00001 /* 00002 * AbstractStableIterator.hpp 00003 * 00004 * Copyright (c) 2000, 2014, Oracle and/or its affiliates. All rights reserved. 00005 * 00006 * Oracle is a registered trademarks of Oracle Corporation and/or its 00007 * affiliates. 00008 * 00009 * This software is the confidential and proprietary information of Oracle 00010 * Corporation. You shall not disclose such confidential and proprietary 00011 * information and shall use it only in accordance with the terms of the 00012 * license agreement you entered into with Oracle. 00013 * 00014 * This notice may not be removed or altered. 00015 */ 00016 #ifndef COH_ABSTACT_STABLE_ITERATOR_HPP 00017 #define COH_ABSTACT_STABLE_ITERATOR_HPP 00018 00019 #include "coherence/lang.ns" 00020 00021 #include "coherence/util/Muterator.hpp" 00022 00023 COH_OPEN_NAMESPACE2(coherence,util) 00024 00025 00026 /** 00027 * An abstract Iterator implementation that is stable between the hasNext() and 00028 * next() methods. 00029 * 00030 * @author mf 2008.02.28 00031 */ 00032 class COH_EXPORT AbstractStableIterator 00033 : public abstract_spec<AbstractStableIterator, 00034 extends<Object>, 00035 implements<Muterator> > 00036 { 00037 // ----- constructors --------------------------------------------------- 00038 00039 protected: 00040 /** 00041 * @internal 00042 */ 00043 AbstractStableIterator(); 00044 00045 00046 // ----- Muterator interface -------------------------------------------- 00047 00048 public: 00049 /** 00050 * {@inheritDoc} 00051 */ 00052 virtual void remove(); 00053 00054 00055 // ----- Iterator interface --------------------------------------------- 00056 00057 public: 00058 /** 00059 * {@inheritDoc} 00060 */ 00061 virtual bool hasNext() const; 00062 00063 /** 00064 * {@inheritDoc} 00065 */ 00066 virtual Object::Holder next(); 00067 00068 00069 // ----- internal ------------------------------------------------------- 00070 00071 protected: 00072 /** 00073 * Obtain the previous object provided by the Iterator. 00074 * 00075 * @return the object previously returned from a call to #next() 00076 */ 00077 virtual Object::Holder getPrevious() const; 00078 00079 /** 00080 * Specify the next object to provide from the Iterator. 00081 * 00082 * @param ohNext the next object to provide from the Iterator 00083 */ 00084 virtual void setNext(Object::Holder ohNext); 00085 00086 /** 00087 * Advance to the next object. 00088 * 00089 * This method must be implemented by the concrete sub-class by calling 00090 * #setNext() if there is a next object. 00091 */ 00092 virtual void advance() = 0; 00093 00094 /** 00095 * Remove the specified item. 00096 * 00097 * This is an optional operation. If the Iterator supports element 00098 * removal, then it should implement this method, which is delegated to by 00099 * the #remove() method. 00100 * 00101 * @param ohPrev the previously iterated object that should be removed 00102 * 00103 * @throws coherence::lang::UnsupportedOperationException if removal 00104 * is not supported 00105 */ 00106 virtual void remove(Object::Holder ohPrev); 00107 00108 00109 // ----- Object interface ----------------------------------------------- 00110 00111 protected: 00112 /** 00113 * {@inheritDoc} 00114 */ 00115 virtual void onInit(); 00116 00117 00118 // ----- data members --------------------------------------------------- 00119 00120 private: 00121 /** 00122 * Set to true when <tt>m_oNext</tt> is the next object to return 00123 * from the iterator. If there is no next object, or if the next object 00124 * is not determined yet, then this will be false. Set up by 00125 * #setNext() and reset by #next(). 00126 */ 00127 bool m_fNextReady; 00128 00129 /** 00130 * The next object to return from this iterator. Set up by 00131 * #setNext() and reset by #next(). 00132 */ 00133 MemberHolder<Object> m_ohNext; 00134 00135 /** 00136 * The object that can be deleted, if any. Set up by #next. 00137 */ 00138 MemberHolder<Object> m_ohPrev; 00139 00140 /** 00141 * Set to true when an element has been returned but not yet 00142 * removed. Set up by #next() and reset by #remove(). 00143 */ 00144 bool m_fCanDelete; 00145 }; 00146 00147 COH_CLOSE_NAMESPACE2 00148 00149 #endif // COH_ABSTACT_STABLE_ITERATOR_HPP