#include "wimlib/compress_common.h"
#include "wimlib/endianness.h"
#include "wimlib/error.h"
-#include "wimlib/lz.h"
-#include "wimlib/lz_bt.h"
+#include "wimlib/lz_mf.h"
#include "wimlib/lzms.h"
#include "wimlib/util.h"
u32 codewords[LZMS_MAX_NUM_SYMS];
};
+struct lzms_compressor_params {
+ u32 min_match_length;
+ u32 nice_match_length;
+ u32 max_search_depth;
+ u32 optim_array_length;
+};
+
/* State of the LZMS compressor. */
struct lzms_compressor {
- struct wimlib_lzms_compressor_params params;
-
/* Pointer to a buffer holding the preprocessed data to compress. */
u8 *window;
/* Size of the data in @buffer. */
u32 window_size;
- /* Binary tree match-finder. */
- struct lz_bt mf;
+ /* Lempel-Ziv match-finder. */
+ struct lz_mf *mf;
/* Temporary space to store found matches. */
struct lz_match *matches;
* allocated size of @window. */
u32 max_block_size;
+ /* Compression parameters. */
+ struct lzms_compressor_params params;
+
/* Raw range encoder which outputs to the beginning of the compressed
* data buffer, proceeding forwards. */
struct lzms_range_encoder_raw rc;
lzms_get_matches(struct lzms_compressor *ctx, struct lz_match **matches_ret)
{
*matches_ret = ctx->matches;
- return lz_bt_get_matches(&ctx->mf, ctx->matches);
+ return lz_mf_get_matches(ctx->mf, ctx->matches);
}
static void
lzms_skip_bytes(struct lzms_compressor *ctx, u32 n)
{
- lz_bt_skip_positions(&ctx->mf, n);
+ lz_mf_skip_positions(ctx->mf, n);
}
static u32
};
}
-/* This is similar to lzx_get_near_optimal_match() in lzx-compress.c.
+/* This is similar to lzx_choose_near_optimal_match() in lzx-compress.c.
* Read that one if you want to understand it. */
static struct lz_match
lzms_get_near_optimal_match(struct lzms_compressor *ctx)
ctx->optimum_end_idx = 0;
longest_rep_len = ctx->params.min_match_length - 1;
- if (lz_bt_get_position(&ctx->mf) >= LZMS_MAX_INIT_RECENT_OFFSET) {
- u32 limit = min(ctx->params.max_match_length,
- lz_bt_get_remaining_size(&ctx->mf));
+ if (lz_mf_get_position(ctx->mf) >= LZMS_MAX_INIT_RECENT_OFFSET) {
+ u32 limit = lz_mf_get_bytes_remaining(ctx->mf);
for (int i = 0; i < LZMS_NUM_RECENT_OFFSETS; i++) {
u32 offset = ctx->lru.lz.recent_offsets[i];
- const u8 *strptr = lz_bt_get_window_ptr(&ctx->mf);
+ const u8 *strptr = lz_mf_get_window_ptr(ctx->mf);
const u8 *matchptr = strptr - offset;
u32 len = 0;
while (len < limit && strptr[len] == matchptr[len])
ctx->optimum[1].state = initial_state;
ctx->optimum[1].cost = lzms_get_literal_cost(ctx,
&ctx->optimum[1].state,
- *(lz_bt_get_window_ptr(&ctx->mf) - 1));
+ *(lz_mf_get_window_ptr(ctx->mf) - 1));
ctx->optimum[1].prev.link = 0;
for (u32 i = 0, len = 2; i < num_matches; i++) {
return lzms_match_chooser_reverse_list(ctx, cur_pos);
longest_rep_len = ctx->params.min_match_length - 1;
- if (lz_bt_get_position(&ctx->mf) >= LZMS_MAX_INIT_RECENT_OFFSET) {
- u32 limit = min(ctx->params.max_match_length,
- lz_bt_get_remaining_size(&ctx->mf));
+ if (lz_mf_get_position(ctx->mf) >= LZMS_MAX_INIT_RECENT_OFFSET) {
+ u32 limit = lz_mf_get_bytes_remaining(ctx->mf);
for (int i = 0; i < LZMS_NUM_RECENT_OFFSETS; i++) {
u32 offset = ctx->optimum[cur_pos].state.lru.recent_offsets[i];
- const u8 *strptr = lz_bt_get_window_ptr(&ctx->mf);
+ const u8 *strptr = lz_mf_get_window_ptr(ctx->mf);
const u8 *matchptr = strptr - offset;
u32 len = 0;
while (len < limit && strptr[len] == matchptr[len])
cost = ctx->optimum[cur_pos].cost +
lzms_get_literal_cost(ctx,
&state,
- *(lz_bt_get_window_ptr(&ctx->mf) - 1));
+ *(lz_mf_get_window_ptr(ctx->mf) - 1));
if (cost < ctx->optimum[cur_pos + 1].cost) {
ctx->optimum[cur_pos + 1].state = state;
ctx->optimum[cur_pos + 1].cost = cost;
*
* Notes:
*
- * - This uses near-optimal LZ parsing backed by a binary tree match-finder.
