Examples with HelixStateTransitionCancellationHandler org.apache.helix.messaging.handling.HelixStateTransitionCancellationHandler used on opensource projects

Example 1 with HelixStateTransitionCancellationHandler

use of org.apache.helix.messaging.handling.HelixStateTransitionCancellationHandler in project helix by apache.

the class HelixStateMachineEngine method createHandler.

@Override
public MessageHandler createHandler(Message message, NotificationContext context) {
    String type = message.getMsgType();
    if (!type.equals(MessageType.STATE_TRANSITION.name()) && !type.equals(MessageType.STATE_TRANSITION_CANCELLATION.name())) {
        throw new HelixException("Expect state-transition message type, but was " + message.getMsgType() + ", msgId: " + message.getMsgId());
    }
    String partitionKey = message.getPartitionName();
    String stateModelName = message.getStateModelDef();
    String resourceName = message.getResourceName();
    String sessionId = message.getTgtSessionId();
    int bucketSize = message.getBucketSize();
    if (stateModelName == null) {
        logger.error("Fail to create msg-handler because message does not contain stateModelDef. msgId: " + message.getId());
        return null;
    }
    String factoryName = message.getStateModelFactoryName();
    if (factoryName == null) {
        factoryName = HelixConstants.DEFAULT_STATE_MODEL_FACTORY;
    }
    StateModelFactory<? extends StateModel> stateModelFactory = getStateModelFactory(stateModelName, factoryName);
    if (stateModelFactory == null) {
        logger.warn("Fail to create msg-handler because cannot find stateModelFactory for model: " + stateModelName + " using factoryName: " + factoryName + " for resource: " + resourceName);
        return null;
    }
    // check if the state model definition exists and cache it
    if (!_stateModelDefs.containsKey(stateModelName)) {
        HelixDataAccessor accessor = _manager.getHelixDataAccessor();
        Builder keyBuilder = accessor.keyBuilder();
        StateModelDefinition stateModelDef = accessor.getProperty(keyBuilder.stateModelDef(stateModelName));
        if (stateModelDef == null) {
            throw new HelixException("fail to create msg-handler because stateModelDef for " + stateModelName + " does NOT exist");
        }
        _stateModelDefs.put(stateModelName, stateModelDef);
    }
    if (message.getBatchMessageMode() == false) {
        String initState = _stateModelDefs.get(message.getStateModelDef()).getInitialState();
        StateModel stateModel = stateModelFactory.getStateModel(resourceName, partitionKey);
        if (stateModel == null) {
            stateModel = stateModelFactory.createAndAddStateModel(resourceName, partitionKey);
            stateModel.updateState(initState);
        }
        if (message.getMsgType().equals(MessageType.STATE_TRANSITION_CANCELLATION.name())) {
            return new HelixStateTransitionCancellationHandler(stateModel, message, context);
        } else {
            // create currentStateDelta for this partition
            // TODO: move currentStateDelta to StateTransitionMsgHandler
            CurrentState currentStateDelta = new CurrentState(resourceName);
            currentStateDelta.setSessionId(sessionId);
            currentStateDelta.setStateModelDefRef(stateModelName);
            currentStateDelta.setStateModelFactoryName(factoryName);
            currentStateDelta.setBucketSize(bucketSize);
            currentStateDelta.setState(partitionKey, (stateModel.getCurrentState() == null) ? initState : stateModel.getCurrentState());
            return new HelixStateTransitionHandler(stateModelFactory, stateModel, message, context, currentStateDelta);
        }
    } else {
        BatchMessageWrapper wrapper = stateModelFactory.getBatchMessageWrapper(resourceName);
        if (wrapper == null) {
            wrapper = stateModelFactory.createAndAddBatchMessageWrapper(resourceName);
        }
        // get executor-service for the message
        TaskExecutor executor = (TaskExecutor) context.get(MapKey.TASK_EXECUTOR.toString());
        if (executor == null) {
            logger.error("fail to get executor-service for batch message: " + message.getId() + ". msgType: " + message.getMsgType() + ", resource: " + message.getResourceName());
            return null;
        }
        return new BatchMessageHandler(message, context, this, wrapper, executor);
    }
}