HSQLDB example source code file (Log.java)
The HSQLDB Log.java source code
/*
* For work developed by the HSQL Development Group:
*
* 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
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL HSQL DEVELOPMENT GROUP, HSQLDB.ORG,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
*
*
* For work originally developed by the Hypersonic SQL Group:
*
* Copyright (c) 1995-2000, The Hypersonic SQL 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 Hypersonic SQL 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
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE HYPERSONIC SQL GROUP,
* OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
* EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
* PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*
* This software consists of voluntary contributions made by many individuals
* on behalf of the Hypersonic SQL Group.
*/
package org.hsqldb.persist;
import java.io.File;
import java.io.IOException;
import org.hsqldb.Database;
import org.hsqldb.DatabaseURL;
import org.hsqldb.HsqlException;
import org.hsqldb.NumberSequence;
import org.hsqldb.Session;
import org.hsqldb.Table;
import org.hsqldb.Trace;
import org.hsqldb.lib.FileAccess;
import org.hsqldb.lib.HashMap;
import org.hsqldb.lib.Iterator;
import org.hsqldb.lib.SimpleLog;
import org.hsqldb.lib.ZipUnzipFile;
import org.hsqldb.scriptio.ScriptReaderBase;
import org.hsqldb.scriptio.ScriptWriterBase;
// fredt@users 20020215 - patch 1.7.0 by fredt
// to move operations on the database.properties files to new
// class HsqlDatabaseProperties
// fredt@users 20020220 - patch 488200 by xclayl@users - throw exception
// throw addded to all methods relying on file io
// fredt@users 20020221 - patch 513005 by sqlbob@users (RMP)
// fredt@users 20020405 - patch 1.7.0 by fredt - no change in db location
// because important information about the database is now stored in the
// *.properties file, all database files should be in the same folder as the
// *.properties file
// tony_lai@users 20020820 - export hsqldb.log_size to .properties file
// tony_lai@users 20020820 - changes to shutdown compact to save memory
// fredt@users 20020910 - patch 1.7.1 by Nitin Chauhan - code improvements
// fredt@users 20021208 - ongoing revamp
// fredt@users 20021212 - do not rewrite the *.backup file if the *.data
// file has not been updated in the current session.
// boucherb@users 20030510 - patch 1.7.2 consolidated all periodic database
// tasks in one timed task queue
// fredt@users - 20050102 patch 1.8.0 - refactoring and clearer separation of concerns
/**
* This class is responsible for managing the database files. An HSQLDB database
* consists of a .properties file, a .script file (contains an SQL script),
* a .data file (contains data of cached tables) a .backup file
* and a .log file.<p>
* When using TEXT tables, a data source for each table is also present.<p>
*
* Notes on OpenOffice.org integration.
*
* A Storage API is used when HSQLDB is integrated into OpenOffice.org. All
* file operations on the 4 main files are performed by OOo, which integrates
* the contents of these files into its database file. The script format is
* always TEXT in this case.
*
* Extensively rewritten and extended in successive versions of HSQLDB.
*
* @author Thomas Mueller (Hypersonic SQL Group)
* @author fredt@users.
* @version 1.8.0
* @since Hypersonic SQL
*/
public class Log {
private HsqlDatabaseProperties properties;
private String fileName;
private Database database;
private FileAccess fa;
private ScriptWriterBase dbLogWriter;
private String scriptFileName;
private String logFileName;
private boolean filesReadOnly;
private long maxLogSize;
private int writeDelay;
private int scriptFormat;
private DataFileCache cache;
private boolean incBackup;
Log(Database db) throws HsqlException {
database = db;
fa = db.getFileAccess();
fileName = db.getPath();
properties = db.getProperties();
}
void initParams() {
// Allows the user to set log size in the properties file.
