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 u32 lzms_length_slot_base[LZMS_NUM_LEN_SYMS + 1];
LZMS_NUM_LEN_SYMS);
}
+extern void
+lzms_init_lru_queues(struct lzms_lru_queues *lru);
+
+extern void
+lzms_update_lru_queues(struct lzms_lru_queues *lru);
+
#endif /* _WIMLIB_LZMS_H */
}
}
}
+
+static void
+lzms_init_lz_lru_queues(struct lzms_lz_lru_queues *lz)
+{
+ /* Recent offsets for LZ matches */
+ for (u32 i = 0; i < LZMS_NUM_RECENT_OFFSETS + 1; i++)
+ lz->recent_offsets[i] = i + 1;
+
+ lz->prev_offset = 0;
+ lz->upcoming_offset = 0;
+}
+
+static void
+lzms_init_delta_lru_queues(struct lzms_delta_lru_queues *delta)
+{
+ /* Recent offsets and powers for LZ matches */
+ for (u32 i = 0; i < LZMS_NUM_RECENT_OFFSETS + 1; i++) {
+ delta->recent_offsets[i] = i + 1;
+ delta->recent_powers[i] = 0;
+ }
+ delta->prev_offset = 0;
+ delta->prev_power = 0;
+ delta->upcoming_offset = 0;
+ delta->upcoming_power = 0;
+}
+
+
+void
+lzms_init_lru_queues(struct lzms_lru_queues *lru)
+{
+ lzms_init_lz_lru_queues(&lru->lz);
+ lzms_init_delta_lru_queues(&lru->delta);
+}
+
+static void
+lzms_update_lz_lru_queues(struct lzms_lz_lru_queues *lz)
+{
+ if (lz->prev_offset != 0) {
+ for (int i = LZMS_NUM_RECENT_OFFSETS - 1; i >= 0; i--)
+ lz->recent_offsets[i + 1] = lz->recent_offsets[i];
+ lz->recent_offsets[0] = lz->prev_offset;
+ }
+ lz->prev_offset = lz->upcoming_offset;
+}
+
+static void
+lzms_update_delta_lru_queues(struct lzms_delta_lru_queues *delta)
+{
+ if (delta->prev_offset != 0) {
+ for (int i = LZMS_NUM_RECENT_OFFSETS - 1; i >= 0; i--) {
+ delta->recent_offsets[i + 1] = delta->recent_offsets[i];
+ delta->recent_powers[i + 1] = delta->recent_powers[i];
+ }
+ delta->recent_offsets[0] = delta->prev_offset;
+ delta->recent_powers[0] = delta->prev_power;
+ }
+
+ delta->prev_offset = delta->upcoming_offset;
+ delta->prev_power = delta->upcoming_power;
+}
+
+void
+lzms_update_lru_queues(struct lzms_lru_queues *lru)
+{
+ lzms_update_lz_lru_queues(&lru->lz);
+ lzms_update_delta_lru_queues(&lru->delta);
+}
#include "wimlib/endianness.h"
#include "wimlib/error.h"
#include "wimlib/lz_hash.h"
+#include "wimlib/lz_sarray.h"
#include "wimlib/lzms.h"
#include "wimlib/util.h"
* as the window. */
u32 *prev_tab;
+ /* Suffix array match-finder. */
+ struct lz_sarray lz_sarray;
+
/* Maximum block size this compressor instantiation allows. This is the
* allocated size of @window. */
u32 max_block_size;
struct lzms_huffman_encoder delta_power_encoder;
struct lzms_huffman_encoder delta_offset_encoder;
- /* LRU (least-recently-used) queue of LZ match offsets. */
- u64 recent_lz_offsets[LZMS_NUM_RECENT_OFFSETS + 1];
-
- /* LRU (least-recently-used) queue of delta match powers. */
- u32 recent_delta_powers[LZMS_NUM_RECENT_OFFSETS + 1];
-
- /* LRU (least-recently-used) queue of delta match offsets. */
- u32 recent_delta_offsets[LZMS_NUM_RECENT_OFFSETS + 1];
-
- /* These variables are used to delay updates to the LRU queues by one
- * decoded item. */
- u32 prev_lz_offset;
- u32 prev_delta_power;
- u32 prev_delta_offset;
- u32 upcoming_lz_offset;
- u32 upcoming_delta_power;
- u32 upcoming_delta_offset;
+ /* LRU (least-recently-used) queues for match information. */
+ struct lzms_lru_queues lru;
/* Used for preprocessing. */
s32 last_target_usages[65536];
};
-struct lzms_match {
- u32 length;
- u32 offset;
