diff options
Diffstat (limited to 'encoder.c')
| -rw-r--r-- | encoder.c | 40 |
1 files changed, 19 insertions, 21 deletions
@@ -1,20 +1,20 @@ -/* Lzlib - Compression library for the lzip format - Copyright (C) 2009-2019 Antonio Diaz Diaz. +/* Lzlib - Compression library for the lzip format + Copyright (C) 2009-2021 Antonio Diaz Diaz. - This library is free software. Redistribution and use in source and - binary forms, with or without modification, are permitted provided - that the following conditions are met: + This library is free software. Redistribution and use in source and + binary forms, with or without modification, are permitted provided + that the following conditions are met: - 1. Redistributions of source code must retain the above copyright - notice, this list of conditions and the following disclaimer. + 1. Redistributions of source code must retain the above copyright + notice, this list of conditions, and the following disclaimer. - 2. Redistributions in binary form must reproduce the above copyright - notice, this list of conditions and the following disclaimer in the - documentation and/or other materials provided with the distribution. + 2. Redistributions in binary form must reproduce the above copyright + notice, this list of conditions, and the following disclaimer in the + documentation and/or other materials provided with the distribution. - This library 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. + This library 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. */ static int LZe_get_match_pairs( struct LZ_encoder * const e, struct Pair * pairs ) @@ -23,7 +23,7 @@ static int LZe_get_match_pairs( struct LZ_encoder * const e, struct Pair * pairs int32_t * ptr1 = ptr0 + 1; int32_t * newptr; int len = 0, len0 = 0, len1 = 0; - int maxlen = 0; + int maxlen = 3; /* only used if pairs != 0 */ int num_pairs = 0; const int pos1 = e->eb.mb.pos + 1; const int min_pos = ( e->eb.mb.pos > e->eb.mb.dictionary_size ) ? @@ -49,8 +49,8 @@ static int LZe_get_match_pairs( struct LZ_encoder * const e, struct Pair * pairs if( pairs ) { - int np2 = e->eb.mb.prev_positions[key2]; - int np3 = e->eb.mb.prev_positions[key3]; + const int np2 = e->eb.mb.prev_positions[key2]; + const int np3 = e->eb.mb.prev_positions[key3]; if( np2 > min_pos && e->eb.mb.buffer[np2-1] == data[0] ) { pairs[0].dis = e->eb.mb.pos - np2; @@ -60,19 +60,17 @@ static int LZe_get_match_pairs( struct LZ_encoder * const e, struct Pair * pairs if( np2 != np3 && np3 > min_pos && e->eb.mb.buffer[np3-1] == data[0] ) { maxlen = 3; - np2 = np3; - pairs[num_pairs].dis = e->eb.mb.pos - np2; - ++num_pairs; + pairs[num_pairs++].dis = e->eb.mb.pos - np3; } if( num_pairs > 0 ) { - const int delta = pos1 - np2; + const int delta = pairs[num_pairs-1].dis + 1; while( maxlen < len_limit && data[maxlen-delta] == data[maxlen] ) ++maxlen; pairs[num_pairs-1].len = maxlen; + if( maxlen < 3 ) maxlen = 3; if( maxlen >= len_limit ) pairs = 0; /* done. now just skip */ } - if( maxlen < 3 ) maxlen = 3; } e->eb.mb.prev_positions[key2] = pos1; |