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-rw-r--r--decoder.h48
1 files changed, 27 insertions, 21 deletions
diff --git a/decoder.h b/decoder.h
index 833701b..662aaf9 100644
--- a/decoder.h
+++ b/decoder.h
@@ -1,5 +1,5 @@
/* Clzip - LZMA lossless data compressor
- Copyright (C) 2010-2015 Antonio Diaz Diaz.
+ Copyright (C) 2010-2016 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
@@ -60,7 +60,8 @@ static inline void Rd_reset_member_position( struct Range_decoder * const rdec )
static inline uint8_t Rd_get_byte( struct Range_decoder * const rdec )
{
- if( Rd_finished( rdec ) ) return 0xAA; /* make code != 0 */
+ /* 0xFF avoids decoder error if member is truncated at EOS marker */
+ if( Rd_finished( rdec ) ) return 0xFF;
return rdec->buffer[rdec->pos++];
}
@@ -232,12 +233,12 @@ struct LZ_decoder
unsigned long long partial_data_pos;
struct Range_decoder * rdec;
unsigned dictionary_size;
- int buffer_size;
uint8_t * buffer; /* output buffer */
- int pos; /* current pos in buffer */
- int stream_pos; /* first byte not yet written to file */
+ unsigned pos; /* current pos in buffer */
+ unsigned stream_pos; /* first byte not yet written to file */
uint32_t crc;
int outfd; /* output file descriptor */
+ bool pos_wrapped;
Bit_model bm_literal[1<<literal_context_bits][0x300];
Bit_model bm_match[states][pos_states];
@@ -258,56 +259,61 @@ void LZd_flush_data( struct LZ_decoder * const d );
static inline uint8_t LZd_peek_prev( const struct LZ_decoder * const d )
{
- const int i = ( ( d->pos > 0 ) ? d->pos : d->buffer_size ) - 1;
+ const unsigned i = ( ( d->pos > 0 ) ? d->pos : d->dictionary_size ) - 1;
return d->buffer[i];
}
static inline uint8_t LZd_peek( const struct LZ_decoder * const d,
- const int distance )
+ const unsigned distance )
{
- int i = d->pos - distance - 1;
- if( i < 0 ) i += d->buffer_size;
+ unsigned i = d->pos - distance - 1;
+ if( d->pos <= distance ) i += d->dictionary_size;
return d->buffer[i];
}
static inline void LZd_put_byte( struct LZ_decoder * const d, const uint8_t b )
{
d->buffer[d->pos] = b;
- if( ++d->pos >= d->buffer_size ) LZd_flush_data( d );
+ if( ++d->pos >= d->dictionary_size ) LZd_flush_data( d );
}
static inline void LZd_copy_block( struct LZ_decoder * const d,
- const int distance, int len )
+ const unsigned distance, unsigned len )
{
- int i = d->pos - distance - 1;
- if( i < 0 ) i += d->buffer_size;
- if( len < d->buffer_size - max( d->pos, i ) && len <= abs( d->pos - i ) )
+ unsigned i = d->pos - distance - 1;
+ bool fast;
+ if( d->pos <= distance )
+ { i += d->dictionary_size;
+ fast = ( len <= d->dictionary_size - i && len <= i - d->pos ); }
+ else
+ fast = ( len < d->dictionary_size - d->pos && len <= d->pos - i );
+ if( fast ) /* no wrap, no overlap */
{
- memcpy( d->buffer + d->pos, d->buffer + i, len ); /* no wrap, no overlap */
+ memcpy( d->buffer + d->pos, d->buffer + i, len );
d->pos += len;
}
else for( ; len > 0; --len )
{
d->buffer[d->pos] = d->buffer[i];
- if( ++d->pos >= d->buffer_size ) LZd_flush_data( d );
- if( ++i >= d->buffer_size ) i = 0;
+ if( ++d->pos >= d->dictionary_size ) LZd_flush_data( d );
+ if( ++i >= d->dictionary_size ) i = 0;
}
}
static inline bool LZd_init( struct LZ_decoder * const d,
struct Range_decoder * const rde,
- const int dict_size, const int ofd )
+ const unsigned dict_size, const int ofd )
{
d->partial_data_pos = 0;
d->rdec = rde;
d->dictionary_size = dict_size;
- d->buffer_size = max( 65536U, d->dictionary_size );
- d->buffer = (uint8_t *)malloc( d->buffer_size );
+ d->buffer = (uint8_t *)malloc( d->dictionary_size );
if( !d->buffer ) return false;
d->pos = 0;
d->stream_pos = 0;
d->crc = 0xFFFFFFFFU;
d->outfd = ofd;
+ d->pos_wrapped = false;
Bm_array_init( d->bm_literal[0], (1 << literal_context_bits) * 0x300 );
Bm_array_init( d->bm_match[0], states * pos_states );
@@ -321,7 +327,7 @@ static inline bool LZd_init( struct LZ_decoder * const d,
Bm_array_init( d->bm_align, dis_align_size );
Lm_init( &d->match_len_model );
Lm_init( &d->rep_len_model );
- d->buffer[d->buffer_size-1] = 0; /* prev_byte of first byte */
+ d->buffer[d->dictionary_size-1] = 0; /* prev_byte of first byte */
return true;
}