diff options
Diffstat (limited to 'decoder.c')
| -rw-r--r-- | decoder.c | 114 |
1 files changed, 54 insertions, 60 deletions
@@ -1,5 +1,5 @@ /* Lzlib - Compression library for lzip files - Copyright (C) 2009, 2010, 2011, 2012, 2013 Antonio Diaz Diaz. + Copyright (C) 2009, 2010, 2011, 2012, 2013, 2014 Antonio Diaz Diaz. This library is free software: you can redistribute it and/or modify it under the terms of the GNU General Public License as published by @@ -25,123 +25,120 @@ Public License. */ -static bool LZd_verify_trailer( struct LZ_decoder * const decoder ) +static bool LZd_verify_trailer( struct LZ_decoder * const d ) { File_trailer trailer; - const unsigned long long member_size = - decoder->rdec->member_position + Ft_size; + const unsigned long long member_size = d->rdec->member_position + Ft_size; - int size = Rd_read_data( decoder->rdec, trailer, Ft_size ); + int size = Rd_read_data( d->rdec, trailer, Ft_size ); if( size < Ft_size ) return false; - return ( decoder->rdec->code == 0 && - Ft_get_data_crc( trailer ) == LZd_crc( decoder ) && - Ft_get_data_size( trailer ) == LZd_data_position( decoder ) && + return ( d->rdec->code == 0 && + Ft_get_data_crc( trailer ) == LZd_crc( d ) && + Ft_get_data_size( trailer ) == LZd_data_position( d ) && Ft_get_member_size( trailer ) == member_size ); } /* Return value: 0 = OK, 1 = decoder error, 2 = unexpected EOF, 3 = trailer error, 4 = unknown marker found. */ -static int LZd_decode_member( struct LZ_decoder * const decoder ) +static int LZd_decode_member( struct LZ_decoder * const d ) { - struct Range_decoder * const rdec = decoder->rdec; - State * const state = &decoder->state; + struct Range_decoder * const rdec = d->rdec; + State * const state = &d->state; - if( decoder->member_finished ) return 0; + if( d->member_finished ) return 0; if( !Rd_try_reload( rdec, false ) ) return 0; - if( decoder->verify_trailer_pending ) + if( d->verify_trailer_pending ) { if( Rd_available_bytes( rdec ) < Ft_size && !rdec->at_stream_end ) return 0; - decoder->verify_trailer_pending = false; - decoder->member_finished = true; - if( LZd_verify_trailer( decoder ) ) return 0; else return 3; + d->verify_trailer_pending = false; + d->member_finished = true; + if( LZd_verify_trailer( d ) ) return 0; else return 3; } while( !Rd_finished( rdec ) ) { - const int pos_state = LZd_data_position( decoder ) & pos_state_mask; - if( !Rd_enough_available_bytes( rdec ) || - !LZd_enough_free_bytes( decoder ) ) + const int pos_state = LZd_data_position( d ) & pos_state_mask; + if( !Rd_enough_available_bytes( rdec ) || !LZd_enough_free_bytes( d ) ) return 0; - if( Rd_decode_bit( rdec, &decoder->bm_match[*state][pos_state] ) == 0 ) /* 1st bit */ + if( Rd_decode_bit( rdec, &d->bm_match[*state][pos_state] ) == 0 ) /* 1st bit */ { - const uint8_t prev_byte = LZd_get_prev_byte( decoder ); + const uint8_t prev_byte = LZd_get_prev_byte( d ); if( St_is_char( *state ) ) { *state -= ( *state < 4 ) ? *state : 3; - LZd_put_byte( decoder, Rd_decode_tree( rdec, - decoder->bm_literal[get_lit_state(prev_byte)], 8 ) ); + LZd_put_byte( d, Rd_decode_tree( rdec, + d->bm_literal[get_lit_state(prev_byte)], 8 ) ); } else { *state -= ( *state < 10 ) ? 3 : 6; - LZd_put_byte( decoder, Rd_decode_matched( rdec, - decoder->bm_literal[get_lit_state(prev_byte)], - LZd_get_byte( decoder, decoder->rep0 ) ) ); + LZd_put_byte( d, Rd_decode_matched( rdec, + d->bm_literal[get_lit_state(prev_byte)], + LZd_get_byte( d, d->rep0 ) ) ); } } else { int len; - if( Rd_decode_bit( rdec, &decoder->bm_rep[*state] ) != 0 ) /* 2nd bit */ + if( Rd_decode_bit( rdec, &d->bm_rep[*state] ) != 0 ) /* 2nd bit */ { - if( Rd_decode_bit( rdec, &decoder->bm_rep0[*state] ) != 0 ) /* 3rd bit */ + if( Rd_decode_bit( rdec, &d->bm_rep0[*state] ) != 0 ) /* 3rd