com.sun.jts.CosTransactions.LogFile Maven / Gradle / Ivy
/*
* Copyright (c) 1997, 2018 Oracle and/or its affiliates. All rights reserved.
* Copyright (c) 1995-1997 IBM Corp. All rights reserved.
*
* This program and the accompanying materials are made available under the
* terms of the Eclipse Public License v. 2.0, which is available at
* http://www.eclipse.org/legal/epl-2.0.
*
* This Source Code may also be made available under the following Secondary
* Licenses when the conditions for such availability set forth in the
* Eclipse Public License v. 2.0 are satisfied: GNU General Public License,
* version 2 with the GNU Classpath Exception, which is available at
* https://www.gnu.org/software/classpath/license.html.
*
* SPDX-License-Identifier: EPL-2.0 OR GPL-2.0 WITH Classpath-exception-2.0
*/
//----------------------------------------------------------------------------
//
// Module: LogFile.java
//
// Description: Log File interface.
//
// Product: com.sun.jts.CosTransactions
//
// Author: Simon Holdsworth
//
// Date: March, 1997
//----------------------------------------------------------------------------
package com.sun.jts.CosTransactions;
import com.sun.jts.utils.LogFormatter;
import com.sun.logging.LogDomains;
import java.util.Vector;
import java.util.logging.Level;
import java.util.logging.Logger;
/**The LogFile interface provides operations that control the
* individual log entries that make up the physical log. It allows writing to
* the log and reading from the log, along with the capability to close a
* portion of the log. Different physical logs can be placed on the system
* with only minor changes to the methods contained in this class.
*
* @version 0.01
*
* @author Simon Holdsworth, IBM Corporation
*
* @see
*/
//----------------------------------------------------------------------------
// CHANGE HISTORY
//
// Version By Change Description
// 0.01 SAJH Initial implementation.
//-----------------------------------------------------------------------------
class LogFile {
/**Constants for write types.
*/
final static int UNFORCED = 0;
final static int FORCED = 1;
/**Constants for log record types.
*/
final static int NORMAL = 0;
final static int KEYPOINT_START = 1;
final static int KEYPOINT_END = 2;
final static int REWRITE = 3;
/*
Logger to log transaction messages
*/
static Logger _logger = LogDomains.getLogger(LogFile.class, LogDomains.TRANSACTION_LOGGER);
/**The handle of the log file.
*/
LogHandle handle = null;
/**LogFile constructor.
*
* @param LogHandle
*
* @return
*
* @see
*/
LogFile( LogHandle handle ) {
// Set up the instance variables to those values passed in.
this.handle = handle;
}
/**Writes a log record to the physical log.
*
* Supports either a force or unforced option with force requiring an immediate
* write to the log and unforced keeping the data until a force is done somewhere
* else in the log service.
*
* The LSN of the written log record is an output parameter.
*
* Returns true if the write completed successfully and false if the write
* did not complete.
*
* @param writeType Forced/non-forced write indicator.
* @param record Log record data.
* @param recordType Log record type.
* @param recordLSN LSN of the written record.
*
* @return
*
* @see
*/
synchronized boolean write( int writeType,
byte[] record,
int recordType,
LogLSN recordLSN ) {
boolean result = true;
// Write the record.
// Set the result based on return code from log write.
try {
LogLSN resultLSN = handle.writeRecord(record,recordType,
(writeType==LogFile.FORCED ? LogHandle.FORCE : LogHandle.BUFFER));
if( recordLSN != null )
recordLSN.copy(resultLSN);
} catch( LogException le ) {
_logger.log(Level.SEVERE,"jts.log_error",le.toString());
String msg = LogFormatter.getLocalizedMessage(_logger,"jts.log_error",
new java.lang.Object[] {le.toString()});
throw (org.omg.CORBA.INTERNAL) (new org.omg.CORBA.INTERNAL(msg)).initCause(le);
//if( recordLSN != null )
//recordLSN.copy(LogLSN.NULL_LSN);
//result = false;
}
return result;
}
/**Informs the log that all log records older than the one with the given LSN
* are no longer required.
*
* The checkpoint marks the point where log processing will begin in the event
* of recovery processing. This will generally correspond to the last record
* before a successful keypoint.
