Package bitronix.tm.journal

Class TransactionLogCursor

java.lang.Object

bitronix.tm.journal.TransactionLogCursor

public class TransactionLogCursor
extends Object

Used to read TransactionLogRecord objects from a log file.

Author:

lorban

Constructor Summary

Constructors

Constructor	Description
TransactionLogCursor(File file)	Create a TransactionLogCursor that will read from the specified file.

Method Summary

Modifier and Type	Method	Description
void	close()	Close the cursor and the underlying file
TransactionLogRecord	readLog()	Fetch the next TransactionLogRecord from log, recalculating the CRC and checking it against the stored one.
TransactionLogRecord	readLog(boolean skipCrcCheck)	Fetch the next TransactionLogRecord from log.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Details

TransactionLogCursor

public TransactionLogCursor(File file)
                     throws IOException

Create a TransactionLogCursor that will read from the specified file. This opens a new read-only file descriptor.

Parameters:

file - the file to read logs from

Throws:

IOException - if an I/O error occurs.

Method Details

readLog

public TransactionLogRecord readLog()
                             throws IOException

Fetch the next TransactionLogRecord from log, recalculating the CRC and checking it against the stored one. InvalidChecksumException is thrown if the check fails.

Returns:

the TransactionLogRecord or null if the end of the log file has been reached

Throws:

IOException - if an I/O error occurs.

readLog

public TransactionLogRecord readLog(boolean skipCrcCheck)
                             throws IOException

Fetch the next TransactionLogRecord from log.

Parameters:

skipCrcCheck - if set to false, the method will thow an InvalidChecksumException if the CRC on disk does not match the recalculated one. Otherwise, the CRC is not recalculated nor checked agains the stored one.

Returns:

the TransactionLogRecord or null if the end of the log file has been reached

Throws:

IOException - if an I/O error occurs.

close

public void close()
           throws IOException

Close the cursor and the underlying file

Throws:

IOException - if an I/O error occurs.