diff options
Diffstat (limited to 'encoder_base.c')
| -rw-r--r-- | encoder_base.c | 194 |
1 files changed, 194 insertions, 0 deletions
diff --git a/encoder_base.c b/encoder_base.c new file mode 100644 index 0000000..047f372 --- /dev/null +++ b/encoder_base.c @@ -0,0 +1,194 @@ +/* Lzlib - Compression library for the lzip format + Copyright (C) 2009-2024 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: + + 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. + + 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 bool Mb_normalize_pos( struct Matchfinder_base * const mb ) + { + if( mb->pos > mb->stream_pos ) + { mb->pos = mb->stream_pos; return false; } + if( !mb->at_stream_end ) + { + int i; + /* offset is int32_t for the min below */ + const int32_t offset = mb->pos - mb->before_size - mb->dictionary_size; + const int size = mb->stream_pos - offset; + memmove( mb->buffer, mb->buffer + offset, size ); + mb->partial_data_pos += offset; + mb->pos -= offset; /* pos = before_size + dictionary_size */ + mb->stream_pos -= offset; + for( i = 0; i < mb->num_prev_positions; ++i ) + mb->prev_positions[i] -= min( mb->prev_positions[i], offset ); + for( i = 0; i < mb->pos_array_size; ++i ) + mb->pos_array[i] -= min( mb->pos_array[i], offset ); + } + return true; + } + + +static bool Mb_init( struct Matchfinder_base * const mb, const int before_size, + const int dict_size, const int after_size, + const int dict_factor, const int num_prev_positions23, + const int pos_array_factor ) + { + const int buffer_size_limit = + ( dict_factor * dict_size ) + before_size + after_size; + int i; + + mb->partial_data_pos = 0; + mb->before_size = before_size; + mb->after_size = after_size; + mb->pos = 0; + mb->cyclic_pos = 0; + mb->stream_pos = 0; + mb->num_prev_positions23 = num_prev_positions23; + mb->at_stream_end = false; + mb->sync_flush_pending = false; + + mb->buffer_size = max( 65536, buffer_size_limit ); + mb->buffer = (uint8_t *)malloc( mb->buffer_size ); + if( !mb->buffer ) return false; + mb->saved_dictionary_size = dict_size; + mb->dictionary_size = dict_size; + mb->pos_limit = mb->buffer_size - after_size; + unsigned size = 1 << max( 16, real_bits( mb->dictionary_size - 1 ) - 2 ); + if( mb->dictionary_size > 1 << 26 ) size >>= 1; /* 64 MiB */ + mb->key4_mask = size - 1; /* increases with dictionary size */ + size += num_prev_positions23; + mb->num_prev_positions = size; + + mb->pos_array_size = pos_array_factor * ( mb->dictionary_size + 1 ); + size += mb->pos_array_size; + if( size * sizeof mb->prev_positions[0] <= size ) mb->prev_positions = 0; + else mb->prev_positions = + (int32_t *)malloc( size * sizeof mb->prev_positions[0] ); + if( !mb->prev_positions ) { free( mb->buffer ); return false; } + mb->pos_array = mb->prev_positions + mb->num_prev_positions; + for( i = 0; i < mb->num_prev_positions; ++i ) mb->prev_positions[i] = 0; + return true; + } + + +static void Mb_adjust_array( struct Matchfinder_base * const mb ) + { + int size = 1 << max( 16, real_bits( mb->dictionary_size - 1 ) - 2 ); + if( mb->dictionary_size > 1 << 26 ) size >>= 1; /* 64 MiB */ + mb->key4_mask = size - 1; + size += mb->num_prev_positions23; + mb->num_prev_positions = size; + mb->pos_array = mb->prev_positions + mb->num_prev_positions; + } + + +static void Mb_adjust_dictionary_size( struct Matchfinder_base * const mb ) + { + if( mb->stream_pos < mb->dictionary_size ) + { + mb->dictionary_size = max( min_dictionary_size, mb->stream_pos ); + Mb_adjust_array( mb ); + mb->pos_limit = mb->buffer_size; + } + } + + +static