org.neo4j.kernel.impl.transaction.xaframework
Class XaLogicalLog

java.lang.Object
  org.neo4j.kernel.impl.transaction.xaframework.XaLogicalLog

All Implemented Interfaces:

LogExtractor.LogLoader

Direct Known Subclasses:

InterceptingXaLogicalLog

public class XaLogicalLog
extends Object
implements LogExtractor.LogLoader

XaLogicalLog is a transaction and logical log combined. In this log information about the transaction (such as started, prepared and committed) will be written. All commands participating in the transaction will also be written to the log.

Normally you don't have to do anything with this log except open it after it has been instanciated (see XaContainer). The only method that may be of use when implementing a XA compatible resource is the getCurrentTxIdentifier(). Leave everything else be unless you know what you're doing.

When the log is opened it will be scaned for uncompleted transactions and those transactions will be re-created. When scan of log is complete all transactions that hasn't entered prepared state will be marked as done (implies rolledback) and dropped. All transactions that have been prepared will be held in memory until the transaction manager tells them to commit. Transaction that already started commit but didn't get flagged as done will be re-committed.

Nested Class Summary

protected class

XaLogicalLog.LogDeserializer

Field Summary

static int

MASTER_ID_REPRESENTING_NO_MASTER

Method Summary

void	applyTransaction(ReadableByteChannel byteChannel)
void	applyTransactionWithoutTxId(ReadableByteChannel byteChannel, long nextTxId)
void	close()
void	commitOnePhase(int identifier, long txId)
void	commitTwoPhase(int identifier, long txId)
boolean	deleteLogicalLog(long version)
void	done(int identifier)
String	getBaseFileName()
int	getCurrentTxIdentifier() If the current thread is committing a transaction the identifier of that XaTransaction can be obtained invoking this method.
String	getFileName(long version)
static long	getHighestHistoryLogVersion(File storeDir, String baseFileName)
long	getHighestLogVersion()
Pattern	getHistoryFileNamePattern()
static Pattern	getHistoryFileNamePattern(String baseFileName)
static long	getHistoryLogVersion(File historyLogFile)
protected XaLogicalLog.LogDeserializer	getLogDeserializer(ReadableByteChannel byteChannel)
LogExtractor	getLogExtractor(long startTxId, long endTxIdHint)
ReadableByteChannel	getLogicalLog(long version)
ReadableByteChannel	getLogicalLog(long version, long position)
long	getLogicalLogLength(long version)
ReadableByteChannel	getLogicalLogOrMyselfCommitted(long version, long position)
long	getLogicalLogTargetSize()
Pair<Integer,Long>	getMasterForCommittedTransaction(long txId)
ReadableByteChannel	getPreparedTransaction(int identifier)
void	getPreparedTransaction(int identifier, LogBuffer targetBuffer)
boolean	hasLogicalLog(long version)
boolean	isLogsAutoRotated()
boolean	isLogsKept()
void	prepare(int identifier)
long	rotate() Rotates this logical log.
boolean	scanIsComplete()
void	setAutoRotateLogs(boolean autoRotate)
void	setKeepLogs(boolean keep)
void	setLogicalLogTargetSize(long size)
int	start(Xid xid, int masterId, int myId)
boolean	wasNonClean()
void	writeCommand(XaCommand command, int identifier)
void	writeStartEntry(int identifier)

Methods inherited from class java.lang.Object

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

Field Detail

MASTER_ID_REPRESENTING_NO_MASTER

public static final int MASTER_ID_REPRESENTING_NO_MASTER

See Also:

Constant Field Values

Method Detail

scanIsComplete

public boolean scanIsComplete()

start

public int start(Xid xid,
                 int masterId,
                 int myId)
          throws XAException

Throws:

XAException

writeStartEntry

public void writeStartEntry(int identifier)
                     throws XAException

Throws:

XAException

prepare

public void prepare(int identifier)
             throws XAException

Throws:

XAException

commitOnePhase

public void commitOnePhase(int identifier,
                           long txId)
                    throws XAException

Throws:

XAException

done

public void done(int identifier)
          throws XAException

Throws:

XAException

commitTwoPhase

public void commitTwoPhase(int identifier,
                           long txId)
                    throws XAException

Throws:

XAException

writeCommand

public void writeCommand(XaCommand command,
                         int identifier)
                  throws IOException

Throws:

IOException

close

public void close()
           throws IOException

Throws:

IOException

getCurrentTxIdentifier

public int getCurrentTxIdentifier()

If the current thread is committing a transaction the identifier of that XaTransaction can be obtained invoking this method.

