove() last item
+         */
+        private A last;
+
+        private int expectedModCount;
+
+        /**
+         * Construct an iterator on this directory.
+         *
+         * @param iterateKeys True if iteration supplies keys, False
+         *                    if iterateKeys supplies values.
+         */
+        HDIterator(boolean iterateKeys)
+                throws IOException {
+            _dirStack = new ArrayList();
+            _childStack = new ArrayList();
+            _dir = HTreeDirectory.this;
+            _child = -1;
+            _iterateKeys = iterateKeys;
+            expectedModCount = tree.modCount;
+
+            prepareNext();
+            next = next2();
+
+        }
+
+
+        /**
+         * Returns the next object.
+         */
+        public A next2() {
+            A next = null;
+            if (_iter != null && _iter.hasNext()) {
+                next = _iter.next();
+            } else {
+                try {
+                    prepareNext();
+                } catch (IOException except) {
+                    throw new IOError(except);
+                }
+                if (_iter != null && _iter.hasNext()) {
+                    return next2();
+                }
+            }
+            return next;
+        }
+
+
+        /**
+         * Prepare internal state so we can answer <code>hasMoreElements</code>
+         * <p/>
+         * Actually, this code prepares an Enumeration on the next
+         * Bucket to enumerate.   If no following bucket is found,
+         * the next Enumeration is set to <code>null</code>.
+         */
+        private void prepareNext() throws IOException {
+            long child_recid = 0;
+
+            // get next bucket/directory to enumerate
+            do {
+                _child++;
+                if (_child >= MAX_CHILDREN) {
+
+                    if (_dirStack.isEmpty()) {
+                        // no more directory in the stack, we're finished
+                        return;
+                    }
+
+                    // try next node
+                    _dir = (HTreeDirectory) _dirStack.remove(_dirStack.size() - 1);
+                    _child = ((Integer) _childStack.remove(_childStack.size() - 1)).intValue();
+                    continue;
+                }
+                child_recid = _dir.getRecid(_child);
+            } while (child_recid == 0);
+
+            if (child_recid == 0) {
+                throw new Error("child_recid cannot be 0");
+            }
+
+            Object node = tree.db.fetch(child_recid, tree.SERIALIZER);
+            // System.out.println("HDEnumeration.get() child is : "+node);
+
+            if (node instanceof HTreeDirectory) {
+                // save current position
+                _dirStack.add(_dir);
+                _childStack.add(new Integer(_child));
+
+                _dir = (HTreeDirectory) node;
+                _child = -1;
+
+                // recurse into
+                _dir.setPersistenceContext(child_recid);
+                prepareNext();
+            } else {
+                // node is a bucket
+                HTreeBucket bucket = (HTreeBucket) node;
+                if (_iterateKeys) {
+                    ArrayList keys2 = bucket.getKeys();
+                    _iter = keys2.iterator();
+                } else {
+                    _iter = bucket.getValues().iterator();
+                }
+            }
+        }
+
+
+        public boolean hasNext() {
+            return next != null;
+        }
+
+
+        public A next() {
+            if (next == null) throw new NoSuchElementException();
+            if (expectedModCount != tree.modCount)
+                throw new ConcurrentModificationException();
+            last = next;
+            next = next2();
+            return last;
+        }
+
+
+        public void remove() {
+            if (last == null) throw new IllegalStateException();
+
+            if (expectedModCount != tree.modCount)
+                throw new ConcurrentModificationException();
+
+            //TODO current delete behaviour may change node layout. INVESTIGATE if this can happen!
+            tree.remove(last);
+            last = null;
+            expectedModCount++;
+        }
+    }
+
+}
+

com.minres.scviewer.database.text/src/org/apache/jdbm/HTreeSet.java

@@ -0,0 +1,47 @@
+package org.apache.jdbm;
+
+
+import java.util.AbstractSet;
+import java.util.Iterator;
+
+/**
+ * Wrapper for HTree to implement java.util.Map interface
+ */
+class HTreeSet<E> extends AbstractSet<E> {
+
+    final HTree<E, Object> map;
+
+    HTreeSet(HTree map) {
+        this.map = map;
+    }
+
+    public Iterator<E> iterator() {
+        return map.keySet().iterator();
+    }
+
+    public int size() {
+        return map.size();
+    }
+
+
+    public boolean isEmpty() {
+        return map.isEmpty();
+    }
+
+    public boolean contains(Object o) {
+        return map.containsKey(o);
+    }
+
+    public boolean add(E e) {
+        return map.put(e, Utils.EMPTY_STRING) == null;
+    }
+
+    public boolean remove(Object o) {
+        return map.remove(o) == Utils.EMPTY_STRING;
+    }
+
+    public void clear() {
+        map.clear();
+    }
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/LinkedList2.java

@@ -0,0 +1,480 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package org.apache.jdbm;
+
+
+import java.io.*;
+import java.util.*;
+import java.util.concurrent.locks.ReentrantReadWriteLock;
+
+/**
+ * LinkedList2 which stores its nodes on disk.
