00001 /*
00002 * The Apache Software License, Version 1.1
00003 *
00004 * Copyright (c) 1999-2000 The Apache Software Foundation. All rights
00005 * reserved.
00006 *
00007 * Redistribution and use in source and binary forms, with or without
00008 * modification, are permitted provided that the following conditions
00009 * are met:
00010 *
00011 * 1. Redistributions of source code must retain the above copyright
00012 * notice, this list of conditions and the following disclaimer.
00013 *
00014 * 2. Redistributions in binary form must reproduce the above copyright
00015 * notice, this list of conditions and the following disclaimer in
00016 * the documentation and/or other materials provided with the
00017 * distribution.
00018 *
00019 * 3. The end-user documentation included with the redistribution,
00020 * if any, must include the following acknowledgment:
00021 * "This product includes software developed by the
00022 * Apache Software Foundation (http://www.apache.org/)."
00023 * Alternately, this acknowledgment may appear in the software itself,
00024 * if and wherever such third-party acknowledgments normally appear.
00025 *
00026 * 4. The names "Xerces" and "Apache Software Foundation" must
00027 * not be used to endorse or promote products derived from this
00028 * software without prior written permission. For written
00029 * permission, please contact apache\@apache.org.
00030 *
00031 * 5. Products derived from this software may not be called "Apache",
00032 * nor may "Apache" appear in their name, without prior written
00033 * permission of the Apache Software Foundation.
00034 *
00035 * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
00036 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
00037 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
00038 * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
00039 * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
00040 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
00041 * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
00042 * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
00043 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
00044 * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
00045 * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
00046 * SUCH DAMAGE.
00047 * ====================================================================
00048 *
00049 * This software consists of voluntary contributions made by many
00050 * individuals on behalf of the Apache Software Foundation, and was
00051 * originally based on software copyright (c) 1999, International
00052 * Business Machines, Inc., http://www.ibm.com . For more information
00053 * on the Apache Software Foundation, please see
00054 * <http://www.apache.org/>.
00055 */
00056
00057 /*
00058 * $Log: StringPool.hpp,v $
00059 * Revision 1.3 2000/02/24 20:05:25 abagchi
00060 * Swat for removing Log from API docs
00061 *
00062 * Revision 1.2 2000/02/06 07:48:04 rahulj
00063 * Year 2K copyright swat.
00064 *
00065 * Revision 1.1.1.1 1999/11/09 01:05:11 twl
00066 * Initial checkin
00067 *
00068 * Revision 1.2 1999/11/08 20:45:15 rahul
00069 * Swat for adding in Product name and CVS comment log variable.
00070 *
00071 */
00072
00073 #if !defined(STRINGPOOL_HPP)
00074 #define STRINGPOOL_HPP
00075
00076 #include <util/RefHashTableOf.hpp>
00077
00078 //
00079 // This class implements a string pool, in which strings can be added and
00080 // given a unique id by which they can be refered. It has to provide fast
00081 // access both mapping from a string to its id and mapping from an id to
00082 // its string. This requires that it provide two separate data structures.
00083 // The map one is a hash table for quick storage and look up by name. The
00084 // other is an array ordered by unique id which maps to the element in the
00085 // hash table.
00086 //
00087 // This works because strings cannot be removed from the pool once added,
00088 // other than flushing it completely, and because ids are assigned
00089 // sequentially from 1.
00090 //
00091 class XMLStringPool
00092 {
00093 public :
00094 // -----------------------------------------------------------------------
00095 // Constructors and Destructor
00096 // -----------------------------------------------------------------------
00097 XMLStringPool
00098 (
00099 const unsigned int modulus = 109
00100 );
00101 ~XMLStringPool();
00102
00103
00104 // -----------------------------------------------------------------------
00105 // Pool management methods
00106 // -----------------------------------------------------------------------
00107 unsigned int addOrFind(const XMLCh* const newString);
00108 bool exists(const XMLCh* const newString) const;
00109 void flushAll();
00110 unsigned int getId(const XMLCh* const toFind) const;
00111 const XMLCh* getValueForId(const unsigned int id) const;
00112
00113
00114 private :
00115 // -----------------------------------------------------------------------
00116 // Private data types
00117 // -----------------------------------------------------------------------
00118 class PoolElem
00119 {
00120 public :
00121 PoolElem(const XMLCh* const string, const unsigned int id);
00122 ~PoolElem();
00123
00124 const XMLCh* getKey() const;
00125 void reset(const XMLCh* const string, const unsigned int id);
00126
00127 unsigned int fId;
00128 XMLCh* fString;
00129 };
00130
00131
00132 // -----------------------------------------------------------------------
00133 // Unimplemented constructors and operators
00134 // -----------------------------------------------------------------------
00135 XMLStringPool(const XMLStringPool&);
00136 void operator=(const XMLStringPool&);
00137
00138
00139 // -----------------------------------------------------------------------
00140 // Private helper methods
00141 // -----------------------------------------------------------------------
00142 unsigned int addNewEntry(const XMLCh* const newString);
00143
00144
00145 // -----------------------------------------------------------------------
00146 // Private data members
00147 //
00148 // fIdMap
00149 // This is an array of pointers to the pool elements. It is ordered
00150 // by unique id, so using an id to index it gives instant access to
00151 // the string of that id. This is grown as required.
00152 //
00153 // fHashTable
00154 // This is the hash table used to store and quickly access the
00155 // strings.
00156 //
00157 // fMapCapacity
00158 // The current capacity of the id map. When the current id hits this
00159 // value the map must must be expanded.
00160 //
00161 // fCurId
00162 // This is the counter used to assign unique ids. It is just bumped
00163 // up one for each new string added.
00164 // -----------------------------------------------------------------------
00165 PoolElem** fIdMap;
00166 RefHashTableOf<PoolElem>* fHashTable;
00167 unsigned int fMapCapacity;
00168 unsigned int fCurId;
00169 };
00170
00171 #endif