/* Copyright (c) 2001-2010, The HSQL Development Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* Redistributions of source code must retain the above copyright notice, this
* list of conditions and the following disclaimer.
*
* Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* Neither the name of the HSQL Development Group nor the names of its
* contributors may be used to endorse or promote products derived from this
* software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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package org.hsqldb.persist;
import java.io.IOException;
import java.io.RandomAccessFile;
import org.hsqldb.Database;
import org.hsqldb.lib.HsqlByteArrayOutputStream;
import org.hsqldb.lib.Storage;
import org.hsqldb.lib.java.JavaSystem;
import org.hsqldb.store.BitMap;
/*
* Wrapper for random access file for incremental backup of the .data file.
*
* @author Fred Toussi (fredt@users dot sourceforge.net)
* @version 1.9.0
* @since 1.9.0
*/
public class RAShadowFile {
final Database database;
final String pathName;
final Storage source;
Storage dest;
final int pageSize;
final long maxSize;
final BitMap bitMap;
boolean zeroPageSet;
HsqlByteArrayOutputStream byteArrayOutputStream =
new HsqlByteArrayOutputStream(new byte[]{});
RAShadowFile(Database database, Storage source, String pathName,
long maxSize, int pageSize) {
this.database = database;
this.pathName = pathName;
this.source = source;
this.pageSize = pageSize;
this.maxSize = maxSize;
int bitSize = (int) (maxSize / pageSize);
if (maxSize % pageSize != 0) {
bitSize++;
}
bitMap = new BitMap(bitSize);
}
void copy(long fileOffset, int size) throws IOException {
// always copy the first page
if (!zeroPageSet) {
copy(0);
bitMap.set(0);
zeroPageSet = true;
}
if (fileOffset >= maxSize) {
return;
}
long endOffset = fileOffset + size;
int startPageOffset = (int) (fileOffset / pageSize);
int endPageOffset = (int) (endOffset / pageSize);
if (endOffset % pageSize == 0) {
endPageOffset--;
}
for (; startPageOffset <= endPageOffset; startPageOffset++) {
copy(startPageOffset);
}
}
private void copy(int pageOffset) throws IOException {
if (bitMap.set(pageOffset) == 1) {
return;
}
long position = (long) pageOffset * pageSize;
int readSize = pageSize;
if (maxSize - position < pageSize) {
readSize = (int) (maxSize - position);
}
try {
if (dest == null) {
open();
}
long writePos = dest.length();
byte[] buffer = new byte[pageSize + 12];
byteArrayOutputStream.setBuffer(buffer);
byteArrayOutputStream.writeInt(pageSize);
byteArrayOutputStream.writeLong(position);
source.seek(position);
source.read(buffer, 12, readSize);
dest.seek(writePos);
dest.write(buffer, 0, buffer.length);
} catch (Throwable t) {
bitMap.unset(pageOffset);
close();
database.logger.logWarningEvent("pos" + position + " " + readSize,
t);
throw JavaSystem.toIOException(t);
} finally {}
}
private void open() throws IOException {
if (database.logger.isStoredFileAccess()) {
dest = ScaledRAFile.newScaledRAFile(database, pathName, false,
ScaledRAFile.DATA_FILE_STORED);
} else {
dest = new ScaledRAFileSimple(pathName, "rwd");
}
}
/**
* Called externally after a series of copy() calls.
* Called internally after a restore or when error in writing
*/
void close() throws IOException {
if (dest != null) {
dest.synch();
dest.close();
dest = null;
}
}
private static Storage getStorage(Database database, String pathName,
String openMode) throws IOException {
if (database.logger.isStoredFileAccess()) {
return ScaledRAFile.newScaledRAFile(database, pathName,
openMode.equals("r"),
ScaledRAFile.DATA_FILE_STORED);
} else {
return new ScaledRAFileSimple(pathName, openMode);
}
}
/** todo - take account of incomplete addition of block due to lack of disk */
// buggy database files had size == position == 0 at the end
public static void restoreFile(Database database, String sourceName,
String destName) throws IOException {
Storage source = getStorage(database, sourceName, "r");
Storage dest = getStorage(database, destName, "rw");
while (source.getFilePointer() != source.length()) {
int size = source.readInt();
long position = source.readLong();
byte[] buffer = new byte[size];
source.read(buffer, 0, buffer.length);
dest.seek(position);
dest.write(buffer, 0, buffer.length);
}
source.close();
dest.close();
}
}