+ *
+ * @author Jan Kotek
+ */
+class LinkedList2<E> extends AbstractSequentialList<E> {
+
+    private DBAbstract db;
+
+    final long rootRecid;
+    /** size limit, is not currently used, but needs to be here for future compatibility.
+     *  Zero means no limit.
+     */
+    long sizeLimit = 0;
+
+    private final ReentrantReadWriteLock lock = new ReentrantReadWriteLock();
+    
+    static final class Root{
+        long first;
+        long last;
+        long size;
+    }
+
+    private static final Serializer<Root> ROOT_SERIALIZER= new Serializer<Root>(){
+
+        public void serialize(DataOutput out, Root obj) throws IOException {
+            LongPacker.packLong(out,obj.first);
+            LongPacker.packLong(out,obj.last);
+            LongPacker.packLong(out,obj.size);
+        }
+
+        public Root deserialize(DataInput in) throws IOException, ClassNotFoundException {
+            Root r = new Root();
+            r.first = LongPacker.unpackLong(in);
+            r.last = LongPacker.unpackLong(in);
+            r.size = LongPacker.unpackLong(in);
+            return r;
+        }
+    };
+
+    private Serializer<E> valueSerializer;
+
+    /**
+     * indicates that entry values should not be loaded during deserialization, used during defragmentation
+     */
+    protected boolean loadValues = true;
+
+    /** constructor used for deserialization */
+    LinkedList2(DBAbstract db,long rootRecid, Serializer<E> valueSerializer) {
+        this.db = db;
+        this.rootRecid = rootRecid;
+        this.valueSerializer = valueSerializer;
+    }
+
+    /** constructor used to create new empty list*/
+    LinkedList2(DBAbstract db, Serializer<E> valueSerializer) throws IOException {
+        this.db = db;
+        if (valueSerializer != null && !(valueSerializer instanceof Serializable))
+            throw new IllegalArgumentException("Serializer does not implement Serializable");
+        this.valueSerializer = valueSerializer;
+        //create root
+        this.rootRecid = db.insert(new Root(), ROOT_SERIALIZER,false);
+    }
+
+    void setPersistenceContext(DBAbstract db) {
+        this.db = db;
+    }
+
+
+    public ListIterator<E> listIterator(int index) {
+        lock.readLock().lock();
+        try{
+        Root r = getRoot();
+        if (index < 0 || index > r.size)
+            throw new IndexOutOfBoundsException();
+
+
+        Iter iter = new Iter();
+        iter.next = r.first;
+
+
+        //scroll to requested position
+        //TODO scroll from end, if beyond half
+        for (int i = 0; i < index; i++) {
+            iter.next();
+        }
+        return iter;
+        }finally {
+            lock.readLock().unlock();
+        }
+
+    }
+
+    Root getRoot(){
+        //expect that caller already holds lock
+        try {
+           return db.fetch(rootRecid,ROOT_SERIALIZER);
+        } catch (IOException e) {
+            throw new IOError(e);
+        }
+    }
+
+
+
+    public int size() {
+        lock.readLock().lock();
+        try{
+        return (int) getRoot().size;
+        }finally {
+            lock.readLock().unlock();
+        }
+    
+            
+    }
+
+    public Iterator<E> descendingIterator() {
+        return null;  //To change body of implemented methods use File | Settings | File Templates.
