protected synchronized ReadNack apply()

in accord-core/src/main/java/accord/messages/ReadTxnData.java [145:190]

40 lines of code
13 McCabe index (conditional complexity)


    protected synchronized ReadNack apply(SafeCommandStore safeStore, SafeCommand safeCommand)
    {
        if (state != State.PENDING)
            return null;

        Command command = safeCommand.current();
        Status status = command.status();

        logger.trace("{}: setting up read with status {} on {}", txnId, status, safeStore);
        switch (status) {
            default:
                throw new AssertionError();
            case Committed:
            case NotWitnessed:
            case PreAccepted:
            case Accepted:
            case AcceptedInvalidate:
            case PreCommitted:
                waitingOn.set(safeStore.commandStore().id());
                ++waitingOnCount;
                safeCommand.addListener(this);

                if (status == Committed)
                {
                    return null;
                }
                else
                {
                    safeStore.progressLog().waiting(txnId, Committed.minKnown, readScope.toUnseekables());
                    return NotCommitted;
                }


            case PreApplied:
            case Applied:
            case Invalidated:
                state = State.OBSOLETE;
                return Redundant;

            case ReadyToExecute:
                waitingOn.set(safeStore.commandStore().id());
                ++waitingOnCount;
                maybeRead(safeStore, safeCommand);
                return null;
        }
    }