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-rw-r--r--decoder.c108
1 files changed, 65 insertions, 43 deletions
diff --git a/decoder.c b/decoder.c
index 20364c0..61777b5 100644
--- a/decoder.c
+++ b/decoder.c
@@ -1,5 +1,5 @@
/* Lunzip - Decompressor for the lzip format
- Copyright (C) 2010-2016 Antonio Diaz Diaz.
+ Copyright (C) 2010-2017 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
@@ -53,7 +53,7 @@ void Pp_show_msg( struct Pretty_print * const pp, const char * const msg )
/* Returns the number of bytes really read.
If (returned value < size) and (errno == 0), means EOF was reached.
*/
-static int readblock( const int fd, uint8_t * const buf, const int size )
+int readblock( const int fd, uint8_t * const buf, const int size )
{
int sz = 0;
errno = 0;
@@ -87,10 +87,10 @@ static int writeblock( const int fd, const uint8_t * const buf, const int size )
}
-int seek_read( const int fd, uint8_t * const buf, const int size,
- const int offset )
+unsigned seek_read_back( const int fd, uint8_t * const buf, const int size,
+ const int offset )
{
- if( lseek( fd, offset, SEEK_END ) >= 0 )
+ if( lseek( fd, -offset, SEEK_END ) >= 0 )
return readblock( fd, buf, size );
return 0;
}
@@ -121,8 +121,9 @@ void LZd_flush_data( struct LZ_decoder * const d )
writeblock( d->outfd, d->buffer + d->stream_pos, size ) != size )
{ show_error( "Write error", errno, false ); cleanup_and_fail( 1 ); }
if( d->pos >= d->buffer_size )
- { d->partial_data_pos += d->pos; d->pos = 0;
- if( d->partial_data_pos >= d->dictionary_size ) d->pos_wrapped = true; }
+ { d->partial_data_pos += d->pos; d->pos = 0; d->pos_wrapped = true;
+ if( d->partial_data_pos >= d->dictionary_size )
+ d->pos_wrapped_dic = true; }
d->stream_pos = d->pos;
}
}
@@ -185,7 +186,7 @@ static bool LZd_verify_trailer( struct LZ_decoder * const d,
( 8.0 * member_size ) / data_size,
100.0 * ( 1.0 - ( (double)member_size / data_size ) ) );
if( !error && verbosity >= 4 )
- fprintf( stderr, "data CRC %08X, data size %9llu, member size %8llu. ",
+ fprintf( stderr, "CRC %08X, decompressed %9llu, compressed %8llu. ",
LZd_crc( d ), data_size, member_size );
return !error;
}
@@ -198,49 +199,77 @@ int LZd_decode_member( struct LZ_decoder * const d,
{
struct Range_decoder * const rdec = d->rdec;
void (* const copy_block)
- ( struct LZ_decoder * const d, const int distance, int len ) =
- ( (unsigned)d->buffer_size >= d->dictionary_size ) ?
+ ( struct LZ_decoder * const d, const unsigned distance, unsigned len ) =
+ ( d->buffer_size >= d->dictionary_size ) ?
&LZd_copy_block : &LZd_copy_block2;
+ Bit_model bm_literal[1<<literal_context_bits][0x300];
+ Bit_model bm_match[states][pos_states];
+ Bit_model bm_rep[states];
+ Bit_model bm_rep0[states];
+ Bit_model bm_rep1[states];
+ Bit_model bm_rep2[states];
+ Bit_model bm_len[states][pos_states];
+ Bit_model bm_dis_slot[len_states][1<<dis_slot_bits];
+ Bit_model bm_dis[modeled_distances-end_dis_model+1];
+ Bit_model bm_align[dis_align_size];
+ struct Len_model match_len_model;
+ struct Len_model rep_len_model;
unsigned rep0 = 0; /* rep[0-3] latest four distances */
unsigned rep1 = 0; /* used for efficient coding of */
unsigned rep2 = 0; /* repeated distances */
unsigned rep3 = 0;
State state = 0;
+ Bm_array_init( bm_literal[0], (1 << literal_context_bits) * 0x300 );
+ Bm_array_init( bm_match[0], states * pos_states );
+ Bm_array_init( bm_rep, states );
+ Bm_array_init( bm_rep0, states );
+ Bm_array_init( bm_rep1, states );
+ Bm_array_init( bm_rep2, states );
+ Bm_array_init( bm_len[0], states * pos_states );
+ Bm_array_init( bm_dis_slot[0], len_states * (1 << dis_slot_bits) );
+ Bm_array_init( bm_dis, modeled_distances - end_dis_model + 1 );
+ Bm_array_init( bm_align, dis_align_size );
+ Lm_init( &match_len_model );
+ Lm_init( &rep_len_model );
+
Rd_load( rdec );
while( !Rd_finished( rdec ) )
{
