SCViewer/com.minres.scviewer.databas.../src/com/minres/scviewer/database/leveldb/TxDBWrapper.java

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2018-11-03 17:48:36 +01:00
package com.minres.scviewer.database.leveldb;
import static java.nio.charset.StandardCharsets.UTF_8;
import java.io.File;
import java.io.IOException;
import org.iq80.leveldb.Options;
import org.iq80.leveldb.Range;
import org.iq80.leveldb.ReadOptions;
import org.iq80.leveldb.Snapshot;
import org.iq80.leveldb.impl.DbImpl;
import org.iq80.leveldb.impl.SeekingIterator;
import org.json.*;
class StringDBWrapper {
private final Options options;
private final File databaseDir;
private DbImpl db;
StringDBWrapper(Options options, File databaseDir) throws IOException {
this.options = options.verifyChecksums(true).createIfMissing(false).errorIfExists(false);
this.databaseDir = databaseDir;
this.db = new DbImpl(options, databaseDir);
}
public String get(String key) {
byte[] slice = db.get(LevelDBLoader.toByteArray(key));
if (slice == null) {
return null;
}
return new String(slice, UTF_8);
}
public String get(String key, Snapshot snapshot) {
byte[] slice = db.get(LevelDBLoader.toByteArray(key), new ReadOptions().snapshot(snapshot));
if (slice == null) {
return null;
}
return new String(slice, UTF_8);
}
public void put(String key, String value) {
db.put(LevelDBLoader.toByteArray(key), LevelDBLoader.toByteArray(value));
}
public void delete(String key) {
db.delete(LevelDBLoader.toByteArray(key));
}
public SeekingIterator<String, String> iterator() {
return new StringDbIterator(db.iterator());
}
public Snapshot getSnapshot() {
return db.getSnapshot();
}
public void close() {
db.close();
}
public long size(String start, String limit) {
return db.getApproximateSizes(new Range(LevelDBLoader.toByteArray(start), LevelDBLoader.toByteArray(limit)));
}
public long getMaxNextLevelOverlappingBytes() {
return db.getMaxNextLevelOverlappingBytes();
}
public void reopen() throws IOException {
reopen(options);
}
public void reopen(Options options) throws IOException {
db.close();
db = new DbImpl(options.verifyChecksums(true).createIfMissing(false).errorIfExists(false), databaseDir);
}
}