+    }
+
+    public boolean add(Object value) {
+        lock.writeLock().lock();
+        try {                           
+            Root r = getRoot();
+            Entry e = new Entry(r.last, 0, value);
+            long recid = db.insert(e, entrySerializer,false);
+
+            //update old last Entry to point to new record
+            if (r.last != 0) {
+                Entry oldLast = db.fetch(r.last, entrySerializer);
+                if (oldLast.next != 0) throw new Error();
+                oldLast.next = recid;
+                db.update(r.last, oldLast, entrySerializer);
+            }
+
+            //update linked list
+            r.last = recid;
+            if (r.first == 0) r.first = recid;
+            r.size++;
+            db.update(rootRecid, r, ROOT_SERIALIZER);
+            modCount++;
+            return true;
+        } catch (IOException e) {
+            throw new IOError(e);
+        }finally {
+            lock.writeLock().unlock();
+        }
+
+
+    }
+
+    private Entry<E> fetch(long recid) {
+        lock.readLock().lock();
+        try {
+            return db.fetch(recid, entrySerializer);
+        } catch (IOException e) {
+            throw new IOError(e);
+        }finally {
+            lock.readLock().unlock();
+        }
+    }
+
+    /**
+     * called from Serialization object
+     */
+    static LinkedList2 deserialize(DataInput is, Serialization ser) throws IOException, ClassNotFoundException {
+        long rootrecid = LongPacker.unpackLong(is);
+        long sizeLimit = LongPacker.unpackLong(is);
+        if(sizeLimit!=0) throw new InternalError("LinkedList.sizeLimit not supported in this JDBM version");
+        Serializer serializer = (Serializer)  ser.deserialize(is);
+        return new LinkedList2(ser.db,rootrecid, serializer);
+    }
+
+    void serialize(DataOutput out) throws IOException {
+        LongPacker.packLong(out, rootRecid);
+        LongPacker.packLong(out, sizeLimit);
+        db.defaultSerializer().serialize(out, valueSerializer);
+    }
+
+    private final Serializer<Entry> entrySerializer = new Serializer<Entry>() {
+
+        public void serialize(DataOutput out, Entry e) throws IOException {
+            LongPacker.packLong(out, e.prev);
+            LongPacker.packLong(out, e.next);
+            if (valueSerializer != null)
+                valueSerializer.serialize(out, (E) e.value);
+            else
+                db.defaultSerializer().serialize(out, e.value);
+        }
+
+        public Entry<E> deserialize(DataInput in) throws IOException, ClassNotFoundException {
+            long prev = LongPacker.unpackLong(in);
+            long next = LongPacker.unpackLong(in);
+            Object value = null;
+            if (loadValues)
+                value = valueSerializer == null ? db.defaultSerializer().deserialize(in) : valueSerializer.deserialize(in);
+            return new LinkedList2.Entry(prev, next, value);
+        }
+    };
+
+    static class Entry<E> {
+        long prev = 0;
+        long next = 0;
+
+        E value;
+
+        public Entry(long prev, long next, E value) {
+            this.prev = prev;
+            this.next = next;
+            this.value = value;
+        }
+    }
+
+    private final class Iter implements ListIterator<E> {
+
+        private int expectedModCount = modCount;
+        private int index = 0;
+
+        private long prev = 0;
+        private long next = 0;
+
+        private byte lastOper = 0;
+
+        public boolean hasNext() {
+            return next != 0;
+        }
+
+
+        public E next() {
+            if (next == 0) throw new NoSuchElementException();
+            checkForComodification();
+
+            Entry<E> e = fetch(next);
+
+            prev = next;
+            next = e.next;
+            index++;
+            lastOper = +1;
+            return e.value;
+        }
+
+        public boolean hasPrevious() {
+            return prev != 0;
+        }
+
+        public E previous() {
+            checkForComodification();
+            Entry<E> e = fetch(prev);
+            next = prev;
+            prev = e.prev;
+            index--;
+            lastOper = -1;
+            return e.value;
+        }
+
+        public int nextIndex() {
+            return index;
+        }
+
+        public int previousIndex() {
+            return index - 1;
+        }
+
+        public void remove() {
+            checkForComodification();
+            lock.writeLock().lock();
+            try {
+                if (lastOper == 1) {
+                    //last operation was next() so remove previous element
+                    lastOper = 0;
+
+                    Entry<E> p = db.fetch(prev, entrySerializer);
+                    //update entry before previous
+                    if (p.prev != 0) {
+                        Entry<E> pp = db.fetch(p.prev, entrySerializer);
+                        pp.next = p.next;
+                        db.update(p.prev, pp, entrySerializer);
+                    }
+                    //update entry after next
+                    if (p.next != 0) {
+                        Entry<E> pn = db.fetch(p.next, entrySerializer);
+                        pn.prev = p.prev;
+                        db.update(p.next, pn, entrySerializer);
+                    }
+                    //remove old record from db
+                    db.delete(prev);
+                    //update list
+                    Root r = getRoot();
+                    if (r.first == prev)
+                        r.first = next;
+                    if (r.last == prev)
+                        r.last = next;
+                    r.size--;
+                    db.update(rootRecid, r,ROOT_SERIALIZER);
+                    modCount++;
+                    expectedModCount++;
+                    //update iterator
+                    prev = p.prev;
+
+                } else if (lastOper == -1) {
+                    //last operation was prev() so remove next element
+                    lastOper = 0;
+