bit */ { unsigned distance; - if( Rd_decode_bit( rdec, &decoder->bm_rep1[*state] ) == 0 ) /* 4th bit */ - distance = decoder->rep1; + if( Rd_decode_bit( rdec, &d->bm_rep1[*state] ) == 0 ) /* 4th bit */ + distance = d->rep1; else { - if( Rd_decode_bit( rdec, &decoder->bm_rep2[*state] ) == 0 ) /* 5th bit */ - distance = decoder->rep2; + if( Rd_decode_bit( rdec, &d->bm_rep2[*state] ) == 0 ) /* 5th bit */ + distance = d->rep2; else - { distance = decoder->rep3; decoder->rep3 = decoder->rep2; } - decoder->rep2 = decoder->rep1; + { distance = d->rep3; d->rep3 = d->rep2; } + d->rep2 = d->rep1; } - decoder->rep1 = decoder->rep0; - decoder->rep0 = distance; + d->rep1 = d->rep0; + d->rep0 = distance; } else { - if( Rd_decode_bit( rdec, &decoder->bm_len[*state][pos_state] ) == 0 ) /* 4th bit */ + if( Rd_decode_bit( rdec, &d->bm_len[*state][pos_state] ) == 0 ) /* 4th bit */ { *state = St_set_short_rep( *state ); - LZd_put_byte( decoder, LZd_get_byte( decoder, decoder->rep0 ) ); continue; } + LZd_put_byte( d, LZd_get_byte( d, d->rep0 ) ); continue; } } *state = St_set_rep( *state ); - len = min_match_len + Rd_decode_len( rdec, &decoder->rep_len_model, pos_state ); + len = min_match_len + Rd_decode_len( rdec, &d->rep_len_model, pos_state ); } else { int dis_slot; - const unsigned rep0_saved = decoder->rep0; - len = min_match_len + Rd_decode_len( rdec, &decoder->match_len_model, pos_state ); - dis_slot = Rd_decode_tree6( rdec, decoder->bm_dis_slot[get_len_state(len)] ); - if( dis_slot < start_dis_model ) decoder->rep0 = dis_slot; + const unsigned rep0_saved = d->rep0; + len = min_match_len + Rd_decode_len( rdec, &d->match_len_model, pos_state ); + dis_slot = Rd_decode_tree6( rdec, d->bm_dis_slot[get_len_state(len)] ); + if( dis_slot < start_dis_model ) d->rep0 = dis_slot; else { const int direct_bits = ( dis_slot >> 1 ) - 1; - decoder->rep0 = ( 2 | ( dis_slot & 1 ) ) << direct_bits; + d->rep0 = ( 2 | ( dis_slot & 1 ) ) << direct_bits; if( dis_slot < end_dis_model ) - decoder->rep0 += Rd_decode_tree_reversed( rdec, - decoder->bm_dis + decoder->rep0 - dis_slot - 1, - direct_bits ); + d->rep0 += Rd_decode_tree_reversed( rdec, + d->bm_dis + d->rep0 - dis_slot - 1, direct_bits ); else { - decoder->rep0 += Rd_decode( rdec, direct_bits - dis_align_bits ) << dis_align_bits; - decoder->rep0 += Rd_decode_tree_reversed4( rdec, decoder->bm_align ); - if( decoder->rep0 == 0xFFFFFFFFU ) /* Marker found */ + d->rep0 += Rd_decode( rdec, direct_bits - dis_align_bits ) << dis_align_bits; + d->rep0 += Rd_decode_tree_reversed4( rdec, d->bm_align ); + if( d->rep0 == 0xFFFFFFFFU ) /* Marker found */ { - decoder->rep0 = rep0_saved; + d->rep0 = rep0_saved; Rd_normalize( rdec ); if( len == min_match_len ) /* End Of Stream marker */ { if( Rd_available_bytes( rdec ) < Ft_size && !rdec->at_stream_end ) - { decoder->verify_trailer_pending = true; return 0; } - decoder->member_finished = true; - if( LZd_verify_trailer( decoder ) ) return 0; else return 3; + { d->verify_trailer_pending = true; return 0; } + d->member_finished = true; + if( LZd_verify_trailer( d ) ) return 0; else return 3; } if( len == min_match_len + 1 ) /* Sync Flush marker */ { @@ -152,15 +149,12 @@ static int LZd_decode_member( struct LZ_decoder * const decoder ) } } } - decoder->rep3 = decoder->rep2; - decoder->rep2 = decoder->rep1; decoder->rep1 = rep0_saved; + d->rep3 = d->rep2; d->rep2 = d->rep1; d->rep1 = rep0_saved; *state = St_set_match( *state ); - if( decoder->rep0 >= (unsigned)decoder->dictionary_size || - ( decoder->rep0 >= (unsigned)decoder->cb.put && - !decoder->partial_data_pos ) ) + if( d->rep0 >= d->dictionary_size || d->rep0 >= LZd_data_position( d ) ) return 1; } - LZd_copy_block( decoder, decoder->rep0, len ); + LZd_copy_block( d, d->rep0, len ); } } return 2; |