- *
* - This does not output any delta matches.
*
* - The costs of literals and matches are estimated using the range encoder
* states and the semi-adaptive Huffman codes. Except for range encoding
* states, costs are assumed to be constant throughout a single run of the
- * parsing algorithm, which can parse up to @optim_array_length (from the
- * `struct wimlib_lzms_compressor_params') bytes of data. This introduces a
- * source of inaccuracy because the probabilities and Huffman codes can change
- * over this part of the data.
+ * parsing algorithm, which can parse up to @optim_array_length bytes of data.
+ * This introduces a source of inaccuracy because the probabilities and
+ * Huffman codes can change over this part of the data.
*/
static void
lzms_encode(struct lzms_compressor *ctx)
{
struct lz_match match;
- /* Load window into the binary tree match-finder. */
- lz_bt_load_window(&ctx->mf, ctx->window, ctx->window_size);
+ /* Load window into the match-finder. */
+ lz_mf_load_window(ctx->mf, ctx->window, ctx->window_size);
/* Reset the match-chooser. */
ctx->optimum_cur_idx = 0;
return compressed_size;
}
+
+static void
+lzms_build_params(unsigned int compression_level,
+ struct lzms_compressor_params *lzms_params)
+{
+ lzms_params->min_match_length = (compression_level >= 50) ? 2 : 3;
+ lzms_params->nice_match_length = ((u64)compression_level * 32) / 50;
+ lzms_params->max_search_depth = ((u64)compression_level * 50) / 50;
+ lzms_params->optim_array_length = 224 + compression_level * 16;
+}
+
+static void
+lzms_build_mf_params(const struct lzms_compressor_params *lzms_params,
+ u32 max_window_size, struct lz_mf_params *mf_params)
+{
+ memset(mf_params, 0, sizeof(*mf_params));
+
+ mf_params->algorithm = LZ_MF_DEFAULT;
+ mf_params->max_window_size = max_window_size;
+ mf_params->min_match_len = lzms_params->min_match_length;
+ mf_params->max_search_depth = lzms_params->max_search_depth;
+ mf_params->nice_match_len = lzms_params->nice_match_length;
+}
+
+static void
+lzms_free_compressor(void *_ctx);
+
+static u64
+lzms_get_needed_memory(size_t max_block_size, unsigned int compression_level)
+{
+ struct lzms_compressor_params params;
+
+ lzms_build_params(compression_level, ¶ms);
+
+ u64 size = 0;
+
+ size += sizeof(struct lzms_compressor);
+ size += max_block_size;
+ size += lz_mf_get_needed_memory(LZ_MF_DEFAULT, max_block_size);
+ size += params.max_search_depth * sizeof(struct lz_match);
+ size += (params.optim_array_length + params.nice_match_length) *
+ sizeof(struct lzms_mc_pos_data);
+
+ return size;
+}
+
+static int
+lzms_create_compressor(size_t max_block_size, unsigned int compression_level,
+ void **ctx_ret)
+{
+ struct lzms_compressor *ctx;
+ struct lzms_compressor_params params;
+ struct lz_mf_params mf_params;
+
+ if (max_block_size >= INT32_MAX)
+ return WIMLIB_ERR_INVALID_PARAM;
+
+ lzms_build_params(compression_level, ¶ms);
+ lzms_build_mf_params(¶ms, max_block_size, &mf_params);
+ if (!lz_mf_params_valid(&mf_params))
+ return WIMLIB_ERR_INVALID_PARAM;
+
+ ctx = CALLOC(1, sizeof(struct lzms_compressor));
+ if (!ctx)
+ goto oom;
+
+ ctx->params = params;