+                    Entry<E> n = db.fetch(next, entrySerializer);
+                    //update entry before next
+                    if (n.prev != 0) {
+                        Entry<E> pp = db.fetch(n.prev, entrySerializer);
+                        pp.next = n.next;
+                        db.update(n.prev, pp, entrySerializer);
+                    }
+                    //update entry after previous
+                    if (n.next != 0) {
+                        Entry<E> pn = db.fetch(n.next, entrySerializer);
+                        pn.prev = n.prev;
+                        db.update(n.next, pn, entrySerializer);
+                    }
+                    //remove old record from db
+                    db.delete(next);
+                    //update list
+                    Root r = getRoot();
+                    if (r.last == next)
+                        r.last = prev;
+                    if (r.first == next)
+                        r.first = prev;
+                    r.size--;
+                    db.update(rootRecid, r,ROOT_SERIALIZER);
+                    modCount++;
+                    expectedModCount++;
+                    //update iterator
+                    next = n.next;
+
+                } else
+                    throw new IllegalStateException();
+            } catch (IOException e) {
+                throw new IOError(e);
+            }finally {
+                lock.writeLock().unlock();
+            }
+
+        }
+
+        public void set(E value) {
+            checkForComodification();
+            lock.writeLock().lock();
+            try {
+                if (lastOper == 1) {
+                    //last operation was next(), so update previous item
+                    lastOper = 0;
+                    Entry<E> n = db.fetch(prev, entrySerializer);
+                    n.value = value;
+                    db.update(prev, n, entrySerializer);
+                } else if (lastOper == -1) {
+                    //last operation was prev() so update next item
+                    lastOper = 0;
+                    Entry<E> n = db.fetch(next, entrySerializer);
+                    n.value = value;
+                    db.update(next, n, entrySerializer);
+                } else
+                    throw new IllegalStateException();
+            } catch (IOException e) {
+                throw new IOError(e);
+            }finally {
+                lock.writeLock().unlock();
+            }
+
+        }
+
+        public void add(E value) {
+            checkForComodification();
+
+            //use more efficient method if possible
+            if (next == 0) {
+                LinkedList2.this.add(value);
+                expectedModCount++;
+                return;
+            }
+            lock.writeLock().lock();
+            try {
+                //insert new entry
+                Entry<E> e = new Entry<E>(prev, next, value);
+                long recid = db.insert(e, entrySerializer,false);
+
+                //update previous entry
+                if (prev != 0) {
+                    Entry<E> p = db.fetch(prev, entrySerializer);
+                    if (p.next != next) throw new Error();
+                    p.next = recid;
+                    db.update(prev, p, entrySerializer);
+                }
+
+                //update next entry
+                Entry<E> n = fetch(next);
+                if (n.prev != prev) throw new Error();
+                n.prev = recid;
+                db.update(next, n, entrySerializer);
+
+                //update List
+                Root r = getRoot();
+                r.size++;
+                db.update(rootRecid, r, ROOT_SERIALIZER);
+
+                //update iterator
+                expectedModCount++;
+                modCount++;
+                prev = recid;
+
+            } catch (IOException e) {
+                throw new IOError(e);
+            }finally {
+                lock.writeLock().unlock();
+            }
+
+        }
+
+        final void checkForComodification() {
+            if (modCount != expectedModCount)
+                throw new ConcurrentModificationException();
+        }
+    }
+
+    /**
+     * Copyes collection from one db to other, while keeping logical recids unchanged
+     */
+    static void defrag(long recid, DBStore r1, DBStore r2) throws IOException {
+        try {
+            //move linked list itself
+            byte[] data = r1.fetchRaw(recid);
+            r2.forceInsert(recid, data);
+            DataInputOutput in = new DataInputOutput();
+            in.reset(data);
+            LinkedList2 l = (LinkedList2) r1.defaultSerializer().deserialize(in);
+            l.loadValues = false;
+            //move linkedlist root
+            if(l.rootRecid == 0) //empty list, done
+                return;
+
+            data = r1.fetchRaw(l.rootRecid);
+            r2.forceInsert(l.rootRecid, data);
+            in.reset(data);
+            Root r = ROOT_SERIALIZER.deserialize(in);
+            //move all other nodes in linked list
+            long current = r.first;
+            while (current != 0) {
+                data = r1.fetchRaw(current);
+                in.reset(data);
+                r2.forceInsert(current, data);
+
+                Entry e = (Entry) l.entrySerializer.deserialize(in);
+                current = e.next;
+            }
+        } catch (ClassNotFoundException e) {
+            throw new IOError(e);
+        }
+
+    }
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/LogicalRowIdManager.java

@@ -0,0 +1,239 @@
+/*******************************************************************************
+ * Copyright 2010 Cees De Groot, Alex Boisvert, Jan Kotek
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *   http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ ******************************************************************************/
+
+package org.apache.jdbm;
+
+import java.io.IOException;
+import java.util.Arrays;
+
+/**
+ * This class manages the linked lists of logical rowid pages.