int logMegas = properties.getIntegerProperty(
HsqlDatabaseProperties.hsqldb_log_size, 0);
maxLogSize = logMegas * 1024L * 1024;
scriptFormat = properties.getIntegerProperty(
HsqlDatabaseProperties.hsqldb_script_format,
ScriptWriterBase.SCRIPT_TEXT_170);
incBackup = properties.isPropertyTrue(
HsqlDatabaseProperties.hsqldb_inc_backup);
writeDelay = properties.getDefaultWriteDelay();
filesReadOnly = database.isFilesReadOnly();
scriptFileName = fileName + ".script";
logFileName = fileName + ".log";
}
/**
* When opening a database, the hsqldb.compatible_version property is
* used to determine if this version of the engine is equal to or greater
* than the earliest version of the engine capable of opening that
* database.<p>
*
* @throws HsqlException
*/
void open() throws HsqlException {
initParams();
int state = properties.getDBModified();
switch (state) {
case HsqlDatabaseProperties.FILES_MODIFIED :
deleteNewAndOldFiles();
restoreBackup();
processScript();
processDataFile();
processLog();
close(false);
if (cache != null) {
cache.open(filesReadOnly);
}
reopenAllTextCaches();
break;
case HsqlDatabaseProperties.FILES_NEW :
try {
deleteBackup();
backupData();
renameNewBackup();
renameNewScript();
deleteLog();
properties.setDBModified(
HsqlDatabaseProperties.FILES_NOT_MODIFIED);
} catch (IOException e) {
database.logger.appLog.logContext(e, null);
}
// continue as non-modified files
// fall through
case HsqlDatabaseProperties.FILES_NOT_MODIFIED :
/**
* if startup is after a SHUTDOWN SCRIPT and there are CACHED
* or TEXT tables, perform a checkpoint so that the .script
* file no longer contains CACHED or TEXT table rows.
*/
processScript();
if (isAnyCacheModified()) {
properties.setDBModified(
HsqlDatabaseProperties.FILES_MODIFIED);
close(false);
if (cache != null) {
cache.open(filesReadOnly);
}
reopenAllTextCaches();
}
break;
}
openLog();
if (!filesReadOnly) {
properties.setDBModified(HsqlDatabaseProperties.FILES_MODIFIED);
}
}
/**
* Close all the database files. If script argument is true, no .data
* or .backup file will remain and the .script file will contain all the
* data of the cached tables as well as memory tables.
*
* This is not used for filesReadOnly databases which use shutdown.
*/
void close(boolean script) throws HsqlException {
closeLog();
deleteNewAndOldFiles();
writeScript(script);
closeAllTextCaches(script);
if (cache != null) {
cache.close(true);
}
properties.setProperty(HsqlDatabaseProperties.db_version,
HsqlDatabaseProperties.THIS_VERSION);
properties.setProperty(
HsqlDatabaseProperties.hsqldb_compatible_version,
HsqlDatabaseProperties.FIRST_COMPATIBLE_VERSION);
// set this one last to save the props
properties.setDBModified(HsqlDatabaseProperties.FILES_NEW);
deleteLog();
if (script) {
deleteBackup();
deleteData();
} else {
try {
backupData();
renameNewBackup();
} catch (IOException e) {}
}
renameNewScript();
properties.setProperty(HsqlDatabaseProperties.hsqldb_cache_version,
HsqlDatabaseProperties.THIS_CACHE_VERSION);
properties.setDBModified(HsqlDatabaseProperties.FILES_NOT_MODIFIED);
}
/**
* Fast counterpart to close(). Does not perform a checkpoint or a backup
* of the .data file.
*/
void shutdown() throws HsqlException {
synchLog();
if (cache != null) {
cache.close(false);
}
closeAllTextCaches(false);
closeLog();
}
/**
* Deletes the leftovers from any previous unfinished operations.
*/
void deleteNewAndOldFiles() {
fa.removeElement(fileName + ".data" + ".old");
fa.removeElement(fileName + ".data" + ".new");
fa.removeElement(fileName + ".backup" + ".new");
fa.removeElement(scriptFileName + ".new");
}
void deleteBackup() {
fa.removeElement(fileName + ".backup");
}
void deleteData() {
fa.removeElement(fileName + ".data");
}
void backupData() throws IOException {
if (incBackup) {
fa.removeElement(fileName + ".backup");
return;
}
if (fa.isStreamElement(fileName + ".data")) {
ZipUnzipFile.compressFile(fileName + ".data",
fileName + ".backup.new",
database.getFileAccess());
}
}
void renameNewBackup() {
if (fa.isStreamElement(fileName + ".backup.new")) {
fa.renameElement(fileName + ".backup.new", fileName + ".backup");
}
}
void renameNewScript() {
if (fa.isStreamElement(scriptFileName + ".new")) {
fa.renameElement(scriptFileName + ".new", scriptFileName);
}
}
void deleteNewScript() {
fa.removeElement(scriptFileName + ".new");
}
void deleteNewBackup() {
fa.removeElement(scriptFileName + ".backup.new");
}
void deleteLog() {
fa.removeElement(logFileName);
}
/**
* Checks all the caches and returns true if the modified flag is set for any
*/
boolean isAnyCacheModified() {
if (cache != null && cache.isFileModified()) {
return true;
}
return isAnyTextCacheModified();
}
/**
* Performs checkpoint including pre and post operations. Returns to the
* same state as before the checkpoint.