-};
-
/* Initialize the output bitstream @os to write forwards to the specified
* compressed data buffer @out that is @out_limit 16-bit integers long. */
static void
static void
lzms_begin_encode_item(struct lzms_compressor *ctx)
{
- ctx->upcoming_delta_offset = 0;
- ctx->upcoming_lz_offset = 0;
- ctx->upcoming_delta_power = 0;
+ ctx->lru.lz.upcoming_offset = 0;
+ ctx->lru.delta.upcoming_offset = 0;
+ ctx->lru.delta.upcoming_power = 0;
}
static void
{
LZMS_ASSERT(ctx->window_size - ctx->cur_window_pos >= length);
ctx->cur_window_pos += length;
-
- /* Update LRU queues */
- if (ctx->prev_lz_offset != 0) {
- for (int i = LZMS_NUM_RECENT_OFFSETS - 1; i >= 0; i--)
- ctx->recent_lz_offsets[i + 1] = ctx->recent_lz_offsets[i];
- ctx->recent_lz_offsets[0] = ctx->prev_lz_offset;
- }
-
- if (ctx->prev_delta_offset != 0) {
- for (int i = LZMS_NUM_RECENT_OFFSETS - 1; i >= 0; i--) {
- ctx->recent_delta_powers[i + 1] = ctx->recent_delta_powers[i];
- ctx->recent_delta_offsets[i + 1] = ctx->recent_delta_offsets[i];
- }
- ctx->recent_delta_powers[0] = ctx->prev_delta_power;
- ctx->recent_delta_offsets[0] = ctx->prev_delta_offset;
- }
-
- ctx->prev_lz_offset = ctx->upcoming_lz_offset;
- ctx->prev_delta_offset = ctx->upcoming_delta_offset;
- ctx->prev_delta_power = ctx->upcoming_delta_power;
+ lzms_update_lru_queues(&ctx->lru);
}
/* Encode a literal byte. */
for (recent_offset_idx = 0;
recent_offset_idx < LZMS_NUM_RECENT_OFFSETS;
recent_offset_idx++)
- if (offset == ctx->recent_lz_offsets[recent_offset_idx])
+ if (offset == ctx->lru.lz.recent_offsets[recent_offset_idx])
break;
if (recent_offset_idx == LZMS_NUM_RECENT_OFFSETS) {
/* Initial update of the LZ match offset LRU queue. */
for (; i < LZMS_NUM_RECENT_OFFSETS; i++)
- ctx->recent_lz_offsets[i] = ctx->recent_lz_offsets[i + 1];
+ ctx->lru.lz.recent_offsets[i] = ctx->lru.lz.recent_offsets[i + 1];
}
/* Encode the match length. */
/* Save the match offset for later insertion at the front of the LZ
* match offset LRU queue. */
- ctx->upcoming_lz_offset = offset;
+ ctx->lru.lz.upcoming_offset = offset;
lzms_end_encode_item(ctx, length);
}
}
-#if 0
+/* Fast heuristic cost evaluation to use in the inner loop of the match-finder.
+ * Unlike lzms_match_cost() which does a true cost evaluation, this simply
+ * prioritize matches based on their offset. */
+static input_idx_t
+lzms_match_cost_fast(input_idx_t length, input_idx_t offset, const void *_lru)
+{
+ const struct lzms_lz_lru_queues *lru = _lru;
+
-static struct lzms_match
-lzms_get_best_match(struct lzms_compressor *ctx)
+ /* It seems well worth it to take the time to give priority to recently
+ * used offsets. */
+ for (input_idx_t i = 0; i < LZMS_NUM_RECENT_OFFSETS; i++)
+ if (offset == lru->recent_offsets[i])
+ return i;
+
+ return offset;
+}
+
+static void
+lzms_lz_skip_bytes(struct lzms_compressor *ctx, u32 n)
{
- struct lzms_match match;
+ while (n--)
+ lz_sarray_skip_position(&ctx->lz_sarray);
+}
- /* TODO */
+static struct raw_match
+lzms_get_near_optimal_match(struct lzms_compressor *ctx)
+{
+ struct raw_match matches[10];
+ u32 num_matches;
+
+ num_matches = lz_sarray_get_matches(&ctx->lz_sarray,
+ matches,
+ lzms_match_cost_fast,
+ &ctx->lru.lz);
+ if (num_matches == 0)
+ return (struct raw_match) { .len = 0 };
- match.length = 0;
+#if 0
+ fprintf(stderr, "Pos %u/%u: %u matches\n",
