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author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 14:23:32 +0000 |
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committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-05-04 14:23:32 +0000 |
commit | 74b9339658d8ea3690d32c237223e5974b601ed9 (patch) | |
tree | 98c0d79abbdcf18b8509c29bacee7e75314732e9 /fast_encoder.h | |
parent | Initial commit. (diff) | |
download | lzip-74b9339658d8ea3690d32c237223e5974b601ed9.tar.xz lzip-74b9339658d8ea3690d32c237223e5974b601ed9.zip |
Adding upstream version 1.23.upstream/1.23upstream
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to '')
-rw-r--r-- | fast_encoder.h | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/fast_encoder.h b/fast_encoder.h new file mode 100644 index 0000000..c41f9e4 --- /dev/null +++ b/fast_encoder.h @@ -0,0 +1,61 @@ +/* Lzip - LZMA lossless data compressor + Copyright (C) 2008-2022 Antonio Diaz Diaz. + + This program is free software: you can redistribute it and/or modify + it under the terms of the GNU General Public License as published by + the Free Software Foundation, either version 2 of the License, or + (at your option) any later version. + + This program is distributed in the hope that it will be useful, + but WITHOUT ANY WARRANTY; without even the implied warranty of + MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + GNU General Public License for more details. + + You should have received a copy of the GNU General Public License + along with this program. If not, see <http://www.gnu.org/licenses/>. +*/ + +class FLZ_encoder : public LZ_encoder_base + { + unsigned key4; // key made from latest 4 bytes + + void reset_key4() + { + key4 = 0; + for( int i = 0; i < 3 && i < available_bytes(); ++i ) + key4 = ( key4 << 4 ) ^ buffer[i]; + } + + int longest_match_len( int * const distance ); + + void update_and_move( int n ) + { + while( --n >= 0 ) + { + if( available_bytes() >= 4 ) + { + key4 = ( ( key4 << 4 ) ^ buffer[pos+3] ) & key4_mask; + pos_array[cyclic_pos] = prev_positions[key4]; + prev_positions[key4] = pos + 1; + } + move_pos(); + } + } + + enum { before_size = 0, + dict_size = 65536, + // bytes to keep in buffer after pos + after_size = max_match_len, + dict_factor = 16, + num_prev_positions23 = 0, + pos_array_factor = 1 }; + +public: + FLZ_encoder( const int ifd, const int outfd ) + : + LZ_encoder_base( before_size, dict_size, after_size, dict_factor, + num_prev_positions23, pos_array_factor, ifd, outfd ) + {} + + bool encode_member( const unsigned long long member_size ); + }; |