*/
void checkpoint(boolean defrag) throws HsqlException {
if (filesReadOnly) {
return;
}
database.logger.appLog.logContext(SimpleLog.LOG_NORMAL, "start");
deleteNewAndOldFiles();
if (cache != null) {
if (forceDefrag()) {
defrag = true;
}
if (defrag) {
try {
cache.defrag();
} catch (Exception e) {}
} else {
cache.close(true);
try {
cache.backupFile();
} catch (IOException e1) {
deleteNewBackup();
cache.open(false);
return;
}
cache.open(false);
}
}
writeScript(false);
properties.setDBModified(HsqlDatabaseProperties.FILES_NEW);
closeLog();
deleteLog();
renameNewScript();
renameNewBackup();
properties.setDBModified(HsqlDatabaseProperties.FILES_MODIFIED);
if (dbLogWriter == null) {
return;
}
openLog();
Session[] sessions = database.sessionManager.getAllSessions();
try {
for (int i = 0; i < sessions.length; i++) {
Session session = sessions[i];
if (session.isAutoCommit() == false) {
dbLogWriter.writeLogStatement(
session, session.getAutoCommitStatement());
}
}
} catch (IOException e) {
throw Trace.error(Trace.FILE_IO_ERROR, logFileName);
}
database.logger.appLog.logContext(SimpleLog.LOG_NORMAL, "end");
}
/**
* Returns true if lost space is above the threshold
*/
boolean forceDefrag() {
long megas = properties.getIntegerProperty(
HsqlDatabaseProperties.hsqldb_defrag_limit, 200);
long defraglimit = megas * 1024L * 1024;
long lostSize = cache.freeBlocks.getLostBlocksSize();
return lostSize > defraglimit;
}
/**
*
*/
boolean hasCache() {
return cache != null;
}
/**
* Responsible for creating the cache instance.
*/
DataFileCache getCache() throws HsqlException {
/*
if (database.isFilesInJar()) {
return null;
}
*/
if (cache == null) {
cache = new DataFileCache(database, fileName);
cache.open(filesReadOnly);
}
return cache;
}
int getLogSize() {
return (int) (maxLogSize / (1024 * 1024));
}
void setLogSize(int megas) {
properties.setProperty(HsqlDatabaseProperties.hsqldb_log_size,
String.valueOf(megas));
maxLogSize = megas * 1024L * 1024;
}
int getScriptType() {
return scriptFormat;
}
/**
* Changing the script format results in a checkpoint, with the .script
* file written in the new format.
*/
void setScriptType(int type) throws HsqlException {
// OOo related code
if (database.isStoredFileAccess()) {
return;
}
// end OOo
boolean needsCheckpoint = scriptFormat != type;
scriptFormat = type;
properties.setProperty(HsqlDatabaseProperties.hsqldb_script_format,
String.valueOf(scriptFormat));
if (needsCheckpoint) {
database.logger.needsCheckpoint = true;
}
}
/**
* Write delay specifies the frequency of FileDescriptor.sync() calls.
*/
int getWriteDelay() {
return writeDelay;
}
/**
* Write delay 0 means sync on each commit. Values larger than 0 and less
* than 10 ms are treated as 10 ms.
*/
void setWriteDelay(int delay) {
if (delay > 0 && delay < 10) {
delay = 10;
}
writeDelay = delay;
if (dbLogWriter != null) {
dbLogWriter.forceSync();
dbLogWriter.stop();
dbLogWriter.setWriteDelay(delay);
dbLogWriter.start();
}
}
public void setIncrementalBackup(boolean val) throws HsqlException {
if (incBackup == val) {
return;
}
incBackup = val;
database.getProperties().setProperty(
HsqlDatabaseProperties.hsqldb_inc_backup, String.valueOf(val));
database.getProperties().save();
if (cache != null) {
// need to set file modified to force a backup if necessary
cache.incBackup = true;
cache.fileModified = true;
}
database.logger.needsCheckpoint = true;
}
/**
* Various writeXXX() methods are used for logging statements.