+ */
+final class LogicalRowIdManager {
+    // our record file and associated page manager
+    private final PageFile file;
+    private final PageManager pageman;
+    static final short ELEMS_PER_PAGE = (short) ((Storage.PAGE_SIZE - Magic.PAGE_HEADER_SIZE) / Magic.PhysicalRowId_SIZE);
+
+    private long[] freeRecordsInTransRowid = new long[4];
+    private int freeRecordsInTransSize = 0;
+
+
+    /** number of free logical rowids on logical free page, is SHORT*/
+    static final int OFFSET_FREE_COUNT = Magic.PAGE_HEADER_SIZE;
+    static final int FREE_HEADER_SIZE = Magic.PAGE_HEADER_SIZE + Magic.SZ_SHORT;
+    /** maximal number of free logical per page */
+    static final int FREE_RECORDS_PER_PAGE = (Storage.PAGE_SIZE -FREE_HEADER_SIZE)/6;
+
+
+    /**
+     * Creates a log rowid manager using the indicated record file and page manager
+     */
+    LogicalRowIdManager(PageFile file, PageManager pageman) throws IOException {
+        this.file = file;
+        this.pageman = pageman;
+    }
+
+    /**
+     * Creates a new logical rowid pointing to the indicated physical id
+     *
+     * @param physloc physical location to point to
+     * @return logical recid
+     */
+    long insert(final long physloc) throws IOException {
+        // check whether there's a free rowid to reuse
+        long retval = getFreeSlot();
+        if (retval == 0) {
+            // no. This means that we bootstrap things by allocating
+            // a new translation page and freeing all the rowids on it.
+            long firstPage = pageman.allocate(Magic.TRANSLATION_PAGE);
+            short curOffset = Magic.PAGE_HEADER_SIZE;
+            for (int i = 0; i < ELEMS_PER_PAGE; i++) {
+                putFreeSlot(((-firstPage) << Storage.PAGE_SIZE_SHIFT) + (long) curOffset);
+
+                curOffset += Magic.PhysicalRowId_SIZE;
+            }
+
+            retval = getFreeSlot();
+            if (retval == 0) {
+                throw new Error("couldn't obtain free translation");
+            }
+        }
+        // write the translation.
+        update(retval, physloc);
+        return retval;
+    }
+
+    /**
+     * Insert at forced location, use only for defragmentation !!
+     *
+     * @param logicalRowId
+     * @param physLoc
+     * @throws IOException
+     */
+    void forceInsert(final long logicalRowId, final long physLoc) throws IOException {
+        if (fetch(logicalRowId) != 0)
+            throw new Error("can not forceInsert, record already exists: " + logicalRowId);
+
+        update(logicalRowId, physLoc);
+    }
+
+
+    /**
+     * Releases the indicated logical rowid.
+     */
+    void delete(final long logicalrowid) throws IOException {
+        //zero out old location, is needed for defragmentation
+        final long pageId = -(logicalrowid>>> Storage.PAGE_SIZE_SHIFT);
+        final PageIo xlatPage = file.get(pageId);
+        xlatPage.pageHeaderSetLocation((short) (logicalrowid & Storage.OFFSET_MASK), 0);
+        file.release(pageId, true);
+        putFreeSlot(logicalrowid);
+    }
+
+    /**
+     * Updates the mapping
+     *
+     * @param logicalrowid The logical rowid
+     * @param physloc   The physical rowid
+     */
+    void update(final long logicalrowid, final long physloc) throws IOException {
+
+        final long pageId =  -(logicalrowid>>> Storage.PAGE_SIZE_SHIFT);
+        final PageIo xlatPage = file.get(pageId);
+        xlatPage.pageHeaderSetLocation((short) (logicalrowid & Storage.OFFSET_MASK), physloc);
+        file.release(pageId, true);
+    }
+
+    /**
+     * Returns a mapping
+     *
+     * @param logicalrowid The logical rowid
+     * @return The physical rowid, 0 if does not exist
+     */
+    long fetch(long logicalrowid) throws IOException {
+        final long pageId = -(logicalrowid>>> Storage.PAGE_SIZE_SHIFT);
+        final long last = pageman.getLast(Magic.TRANSLATION_PAGE);
+        if (last - 1 > pageId)
+            return 0;
+
+        final short offset = (short) (logicalrowid & Storage.OFFSET_MASK);
+
+        final PageIo xlatPage = file.get(pageId);
+        final long ret =  xlatPage.pageHeaderGetLocation(offset);
+
+
+        file.release(pageId, false);
+        return ret;
+    }
+
+    void commit() throws IOException {
+        if(freeRecordsInTransSize==0) return;
+
+        long freeRecPageId = pageman.getLast(Magic.FREELOGIDS_PAGE);
+        if(freeRecPageId == 0){