Returns:

the identifier of the transaction committing or -1 if current thread isn't committing any transaction

getLogicalLog

public ReadableByteChannel getLogicalLog(long version)
                                  throws IOException

Throws:

IOException

getLogicalLog

public ReadableByteChannel getLogicalLog(long version,
                                         long position)
                                  throws IOException

Throws:

IOException

getPreparedTransaction

public ReadableByteChannel getPreparedTransaction(int identifier)
                                           throws IOException

Throws:

IOException

getPreparedTransaction

public void getPreparedTransaction(int identifier,
                                   LogBuffer targetBuffer)
                            throws IOException

Throws:

IOException

getLogExtractor

public LogExtractor getLogExtractor(long startTxId,
                                    long endTxIdHint)
                             throws IOException

Throws:

IOException

getMasterForCommittedTransaction

public Pair<Integer,Long> getMasterForCommittedTransaction(long txId)
                                                    throws IOException

Throws:

IOException

getLogicalLogOrMyselfCommitted

public ReadableByteChannel getLogicalLogOrMyselfCommitted(long version,
                                                          long position)
                                                   throws IOException

Specified by:

getLogicalLogOrMyselfCommitted in interface LogExtractor.LogLoader

Throws:

IOException

getLogicalLogLength

public long getLogicalLogLength(long version)

hasLogicalLog

public boolean hasLogicalLog(long version)

deleteLogicalLog

public boolean deleteLogicalLog(long version)

getLogDeserializer

protected XaLogicalLog.LogDeserializer getLogDeserializer(ReadableByteChannel byteChannel)

applyTransactionWithoutTxId

public void applyTransactionWithoutTxId(ReadableByteChannel byteChannel,
                                        long nextTxId)
                                 throws IOException

Throws:

IOException

applyTransaction

public void applyTransaction(ReadableByteChannel byteChannel)
                      throws IOException

Throws:

IOException

rotate

public long rotate()
            throws IOException

Rotates this logical log. The pending transactions are moved over to a new log buffer and the internal structures updated to reflect the new file offsets. The old log is either renamed or thrown away, depending on the value of the last call to setKeepLogs(boolean). Additional side effects include a force() of the store and increment of the log version. Outline of how rotation happens:

The store is flushed - can't have pending changes if there is no log that contains the commands

Switch current filename with old and check that new doesn't exist and the versioned backup isn't there also

Force the current log buffer

Create new log file, write header

Find the position for the first pending transaction. From there start scanning, transferring the entries of the pending transactions from the old log to the new, updating the start positions in the in-memory tables

Keep or delete old log

Update the log version stored

Instantiate the new log buffer

Returns:

the last tx in the produced log

Throws:

IOException - I/O error.

setKeepLogs

public void setKeepLogs(boolean keep)

isLogsKept

public boolean isLogsKept()

setAutoRotateLogs

public void setAutoRotateLogs(boolean autoRotate)

isLogsAutoRotated

public boolean isLogsAutoRotated()

setLogicalLogTargetSize

public void setLogicalLogTargetSize(long size)

getLogicalLogTargetSize

public long getLogicalLogTargetSize()

getFileName

public String getFileName(long version)

getBaseFileName

public String getBaseFileName()

getHistoryFileNamePattern

public Pattern getHistoryFileNamePattern()

getHistoryFileNamePattern

public static Pattern getHistoryFileNamePattern(String baseFileName)

getHistoryLogVersion

public static long getHistoryLogVersion(File historyLogFile)

getHighestHistoryLogVersion

public static long getHighestHistoryLogVersion(File storeDir,
                                               String baseFileName)

wasNonClean

public boolean wasNonClean()

getHighestLogVersion

public long getHighestLogVersion()

Specified by:

getHighestLogVersion in interface LogExtractor.LogLoader