X-Git-Url: https://wimlib.net/git/?a=blobdiff_plain;f=include%2Fwimlib%2Flzms.h;h=798b339c5fc63856586c971158a5e183355cee4a;hb=1238789866c94796eb4a3ee4f203481aabec8940;hp=de965fe75139ee395b65ab43571e5acf282bb931;hpb=e176e9731e696562bab8de7b9bd34c019deef3e8;p=wimlib

diff --git a/include/wimlib/lzms.h b/include/wimlib/lzms.h
index de965fe7..798b339c 100644
--- a/include/wimlib/lzms.h
+++ b/include/wimlib/lzms.h
@@ -8,6 +8,8 @@
 #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(...)
@@ -45,4 +47,122 @@
 #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  */