http://xml.apache.org/http://www.apache.org/http://www.w3.org/

Home

Readme
Installation
Build

API Docs
Samples
Programming
Migration
FAQs

Releases
Feedback

PDF Document

Download
Dev Snapshots
CVS Repository
Mail Archive

API Docs for SAX and DOM
 

Main Page   Class Hierarchy   Alphabetical List   Compound List   File List   Compound Members   File Members  

StringPool.hpp

Go to the documentation of this file.
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


Copyright © 2000 The Apache Software Foundation. All Rights Reserved.