+/*
+ * lzx.h
+ *
+ * Declarations shared between LZX compression and decompression.
+ */
+
#ifndef _WIMLIB_LZX_H
#define _WIMLIB_LZX_H
-/* Constants for the LZX data compression format. See the comments in
- * lzx-compress.c and lzx-decompress.c for more information about this format.
- * */
-
#include "wimlib/assert.h"
+#include "wimlib/compiler.h"
+#include "wimlib/lzx_constants.h"
#include "wimlib/util.h"
#include "wimlib/types.h"
//#define ENABLE_LZX_DEBUG
#ifdef ENABLE_LZX_DEBUG
-# define LZX_DEBUG DEBUG
# define LZX_ASSERT wimlib_assert
#else
-# define LZX_DEBUG(format, ...)
# define LZX_ASSERT(...)
#endif
-/* Constants, most of which are defined by the LZX specification: */
-
-/* The smallest and largest allowed match lengths. */
-#define LZX_MIN_MATCH_LEN 2
-#define LZX_MAX_MATCH_LEN 257
-
-/* 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. 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
-
-#define LZX_NUM_PRIMARY_LENS 7
-
-/* The number of position slots varies from 30 to 51 depending on the window
- * size (see comment in lzx-decompress.c). */
-#define LZX_MAX_POSITION_SLOTS 51
-
-#define LZX_MIN_WINDOW_ORDER 15
-#define LZX_MAX_WINDOW_ORDER 21
-#define LZX_MIN_WINDOW_SIZE (1U << LZX_MIN_WINDOW_ORDER) /* 32768 */
-#define LZX_MAX_WINDOW_SIZE (1U << LZX_MAX_WINDOW_ORDER) /* 2097152 */
-
-/* Read the LZX specification for information about the Huffman trees used in
- * the LZX compression format. Basically there are 4 of them: The main tree,
- * the length tree, the pre tree, and the aligned tree. The main tree and
- * length tree are given at the beginning of VERBATIM and ALIGNED blocks as a
- * list of *_NUM_SYMBOLS code length values. They are read using the
- * 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.
- *
- * The ALIGNED tree is only present on ALIGNED blocks.
- *
- * A PRECODE is used to encode the code lengths for the main tree and the length
- * tree. There is a separate pretree for each half of the main tree. */
-
-#define LZX_MAINCODE_MAX_NUM_SYMBOLS (LZX_NUM_CHARS + (LZX_MAX_POSITION_SLOTS << 3))
-#define LZX_MAINCODE_TABLEBITS 11
-
-#define LZX_LENCODE_NUM_SYMBOLS 249
-#define LZX_LENCODE_TABLEBITS 10
-
-#define LZX_PRECODE_NUM_SYMBOLS 20
-#define LZX_PRECODE_TABLEBITS 6
-#define LZX_PRECODE_ELEMENT_SIZE 4
-
-#define LZX_ALIGNEDCODE_NUM_SYMBOLS 8
-#define LZX_ALIGNEDCODE_TABLEBITS 7
-#define LZX_ALIGNEDCODE_ELEMENT_SIZE 3
-
-/* Maximum allowed length of Huffman codewords. */
-#define LZX_MAX_MAIN_CODEWORD_LEN 16
-#define LZX_MAX_LEN_CODEWORD_LEN 16
-#define LZX_MAX_PRE_CODEWORD_LEN 16
-#define LZX_MAX_ALIGNED_CODEWORD_LEN 8
-
-/* For the LZX-compressed blocks in WIM files, this value is always used as the
- * filesize parameter for the call instruction (0xe8 byte) preprocessing, even
- * though the blocks themselves are not this size, and the size of the actual
- * file resource in the WIM file is very likely to be something entirely
- * different as well. */
-#define LZX_WIM_MAGIC_FILESIZE 12000000
-
-/* Assumed LZX block size when the encoded block size begins with a 0 bit. */
-#define LZX_DEFAULT_BLOCK_SIZE 32768
-
#define USE_LZX_EXTRA_BITS_ARRAY
#ifdef USE_LZX_EXTRA_BITS_ARRAY
extern const u8 lzx_extra_bits[LZX_MAX_POSITION_SLOTS];
#endif
-/* Given the number of a LZX position slot, return the number of extra bits that
+/* Given the number of an LZX position slot, return the number of extra bits that
* are needed to encode the match offset. */
static inline unsigned
lzx_get_num_extra_bits(unsigned position_slot)
* the formatted offset without actually looking at the array.
*/
static inline unsigned
-lzx_get_position_slot_raw(unsigned formatted_offset)
+lzx_get_position_slot_raw(u32 formatted_offset)
{
if (formatted_offset >= 196608) {
return (formatted_offset >> 17) + 34;
}
}
-extern bool lzx_window_size_valid(size_t window_size);
-extern unsigned lzx_get_num_main_syms(u32 window_size);
+extern unsigned lzx_get_window_order(size_t max_block_size);
-#define LZX_NUM_RECENT_OFFSETS 3
+extern unsigned lzx_get_num_main_syms(unsigned window_order);
/* Least-recently used queue for match offsets. */
struct lzx_lru_queue {
u32 R[LZX_NUM_RECENT_OFFSETS];
-};
-
-/* In the LZX format, an offset of n bytes is actually encoded
- * as (n + LZX_OFFSET_OFFSET). */
-#define LZX_OFFSET_OFFSET (LZX_NUM_RECENT_OFFSETS - 1)
+}
+#ifdef __x86_64__
+_aligned_attribute(8) /* Improves performance of LZX compression by 1% - 2%;
+ specifically, this speeds up
+ lzx_choose_near_optimal_item(). */
+#endif
+;
+/* Initialize the LZX least-recently-used match offset queue at the beginning of
+ * a new window for either decompression or compression. */
static inline void
lzx_lru_queue_init(struct lzx_lru_queue *queue)
{
queue->R[i] = 1;
}
+extern void
+lzx_do_e8_preprocessing(u8 *data, u32 size);
+
+extern void
+lzx_undo_e8_preprocessing(u8 *data, u32 size);
+
#endif /* _WIMLIB_LZX_H */
git://wimlib.net / wimlib / blobdiff