X-Git-Url: https://wimlib.net/git/?p=wimlib;a=blobdiff_plain;f=src%2Flzx.h;h=ab158d866d21a705fcec9a5f23bcccff837dd90c;hp=b44fecffb74c0c1710923bb45b75e5699a257703;hb=a6f5add5e9811584ebd75591a6a25cb9686da9a8;hpb=6f77434ea6ff1407603410e28d1edb966c40e568 diff --git a/src/lzx.h b/src/lzx.h index b44fecff..ab158d86 100644 --- a/src/lzx.h +++ b/src/lzx.h @@ -10,8 +10,7 @@ # define LZX_DEBUG(format, ...) #endif - -/* Constants, some defined by the LZX specification: */ +/* Constants, most of which are defined by the LZX specification: */ /* The smallest and largest allowed match lengths. */ #define LZX_MIN_MATCH 2 @@ -20,16 +19,17 @@ /* Number of values an uncompressed literal byte can represent. */ #define LZX_NUM_CHARS 256 -/* Each LZX block begins with 3 bits that determines the block type: */ +/* Each LZX block begins with 3 bits that determines the block type. Below are + * the valid block types. Values 0, and 4 through 7, are invalid. */ #define LZX_BLOCKTYPE_VERBATIM 1 #define LZX_BLOCKTYPE_ALIGNED 2 #define LZX_BLOCKTYPE_UNCOMPRESSED 3 -/* values 0, and 4 through 7, are invalid. */ - #define LZX_NUM_PRIMARY_LENS 7 /* this one missing from spec! */ -/* Only valid for 32768 block size! */ +/* NOTE: There are really 51 position slots in the LZX format as a whole, but + * only 30 are needed to allow for the window to be up to 32768 bytes long, + * which is the maximum in the WIM format. */ #define LZX_NUM_POSITION_SLOTS 30 /* Read the LZX specification for information about the Huffman trees used in @@ -40,7 +40,7 @@ * read_code_lens() function and built using the make_decode_table() function. * The decode table is not a real tree but rather a table that we can index by * some number of bits (*_TABLEBITS) of the input to quickly look up the symbol - * corresponding to a Huffman code. + * corresponding to a Huffman code. * * The ALIGNED tree is only present on ALIGNED blocks. * @@ -49,16 +49,15 @@ #define LZX_MAINTREE_NUM_SYMBOLS (LZX_NUM_CHARS + \ (LZX_NUM_POSITION_SLOTS << 3)) -#define LZX_MAINTREE_TABLEBITS 12 +#define LZX_MAINTREE_TABLEBITS 11 #define LZX_LENTREE_NUM_SYMBOLS 249 -#define LZX_LENTREE_TABLEBITS 12 +#define LZX_LENTREE_TABLEBITS 10 #define LZX_PRETREE_NUM_SYMBOLS 20 #define LZX_PRETREE_TABLEBITS 6 #define LZX_PRETREE_ELEMENT_SIZE 4 - #define LZX_ALIGNEDTREE_NUM_SYMBOLS 8 #define LZX_ALIGNEDTREE_TABLEBITS 7 #define LZX_ALIGNEDTREE_ELEMENT_SIZE 3 @@ -73,8 +72,8 @@ * different as well. */ #define LZX_MAGIC_FILESIZE 12000000 -extern const u8 lzx_extra_bits[51]; -extern const u32 lzx_position_base[51]; +extern const u8 lzx_extra_bits[LZX_NUM_POSITION_SLOTS]; +extern const u32 lzx_position_base[LZX_NUM_POSITION_SLOTS]; /* Least-recently used queue for match offsets. */ struct lru_queue { @@ -83,10 +82,10 @@ struct lru_queue { int R2; }; -extern int lzx_decompress(const void *compressed_data, uint compressed_len, - void *uncompressed_data, uint uncompressed_len); +extern int lzx_decompress(const void *compressed_data, unsigned compressed_len, + void *uncompressed_data, unsigned uncompressed_len); -extern int lzx_compress(const void *uncompressed_data, uint uncompressed_len, - void *compressed_data, uint *compressed_len_ret); +extern int lzx_compress(const void *uncompressed_data, unsigned uncompressed_len, + void *compressed_data, unsigned *compressed_len_ret); #endif /* _WIMLIB_LZX_H */