/** Do not call this method directly - it should only be invoked from a Prevayler command. */
int prepare(TxnState aState) throws UnknownTransactionException, IOException {
/*
Do we know about this transaction?
If we don't we've failed and are now doing recovery so we must
re-insert the state.
*/
boolean needsRestore = (getState(aState.getId()) == null);
if (needsRestore) {
theTxns.put(aState.getId(), aState);
}
return aState.prepare(needsRestore);
}
private void readObject(ObjectInputStream anIn) throws IOException, ClassNotFoundException {
boolean isUpgrade = false;
theTxns = new ConcurrentHashMap();
theSnapshotContributors = new ArrayList();
Object myFirst = anIn.readObject();
/*
If there's no LogVersion, chances are we're looking at a pre 1.13
log format - upgrade is simple as there's no LogVersion and there
will be no user checkpoint data so we just ignore those fields.
*/
if (!(myFirst instanceof LogVersion)) {
TxnDispatcher.theLogger.log(Level.SEVERE, "Upgrading old transaction log");
isUpgrade = true;
theClock = (AlarmClock) myFirst;
} else {
LogVersion myVersion = (LogVersion) myFirst;
if (!myVersion.equals(LogVersion.VERSION))
throw new IOException("Yikes - log versions don't match - upgrade?" + myVersion);
theClock = (AlarmClock) anIn.readObject();
}
int myNumRecords = anIn.readInt();
for (int i = 0; i < myNumRecords; i++) {
TxnState myState = (TxnState) anIn.readObject();
try {
myState.prepare(true);
} catch (UnknownTransactionException aUTE) {
IOException anIOE = new IOException("Failed to recover prepare");
anIOE.initCause(aUTE);
throw anIOE;
}
theTxns.put(myState.getId(), myState);
}
if (isUpgrade) theSnapshotContributions = new Serializable[0];
else theSnapshotContributions = (Serializable[]) anIn.readObject();
}