geode-core/src/main/java/org/apache/geode/cache/execute/RegionFunctionContext.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one or more contributor license
 * agreements. See the NOTICE file distributed with this work for additional information regarding
 * copyright ownership. The ASF licenses this file to You 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.
 */
package org.apache.geode.cache.execute;

import java.util.Set;

import org.apache.geode.cache.PartitionAttributesFactory;
import org.apache.geode.cache.Region;
import org.apache.geode.cache.partition.PartitionRegionHelper;

/**
 * Defines the execution context of a data dependent {@link Function}.
 *
 * Applications can use the methods provided to retrieve the Region and context specific routing
 * objects. When the function is executed using {@link FunctionService#onRegion(Region)}, the
 * {@link Function#execute(FunctionContext) FunctionContext} can be typecast to this type.
 * </p>
 * <p>
 * If the region is a partitioned region, {@link PartitionRegionHelper} can be used to get local and
 * {@linkplain PartitionAttributesFactory#setColocatedWith(String) colocated} data references.
 * </p>
 *
 *
 * @since GemFire 6.0
 *
 * @see FunctionContext
 * @see PartitionRegionHelper
 */
public interface RegionFunctionContext extends FunctionContext {

  /**
   * Returns subset of keys (filter) provided by the invoking thread (aka routing objects). The set
   * of filter keys are locally present in the datastore on the executing cluster member.
   *
   * @see Execution#withFilter(Set)
   *
   * @return the objects that caused the function to be routed to this cluster member
   * @since GemFire 6.0
   */
  Set<?> getFilter();

  /**
   * Returns the reference to the Region on which the function is executed
   *
   * @see FunctionService#onRegion(Region)
   *
   * @return returns the Region on which the function is executed
   *
   * @since GemFire 6.0
   */
  <K, V> Region<K, V> getDataSet();

}