dlvhex  2.5.0
vs12/bm/bmgamma.h
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00001 /*
00002 Copyright(c) 2002-2009 Anatoliy Kuznetsov(anatoliy_kuznetsov at yahoo.com)
00003 
00004 Permission is hereby granted, free of charge, to any person 
00005 obtaining a copy of this software and associated documentation 
00006 files (the "Software"), to deal in the Software without restriction, 
00007 including without limitation the rights to use, copy, modify, merge, 
00008 publish, distribute, sublicense, and/or sell copies of the Software, 
00009 and to permit persons to whom the Software is furnished to do so, 
00010 subject to the following conditions:
00011 
00012 The above copyright notice and this permission notice shall be included 
00013 in all copies or substantial portions of the Software.
00014 
00015 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 
00016 EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES 
00017 OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 
00018 IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, 
00019 DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, 
00020 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR 
00021 OTHER DEALINGS IN THE SOFTWARE.
00022 
00023 For more information please visit:  http://bmagic.sourceforge.net
00024 
00025 */
00026 
00027 #ifndef BMGAMMAENC__H__INCLUDED__
00028 #define BMGAMMAENC__H__INCLUDED__
00029 
00030 
00031 namespace bm
00032 {
00033 
00034 
00038 template<typename T, typename TBitIO>
00039 class gamma_decoder
00040 {
00041 public:
00042     gamma_decoder(TBitIO& bin) : bin_(bin) 
00043     {}
00044     
00048     void start()
00049     {}
00050     
00054     void stop()
00055     {}
00056     
00060     T operator()(void)
00061     {
00062         unsigned l = bin_.eat_zero_bits();
00063         bin_.get_bit(); // get border bit
00064         T current = 0;
00065         for (unsigned i = 0; i < l; ++i)
00066         {
00067             if (bin_.get_bit())
00068             {
00069                 current += 1 << i;
00070             }
00071         }
00072         current |= (1 << l);
00073         return current;
00074     }
00075 private:
00076     gamma_decoder(const gamma_decoder&);
00077     gamma_decoder& operator=(const gamma_decoder&);
00078 private:
00079     TBitIO&  bin_;
00080 };
00081 
00082 
00083 
00084 } // bm
00085 
00086 #endif
00087