*
* @param firstLSN
*
* @return
*
* @see
*/
synchronized boolean checkpoint( LogLSN firstLSN ) {
boolean result = true;
LogLSN checkLSN;
// If the LSN passed in is NULL, assume it means the head.
if( firstLSN.isNULL() )
checkLSN = new LogLSN(LogLSN.HEAD_LSN);
else
checkLSN = new LogLSN(firstLSN);
// Checkpoint the log.
try {
handle.checkLSN(checkLSN);
handle.truncate(checkLSN,LogHandle.TAIL_NOT_INCLUSIVE);
} catch( LogException le ) {
result = false;
}
return result;
}
/**Writes the given information in the restart record for the log.
*
*
* @param record The information to be written.
*
* @return Indicates success of the operation.
*
* @see
*/
synchronized boolean writeRestart( byte[] record ) {
boolean result = false;
// Write the restart information.
try {
handle.writeRestart(record);
result = true;
} catch( LogException le ) {
result = false;
}
return result;
}
/**Reads the restart record from the log.
*
*
* @param
*
* @return The restart record.
*
* @see
*/
synchronized byte[] readRestart() {
byte[] result = null;
// Write the restart information.
try {
result = handle.readRestart();
} catch( LogException le ) {
}
return result;
}
/**Closes the portion of the log defined by the LogFile object reference.
*
* Deletes the associated logfile if requested.
*
* @param deleteFile
*
* @return
*
* @see
*/
synchronized boolean close( boolean deleteFile ) {
boolean result = true;
// Call to close the physical log.
try {
handle.closeFile(deleteFile);
} catch( LogException le ) {
result = false;
}
return result;
}
/**Returns all of the log records written to the log since the last checkpoint.
*
* The caller is responsible for freeing the sequence storage.
*
* If the log is empty, an empty sequence is returned.
*
* The result is returned in a Vector as we do not know ahead of time how
* many log records there are.
*
* @param
*
* @return The log records.
*
* @see
*/
synchronized Vector getLogRecords() {
Vector logRecords = new Vector();
boolean keypointEndFound = false;
LogCursor logCursor;
// Open a cursor for use with the log.
try {
logCursor = handle.openCursor(LogLSN.HEAD_LSN,LogLSN.TAIL_LSN);
} catch( LogException le ) {
return new Vector();
}
// Read each log record from the physical log and place in temporary queue.
try {
LogLSN lsn = new LogLSN();
int[] recordType = new int[1];
for(;;) {
byte[] logRecord = logCursor.readCursor(recordType,lsn);
// Process the log record depending on its type.
switch( recordType[0] ) {
// If the record is a keypoint start, and we have found the end of the
// keypoint, then we can stop processing the log. If the end has not been
// found then a failure must have occurred during the keypoint operation,
// so we must continue to process the log.
// We do not do anything with the contents of the keypoint start record.
case LogFile.KEYPOINT_START :
if( keypointEndFound )
throw new LogException(null,LogException.LOG_END_OF_CURSOR,2);
break;
// If the record is a keypoint end, remember this so that we can stop when
// we find the start of the keypoint.
// We do not do anything with the contents of the keypoint end record.
case LogFile.KEYPOINT_END :
keypointEndFound = true;
break;
// For a normal log record, add the records to the list.
// For a rewritten record, only add the record to the list if the
// keypoint end record has been found.
case LogFile.NORMAL :
case LogFile.REWRITE :
if( (recordType[0] == LogFile.NORMAL) || keypointEndFound )
logRecords.addElement(logRecord);
break;
// Any other type of log record is ignored.
default :
break;
}
}
} catch( LogException le ) {
// If any exception other that END_OF_CURSOR was thrown, then return an empty
// list.
if( le.errorCode != LogException.LOG_END_OF_CURSOR ) {
return new Vector();
}
}
// Close the cursor.
try {
handle.closeCursor(logCursor);
} catch( LogException le ) {
}
return logRecords;
}
/**Dumps the state of the object.
*
* @param
*
* @return
*
* @see
*/
void dump() {
//! somtrDump_OBJECT_HEADER;
// Dump all of the instance variables in the LogFile object, without going
// any further down object references.
}
}