X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=include%2Fwimlib%2Flzms.h;h=76381a416829de89773d65de795d788cd7b06b7f;hb=a1a043899627341eb5117a48098d8d92abd43827;hp=5584b9a4ceb5a27fae756133678743c0a3ae40cc;hpb=60523d25f34692d6f3a7c8bbda88eead17f23b12;p=wimlib

diff --git a/include/wimlib/lzms.h b/include/wimlib/lzms.h
index 5584b9a4..76381a41 100644
--- a/include/wimlib/lzms.h
+++ b/include/wimlib/lzms.h
@@ -1,8 +1,169 @@
 #ifndef _WIMLIB_LZMS_H
 #define _WIMLIB_LZMS_H
 
-int
-lzms_decompress(const void *cdata, unsigned clen, void *udata, unsigned unlen,
-		unsigned window_size);
+/* Constants for the LZMS data compression format.  See the comments in
+ * lzms-decompress.c for more information about this format.  */
 
+//#define ENABLE_LZMS_DEBUG
+#ifdef ENABLE_LZMS_DEBUG
+#	define LZMS_DEBUG DEBUG
+#       define LZMS_ASSERT wimlib_assert
+#       include "wimlib/assert.h"
+#       include "wimlib/error.h"
+#else
+#	define LZMS_DEBUG(format, ...)
+#	define LZMS_ASSERT(...)
 #endif
+
+#define LZMS_NUM_RECENT_OFFSETS			3
+#define LZMS_MAX_INIT_RECENT_OFFSET		(LZMS_NUM_RECENT_OFFSETS + 1)
+
+#define LZMS_PROBABILITY_BITS			6
+#define LZMS_PROBABILITY_MAX			(1U << LZMS_PROBABILITY_BITS)
+#define LZMS_INITIAL_PROBABILITY		48
+#define LZMS_INITIAL_RECENT_BITS		0x0000000055555555ULL
+
+#define LZMS_NUM_MAIN_STATES			16
+#define LZMS_NUM_MATCH_STATES			32
+#define LZMS_NUM_LZ_MATCH_STATES		64
+#define LZMS_NUM_LZ_REPEAT_MATCH_STATES		64
+#define LZMS_NUM_DELTA_MATCH_STATES		64
+#define LZMS_NUM_DELTA_REPEAT_MATCH_STATES	64
+#define LZMS_MAX_NUM_STATES			64
+
+#define LZMS_NUM_LITERAL_SYMS			256
+#define LZMS_NUM_LEN_SYMS			54
+#define LZMS_NUM_DELTA_POWER_SYMS		8
+#define LZMS_MAX_NUM_OFFSET_SYMS		799
+#define LZMS_MAX_NUM_SYMS			799
+
+#define LZMS_MAX_CODEWORD_LEN			15
+
+#define LZMS_LITERAL_CODE_REBUILD_FREQ		1024
+#define LZMS_LZ_OFFSET_CODE_REBUILD_FREQ	1024
+#define LZMS_LENGTH_CODE_REBUILD_FREQ		512
+#define LZMS_DELTA_OFFSET_CODE_REBUILD_FREQ	1024
+#define LZMS_DELTA_POWER_CODE_REBUILD_FREQ	512
+
+#define LZMS_X86_MAX_GOOD_TARGET_OFFSET		65535
+#define LZMS_X86_MAX_TRANSLATION_OFFSET		1023
+
+/* Code shared between the LZMS decompressor and compressor.  */
+
+#include <wimlib/util.h>
+
+extern void
+lzms_x86_filter(u8 data[], s32 size, s32 last_target_usages[], bool undo);
+
+/* Probability entry for use by the range coder when in a specific state.  */
+struct lzms_probability_entry {
+
+	/* Number of zeroes in the most recent LZMS_PROBABILITY_MAX bits that
+	 * have been coded using this probability entry.  This is a cached value
+	 * because it can be computed as LZMS_PROBABILITY_MAX minus the Hamming
+	 * weight of the low-order LZMS_PROBABILITY_MAX bits of @recent_bits.
+	 * */
