GNU CommonC++

objmap.h

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00001 // Copyright (C) 2001-2005 Open Source Telecom Corporation.
00002 // Copyright (C) 2006-2010 David Sugar, Tycho Softworks.
00003 //
00004 // This program is free software; you can redistribute it and/or modify
00005 // it under the terms of the GNU General Public License as published by
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00007 // (at your option) any later version.
00008 //
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00010 // but WITHOUT ANY WARRANTY; without even the implied warranty of
00011 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
00012 // GNU General Public License for more details.
00013 //
00014 // You should have received a copy of the GNU General Public License
00015 // along with this program; if not, write to the Free Software
00016 // Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
00017 //
00018 // As a special exception to the GNU General Public License, permission is
00019 // granted for additional uses of the text contained in its release
00020 // of Common C++.
00021 //
00022 // The exception is that, if you link the Common C++ library with other
00023 // files to produce an executable, this does not by itself cause the
00024 // resulting executable to be covered by the GNU General Public License.
00025 // Your use of that executable is in no way restricted on account of
00026 // linking the Common C++ library code into it.
00027 //
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00029 // the executable file might be covered by the GNU General Public License.
00030 //
00031 // This exception applies only to the code released under the
00032 // name Common C++.  If you copy code from other releases into a copy of
00033 // Common C++, as the General Public License permits, the exception does
00034 // not apply to the code that you add in this way.  To avoid misleading
00035 // anyone as to the status of such modified files, you must delete
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00037 //
00038 // If you write modifications of your own for Common C++, it is your choice
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00040 // If you do not wish that, delete this exception notice.
00041 
00047 #ifndef CCXX_OBJMAP_H
00048 #define CCXX_OBJMAP_H
00049 
00050 #include <cc++/strchar.h>
00051 
00052 #ifdef  CCXX_NAMESPACES
00053 namespace ost {
00054 #endif
00055 
00064 template <class T, class K, unsigned S>
00065 class objMap {
00066 protected:
00067     static T *objIndex[S];
00068     T* objNext;
00069     const K objKey;
00070 
00071     virtual unsigned keyIndex(K k)
00072     {
00073         unsigned idx = 0;
00074         unsigned char *p = (unsigned char *)&k;
00075         unsigned len = sizeof(K);
00076 
00077         while(len--) {
00078             idx ^= (idx << 1) ^ *p;
00079             ++p;
00080         }
00081         return idx % S;
00082     }
00083 
00084     inline unsigned getSize(void)
00085         {return S;}
00086 
00087     objMap(const K key)
00088     {
00089         unsigned idx = keyIndex(key);
00090         objKey = key;
00091         objNext = objIndex[idx];
00092         objIndex[idx] = (T *)this;
00093     }
00094 public:
00095     static T *getObject(keystring key);
00096 };
00097 
00098 template <class T, unsigned S>
00099 class keyMap : public objMap<T, keystring, S>
00100 {
00101     keyMap(keystring key) : objMap<T, keystring, S>(key) {};
00102 
00103     unsigned keyIndex(keystring k)
00104     {
00105         unsigned idx = 0;
00106         while(*k) {
00107             idx = (idx << 1) ^ (unsigned)*k;
00108             ++k;
00109         }
00110         return idx % S;
00111     }
00112 };
00113 
00114 template <class T, class K, unsigned S>
00115 T *objMap<T, K, S>::objIndex[S](0);
00116 
00117 template <class T, class K, unsigned S>
00118 T *objMap<T, K, S>::getObject(const keystring key)
00119 {
00120     T *obj = objIndex[keyIndex(key)];
00121     while(obj) {
00122         if(key == obj->objKey)
00123             break;
00124         obj = obj->objNext;
00125     }
00126     return obj;
00127 }
00128 
00129 #ifdef  CCXX_NAMESPACES
00130 } // namespace
00131 #endif
00132 
00133 #endif