org.objectweb.cjdbc.controller.recoverylog
Class LoggerThread

java.lang.Object
  java.lang.Thread
      org.objectweb.cjdbc.controller.recoverylog.LoggerThread

All Implemented Interfaces:

java.lang.Runnable

public class LoggerThread

extends java.lang.Thread

Logger thread for the RecoveryLog.

Version:

1.0

Author:

Emmanuel Cecchet

Field Summary

private boolean	killed
private Trace	logger
private java.util.LinkedList	logQueue
private java.sql.PreparedStatement	logStmt
private RecoveryLog	recoveryLog
private java.sql.PreparedStatement	unlogStmt

Fields inherited from class java.lang.Thread

MAX_PRIORITY, MIN_PRIORITY, NORM_PRIORITY

Constructor Summary

LoggerThread(RecoveryLog log)
Creates a new LoggerThread object

Method Summary

void	deleteCheckpointTable() Delete all entries from the CheckpointTable.
void	deleteLogEntriesBeforeId(long oldId) Delete all LogEntries with an identifier lower than oldId (inclusive).
Trace	getLogger() Returns the logger value.
java.sql.PreparedStatement	getLogPreparedStatement() Return a PreparedStatement to log an entry as follows: INSERT INTO LogTableName VALUES(?
boolean	getLogQueueIsEmpty() Tells whether there are pending logs
RecoveryLog	getRecoveryLog() Returns the recoveryLog value.
java.sql.PreparedStatement	getUnlogPreparedStatement() Return a PreparedStatement to unlog an entry as follows: DELETE FROM LogTableName WHERE id=?
void	invalidateLogStatements() Invalidate both logStmt and unlogStmt so that they can be renewed from a fresh connection.
void	log(LogEvent logObject) Log a write-query into the recovery log.
void	putBackAtHeadOfQueue(LogEvent event) Put back a log entry at the head of the queue in case a problem happened with this entry and we need to retry it right away.
void	removeQueriesOfTransactionFromQueue(long tid) Remove all queries that have not been logged yet and belonging to the specified transaction.
void	removeRollbackedTransaction(long transactionId) Remove a transaction that has rollbacked (no check is made if the transaction has really rollbacked or not).
void	run() Log the requests from queue until the thread is explicetly killed.
void	shiftLogEntriesIds(long shiftValue) Shift LogEntries identifiers from the specified value (value is added to existing identifiers).
void	shutdown() Shutdown the current thread.
void	storeCheckpoint(java.lang.String checkpointName, long checkpointId) Looks like a copy paste from RecoveryLog#storeCheckpoint(String, long), but does not wait for queue completion to store the checkpoint.

Methods inherited from class java.lang.Thread

activeCount, checkAccess, countStackFrames, currentThread, destroy, dumpStack, enumerate, getContextClassLoader, getName, getPriority, getThreadGroup, holdsLock, interrupt, interrupted, isAlive, isDaemon, isInterrupted, join, join, join, resume, setContextClassLoader, setDaemon, setName, setPriority, sleep, sleep, start, stop, stop, suspend, toString, yield

Methods inherited from class java.lang.Object

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

Field Detail

killed

private boolean killed

logQueue

private java.util.LinkedList logQueue

logger

private Trace logger

logStmt

private java.sql.PreparedStatement logStmt

unlogStmt

private java.sql.PreparedStatement unlogStmt

recoveryLog

private RecoveryLog recoveryLog

Constructor Detail

LoggerThread

public LoggerThread(RecoveryLog log)

Creates a new LoggerThread object

Parameters:

log - the RecoveryLog that instanciates this thread

Method Detail

getLogger

public Trace getLogger()

Returns the logger value.

Returns:

Returns the logger.

getLogQueueIsEmpty

public boolean getLogQueueIsEmpty()

Tells whether there are pending logs

Returns:

true if no more jobs in the log queue

getLogPreparedStatement

public java.sql.PreparedStatement getLogPreparedStatement()
                                                   throws java.sql.SQLException

Return a PreparedStatement to log an entry as follows:

INSERT INTO LogTableName VALUES(?,?,?,?)

Returns:

a PreparedStatement

Throws:

java.sql.SQLException - if an error occurs

getRecoveryLog

public RecoveryLog getRecoveryLog()

Returns the recoveryLog value.

Returns:

Returns the recoveryLog.

getUnlogPreparedStatement

public java.sql.PreparedStatement getUnlogPreparedStatement()
                                                     throws java.sql.SQLException

Return a PreparedStatement to unlog an entry as follows:

DELETE FROM LogTableName WHERE id=? AND vlogin=? AND SqlColumnName=? AND transaction_id=?

Returns:

a PreparedStatement

Throws:

java.sql.SQLException - if an error occurs

invalidateLogStatements

public void invalidateLogStatements()

Invalidate both logStmt and unlogStmt so that they can be renewed from a fresh connection.

See Also:

getLogPreparedStatement(), getUnlogPreparedStatement()

log

public void log(LogEvent logObject)

Log a write-query into the recovery log. This posts the specified logObject (query) into this loggerThread queue. The actual write to the recoverly-log db is performed asynchronously by the thread.

Parameters:

logObject - the log event to be processed

putBackAtHeadOfQueue

public void putBackAtHeadOfQueue(LogEvent event)

Put back a log entry at the head of the queue in case a problem happened with this entry and we need to retry it right away.

Parameters:

event - the event to be used next by the logger thread.

removeQueriesOfTransactionFromQueue

public void removeQueriesOfTransactionFromQueue(long tid)

Remove all queries that have not been logged yet and belonging to the specified transaction.

Parameters:

tid - transaction id to rollback

removeRollbackedTransaction

public void removeRollbackedTransaction(long transactionId)
                                 throws java.sql.SQLException

Remove a transaction that has rollbacked (no check is made if the transaction has really rollbacked or not).

Parameters:

transactionId - the id of the transaction

Throws:

java.sql.SQLException - if an error occurs

deleteCheckpointTable

public void deleteCheckpointTable()
                           throws java.sql.SQLException

Delete all entries from the CheckpointTable.

Throws:

java.sql.SQLException - if an error occurs

storeCheckpoint

public void storeCheckpoint(java.lang.String checkpointName,
                            long checkpointId)
                     throws java.sql.SQLException

Looks like a copy paste from RecoveryLog#storeCheckpoint(String, long), but does not wait for queue completion to store the checkpoint. Moreover, in case of error, additionely closes and invalidates log and unlog statements (internal) before calling RecoveryLog#invalidateInternalConnection().

Parameters:

checkpointName - checkpoint name to insert

checkpointId - checkpoint request identifier

Throws:

java.sql.SQLException - if a database access error occurs

See Also:

RecoveryLog.storeCheckpoint(String, long), invalidateLogStatements()

deleteLogEntriesBeforeId

public void deleteLogEntriesBeforeId(long oldId)
                              throws java.sql.SQLException

Delete all LogEntries with an identifier lower than oldId (inclusive). oldId is normally derived from a checkpoint name, which marks the last request before the checkpoint.

Parameters:

oldId - the id up to which entries should be removed.

Throws:

java.sql.SQLException - if an error occurs

shiftLogEntriesIds

public void shiftLogEntriesIds(long shiftValue)
                        throws java.sql.SQLException

Shift LogEntries identifiers from the specified value (value is added to existing identifiers).

Parameters:

shiftValue - the value to shift

Throws:

java.sql.SQLException - if an error occurs

run

public void run()

Log the requests from queue until the thread is explicetly killed. The logger used is the one of the RecoveryLog.

shutdown

public void shutdown()

Shutdown the current thread.