void Mb_reset( struct Matchfinder_base * const mb ) + { + int i; + if( mb->stream_pos > mb->pos ) + memmove( mb->buffer, mb->buffer + mb->pos, mb->stream_pos - mb->pos ); + mb->partial_data_pos = 0; + mb->stream_pos -= mb->pos; + mb->pos = 0; + mb->cyclic_pos = 0; + mb->at_stream_end = false; + mb->sync_flush_pending = false; + mb->dictionary_size = mb->saved_dictionary_size; + Mb_adjust_array( mb ); + mb->pos_limit = mb->buffer_size - mb->after_size; + for( i = 0; i < mb->num_prev_positions; ++i ) mb->prev_positions[i] = 0; + } + + +/* End Of Stream marker => (dis == 0xFFFFFFFFU, len == min_match_len) */ +static void LZeb_try_full_flush( struct LZ_encoder_base * const eb ) + { + if( eb->member_finished || + Cb_free_bytes( &eb->renc.cb ) < max_marker_size + eb->renc.ff_count + Lt_size ) + return; + eb->member_finished = true; + const int pos_state = Mb_data_position( &eb->mb ) & pos_state_mask; + const State state = eb->state; + Re_encode_bit( &eb->renc, &eb->bm_match[state][pos_state], 1 ); + Re_encode_bit( &eb->renc, &eb->bm_rep[state], 0 ); + LZeb_encode_pair( eb, 0xFFFFFFFFU, min_match_len, pos_state ); + Re_flush( &eb->renc ); + Lzip_trailer trailer; + Lt_set_data_crc( trailer, LZeb_crc( eb ) ); + Lt_set_data_size( trailer, Mb_data_position( &eb->mb ) ); + Lt_set_member_size( trailer, Re_member_position( &eb->renc ) + Lt_size ); + int i; for( i = 0; i < Lt_size; ++i ) Cb_put_byte( &eb->renc.cb, trailer[i] ); + } + + +/* Sync Flush marker => (dis == 0xFFFFFFFFU, len == min_match_len + 1) */ +static void LZeb_try_sync_flush( struct LZ_encoder_base * const eb ) + { + const unsigned min_size = eb->renc.ff_count + max_marker_size; + if( eb->member_finished || + Cb_free_bytes( &eb->renc.cb ) < min_size + max_marker_size ) return; + eb->mb.sync_flush_pending = false; + const unsigned long long old_mpos = Re_member_position( &eb->renc ); + const int pos_state = Mb_data_position( &eb->mb ) & pos_state_mask; + const State state = eb->state; + do { /* size of markers must be >= rd_min_available_bytes + 5 */ + Re_encode_bit( &eb->renc, &eb->bm_match[state][pos_state], 1 ); + Re_encode_bit( &eb->renc, &eb->bm_rep[state], 0 ); + LZeb_encode_pair( eb, 0xFFFFFFFFU, min_match_len + 1, pos_state ); + Re_flush( &eb->renc ); + } + while( Re_member_position( &eb->renc ) - old_mpos < min_size ); + } + + +static void LZeb_reset( struct LZ_encoder_base * const eb, + const unsigned long long member_size ) + { + const unsigned long long min_member_size = min_dictionary_size; + const unsigned long long max_member_size = 0x0008000000000000ULL; /* 2 PiB */ + int i; + Mb_reset( &eb->mb ); + eb->member_size_limit = + min( max( min_member_size, member_size ), max_member_size ) - + Lt_size - max_marker_size; + eb->crc = 0xFFFFFFFFU; + Bm_array_init( eb->bm_literal[0], (1 << literal_context_bits) * 0x300 ); + Bm_array_init( eb->bm_match[0], states * pos_states ); + Bm_array_init( eb->bm_rep, states ); + Bm_array_init( eb->bm_rep0, states ); + Bm_array_init( eb->bm_rep1, states ); + Bm_array_init( eb->bm_rep2, states ); + Bm_array_init( eb->bm_len[0], states * pos_states ); + Bm_array_init( eb->bm_dis_slot[0], len_states * (1 << dis_slot_bits) ); + Bm_array_init( eb->bm_dis, modeled_distances - end_dis_model + 1 ); + Bm_array_init( eb->bm_align, dis_align_size ); + Lm_init( &eb->match_len_model ); + Lm_init( &eb->rep_len_model ); + Re_reset( &eb->renc, eb->mb.dictionary_size ); + for( i = 0; i < num_rep_distances; ++i ) eb->reps[i] = 0; + eb->state = 0; + eb->member_finished = false; + } |