--- /dev/null
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \file lzma_encoder.c
+/// \brief LZMA encoder
+///
+// Authors: Igor Pavlov
+// Lasse Collin
+//
+// This file has been put into the public domain.
+// You can do whatever you want with this file.
+//
+///////////////////////////////////////////////////////////////////////////////
+
+#include "lzma2_encoder.h"
+#include "lzma_encoder_private.h"
+#include "fastpos.h"
+
+
+/////////////
+// Literal //
+/////////////
+
+static inline void
+literal_matched(lzma_range_encoder *rc, probability *subcoder,
+ uint32_t match_byte, uint32_t symbol)
+{
+ uint32_t offset = 0x100;
+ symbol += UINT32_C(1) << 8;
+
+ do {
+ match_byte <<= 1;
+ const uint32_t match_bit = match_byte & offset;
+ const uint32_t subcoder_index
+ = offset + match_bit + (symbol >> 8);
+ const uint32_t bit = (symbol >> 7) & 1;
+ rc_bit(rc, &subcoder[subcoder_index], bit);
+
+ symbol <<= 1;
+ offset &= ~(match_byte ^ symbol);
+
+ } while (symbol < (UINT32_C(1) << 16));
+}
+
+
+static inline void
+literal(lzma_coder *coder, lzma_mf *mf, uint32_t position)
+{
+ // Locate the literal byte to be encoded and the subcoder.
+ const uint8_t cur_byte = mf->buffer[
+ mf->read_pos - mf->read_ahead];
+ probability *subcoder = literal_subcoder(coder->literal,
+ coder->literal_context_bits, coder->literal_pos_mask,
+ position, mf->buffer[mf->read_pos - mf->read_ahead - 1]);
+
+ if (is_literal_state(coder->state)) {
+ // Previous LZMA-symbol was a literal. Encode a normal
+ // literal without a match byte.
+ rc_bittree(&coder->rc, subcoder, 8, cur_byte);
+ } else {
+ // Previous LZMA-symbol was a match. Use the last byte of
+ // the match as a "match byte". That is, compare the bits
+ // of the current literal and the match byte.
+ const uint8_t match_byte = mf->buffer[
+ mf->read_pos - coder->reps[0] - 1
+ - mf->read_ahead];
+ literal_matched(&coder->rc, subcoder, match_byte, cur_byte);
+ }
+
+ update_literal(coder->state);
+}
+
+
+//////////////////
+// Match length //
+//////////////////
+
+static void
+length_update_prices(lzma_length_encoder *lc, const uint32_t pos_state)
+{
+ const uint32_t table_size = lc->table_size;
+ lc->counters[pos_state] = table_size;
+
+ const uint32_t a0 = rc_bit_0_price(lc->choice);
+ const uint32_t a1 = rc_bit_1_price(lc->choice);
+ const uint32_t b0 = a1 + rc_bit_0_price(lc->choice2);
+ const uint32_t b1 = a1 + rc_bit_1_price(lc->choice2);
+ uint32_t *const prices = lc->prices[pos_state];
+
+ uint32_t i;
+ for (i = 0; i < table_size && i < LEN_LOW_SYMBOLS; ++i)
+ prices[i] = a0 + rc_bittree_price(lc->low[pos_state],
+ LEN_LOW_BITS, i);
+
+ for (; i < table_size && i < LEN_LOW_SYMBOLS + LEN_MID_SYMBOLS; ++i)
+ prices[i] = b0 + rc_bittree_price(lc->mid[pos_state],
+ LEN_MID_BITS, i - LEN_LOW_SYMBOLS);
+
+ for (; i < table_size; ++i)
+ prices[i] = b1 + rc_bittree_price(lc->high, LEN_HIGH_BITS,
+ i - LEN_LOW_SYMBOLS - LEN_MID_SYMBOLS);
+
+ return;
+}
+
+
+static inline void
+length(lzma_range_encoder *rc, lzma_length_encoder *lc,
+ const uint32_t pos_state, uint32_t len, const bool fast_mode)
+{
+ assert(len <= MATCH_LEN_MAX);
+ len -= MATCH_LEN_MIN;
+
+ if (len < LEN_LOW_SYMBOLS) {
+ rc_bit(rc, &lc->choice, 0);
+ rc_bittree(rc, lc->low[pos_state], LEN_LOW_BITS, len);
+ } else {
+ rc_bit(rc, &lc->choice, 1);
+ len -= LEN_LOW_SYMBOLS;
+
+ if (len < LEN_MID_SYMBOLS) {
+ rc_bit(rc, &lc->choice2, 0);
+ rc_bittree(rc, lc->mid[pos_state], LEN_MID_BITS, len);
+ } else {
+ rc_bit(rc, &lc->choice2, 1);
+ len -= LEN_MID_SYMBOLS;
+ rc_bittree(rc, lc->high, LEN_HIGH_BITS, len);
+ }
+ }
+
+ // Only getoptimum uses the prices so don't update the table when
+ // in fast mode.
