/**
* Get the last applied event. We first try the disk log then if that is absent try the catalog.
* If there is nothing there we must be starting from scratch and return null.
*
* @return An event header or null if log is newly initialized
* @throws InterruptedException
* @throws ReplicatorException
*/
public ReplDBMSHeader getLastAppliedEvent() throws ReplicatorException, InterruptedException {
// Look for maximum sequence number in log and use that if available.
if (diskLog != null) {
long maxSeqno = diskLog.getMaxSeqno();
if (maxSeqno > -1) {
LogConnection conn = null;
try {
// Try to connect and find the event.
THLEvent thlEvent = null;
conn = diskLog.connect(true);
conn.seek(maxSeqno);
while ((thlEvent = conn.next(false)) != null && thlEvent.getSeqno() == maxSeqno) {
// Return only the last fragment.
if (thlEvent.getLastFrag()) {
ReplEvent event = thlEvent.getReplEvent();
if (event instanceof ReplDBMSEvent) return (ReplDBMSEvent) event;
else if (event instanceof ReplControlEvent)
return ((ReplControlEvent) event).getHeader();
}
}
// If we did not find the last fragment of the event
// we need to warn somebody.
if (thlEvent != null)
logger.warn("Unable to find last fragment of event: seqno=" + maxSeqno);
} finally {
conn.release();
}
}
}
// If that does not work, try the catalog.
if (catalog != null) {
return catalog.getLastEvent();
}
// If we get to this point, the log is newly initialized and there is no
// such event to return.
return null;
}
/**
* Disconnect from the log. Adapters must call this to free resources and avoid leaks.
*
* @param client a Disk log client to be disconnected
* @throws ReplicatorException
*/
public void disconnect(LogConnection client) throws ReplicatorException {
client.release();
}