*/
void writeStatement(Session session, String s) throws HsqlException {
if (s == null || s.length() == 0) {
return;
}
try {
dbLogWriter.writeLogStatement(session, s);
} catch (IOException e) {
throw Trace.error(Trace.FILE_IO_ERROR, logFileName);
}
if (maxLogSize > 0 && dbLogWriter.size() > maxLogSize) {
database.logger.needsCheckpoint = true;
}
}
void writeInsertStatement(Session session, Table t,
Object[] row) throws HsqlException {
try {
dbLogWriter.writeInsertStatement(session, t, row);
} catch (IOException e) {
throw Trace.error(Trace.FILE_IO_ERROR, logFileName);
}
if (maxLogSize > 0 && dbLogWriter.size() > maxLogSize) {
database.logger.needsCheckpoint = true;
}
}
void writeDeleteStatement(Session session, Table t,
Object[] row) throws HsqlException {
try {
dbLogWriter.writeDeleteStatement(session, t, row);
} catch (IOException e) {
throw Trace.error(Trace.FILE_IO_ERROR, logFileName);
}
if (maxLogSize > 0 && dbLogWriter.size() > maxLogSize) {
database.logger.needsCheckpoint = true;
}
}
void writeSequenceStatement(Session session,
NumberSequence s) throws HsqlException {
try {
dbLogWriter.writeSequenceStatement(session, s);
} catch (IOException e) {
throw Trace.error(Trace.FILE_IO_ERROR, logFileName);
}
if (maxLogSize > 0 && dbLogWriter.size() > maxLogSize) {
database.logger.needsCheckpoint = true;
}
}
void writeCommitStatement(Session session) throws HsqlException {
try {
dbLogWriter.writeCommitStatement(session);
} catch (IOException e) {
throw Trace.error(Trace.FILE_IO_ERROR, logFileName);
}
if (maxLogSize > 0 && dbLogWriter.size() > maxLogSize) {
database.logger.needsCheckpoint = true;
}
}
void synchLog() {
if (dbLogWriter != null) {
dbLogWriter.sync();
}
}
/**
* Wrappers for openning-starting / stoping-closing the log file and
* writer.
*/
private void openLog() throws HsqlException {
if (filesReadOnly) {
return;
}
try {
dbLogWriter = ScriptWriterBase.newScriptWriter(database,
logFileName, false, false,
ScriptWriterBase.SCRIPT_TEXT_170);
dbLogWriter.setWriteDelay(writeDelay);
dbLogWriter.start();
} catch (Exception e) {
throw Trace.error(Trace.FILE_IO_ERROR, logFileName);
}
}
private synchronized void closeLog() throws HsqlException {
if (dbLogWriter != null) {
dbLogWriter.close();
}
}
/**
* Write the .script file as .script.new.
*/
private void writeScript(boolean full) throws HsqlException {
deleteNewScript();
//fredt - to do - flag for chache set index
ScriptWriterBase scw = ScriptWriterBase.newScriptWriter(database,
scriptFileName + ".new", full, true, scriptFormat);
scw.writeAll();
scw.close();
}
/**
* Performs all the commands in the .script file.
*/
private void processScript() throws HsqlException {
ScriptReaderBase scr = null;
try {
if (database.isFilesInJar()
|| fa.isStreamElement(scriptFileName)) {
scr = ScriptReaderBase.newScriptReader(database,
scriptFileName,
scriptFormat);
scr.readAll(database.sessionManager.getSysSession(null, true));
scr.close();
}
} catch (Throwable e) {
if (scr != null) {
scr.close();
if (cache != null) {
cache.close(false);
}
closeAllTextCaches(false);
}
database.logger.appLog.logContext(e, null);
if (e instanceof HsqlException) {
throw (HsqlException) e;
} else if (e instanceof IOException) {
throw Trace.error(Trace.FILE_IO_ERROR, e.toString());
} else if (e instanceof OutOfMemoryError) {
throw Trace.error(Trace.OUT_OF_MEMORY);
} else {
throw Trace.error(Trace.GENERAL_ERROR, e.toString());
}
}
}
/**
* Defrag large data files when the sum of .log and .data files is large.
