72 lines
1.8 KiB
Java
72 lines
1.8 KiB
Java
package org.apache.jdbm;
|
|
|
|
import java.io.*;
|
|
import java.nio.ByteBuffer;
|
|
import java.util.zip.ZipEntry;
|
|
import java.util.zip.ZipFile;
|
|
|
|
/**
|
|
* A read-only storage which reads data from compressed zip archive.
|
|
* <p/>
|
|
* To improve performance with compressed archives
|
|
* each page is stored in separate file (zip archive entry).
|
|
*/
|
|
class StorageZip implements Storage {
|
|
|
|
|
|
private String zip;
|
|
private String zip2;
|
|
private ZipFile z;
|
|
|
|
StorageZip(String zipFile) throws IOException {
|
|
zip = zipFile;
|
|
z = new ZipFile(zip);
|
|
zip2 = "db";
|
|
}
|
|
|
|
public void write(long pageNumber, ByteBuffer data) throws IOException {
|
|
throw new UnsupportedOperationException("readonly");
|
|
}
|
|
|
|
public ByteBuffer read(long pageNumber) throws IOException {
|
|
ByteBuffer data = ByteBuffer.allocate(PAGE_SIZE);
|
|
|
|
ZipEntry e = z.getEntry(zip2 + pageNumber);
|
|
if(e == null)
|
|
return ByteBuffer.wrap(PageFile.CLEAN_DATA).asReadOnlyBuffer();
|
|
|
|
InputStream i = z.getInputStream(e);
|
|
new DataInputStream(i).readFully(data.array());
|
|
i.close();
|
|
return data;
|
|
}
|
|
|
|
public void forceClose() throws IOException {
|
|
z.close();
|
|
z = null;
|
|
}
|
|
|
|
public DataInputStream readTransactionLog() {
|
|
throw new UnsupportedOperationException("readonly");
|
|
}
|
|
|
|
public void deleteTransactionLog() {
|
|
throw new UnsupportedOperationException("readonly");
|
|
}
|
|
|
|
public void sync() throws IOException {
|
|
throw new UnsupportedOperationException("readonly");
|
|
}
|
|
|
|
public DataOutputStream openTransactionLog() throws IOException {
|
|
throw new UnsupportedOperationException("readonly");
|
|
}
|
|
|
|
public void deleteAllFiles() throws IOException {
|
|
}
|
|
|
|
public boolean isReadonly() {
|
|
return true;
|
|
}
|
|
}
|