+ if (!fast_mode)
+ if (--lc->counters[pos_state] == 0)
+ length_update_prices(lc, pos_state);
+}
+
+
+///////////
+// Match //
+///////////
+
+static inline void
+match(lzma_coder *coder, const uint32_t pos_state,
+ const uint32_t distance, const uint32_t len)
+{
+ update_match(coder->state);
+
+ length(&coder->rc, &coder->match_len_encoder, pos_state, len,
+ coder->fast_mode);
+
+ const uint32_t dist_slot = get_dist_slot(distance);
+ const uint32_t dist_state = get_dist_state(len);
+ rc_bittree(&coder->rc, coder->dist_slot[dist_state],
+ DIST_SLOT_BITS, dist_slot);
+
+ if (dist_slot >= DIST_MODEL_START) {
+ const uint32_t footer_bits = (dist_slot >> 1) - 1;
+ const uint32_t base = (2 | (dist_slot & 1)) << footer_bits;
+ const uint32_t dist_reduced = distance - base;
+
+ if (dist_slot < DIST_MODEL_END) {
+ // Careful here: base - dist_slot - 1 can be -1, but
+ // rc_bittree_reverse starts at probs[1], not probs[0].
+ rc_bittree_reverse(&coder->rc,
+ coder->dist_special + base - dist_slot - 1,
+ footer_bits, dist_reduced);
+ } else {
+ rc_direct(&coder->rc, dist_reduced >> ALIGN_BITS,
+ footer_bits - ALIGN_BITS);
+ rc_bittree_reverse(
+ &coder->rc, coder->dist_align,
+ ALIGN_BITS, dist_reduced & ALIGN_MASK);
+ ++coder->align_price_count;
+ }
+ }
+
+ coder->reps[3] = coder->reps[2];
+ coder->reps[2] = coder->reps[1];
+ coder->reps[1] = coder->reps[0];
+ coder->reps[0] = distance;
+ ++coder->match_price_count;
+}
+
+
+////////////////////
+// Repeated match //
+////////////////////
+
+static inline void
+rep_match(lzma_coder *coder, const uint32_t pos_state,
+ const uint32_t rep, const uint32_t len)
+{
+ if (rep == 0) {
+ rc_bit(&coder->rc, &coder->is_rep0[coder->state], 0);
+ rc_bit(&coder->rc,
+ &coder->is_rep0_long[coder->state][pos_state],
+ len != 1);
+ } else {
+ const uint32_t distance = coder->reps[rep];
+ rc_bit(&coder->rc, &coder->is_rep0[coder->state], 1);
+
+ if (rep == 1) {
+ rc_bit(&coder->rc, &coder->is_rep1[coder->state], 0);
+ } else {
+ rc_bit(&coder->rc, &coder->is_rep1[coder->state], 1);
+ rc_bit(&coder->rc, &coder->is_rep2[coder->state],
+ rep - 2);
+
+ if (rep == 3)
+ coder->reps[3] = coder->reps[2];
+
+ coder->reps[2] = coder->reps[1];
+ }
+
+ coder->reps[1] = coder->reps[0];
+ coder->reps[0] = distance;
+ }
+
+ if (len == 1) {
+ update_short_rep(coder->state);
+ } else {
+ length(&coder->rc, &coder->rep_len_encoder, pos_state, len,
+ coder->fast_mode);
+ update_long_rep(coder->state);
+ }
+}
+
+
+//////////
+// Main //
+//////////
+
+static void
+encode_symbol(lzma_coder *coder, lzma_mf *mf,
+ uint32_t back, uint32_t len, uint32_t position)
+{
+ const uint32_t pos_state = position & coder->pos_mask;
+
+ if (back == UINT32_MAX) {
+ // Literal i.e. eight-bit byte
+ assert(len == 1);
+ rc_bit(&coder->rc,
+ &coder->is_match[coder->state][pos_state], 0);
+ literal(coder, mf, position);
+ } else {
+ // Some type of match
+ rc_bit(&coder->rc,
+ &coder->is_match[coder->state][pos_state], 1);
+
+ if (back < REPS) {
+ // It's a repeated match i.e. the same distance
+ // has been used earlier.