const int pos_state = LZd_data_position( d ) & pos_state_mask;
- if( Rd_decode_bit( rdec, &d->bm_match[state][pos_state] ) == 0 ) /* 1st bit */
+ if( Rd_decode_bit( rdec, &bm_match[state][pos_state] ) == 0 ) /* 1st bit */
{
- const uint8_t prev_byte = LZd_peek_prev( d );
+ Bit_model * const bm = bm_literal[get_lit_state(LZd_peek_prev( d ))];
if( St_is_char( state ) )
{
state -= ( state < 4 ) ? state : 3;
- LZd_put_byte( d, Rd_decode_tree( rdec,
- d->bm_literal[get_lit_state(prev_byte)], 8 ) );
+ LZd_put_byte( d, Rd_decode_tree8( rdec, bm ) );
}
else
{
state -= ( state < 10 ) ? 3 : 6;
- LZd_put_byte( d, Rd_decode_matched( rdec,
- d->bm_literal[get_lit_state(prev_byte)],
- LZd_peek( d, rep0 ) ) );
+ LZd_put_byte( d, Rd_decode_matched( rdec, bm, LZd_peek( d, rep0 ) ) );
}
}
else /* match or repeated match */
{
int len;
- if( Rd_decode_bit( rdec, &d->bm_rep[state] ) != 0 ) /* 2nd bit */
+ if( Rd_decode_bit( rdec, &bm_rep[state] ) != 0 ) /* 2nd bit */
{
- if( Rd_decode_bit( rdec, &d->bm_rep0[state] ) != 0 ) /* 3rd bit */
+ if( Rd_decode_bit( rdec, &bm_rep0[state] ) == 0 ) /* 3rd bit */
+ {
+ if( Rd_decode_bit( rdec, &bm_len[state][pos_state] ) == 0 ) /* 4th bit */
+ { state = St_set_short_rep( state );
+ LZd_put_byte( d, LZd_peek( d, rep0 ) ); continue; }
+ }
+ else
{
unsigned distance;
- if( Rd_decode_bit( rdec, &d->bm_rep1[state] ) == 0 ) /* 4th bit */
+ if( Rd_decode_bit( rdec, &bm_rep1[state] ) == 0 ) /* 4th bit */
distance = rep1;
else
{
- if( Rd_decode_bit( rdec, &d->bm_rep2[state] ) == 0 ) /* 5th bit */
+ if( Rd_decode_bit( rdec, &bm_rep2[state] ) == 0 ) /* 5th bit */
distance = rep2;
else
{ distance = rep3; rep3 = rep2; }
@@ -249,36 +278,29 @@ int LZd_decode_member( struct LZ_decoder * const d,
rep1 = rep0;
rep0 = distance;
}
- else
- {
- if( Rd_decode_bit( rdec, &d->bm_len[state][pos_state] ) == 0 ) /* 4th bit */
- { state = St_set_short_rep( state );
- LZd_put_byte( d, LZd_peek( d, rep0 ) ); continue; }
- }
state = St_set_rep( state );
- len = min_match_len + Rd_decode_len( rdec, &d->rep_len_model, pos_state );
+ len = min_match_len + Rd_decode_len( rdec, &rep_len_model, pos_state );
}
else /* match */
{
- int dis_slot;
- const unsigned rep0_saved = 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 ) rep0 = dis_slot;
- else
+ unsigned distance;
+ len = min_match_len + Rd_decode_len( rdec, &match_len_model, pos_state );
+ distance = Rd_decode_tree6( rdec, bm_dis_slot[get_len_state(len)] );
+ if( distance >= start_dis_model )
{
+ const unsigned dis_slot = distance;
const int direct_bits = ( dis_slot >> 1 ) - 1;
- rep0 = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
+ distance = ( 2 | ( dis_slot & 1 ) ) << direct_bits;
if( dis_slot < end_dis_model )
- rep0 += Rd_decode_tree_reversed( rdec,
- d->bm_dis + rep0 - dis_slot - 1, direct_bits );
+ distance += Rd_decode_tree_reversed( rdec,
+ bm_dis + ( distance - dis_slot ), direct_bits );
else
{
- rep0 += Rd_decode( rdec, direct_bits - dis_align_bits ) << dis_align_bits;
- rep0 += Rd_decode_tree_reversed4( rdec, d->bm_align );
- if( rep0 == 0xFFFFFFFFU ) /* marker found */
+ distance +=
+ Rd_decode( rdec, direct_bits - dis_align_bits ) << dis_align_bits;
+ distance += Rd_decode_tree_reversed4( rdec, bm_align );
+ if( distance == 0xFFFFFFFFU ) /* marker found */
{
- rep0 = rep0_saved;
Rd_normalize( rdec );
LZd_flush_data( d );
if( len == min_match_len ) /* End Of Stream marker */
@@ -298,10 +320,10 @@ int LZd_decode_member( struct LZ_decoder * const d,
}
}
}
- rep3 = rep2; rep2 = rep1; rep1 = rep0_saved;
+ rep3 = rep2; rep2 = rep1; rep1 = rep0; rep0 = distance;
state = St_set_match( state );
if( rep0 >= d->dictionary_size ||
- ( rep0 >= LZd_data_position( d ) && !d->pos_wrapped ) )
+ ( rep0 >= LZd_data_position( d ) && !d->pos_wrapped_dic ) )
{ LZd_flush_data( d ); return 1; }
}
copy_block( d, rep0, len );
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-16 08:14:20 +0000