SequencingCallbackImpl getCallbackImpl(AbstractSession writeSession, Accessor accessor) {
SequencingCallbackImpl seqCallbackImpl;
if (writeSession.hasExternalTransactionController()) {
// note that controller obtained from writeSession (not from ownerSession) -
// the difference is important in case of ownerSession being a member of SessionBroker:
// in that case only writeSession (which is either ClientSession or DatabaseSession) always
// has
// the correct controller.
seqCallbackImpl =
(SequencingCallbackImpl)
writeSession
.getExternalTransactionController()
.getActiveSequencingCallback(getOwnerSession(), getSequencingCallbackFactory());
} else {
seqCallbackImpl =
(SequencingCallbackImpl) accessor.getSequencingCallback(getSequencingCallbackFactory());
}
return seqCallbackImpl;
}
public Object getNextValue(Sequence sequence, AbstractSession writeSession) {
String seqName = sequence.getName();
if (sequence.getPreallocationSize() > 1) {
Queue sequencesForName = getPreallocationHandler().getPreallocated(seqName);
// First try to get the next sequence value without locking.
Object sequenceValue = sequencesForName.poll();
if (sequenceValue != null) {
return sequenceValue;
}
// Sequences are empty, so must lock and allocate next batch of sequences.
acquireLock(seqName);
try {
sequenceValue = sequencesForName.poll();
if (sequenceValue != null) {
return sequenceValue;
}
// note that accessor.getLogin().shouldUseExternalTransactionController()
// should be set to false
Accessor accessor = getConnectionHandler().acquireAccessor();
try {
accessor.beginTransaction(writeSession);
try {
Vector sequences = sequence.getGeneratedVector(accessor, writeSession);
accessor.commitTransaction(writeSession);
// Remove the first value before adding to the global cache to ensure this thread gets
// one.
sequenceValue = sequences.remove(0);
// copy remaining values to global cache.
getPreallocationHandler().setPreallocated(seqName, sequences);
logDebugPreallocation(seqName, sequenceValue, sequences);
} catch (RuntimeException ex) {
try {
// make sure to rollback the transaction we've begun
accessor.rollbackTransaction(writeSession);
} catch (Exception rollbackException) {
// ignore rollback exception
}
// don't eat the original exception
throw ex;
}
} finally {
getConnectionHandler().releaseAccessor(accessor);
}
} finally {
releaseLock(seqName);
}
return sequenceValue;
} else {
// note that accessor.getLogin().shouldUseExternalTransactionController()
// should be set to false
Accessor accessor = getConnectionHandler().acquireAccessor();
try {
accessor.beginTransaction(writeSession);
try {
// preallocation size is 1 - just return the first (and only) element of the allocated
// vector.
Object sequenceValue =
sequence.getGeneratedVector(accessor, writeSession).firstElement();
accessor.commitTransaction(writeSession);
return sequenceValue;
} catch (RuntimeException ex) {
try {
// make sure to rollback the transaction we've begun
accessor.rollbackTransaction(writeSession);
} catch (Exception rollbackException) {
// ignore rollback exception
}
// don't eat the original exception
throw ex;
}
} finally {
getConnectionHandler().releaseAccessor(accessor);
}
}
}