+            //allocate new
+            freeRecPageId = pageman.allocate(Magic.FREELOGIDS_PAGE);
+        }
+        PageIo freeRecPage = file.get(freeRecPageId);
+        //write all uncommited free records
+        for(int rowPos = 0;rowPos<freeRecordsInTransSize;rowPos++){
+            short count = freeRecPage.readShort(OFFSET_FREE_COUNT);
+            if(count == FREE_RECORDS_PER_PAGE){
+                //allocate new free recid page
+                file.release(freeRecPage);
+                freeRecPageId = pageman.allocate(Magic.FREELOGIDS_PAGE);
+                freeRecPage = file.get(freeRecPageId);
+                freeRecPage.writeShort(FREE_RECORDS_PER_PAGE, (short)0);
+                count = 0;
+            }
+            final int offset =  (count ) *6 + FREE_HEADER_SIZE;
+            //write free recid and increase counter
+            freeRecPage.writeSixByteLong(offset,freeRecordsInTransRowid[rowPos]);
+            count++;
+            freeRecPage.writeShort(OFFSET_FREE_COUNT, count);
+
+        }
+        file.release(freeRecPage);
+
+        clearFreeRecidsInTransaction();
+    }
+
+    private void clearFreeRecidsInTransaction() {
+        if(freeRecordsInTransRowid.length>128)
+            freeRecordsInTransRowid = new long[4];
+        freeRecordsInTransSize = 0;
+    }
+
+    void rollback() throws IOException {
+        clearFreeRecidsInTransaction();
+    }
+
+
+    /**
+     * Returns a free Logical rowid, or
+     * 0 if nothing was found.
+     */
+    long getFreeSlot() throws IOException {
+        if (freeRecordsInTransSize != 0) {
+            return freeRecordsInTransRowid[--freeRecordsInTransSize];
+        }
+
+        final long logicFreePageId = pageman.getLast(Magic.FREELOGIDS_PAGE);
+        if(logicFreePageId == 0) {
+            return 0;
+        }
+        PageIo logicFreePage = file.get(logicFreePageId);
+        short recCount = logicFreePage.readShort(OFFSET_FREE_COUNT);
+        if(recCount <= 0){
+            throw new InternalError();
+        }
+
+
+        final int offset = (recCount -1) *6 + FREE_HEADER_SIZE;
+        final long ret = logicFreePage.readSixByteLong(offset);
+
+        recCount--;
+
+        if(recCount>0){
+            //decrease counter and zero out old record
+            logicFreePage.writeSixByteLong(offset,0);
+            logicFreePage.writeShort(OFFSET_FREE_COUNT, recCount);
+            file.release(logicFreePage);
+        }else{
+            //release this page
+            file.release(logicFreePage);
+            pageman.free(Magic.FREELOGIDS_PAGE,logicFreePageId);
+        }
+
+        return ret;
+    }
+
+    /**
+     * Puts the indicated rowid on the free list
+     */
+    void putFreeSlot(long rowid) throws IOException {
+        //ensure capacity
+        if(freeRecordsInTransSize == freeRecordsInTransRowid.length)
+            freeRecordsInTransRowid = Arrays.copyOf(freeRecordsInTransRowid, freeRecordsInTransRowid.length * 4);
+        //add record and increase size
+        freeRecordsInTransRowid[freeRecordsInTransSize]=rowid;
+        freeRecordsInTransSize++;
+    }
+
+
+
+}

com.minres.scviewer.database.text/src/org/apache/jdbm/LongHashMap.java

@@ -0,0 +1,432 @@
+/*
+ *  Licensed to the Apache Software Foundation (ASF) under one or more
+ *  contributor license agreements.  See the NOTICE file distributed with
+ *  this work for additional information regarding copyright ownership.
+ *  The ASF licenses this file to You under the Apache License, Version 2.0
+ *  (the "License"); you may not use this file except in compliance with
+ *  the License.  You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ *  Unless required by applicable law or agreed to in writing, software
+ *  distributed under the License is distributed on an "AS IS" BASIS,
+ *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ *  See the License for the specific language governing permissions and
+ *  limitations under the License.
+ */
+
+package org.apache.jdbm;
+
+import java.io.Serializable;
+import java.util.Arrays;
+import java.util.Iterator;
+import java.util.NoSuchElementException;
+
+/**
+ * Hash Map which uses primitive long as key.
+ * Main advantage is new instanceof of Long does not have to be created for each lookup.
+ * <p/>
+ * This code comes from Android, which in turns comes from Apache Harmony.
+ * This class was modified to use primitive longs and stripped down to consume less space.