+	u32 num_recent_zero_bits;
+
+	/* The most recent LZMS_PROBABILITY_MAX bits that have been coded using
+	 * this probability entry.  The size of this variable, in bits, must be
+	 * at least LZMS_PROBABILITY_MAX.  */
+	u64 recent_bits;
+};
+
+/* LRU queues for LZ matches.  */
+struct lzms_lz_lru_queues {
+
+        /* Recent LZ match offsets  */
+	u32 recent_offsets[LZMS_NUM_RECENT_OFFSETS + 1];
+
+        /* These variables are used to delay updates to the LRU queues by one
+         * decoded item.  */
+	u32 prev_offset;
+	u32 upcoming_offset;
+};
+
+/* LRU queues for delta matches.  */
+struct lzms_delta_lru_queues {
+
+        /* Recent delta match powers and offsets  */
+	u32 recent_powers[LZMS_NUM_RECENT_OFFSETS + 1];
+	u32 recent_offsets[LZMS_NUM_RECENT_OFFSETS + 1];
+
+        /* These variables are used to delay updates to the LRU queues by one
+         * decoded item.  */
+	u32 prev_power;
+	u32 prev_offset;
+	u32 upcoming_power;
+	u32 upcoming_offset;
+};
+
+/* LRU (least-recently-used) queues for match information.  */
+struct lzms_lru_queues {
+        struct lzms_lz_lru_queues lz;
+        struct lzms_delta_lru_queues delta;
+};
+
+extern u32 lzms_position_slot_base[LZMS_MAX_NUM_OFFSET_SYMS + 1];
+
+extern u8 lzms_extra_position_bits[LZMS_MAX_NUM_OFFSET_SYMS];
+
+extern u16 lzms_order_to_position_slot_bounds[30][2];
+
+extern u32 lzms_length_slot_base[LZMS_NUM_LEN_SYMS + 1];
+
+#define LZMS_NUM_FAST_LENGTHS 1024
+extern u8 lzms_length_slot_fast[LZMS_NUM_FAST_LENGTHS];
+
+extern u8 lzms_extra_length_bits[LZMS_NUM_LEN_SYMS];
+
+extern void
+lzms_init_slots(void);
+
+/* Return the slot for the specified value.  */
+extern u32
+lzms_get_slot(u32 value, const u32 slot_base_tab[], u32 num_slots);
+
+static inline u32
+lzms_get_position_slot(u32 position)
+{
+	u32 order = bsr32(position);
+	u32 l = lzms_order_to_position_slot_bounds[order][0];
+	u32 r = lzms_order_to_position_slot_bounds[order][1];
+
+	for (;;) {
+		u32 slot = (l + r) / 2;
+		if (position >= lzms_position_slot_base[slot]) {
+			if (position < lzms_position_slot_base[slot + 1])
+				return slot;
+			else
+				l = slot + 1;
+		} else {
+			r = slot - 1;
+		}
+	}
+}
+
+static inline u32
+lzms_get_length_slot(u32 length)
+{
+	if (likely(length < LZMS_NUM_FAST_LENGTHS))
+		return lzms_length_slot_fast[length];
+	else
+		return lzms_get_slot(length, lzms_length_slot_base,
+				     LZMS_NUM_LEN_SYMS);
+}
+
+extern void
+lzms_init_lru_queues(struct lzms_lru_queues *lru);
+
+extern void
+lzms_update_lz_lru_queues(struct lzms_lz_lru_queues *lz);
+
+extern void
+lzms_update_delta_lru_queues(struct lzms_delta_lru_queues *delta);
+
+extern void
+lzms_update_lru_queues(struct lzms_lru_queues *lru);
+
+#endif /* _WIMLIB_LZMS_H  */