summaryrefslogtreecommitdiffstats
path: root/fast_encoder.h
diff options
context:
space:
mode:
Diffstat (limited to 'fast_encoder.h')
-rw-r--r--fast_encoder.h70
1 files changed, 70 insertions, 0 deletions
diff --git a/fast_encoder.h b/fast_encoder.h
new file mode 100644
index 0000000..b9421f4
--- /dev/null
+++ b/fast_encoder.h
@@ -0,0 +1,70 @@
+/* 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.
+*/
+
+struct FLZ_encoder
+ {
+ struct LZ_encoder_base eb;
+ unsigned key4; /* key made from latest 4 bytes */
+ };
+
+static inline void FLZe_reset_key4( struct FLZ_encoder * const fe )
+ {
+ int i;
+ fe->key4 = 0;
+ for( i = 0; i < 3 && i < Mb_available_bytes( &fe->eb.mb ); ++i )
+ fe->key4 = ( fe->key4 << 4 ) ^ fe->eb.mb.buffer[i];
+ }
+
+static inline bool FLZe_update_and_move( struct FLZ_encoder * const fe, int n )
+ {
+ struct Matchfinder_base * const mb = &fe->eb.mb;
+ while( --n >= 0 )
+ {
+ if( Mb_available_bytes( mb ) >= 4 )
+ {
+ fe->key4 = ( ( fe->key4 << 4 ) ^ mb->buffer[mb->pos+3] ) & mb->key4_mask;
+ mb->pos_array[mb->cyclic_pos] = mb->prev_positions[fe->key4];
+ mb->prev_positions[fe->key4] = mb->pos + 1;
+ }
+ else mb->pos_array[mb->cyclic_pos] = 0;
+ if( !Mb_move_pos( mb ) ) return false;
+ }
+ return true;
+ }
+
+static inline bool FLZe_init( struct FLZ_encoder * const fe,
+ const unsigned long long member_size )
+ {
+ enum { before_size = 0,
+ dict_size = 65536,
+ /* bytes to keep in buffer after pos */
+ after_size = max_match_len,
+ dict_factor = 16,
+ min_free_bytes = max_marker_size,
+ num_prev_positions23 = 0,
+ pos_array_factor = 1 };
+
+ return LZeb_init( &fe->eb, before_size, dict_size, after_size, dict_factor,
+ num_prev_positions23, pos_array_factor, min_free_bytes,
+ member_size );
+ }
+
+static inline void FLZe_reset( struct FLZ_encoder * const fe,
+ const unsigned long long member_size )
+ { LZeb_reset( &fe->eb, member_size ); }