Examples with IdealStateChangeListener org.apache.helix.api.listeners.IdealStateChangeListener used on opensource projects

Example 1 with IdealStateChangeListener

use of org.apache.helix.api.listeners.IdealStateChangeListener in project helix by apache.

the class CallbackHandler method invoke.

public void invoke(NotificationContext changeContext) throws Exception {
    Type type = changeContext.getType();
    long start = System.currentTimeMillis();
    // This allows the listener to work with one change at a time
    synchronized (_manager) {
        if (logger.isInfoEnabled()) {
            logger.info(Thread.currentThread().getId() + " START:INVOKE " + _path + " listener:" + _listener + " type: " + type);
        }
        if (!_expectTypes.contains(type)) {
            logger.warn("Callback handler received event in wrong order. Listener: " + _listener + ", path: " + _path + ", expected types: " + _expectTypes + " but was " + type);
            return;
        }
        _expectTypes = nextNotificationType.get(type);
        if (type == Type.INIT || type == Type.FINALIZE) {
            subscribeForChanges(changeContext.getType(), _path, _watchChild);
        } else {
            // put SubscribeForChange run in async thread to reduce the latency of zk callback handling.
            subscribeForChangesAsyn(changeContext.getType(), _path, _watchChild);
        }
        _expectTypes = nextNotificationType.get(type);
        if (_changeType == IDEAL_STATE) {
            IdealStateChangeListener idealStateChangeListener = (IdealStateChangeListener) _listener;
            List<IdealState> idealStates = preFetch(_propertyKey);
            idealStateChangeListener.onIdealStateChange(idealStates, changeContext);
        } else if (_changeType == INSTANCE_CONFIG) {
            if (_listener instanceof ConfigChangeListener) {
                ConfigChangeListener configChangeListener = (ConfigChangeListener) _listener;
                List<InstanceConfig> configs = preFetch(_propertyKey);
                configChangeListener.onConfigChange(configs, changeContext);
            } else if (_listener instanceof InstanceConfigChangeListener) {
                InstanceConfigChangeListener listener = (InstanceConfigChangeListener) _listener;
                List<InstanceConfig> configs = preFetch(_propertyKey);
                listener.onInstanceConfigChange(configs, changeContext);
            }
        } else if (_changeType == RESOURCE_CONFIG) {
            ResourceConfigChangeListener listener = (ResourceConfigChangeListener) _listener;
            List<ResourceConfig> configs = preFetch(_propertyKey);
            listener.onResourceConfigChange(configs, changeContext);
        } else if (_changeType == CLUSTER_CONFIG) {
            ClusterConfigChangeListener listener = (ClusterConfigChangeListener) _listener;
            ClusterConfig config = null;
            if (_preFetchEnabled) {
                config = _accessor.getProperty(_propertyKey);
            }
            listener.onClusterConfigChange(config, changeContext);
        } else if (_changeType == CONFIG) {
            ScopedConfigChangeListener listener = (ScopedConfigChangeListener) _listener;
            List<HelixProperty> configs = preFetch(_propertyKey);
            listener.onConfigChange(configs, changeContext);
        } else if (_changeType == LIVE_INSTANCE) {
            LiveInstanceChangeListener liveInstanceChangeListener = (LiveInstanceChangeListener) _listener;
            List<LiveInstance> liveInstances = preFetch(_propertyKey);
            liveInstanceChangeListener.onLiveInstanceChange(liveInstances, changeContext);
        } else if (_changeType == CURRENT_STATE) {
            CurrentStateChangeListener currentStateChangeListener = (CurrentStateChangeListener) _listener;
            String instanceName = PropertyPathConfig.getInstanceNameFromPath(_path);
            List<CurrentState> currentStates = preFetch(_propertyKey);
            currentStateChangeListener.onStateChange(instanceName, currentStates, changeContext);
        } else if (_changeType == MESSAGE) {
            MessageListener messageListener = (MessageListener) _listener;
            String instanceName = PropertyPathConfig.getInstanceNameFromPath(_path);
            List<Message> messages = preFetch(_propertyKey);
            messageListener.onMessage(instanceName, messages, changeContext);
        } else if (_changeType == MESSAGES_CONTROLLER) {
            MessageListener messageListener = (MessageListener) _listener;
            List<Message> messages = preFetch(_propertyKey);
            messageListener.onMessage(_manager.getInstanceName(), messages, changeContext);
        } else if (_changeType == EXTERNAL_VIEW || _changeType == TARGET_EXTERNAL_VIEW) {
            ExternalViewChangeListener externalViewListener = (ExternalViewChangeListener) _listener;
            List<ExternalView> externalViewList = preFetch(_propertyKey);
            externalViewListener.onExternalViewChange(externalViewList, changeContext);
        } else if (_changeType == CONTROLLER) {
            ControllerChangeListener controllerChangelistener = (ControllerChangeListener) _listener;
            controllerChangelistener.onControllerChange(changeContext);
        } else {
            logger.warn("Unknown change type: " + _changeType);
        }
        long end = System.currentTimeMillis();
        if (logger.isInfoEnabled()) {
            logger.info(Thread.currentThread().getId() + " END:INVOKE " + _path + " listener:" + _listener + " type: " + type + " Took: " + (end - start) + "ms");
        }
        if (_monitor != null) {
            _monitor.increaseCallbackCounters(end - start);
        }
    }
}