+ ctx->max_block_size = max_block_size;
+
+ ctx->window = MALLOC(max_block_size);
+ if (!ctx->window)
+ goto oom;
+
+ ctx->mf = lz_mf_alloc(&mf_params);
+ if (!ctx->mf)
+ goto oom;
+
+ ctx->matches = MALLOC(params.max_search_depth * sizeof(struct lz_match));
+ if (!ctx->matches)
+ goto oom;
+
+ ctx->optimum = MALLOC((params.optim_array_length +
+ params.nice_match_length) *
+ sizeof(struct lzms_mc_pos_data));
+ if (!ctx->optimum)
+ goto oom;
+
+ /* Initialize position and length slot data if not done already. */
+ lzms_init_slots();
+
+ /* Initialize range encoding cost table if not done already. */
+ lzms_init_rc_costs();
+
+ *ctx_ret = ctx;
+ return 0;
+
+oom:
+ lzms_free_compressor(ctx);
+ return WIMLIB_ERR_NOMEM;
+}
+
static size_t
lzms_compress(const void *uncompressed_data, size_t uncompressed_size,
void *compressed_data, size_t compressed_size_avail, void *_ctx)
LZMS_DEBUG("uncompressed_size=%zu, compressed_size_avail=%zu",
uncompressed_size, compressed_size_avail);
- /* Make sure the uncompressed size is compatible with this compressor.
- */
- if (uncompressed_size > ctx->max_block_size) {
- LZMS_DEBUG("Can't compress %zu bytes: LZMS context "
- "only supports %u bytes",
- uncompressed_size, ctx->max_block_size);
- return 0;
- }
-
/* Don't bother compressing extremely small inputs. */
if (uncompressed_size < 4) {
LZMS_DEBUG("Input too small to bother compressing.");
LZMS_DEBUG("Compressed %zu => %zu bytes",
uncompressed_size, compressed_size);
-#if defined(ENABLE_VERIFY_COMPRESSION) || defined(ENABLE_LZMS_DEBUG)
- /* Verify that we really get the same thing back when decompressing. */
- {
- struct wimlib_decompressor *decompressor;
-
- LZMS_DEBUG("Verifying LZMS compression.");
-
- if (0 == wimlib_create_decompressor(WIMLIB_COMPRESSION_TYPE_LZMS,
- ctx->max_block_size,
- NULL,
- &decompressor))
- {
- int ret;
- ret = wimlib_decompress(compressed_data,
- compressed_size,
- ctx->window,
- uncompressed_size,
- decompressor);
- wimlib_free_decompressor(decompressor);
-
- if (ret) {
- ERROR("Failed to decompress data we "
- "compressed using LZMS algorithm");
- wimlib_assert(0);
- return 0;
- }
- if (memcmp(uncompressed_data, ctx->window,
- uncompressed_size))
- {
- ERROR("Data we compressed using LZMS algorithm "
- "didn't decompress to original");
- wimlib_assert(0);
- return 0;
- }
- } else {
- WARNING("Failed to create decompressor for "
- "data verification!");
- }
- }
-#endif /* ENABLE_LZMS_DEBUG || ENABLE_VERIFY_COMPRESSION */
-
return compressed_size;
}
if (ctx) {
FREE(ctx->window);
+ lz_mf_free(ctx->mf);
FREE(ctx->matches);
- lz_bt_destroy(&ctx->mf);
FREE(ctx->optimum);
FREE(ctx);
}
}
-static const struct wimlib_lzms_compressor_params lzms_default = {
- .hdr = {
- .size = sizeof(struct wimlib_lzms_compressor_params),
- },
- .min_match_length = 2,
- .max_match_length = UINT32_MAX,
- .nice_match_length = 32,
- .max_search_depth = 50,
- .optim_array_length = 1024,
-};
-
-static bool
-lzms_params_valid(const struct wimlib_compressor_params_header *);
-
-static const struct wimlib_lzms_compressor_params *
-lzms_get_params(const struct wimlib_compressor_params_header *_params)