+ lz_sarray_get_pos(&ctx->lz_sarray) - 1,
+ ctx->window_size, num_matches);
+ for (u32 i = 0; i < num_matches; i++)
+ fprintf(stderr, "\tLen %u Offset %u\n", matches[i].len, matches[i].offset);
+#endif
- return match;
+ lzms_lz_skip_bytes(ctx, matches[0].len - 1);
+ return matches[0];
}
static void
lzms_slow_encode(struct lzms_compressor *ctx)
{
- struct lzms_match match;
+ struct raw_match match;
+
+ /* Load window into suffix array match-finder. */
+ lz_sarray_load_window(&ctx->lz_sarray, ctx->window, ctx->window_size);
/* TODO */
while (ctx->cur_window_pos != ctx->window_size) {
- match = lzms_get_best_match(ctx);
- if (match.length == 0) {
+
+ match = lzms_get_near_optimal_match(ctx);
+ if (match.len == 0) {
/* Literal */
lzms_encode_literal(ctx, ctx->window[ctx->cur_window_pos]);
} else {
/* LZ match */
- lzms_encode_lz_match(ctx, match.length, match.offset);
+ lzms_encode_lz_match(ctx, match.len, match.offset);
}
}
}
-#endif
static void
lzms_init_range_encoder(struct lzms_range_encoder *enc,
lzms_init_range_encoder(&ctx->delta_repeat_match_range_encoders[i],
&ctx->rc, LZMS_NUM_DELTA_REPEAT_MATCH_STATES);
- /* Initialize the LRU queue for recent match offsets. */
- for (size_t i = 0; i < LZMS_NUM_RECENT_OFFSETS + 1; i++)
- ctx->recent_lz_offsets[i] = i + 1;
-
- for (size_t i = 0; i < LZMS_NUM_RECENT_OFFSETS + 1; i++) {
- ctx->recent_delta_powers[i] = 0;
- ctx->recent_delta_offsets[i] = i + 1;
- }
- ctx->prev_lz_offset = 0;
- ctx->prev_delta_offset = 0;
- ctx->prev_delta_power = 0;
- ctx->upcoming_lz_offset = 0;
- ctx->upcoming_delta_offset = 0;
- ctx->upcoming_delta_power = 0;
+ /* Initialize LRU match information. */
+ lzms_init_lru_queues(&ctx->lru);
}
/* Flush the output streams, prepare the final compressed data, and return its
/* Determine and output a literal/match sequence that decompresses to
* the preprocessed data. */
- lzms_fast_encode(ctx);
+ if (1)
+ lzms_slow_encode(ctx);
+ else
+ lzms_fast_encode(ctx);
/* Get and return the compressed data size. */
compressed_size = lzms_finalize(ctx, compressed_data,
if (ctx) {
FREE(ctx->window);
FREE(ctx->prev_tab);
+ lz_sarray_destroy(&ctx->lz_sarray);
FREE(ctx);
}
}
if (ctx->prev_tab == NULL)
goto oom;
+ if (!lz_sarray_init(&ctx->lz_sarray,
+ max_block_size,
+ 2,
+ max_block_size,
+ 100,
+ 10))
+ goto oom;
+
+
ctx->max_block_size = max_block_size;
*ctx_ret = ctx;
struct lzms_huffman_decoder delta_power_decoder;
struct lzms_huffman_decoder delta_offset_decoder;
- /* LRU (least-recently-used) queue of LZ match offsets. */
- u64 recent_lz_offsets[LZMS_NUM_RECENT_OFFSETS + 1];
-
- /* LRU (least-recently-used) queue of delta match powers. */
- u32 recent_delta_powers[LZMS_NUM_RECENT_OFFSETS + 1];
-
- /* LRU (least-recently-used) queue of delta match offsets. */
- u32 recent_delta_offsets[LZMS_NUM_RECENT_OFFSETS + 1];
-
- /* These variables are used to delay updates to the LRU queues by one
- * decoded item. */
- u32 prev_lz_offset;
- u32 prev_delta_power;
- u32 prev_delta_offset;
- u32 upcoming_lz_offset;
- u32 upcoming_delta_power;
- u32 upcoming_delta_offset;
+ /* LRU (least-recently-used) queues for match information. */
+ struct lzms_lru_queues lru;
/* Used for postprocessing. */
s32 last_target_usages[65536];
if (!lzms_range_decode_bit(&ctx->lz_repeat_match_range_decoders[i]))
break;
- offset = ctx->recent_lz_offsets[i];
