Claw
1.7.3
|
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 <climits> 00031 00032 /*----------------------------------------------------------------------------*/ 00037 template<typename Stream> 00038 claw::bit_ostream<Stream>::bit_ostream( stream_type& f ) 00039 : m_stream(f), m_pending(0), m_pending_length(0) 00040 { 00041 00042 } // bit_ostream::bit_ostream() 00043 00044 /*----------------------------------------------------------------------------*/ 00048 template<typename Stream> 00049 claw::bit_ostream<Stream>::~bit_ostream() 00050 { 00051 if (m_pending_length != 0) 00052 m_stream.write( (char*)&m_pending, sizeof(m_pending) ); 00053 } // bit_ostream::~bit_ostream() 00054 00055 /*----------------------------------------------------------------------------*/ 00061 template<typename Stream> 00062 void claw::bit_ostream<Stream>::write( const char* buf, unsigned int n ) 00063 { 00064 if ( n == 0 ) 00065 return; 00066 00067 unsigned int cur_size = 0; 00068 unsigned char data = *buf; 00069 00070 while ( n != 0 ) 00071 { 00072 while( (m_pending_length != CHAR_BIT) && (n!=0) ) 00073 { 00074 unsigned int bits = 00075 std::min(CHAR_BIT - (unsigned int)m_pending_length, n); 00076 00077 if ( CHAR_BIT - cur_size < bits ) 00078 bits = CHAR_BIT - cur_size; 00079 00080 unsigned int mask = (1 << bits) - 1; 00081 00082 m_pending |= (data & mask) << m_pending_length; 00083 cur_size += bits; 00084 m_pending_length += bits; 00085 data >>= bits; 00086 n -= bits; 00087 00088 if ( (cur_size == CHAR_BIT) && (n!=0) ) 00089 { 00090 ++buf; 00091 cur_size = 0; 00092 data = *buf; 00093 } 00094 } 00095 00096 if ( m_pending_length == CHAR_BIT ) 00097 { 00098 m_stream.write( (char*)&m_pending, sizeof(m_pending) ); 00099 m_pending = 0; 00100 m_pending_length = 0; 00101 } 00102 } 00103 } // bit_ostream::write()