*/
private void processDataFile() throws HsqlException {
// OOo related code
if (database.isStoredFileAccess()) {
return;
}
// OOo end
if (cache == null || filesReadOnly
|| !fa.isStreamElement(logFileName)) {
return;
}
File file = new File(logFileName);
long logLength = file.length();
long dataLength = cache.getFileFreePos();
if (logLength + dataLength > cache.maxDataFileSize) {
database.logger.needsCheckpoint = true;
}
}
/**
* Performs all the commands in the .log file.
*/
private void processLog() throws HsqlException {
if (!database.isFilesInJar() && fa.isStreamElement(logFileName)) {
ScriptRunner.runScript(database, logFileName,
ScriptWriterBase.SCRIPT_TEXT_170);
}
}
/**
* Restores a compressed backup or the .data file.
*/
private void restoreBackup() throws HsqlException {
if (incBackup) {
restoreBackupIncremental();
return;
}
// in case data file cannot be deleted, reset it
DataFileCache.deleteOrResetFreePos(database, fileName + ".data");
try {
ZipUnzipFile.decompressFile(fileName + ".backup",
fileName + ".data",
database.getFileAccess());
} catch (Exception e) {
throw Trace.error(Trace.FILE_IO_ERROR, Trace.Message_Pair,
new Object[] {
fileName + ".backup", e.toString()
});
}
}
/**
* Restores in from an incremental backup
*/
private void restoreBackupIncremental() throws HsqlException {
try {
if (fa.isStreamElement(fileName + ".backup")) {
RAShadowFile.restoreFile(fileName + ".backup",
fileName + ".data");
} else {
/*
// this is to ensure file has been written fully but it is not necessary
// as semantics dictate that if a backup does not exist, the file
// was never changed or was fully written to
if (FileUtil.exists(cacheFileName)) {
int flags = DataFileCache.getFlags(cacheFileName);
if (!BitMap.isSet(flags, DataFileCache.FLAG_ISSAVED)) {
FileUtil.delete(cacheFileName);
}
}
*/
}
deleteBackup();
} catch (IOException e) {
throw Trace.error(Trace.FILE_IO_ERROR, fileName + ".backup");
}
}
// fredt@users 20020221 - patch 513005 by sqlbob@users (RMP) - text tables
private HashMap textCacheList = new HashMap();
DataFileCache openTextCache(Table table, String source,
boolean readOnlyData,
boolean reversed) throws HsqlException {
closeTextCache(table);
if (database.getType() != DatabaseURL.S_RES
&& !properties.isPropertyTrue(
HsqlDatabaseProperties.textdb_allow_full_path)) {
if (source.indexOf("..") != -1) {
throw (Trace.error(Trace.ACCESS_IS_DENIED, source));
}
String path = new File(
new File(
database.getPath()
+ ".properties").getAbsolutePath()).getParent();
if (path != null) {
source = path + File.separator + source;
}
}
TextCache c;
int type;
if (reversed) {
c = new TextCache(table, source);
} else {
c = new TextCache(table, source);
}
c.open(readOnlyData || filesReadOnly);
textCacheList.put(table.getName(), c);
return c;
}
void closeTextCache(Table table) throws HsqlException {
TextCache c = (TextCache) textCacheList.remove(table.getName());
if (c != null) {
c.close(true);
}
}
private void closeAllTextCaches(boolean compact) throws HsqlException {
Iterator it = textCacheList.values().iterator();
while (it.hasNext()) {
if (compact) {
((TextCache) it.next()).purge();
} else {
((TextCache) it.next()).close(true);
}
}
}
private void reopenAllTextCaches() throws HsqlException {
Iterator it = textCacheList.values().iterator();
while (it.hasNext()) {
((TextCache) it.next()).reopen();
}
}
private boolean isAnyTextCacheModified() {
Iterator it = textCacheList.values().iterator();
while (it.hasNext()) {
if (((TextCache) it.next()).isFileModified()) {
return true;
}
}
return false;
}
}
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