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TIBCO ComputeDB store based off Pivotal GemFireXD
/*
* Copyright (c) 2010-2015 Pivotal Software, Inc. All rights reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License"); you
* may not use this file except in compliance with the License. You
* may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or
* implied. See the License for the specific language governing
* permissions and limitations under the License. See accompanying
* LICENSE file.
*/
package com.gemstone.gemfire.cache.query;
import com.gemstone.gemfire.cache.CacheCallback;
/**
* Application plug-in interface for handling continuous query events after
* they occur. The listener has two methods, one that is called when there
* is an event satisfied by the CQ and the other called when there is an
* error during CQ processing.
*
* @author Anil
* @since 5.5
*/
public interface CqListener extends CacheCallback {
/**
* This method is invoked when an event is occurred on the region
* that satisfied the query condition of this CQ.
* This event does not contain an error.
* If CQ is executed using ExecuteWithInitialResults the returned
* result may already include the changes with respect to this event.
* This could arise when updates are happening on the region while
* CQ registration is in progress. The CQ does not block any region
* operation as it could affect the performance of region operation.
* Its up to the application to synchronize between the region
* operation and CQ registration to avoid duplicate event being
* delivered.
*
* @see com.gemstone.gemfire.cache.query.CqQuery#executeWithInitialResults
*/
public void onEvent(CqEvent aCqEvent);
/**
* This method is invoked when there is an error during CQ processing.
* The error can appear while applying query condition on the event.
* e.g if the event doesn't has attributes as specified in the CQ query.
* This event does contain an error. The newValue may or may not be
* available, and will be null if not available.
*/
public void onError(CqEvent aCqEvent);
}