+ * <p/>
+ * Author of JDBM modifications: Jan Kotek
+ */
+class LongHashMap<V> implements Serializable {
+    private static final long serialVersionUID = 362499999763181265L;
+
+    private int elementCount;
+
+    private Entry<V>[] elementData;
+
+    private final float loadFactor;
+
+    private int threshold;
+
+    private int defaultSize = 16;
+
+    private transient Entry<V> reuseAfterDelete = null;
+
+    static final class Entry<V> implements  Serializable{
+        private static final long serialVersionUID = 362445231113181265L;
+
+        Entry<V> next;
+
+        V value;
+
+        long key;
+
+        Entry(long theKey) {
+            this.key = theKey;
+            this.value = null;
+        }
+
+
+    }
+
+
+    static class HashMapIterator<V> implements Iterator<V> {
+        private int position = 0;
+
+
+        boolean canRemove = false;
+
+        Entry<V> entry;
+
+        Entry<V> lastEntry;
+
+        final LongHashMap<V> associatedMap;
+
+        HashMapIterator(LongHashMap<V> hm) {
+            associatedMap = hm;
+        }
+
+        public boolean hasNext() {
+            if (entry != null) {
+                return true;
+            }
+
+            Entry<V>[] elementData = associatedMap.elementData;
+            int length = elementData.length;
+            int newPosition = position;
+            boolean result = false;
+
+            while (newPosition < length) {
+                if (elementData[newPosition] == null) {
+                    newPosition++;
+                } else {
+                    result = true;
+                    break;
+                }
+            }
+
+            position = newPosition;
+            return result;
+        }
+
+        public V next() {
+
+            if (!hasNext()) {
+                throw new NoSuchElementException();
+            }
+
+            Entry<V> result;
+            Entry<V> _entry = entry;
+            if (_entry == null) {
+                result = lastEntry = associatedMap.elementData[position++];
+                entry = lastEntry.next;
+            } else {
+                if (lastEntry.next != _entry) {
+                    lastEntry = lastEntry.next;
+                }
+                result = _entry;
+                entry = _entry.next;
+            }
+            canRemove = true;
+            return result.value;
+        }
+
+        public void remove() {
+            if (!canRemove) {
+                throw new IllegalStateException();
+            }
+
+            canRemove = false;
+
+            if (lastEntry.next == entry) {
+                while (associatedMap.elementData[--position] == null) {
+                    // Do nothing
+                }
+                associatedMap.elementData[position] = associatedMap.elementData[position].next;
+                entry = null;
+            } else {
+                lastEntry.next = entry;
+            }
+            if (lastEntry != null) {
+                Entry<V> reuse = lastEntry;
+                lastEntry = null;
+                reuse.key = Long.MIN_VALUE;
+                reuse.value = null;
+                associatedMap.reuseAfterDelete = reuse;
+            }
+
+            associatedMap.elementCount--;
+        }
+    }
+
+
+    @SuppressWarnings("unchecked")
+    private Entry<V>[] newElementArray(int s) {
+        return new Entry[s];
+    }
+
+    /**
+     * Constructs a new empty {@code HashMap} instance.
+     *
+     * @since Android 1.0
+     */
+    public LongHashMap() {
+        this(16);
+    }
+
+    /**
+     * Constructs a new {@code HashMap} instance with the specified capacity.
+     *
+     * @param capacity the initial capacity of this hash map.
+     * @throws IllegalArgumentException when the capacity is less than zero.
+     * @since Android 1.0
+     */
+    public LongHashMap(int capacity) {
+        defaultSize = capacity;
+        if (capacity >= 0) {
+            elementCount = 0;
+            elementData = newElementArray(capacity == 0 ? 1 : capacity);
+            loadFactor = 0.75f; // Default load factor of 0.75
+            computeMaxSize();
+        } else {
+            throw new IllegalArgumentException();
+        }
+    }
+
+
+    // BEGIN android-changed
+
+    /**
+     * Removes all mappings from this hash map, leaving it empty.
+     *
+     * @see #isEmpty
+     * @see #size
+     * @since Android 1.0
+     */
+
+    public void clear() {
+        if (elementCount > 0) {            
+            elementCount = 0;            
+        }
+        if(elementData.length>1024 && elementData.length>defaultSize)
+            elementData = new Entry[defaultSize];
+        else
+            Arrays.fill(elementData, null);
+        computeMaxSize();
+    }
+    // END android-changed
+
+    /**
+     * Returns a shallow copy of this map.
+     *
+     * @return a shallow copy of this map.
+     * @since Android 1.0
+     */
+
+
+    private void computeMaxSize() {
+        threshold = (int) (elementData.length * loadFactor);
+    }
+
+
+    /**
+     * Returns the value of the mapping with the specified key.
+     *
+     * @param key the key.
+     * @return the value of the mapping with the specified key, or {@code null}
+     *         if no mapping for the specified key is found.
