+/*
+ * lzms.h
+ *
+ * Declarations shared between LZMS compression and decompression.
+ */
+
#ifndef _WIMLIB_LZMS_H
#define _WIMLIB_LZMS_H
-int
-lzms_decompress(const void *cdata, unsigned clen, void *udata, unsigned unlen,
- unsigned window_size);
+#include "wimlib/lzms_constants.h"
+#include "wimlib/util.h"
+//#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
+
+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 number
+ * of bits set in 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;
+};
+
+/* Offset slot tables */
+extern u32 lzms_offset_slot_base[LZMS_MAX_NUM_OFFSET_SYMS + 1];
+extern u8 lzms_extra_offset_bits[LZMS_MAX_NUM_OFFSET_SYMS];
+
+/* Length slot tables */
+extern u32 lzms_length_slot_base[LZMS_NUM_LEN_SYMS + 1];
+extern u8 lzms_extra_length_bits[LZMS_NUM_LEN_SYMS];
+
+extern void
+lzms_init_slots(void);
+
+extern unsigned
+lzms_get_slot(u32 value, const u32 slot_base_tab[], unsigned num_slots);
+
+/* Return the offset slot for the specified offset */
+static inline unsigned
+lzms_get_offset_slot(u32 offset)
+{
+ return lzms_get_slot(offset, lzms_offset_slot_base, LZMS_MAX_NUM_OFFSET_SYMS);
+}
+
+/* Return the length slot for the specified length */
+static inline unsigned
+lzms_get_length_slot(u32 length)
+{
+ return lzms_get_slot(length, lzms_length_slot_base, LZMS_NUM_LEN_SYMS);
+}
+
+extern void
+lzms_init_lz_lru_queues(struct lzms_lz_lru_queues *lz);
+
+extern void
+lzms_init_delta_lru_queues(struct lzms_delta_lru_queues *delta);
+
+extern void
+lzms_init_lru_queues(struct lzms_lru_queues *lru);
+
+extern void
+lzms_update_lz_lru_queue(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);
+
+/* Given a decoded bit, update the probability entry. */
+static inline void
+lzms_update_probability_entry(struct lzms_probability_entry *prob_entry, int bit)
+{
+ s32 delta_zero_bits;
+
+ BUILD_BUG_ON(LZMS_PROBABILITY_MAX != sizeof(prob_entry->recent_bits) * 8);
+
+ delta_zero_bits = (s32)(prob_entry->recent_bits >> (LZMS_PROBABILITY_MAX - 1)) - bit;
+
+ prob_entry->num_recent_zero_bits += delta_zero_bits;
+ prob_entry->recent_bits <<= 1;
+ prob_entry->recent_bits |= bit;
+}
+
+/* Given a probability entry, return the chance out of LZMS_PROBABILITY_MAX that
+ * the next decoded bit will be a 0. */
+static inline u32
+lzms_get_probability(const struct lzms_probability_entry *prob_entry)
+{
+ u32 prob;
+
+ prob = prob_entry->num_recent_zero_bits;
+
+ /* 0% and 100% probabilities aren't allowed. */
+ if (prob == 0)
+ prob++;
+ if (prob == LZMS_PROBABILITY_MAX)
+ prob--;
+ return prob;
+}
+
+#endif /* _WIMLIB_LZMS_H */
git://wimlib.net / wimlib / blobdiff