Claw 1.7.0
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00001 /* 00002 CLAW - a C++ Library Absolutely Wonderful 00003 00004 CLAW is a free library without any particular aim but being useful to 00005 anyone. 00006 00007 Copyright (C) 2005-2011 Julien Jorge 00008 00009 This library is free software; you can redistribute it and/or 00010 modify it under the terms of the GNU Lesser General Public 00011 License as published by the Free Software Foundation; either 00012 version 2.1 of the License, or (at your option) any later version. 00013 00014 This library is distributed in the hope that it will be useful, 00015 but WITHOUT ANY WARRANTY; without even the implied warranty of 00016 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 00017 Lesser General Public License for more details. 00018 00019 You should have received a copy of the GNU Lesser General Public 00020 License along with this library; if not, write to the Free Software 00021 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 00022 00023 contact: julien.jorge@gamned.org 00024 */ 00030 #include <cassert> 00031 00032 /*----------------------------------------------------------------------------*/ 00041 template<typename OutputBuffer > 00042 template<typename Iterator> 00043 void claw::rle_encoder<OutputBuffer>::encode( Iterator first, Iterator last, 00044 output_buffer_type& output ) const 00045 { 00046 const unsigned int max_encodable = output.max_encodable(); 00047 const unsigned int min_interesting = output.min_interesting(); 00048 raw_buffer_type raw_buffer; 00049 00050 assert( max_encodable > 0 ); 00051 00052 while (first != last) 00053 { 00054 unsigned int count = 1; 00055 pattern_type pattern = *first; 00056 Iterator saved_it = first; 00057 ++first; 00058 bool ok = true; 00059 00060 // try to find enough similar data 00061 while ( ok && (first != last) && (count < max_encodable) ) 00062 if (*first == pattern) 00063 { 00064 ++count; 00065 ++first; 00066 } 00067 else 00068 ok = false; 00069 00070 // if we have enough data 00071 if ( count >= min_interesting ) 00072 { 00073 if ( !raw_buffer.empty() ) 00074 { 00075 output.raw( raw_buffer.begin(), raw_buffer.end() ); 00076 raw_buffer.clear(); 00077 } 00078 00079 output.encode( count, pattern ); 00080 } 00081 else 00082 raw_buffer.insert( raw_buffer.end(), saved_it, first ); 00083 } 00084 00085 00086 if ( !raw_buffer.empty() ) 00087 output.raw( raw_buffer.begin(), raw_buffer.end() ); 00088 } // rle_encoder::encode()