-{
- const struct wimlib_lzms_compressor_params *params =
- (const struct wimlib_lzms_compressor_params*)_params;
-
- if (params == NULL)
- params = &lzms_default;
-
- LZMS_ASSERT(lzms_params_valid(¶ms->hdr));
-
- return params;
-}
-
-static int
-lzms_create_compressor(size_t max_block_size,
- const struct wimlib_compressor_params_header *_params,
- void **ctx_ret)
-{
- struct lzms_compressor *ctx;
- const struct wimlib_lzms_compressor_params *params = lzms_get_params(_params);
-
- if (max_block_size == 0 || max_block_size >= INT32_MAX) {
- LZMS_DEBUG("Invalid max_block_size (%u)", max_block_size);
- return WIMLIB_ERR_INVALID_PARAM;
- }
-
- ctx = CALLOC(1, sizeof(struct lzms_compressor));
- if (ctx == NULL)
- goto oom;
-
- ctx->window = MALLOC(max_block_size);
- if (ctx->window == NULL)
- goto oom;
-
- ctx->matches = MALLOC(min(params->max_match_length -
- params->min_match_length + 1,
- params->max_search_depth + 2) *
- sizeof(ctx->matches[0]));
- if (ctx->matches == NULL)
- goto oom;
-
- if (!lz_bt_init(&ctx->mf,
- max_block_size,
- params->min_match_length,
- params->max_match_length,
- params->nice_match_length,
- params->max_search_depth))
- goto oom;
-
- ctx->optimum = MALLOC((params->optim_array_length +
- min(params->nice_match_length,
- params->max_match_length)) *
- sizeof(ctx->optimum[0]));
- if (!ctx->optimum)
- goto oom;
-
- /* Initialize position and length slot data if not done already. */
- lzms_init_slots();
-
- /* Initialize range encoding cost table if not done already. */
- lzms_init_rc_costs();
-
- ctx->max_block_size = max_block_size;
- memcpy(&ctx->params, params, sizeof(*params));
-
- *ctx_ret = ctx;
- return 0;
-
-oom:
- lzms_free_compressor(ctx);
- return WIMLIB_ERR_NOMEM;
-}
-
-static u64
-lzms_get_needed_memory(size_t max_block_size,
- const struct wimlib_compressor_params_header *_params)
-{
- const struct wimlib_lzms_compressor_params *params = lzms_get_params(_params);
-
- u64 size = 0;
-
- size += max_block_size;
- size += sizeof(struct lzms_compressor);
- size += lz_bt_get_needed_memory(max_block_size);
- size += (params->optim_array_length +
- min(params->nice_match_length,
- params->max_match_length)) *
- sizeof(((struct lzms_compressor *)0)->optimum[0]);
- size += min(params->max_match_length - params->min_match_length + 1,
- params->max_search_depth + 2) *
- sizeof(((struct lzms_compressor*)0)->matches[0]);
- return size;
-}
-
-static bool
-lzms_params_valid(const struct wimlib_compressor_params_header *_params)
-{
- const struct wimlib_lzms_compressor_params *params =
- (const struct wimlib_lzms_compressor_params*)_params;
-
- if (params->hdr.size != sizeof(*params) ||
- params->max_match_length < params->min_match_length ||
- params->min_match_length < 2 ||
- params->optim_array_length == 0 ||
- min(params->max_match_length, params->nice_match_length) > 65536)
- return false;
-
- return true;
-}
-
const struct compressor_ops lzms_compressor_ops = {
- .params_valid = lzms_params_valid,
.get_needed_memory = lzms_get_needed_memory,
.create_compressor = lzms_create_compressor,
.compress = lzms_compress,
git://wimlib.net / wimlib / blobdiff