+     * @since Android 1.0
+     */
+
+    public V get(final long key) {
+
+        final int hash = powerHash(key);
+        final int index = (hash & 0x7FFFFFFF) % elementData.length;
+
+        //find non null entry
+        Entry<V> m = elementData[index];
+        while (m != null) {
+            if (key == m.key)
+                return m.value;
+            m = m.next;
+        }
+
+        return null;
+
+    }
+
+
+    /**
+     * Returns whether this map is empty.
+     *
+     * @return {@code true} if this map has no elements, {@code false}
+     *         otherwise.
+     * @see #size()
+     * @since Android 1.0
+     */
+
+    public boolean isEmpty() {
+        return elementCount == 0;
+    }
+
+    /**
+     * @return iterator over keys
+     */
+
+//      public Iterator<K> keyIterator(){
+//                 return new HashMapIterator<K, K, V>(
+//                            new MapEntry.Type<K, K, V>() {
+//                                public K get(Entry<K, V> entry) {
+//                                    return entry.key;
+//                                }
+//                            }, HashMap.this);
+//
+//     }
+
+    /**
+     * Maps the specified key to the specified value.
+     *
+     * @param key   the key.
+     * @param value the value.
+     * @return the value of any previous mapping with the specified key or
+     *         {@code null} if there was no such mapping.
+     * @since Android 1.0
+     */
+
+
+    public V put(final long key, final V value) {
+
+        int hash = powerHash(key);
+        int index = (hash & 0x7FFFFFFF) % elementData.length;
+
+        //find non null entry
+        Entry<V> entry = elementData[index];
+        while (entry != null && key != entry.key) {
+            entry = entry.next;
+        }
+
+        if (entry == null) {
+            if (++elementCount > threshold) {
+                rehash();
+                index = (hash & 0x7FFFFFFF) % elementData.length;
+            }
+            entry = createHashedEntry(key, index);
+        }
+
+
+        V result = entry.value;
+        entry.value = value;
+        return result;
+    }
+
+
+    Entry<V> createHashedEntry(final long key, final int index) {
+        Entry<V> entry = reuseAfterDelete;
+        if (entry == null) {
+            entry = new Entry<V>(key);
+        } else {
+            reuseAfterDelete = null;
+            entry.key = key;
+            entry.value = null;
+        }
+
+        entry.next = elementData[index];
+        elementData[index] = entry;
+        return entry;
+    }
+
+
+    void rehash(final int capacity) {
+        int length = (capacity == 0 ? 1 : capacity << 1);
+
+        Entry<V>[] newData = newElementArray(length);
+        for (int i = 0; i < elementData.length; i++) {
+            Entry<V> entry = elementData[i];
+            while (entry != null) {
+                int index = ((int) powerHash(entry.key) & 0x7FFFFFFF) % length;
+                Entry<V> next = entry.next;
+                entry.next = newData[index];
+                newData[index] = entry;
+                entry = next;
+            }
+        }
+        elementData = newData;
+        computeMaxSize();
+    }
+
+    void rehash() {
+        rehash(elementData.length);
+    }
+
+    /**
+     * Removes the mapping with the specified key from this map.
+     *
+     * @param key the key of the mapping to remove.
+     * @return the value of the removed mapping or {@code null} if no mapping
+     *         for the specified key was found.
+     * @since Android 1.0
+     */
+
+    public V remove(final long key) {
+        Entry<V> entry = removeEntry(key);
+        if (entry == null)
+            return null;
+        V ret = entry.value;
+        entry.value = null;
+        entry.key = Long.MIN_VALUE;
+        reuseAfterDelete = entry;
+
+        return ret;
+    }
+
+    Entry<V> removeEntry(final long key) {
+        Entry<V> last = null;
+
+        final int hash = powerHash(key);
+        final int index = (hash & 0x7FFFFFFF) % elementData.length;
+        Entry<V> entry = elementData[index];
+
+        while (true) {
+            if (entry == null) {
+                return null;
+            }
+
+            if (key == entry.key) {
+                if (last == null) {
+                    elementData[index] = entry.next;
+                } else {
+                    last.next = entry.next;
+                }
+                elementCount--;
+                return entry;
+            }
+
+            last = entry;
+            entry = entry.next;
+        }
+    }
+
+    /**
+     * Returns the number of elements in this map.
+     *
+     * @return the number of elements in this map.
+     * @since Android 1.0
+     */
+
+    public int size() {
+        return elementCount;
+    }
+
+    /**
+     * @returns iterator over values in map
+     */
+    public Iterator<V> valuesIterator() {
+        return new HashMapIterator<V>(this);
+
+    }
+    
+    static final private int powerHash(final long key){
+        int h = (int)(key ^ (key >>> 32));
+        h ^= (h >>> 20) ^ (h >>> 12);
+        return h ^ (h >>> 7) ^ (h >>> 4);
+    }
+
+
+}
+
+
+