00001 /* 00002 * Copyright (c) 2000, 2020, Oracle and/or its affiliates. 00003 * 00004 * Licensed under the Universal Permissive License v 1.0 as shown at 00005 * http://oss.oracle.com/licenses/upl. 00006 */ 00007 #ifndef COH_KEY_ASSOCIATION_HPP 00008 #define COH_KEY_ASSOCIATION_HPP 00009 00010 #include "coherence/lang.ns" 00011 00012 COH_OPEN_NAMESPACE3(coherence,net,cache) 00013 00014 00015 /** 00016 * A KeyAssociation represents a key object that has a natural association 00017 * with another key object. 00018 * 00019 * The key object and the associated key may refer to entries in the same or 00020 * different caches. 00021 * 00022 * For example, the information provided by a key that implements 00023 * <b>KeyAssociation</b> may be used to place the key into the same partition 00024 * as its associated key. 00025 * 00026 * See KeyAssociatedFilter for an example of a distributed query that takes 00027 * advantage of a custom KeyAssociation implementation to dramatically optimize 00028 * its performance. 00029 * 00030 * @author gm 2009.03.18 00031 */ 00032 class COH_EXPORT KeyAssociation 00033 : public interface_spec<KeyAssociation> 00034 { 00035 // ----- KeyAssociation interface --------------------------------------- 00036 00037 public: 00038 /** 00039 * Determine the key object to which this key object is associated. 00040 * The key object returned by this method is often referred to as a 00041 * <i>host key</i>. 00042 * 00043 * @return the host key that for this key object, or <tt>NULL</tt> if 00044 * this key has no association. 00045 */ 00046 virtual Object::View getAssociatedKey() const = 0; 00047 }; 00048 00049 COH_CLOSE_NAMESPACE3 00050 00051 #endif // COH_KEY_ASSOCIATION_HPP