/* 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 )
{
struct Range_decoder * const rdec = decoder->rdec;
State * const state = &decoder->state;
if( decoder->member_finished ) return 0;
if( !Rd_try_reload( rdec, false ) ) return 0;
if( decoder->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;
}
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 ) )
return 0;
if( Rd_decode_bit( rdec, &decoder->bm_match[*state][pos_state] ) == 0 ) /* 1st bit */
{
const uint8_t prev_byte = LZd_get_prev_byte( decoder );
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 ) );
}
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 ) ) );
}
}
else
{
int len;
if( Rd_decode_bit( rdec, &decoder->bm_rep[*state] ) != 0 ) /* 2nd bit */
{
if( Rd_decode_bit( rdec, &decoder->bm_rep0[*state] ) != 0 ) /* 3rd bit */
{
unsigned distance;
if( Rd_decode_bit( rdec, &decoder->bm_rep1[*state] ) == 0 ) /* 4th bit */
distance = decoder->rep1;
else
{
if( Rd_decode_bit( rdec, &decoder->bm_rep2[*state] ) == 0 ) /* 5th bit */
distance = decoder->rep2;
else
{ distance = decoder->rep3; decoder->rep3 = decoder->rep2; }
decoder->rep2 = decoder->rep1;
}
decoder->rep1 = decoder->rep0;
decoder->rep0 = distance;
}
else
{
if( Rd_decode_bit( rdec, &decoder->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; }
}
*state = St_set_rep( *state );
len = min_match_len + Rd_decode_len( rdec, &decoder->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;
else
{
const int direct_bits = ( dis_slot >> 1 ) - 1;
decoder->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 );
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 */
{
decoder->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;
}
if( len == min_match_len + 1 ) /* Sync Flush marker */
{
if( Rd_try_reload( rdec, true ) ) continue;
else return 0;
}
return 4;
}
}
}
decoder->rep3 = decoder->rep2;
decoder->rep2 = decoder->rep1; decoder->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 ) )
return 1;
}
LZd_copy_block( decoder, decoder->rep0, len );
}
}
return 2;
}
bool FLZe_encode_member( struct FLZ_encoder * const fe )
{
int rep = 0, i;
State * const state = &fe->eb.state;
if( fe->eb.member_finished ) return true;
if( Re_member_position( &fe->eb.renc ) >= fe->eb.member_size_limit )
{
if( LZeb_full_flush( &fe->eb ) ) fe->eb.member_finished = true;
return true;
}
if( Mb_data_position( &fe->eb.mb ) == 0 &&
!Mb_data_finished( &fe->eb.mb ) ) /* encode first byte */
{
const uint8_t prev_byte = 0;
uint8_t cur_byte;
if( !Mb_enough_available_bytes( &fe->eb.mb ) ||
!Re_enough_free_bytes( &fe->eb.renc ) ) return true;
cur_byte = Mb_peek( &fe->eb.mb, 0 );
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[*state][0], 0 );
LZeb_encode_literal( &fe->eb, prev_byte, cur_byte );
CRC32_update_byte( &fe->eb.crc, cur_byte );
FLZe_reset_key4( fe );
if( !FLZe_update_and_move( fe, 1 ) ) return false;
}
while( !Mb_data_finished( &fe->eb.mb ) &&
Re_member_position( &fe->eb.renc ) < fe->eb.member_size_limit )
{
int match_distance;
int main_len, pos_state, len;
if( !Mb_enough_available_bytes( &fe->eb.mb ) ||
!Re_enough_free_bytes( &fe->eb.renc ) ) return true;
main_len = FLZe_longest_match_len( fe, &match_distance );
pos_state = Mb_data_position( &fe->eb.mb ) & pos_state_mask;
len = 0;
for( i = 0; i < num_rep_distances; ++i )
{
const int tlen = Mb_true_match_len( &fe->eb.mb, 0,
fe->eb.reps[i] + 1, max_match_len );
if( tlen > len ) { len = tlen; rep = i; }
}
if( len > min_match_len && len + 3 > main_len )
{
CRC32_update_buf( &fe->eb.crc, Mb_ptr_to_current_pos( &fe->eb.mb ), len );
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[*state][pos_state], 1 );
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep[*state], 1 );
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep0[*state], rep != 0 );
if( rep == 0 )
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_len[*state][pos_state], 1 );
else
{
int distance;
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep1[*state], rep > 1 );
if( rep > 1 )
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep2[*state], rep > 2 );
distance = fe->eb.reps[rep];
for( i = rep; i > 0; --i ) fe->eb.reps[i] = fe->eb.reps[i-1];
fe->eb.reps[0] = distance;
}
*state = St_set_rep( *state );
Re_encode_len( &fe->eb.renc, &fe->eb.rep_len_model, len, pos_state );
if( !Mb_move_pos( &fe->eb.mb ) ) return false;
if( !FLZe_update_and_move( fe, len - 1 ) ) return false;
continue;
}
if( main_len > min_match_len )
{
CRC32_update_buf( &fe->eb.crc, Mb_ptr_to_current_pos( &fe->eb.mb ), main_len );
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[*state][pos_state], 1 );
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep[*state], 0 );
*state = St_set_match( *state );
for( i = num_rep_distances - 1; i > 0; --i ) fe->eb.reps[i] = fe->eb.reps[i-1];
fe->eb.reps[0] = match_distance;
LZeb_encode_pair( &fe->eb, match_distance, main_len, pos_state );
if( !Mb_move_pos( &fe->eb.mb ) ) return false;
if( !FLZe_update_and_move( fe, main_len - 1 ) ) return false;
continue;
}
{
const uint8_t prev_byte = Mb_peek( &fe->eb.mb, 1 );
const uint8_t cur_byte = Mb_peek( &fe->eb.mb, 0 );
const uint8_t match_byte = Mb_peek( &fe->eb.mb, fe->eb.reps[0] + 1 );
if( !Mb_move_pos( &fe->eb.mb ) ) return false;
CRC32_update_byte( &fe->eb.crc, cur_byte );
if( match_byte == cur_byte )
{
const int short_rep_price = price1( fe->eb.bm_match[*state][pos_state] ) +
price1( fe->eb.bm_rep[*state] ) +
price0( fe->eb.bm_rep0[*state] ) +
price0( fe->eb.bm_len[*state][pos_state] );
int price = price0( fe->eb.bm_match[*state][pos_state] );
if( St_is_char( *state ) )
price += LZeb_price_literal( &fe->eb, prev_byte, cur_byte );
else
price += LZeb_price_matched( &fe->eb, prev_byte, cur_byte, match_byte );
if( short_rep_price < price )
{
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[*state][pos_state], 1 );
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep[*state], 1 );
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_rep0[*state], 0 );
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_len[*state][pos_state], 0 );
*state = St_set_short_rep( *state );
continue;
}
}
/* literal byte */
Re_encode_bit( &fe->eb.renc, &fe->eb.bm_match[*state][pos_state], 0 );
if( St_is_char( *state ) )
LZeb_encode_literal( &fe->eb, prev_byte, cur_byte );
else
LZeb_encode_matched( &fe->eb, prev_byte, cur_byte, match_byte );
*state = St_set_char( *state );
}
}
if( LZeb_full_flush( &fe->eb ) ) fe->eb.member_finished = true;
return true;
}