+ offset = ctx->lru.lz.recent_offsets[i];
for (; i < LZMS_NUM_RECENT_OFFSETS; i++)
- ctx->recent_lz_offsets[i] = ctx->recent_lz_offsets[i + 1];
+ ctx->lru.lz.recent_offsets[i] = ctx->lru.lz.recent_offsets[i + 1];
}
/* Decode match length, which is always given explicitly (there is no
* LRU queue for repeat lengths). */
length = lzms_decode_value(&ctx->length_decoder);
- ctx->upcoming_lz_offset = offset;
+ ctx->lru.lz.upcoming_offset = offset;
LZMS_DEBUG("Decoded %s LZ match: length=%u, offset=%u",
(bit ? "repeat" : "explicit"), length, offset);
if (!lzms_range_decode_bit(&ctx->delta_repeat_match_range_decoders[i]))
break;
- power = ctx->recent_delta_powers[i];
- raw_offset = ctx->recent_delta_offsets[i];
+ power = ctx->lru.delta.recent_powers[i];
+ raw_offset = ctx->lru.delta.recent_offsets[i];
for (; i < LZMS_NUM_RECENT_OFFSETS; i++) {
- ctx->recent_delta_powers[i] = ctx->recent_delta_powers[i + 1];
- ctx->recent_delta_offsets[i] = ctx->recent_delta_offsets[i + 1];
+ ctx->lru.delta.recent_powers[i] = ctx->lru.delta.recent_powers[i + 1];
+ ctx->lru.delta.recent_offsets[i] = ctx->lru.delta.recent_offsets[i + 1];
}
}
length = lzms_decode_value(&ctx->length_decoder);
- ctx->upcoming_delta_power = power;
- ctx->upcoming_delta_offset = raw_offset;
+ ctx->lru.delta.upcoming_power = power;
+ ctx->lru.delta.upcoming_offset = raw_offset;
LZMS_DEBUG("Decoded %s delta match: length=%u, power=%u, raw_offset=%u",
(bit ? "repeat" : "explicit"), length, power, raw_offset);
{
int ret;
- ctx->upcoming_delta_offset = 0;
- ctx->upcoming_lz_offset = 0;
- ctx->upcoming_delta_power = 0;
+ ctx->lru.lz.upcoming_offset = 0;
+ ctx->lru.delta.upcoming_power = 0;
+ ctx->lru.delta.upcoming_offset = 0;
if (lzms_range_decode_bit(&ctx->main_range_decoder))
ret = lzms_decode_match(ctx);
return ret;
/* Update LRU queues */
- if (ctx->prev_lz_offset != 0) {
- for (int i = LZMS_NUM_RECENT_OFFSETS - 1; i >= 0; i--)
- ctx->recent_lz_offsets[i + 1] = ctx->recent_lz_offsets[i];
- ctx->recent_lz_offsets[0] = ctx->prev_lz_offset;
- }
-
- if (ctx->prev_delta_offset != 0) {
- for (int i = LZMS_NUM_RECENT_OFFSETS - 1; i >= 0; i--) {
- ctx->recent_delta_powers[i + 1] = ctx->recent_delta_powers[i];
- ctx->recent_delta_offsets[i + 1] = ctx->recent_delta_offsets[i];
- }
- ctx->recent_delta_powers[0] = ctx->prev_delta_power;
- ctx->recent_delta_offsets[0] = ctx->prev_delta_offset;
- }
-
- ctx->prev_lz_offset = ctx->upcoming_lz_offset;
- ctx->prev_delta_offset = ctx->upcoming_delta_offset;
- ctx->prev_delta_power = ctx->upcoming_delta_power;
+ lzms_update_lru_queues(&ctx->lru);
return 0;
}
lzms_init_range_decoder(&ctx->delta_repeat_match_range_decoders[i],
&ctx->rd, LZMS_NUM_DELTA_REPEAT_MATCH_STATES);
- /* Initialize the LRU queue for recent match offsets. */
- for (size_t i = 0; i < LZMS_NUM_RECENT_OFFSETS + 1; i++)
- ctx->recent_lz_offsets[i] = i + 1;
-
- for (size_t i = 0; i < LZMS_NUM_RECENT_OFFSETS + 1; i++) {
- ctx->recent_delta_powers[i] = 0;
- ctx->recent_delta_offsets[i] = i + 1;
- }
- ctx->prev_lz_offset = 0;
- ctx->prev_delta_offset = 0;
- ctx->prev_delta_power = 0;
- ctx->upcoming_lz_offset = 0;
- ctx->upcoming_delta_offset = 0;
- ctx->upcoming_delta_power = 0;
+ /* Initialize LRU match information. */
+ lzms_init_lru_queues(&ctx->lru);
LZMS_DEBUG("Decompressor successfully initialized");
}