Mercurial > hg > blitz_condensed
diff src/org/dancres/blitz/txn/OpCountingCheckpointTrigger.java @ 0:3dc0c5604566
Initial checkin of blitz 2.0 fcs - no installer yet.
author | Dan Creswell <dan.creswell@gmail.com> |
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date | Sat, 21 Mar 2009 11:00:06 +0000 |
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--- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/src/org/dancres/blitz/txn/OpCountingCheckpointTrigger.java Sat Mar 21 11:00:06 2009 +0000 @@ -0,0 +1,95 @@ +package org.dancres.blitz.txn; + +import java.io.IOException; + +import java.util.logging.Level; + +import org.dancres.blitz.ActiveObjectRegistry; + +/** + A checkpoint trigger that fires off a checkpoint every time a certain + number of operations have been logged. + */ +class OpCountingCheckpointTrigger implements CheckpointTrigger, Runnable { + private Checkpointer theCheckpointer; + + private int theCommandThreshold; + + private Thread theCheckpointThread; + private boolean stopCheckpointing = false; + private int theLogCount = 0; + + OpCountingCheckpointTrigger(Checkpointer aCheckpointer, + int aCommandThreshold) { + theCheckpointer = aCheckpointer; + theCommandThreshold = aCommandThreshold; + + ActiveObjectRegistry.add(this); + } + + public void loggedCommand() { + synchronized(this) { + ++theLogCount; + + if (theLogCount == theCommandThreshold) { + theLogCount = 0; + notify(); + } + } + } + + public void begin() { + theCheckpointThread = new Thread(this, "Checkpointer"); + theCheckpointThread.start(); + } + + public void halt() { + synchronized(this) { + stopCheckpointing = true; + notify(); + } + + try { + theCheckpointThread.join(); + theCheckpointThread = null; + } catch (InterruptedException anIE) { + TxnManager.theLogger.log(Level.SEVERE, + "Failed to wait for checkpointer", + anIE); + } + } + + public void run() { + boolean timeToExit = false; + + while(!timeToExit) { + synchronized(this) { + if (!stopCheckpointing) { + try { + wait(); + } catch (InterruptedException anIE) { + TxnManager.theLogger.log(Level.INFO, + "Checkpointer interrupted", + anIE); + } + } + + timeToExit = stopCheckpointing; + } + + if (!timeToExit) { + try { + theCheckpointer.sync(); + } catch (IOException anIOE) { + TxnManager.theLogger.log(Level.SEVERE, + "Checkpoint failed", + anIOE); + } + } + } + } + + public boolean checkpointsDisabled() { + return false; + } +}