+ rc_bit(&coder->rc, &coder->is_rep[coder->state], 1);
+ rep_match(coder, pos_state, back, len);
+ } else {
+ // Normal match
+ rc_bit(&coder->rc, &coder->is_rep[coder->state], 0);
+ match(coder, pos_state, back - REPS, len);
+ }
+ }
+
+ assert(mf->read_ahead >= len);
+ mf->read_ahead -= len;
+}
+
+
+static bool
+encode_init(lzma_coder *coder, lzma_mf *mf)
+{
+ assert(mf_position(mf) == 0);
+
+ if (mf->read_pos == mf->read_limit) {
+ if (mf->action == LZMA_RUN)
+ return false; // We cannot do anything.
+
+ // We are finishing (we cannot get here when flushing).
+ assert(mf->write_pos == mf->read_pos);
+ assert(mf->action == LZMA_FINISH);
+ } else {
+ // Do the actual initialization. The first LZMA symbol must
+ // always be a literal.
+ mf_skip(mf, 1);
+ mf->read_ahead = 0;
+ rc_bit(&coder->rc, &coder->is_match[0][0], 0);
+ rc_bittree(&coder->rc, coder->literal[0], 8, mf->buffer[0]);
+ }
+
+ // Initialization is done (except if empty file).
+ coder->is_initialized = true;
+
+ return true;
+}
+
+
+static void
+encode_eopm(lzma_coder *coder, uint32_t position)
+{
+ const uint32_t pos_state = position & coder->pos_mask;
+ rc_bit(&coder->rc, &coder->is_match[coder->state][pos_state], 1);
+ rc_bit(&coder->rc, &coder->is_rep[coder->state], 0);
+ match(coder, pos_state, UINT32_MAX, MATCH_LEN_MIN);
+}
+
+
+/// Number of bytes that a single encoding loop in lzma_lzma_encode() can
+/// consume from the dictionary. This limit comes from lzma_lzma_optimum()
+/// and may need to be updated if that function is significantly modified.
+#define LOOP_INPUT_MAX (OPTS + 1)
+
+
+extern lzma_ret
+lzma_lzma_encode(lzma_coder *restrict coder, lzma_mf *restrict mf,
+ uint8_t *restrict out, size_t *restrict out_pos,
+ size_t out_size, uint32_t limit)
+{
+ // Initialize the stream if no data has been encoded yet.
+ if (!coder->is_initialized && !encode_init(coder, mf))
+ return LZMA_OK;
+
+ // Get the lowest bits of the uncompressed offset from the LZ layer.
+ uint32_t position = mf_position(mf);
+
+ while (true) {
+ // Encode pending bits, if any. Calling this before encoding
+ // the next symbol is needed only with plain LZMA, since
+ // LZMA2 always provides big enough buffer to flush
+ // everything out from the range encoder. For the same reason,
+ // rc_encode() never returns true when this function is used
+ // as part of LZMA2 encoder.
+ if (rc_encode(&coder->rc, out, out_pos, out_size)) {
+ assert(limit == UINT32_MAX);
+ return LZMA_OK;
+ }
+
+ // With LZMA2 we need to take care that compressed size of
+ // a chunk doesn't get too big.
+ // FIXME? Check if this could be improved.
+ if (limit != UINT32_MAX
+ && (mf->read_pos - mf->read_ahead >= limit
+ || *out_pos + rc_pending(&coder->rc)
+ >= LZMA2_CHUNK_MAX
+ - LOOP_INPUT_MAX))
+ break;
+
+ // Check that there is some input to process.
+ if (mf->read_pos >= mf->read_limit) {
+ if (mf->action == LZMA_RUN)
+ return LZMA_OK;
+
+ if (mf->read_ahead == 0)
+ break;
+ }
+
+ // Get optimal match (repeat position and length).
+ // Value ranges for pos:
+ // - [0, REPS): repeated match
+ // - [REPS, UINT32_MAX):
+ // match at (pos - REPS)
+ // - UINT32_MAX: not a match but a literal
+ // Value ranges for len:
+ // - [MATCH_LEN_MIN, MATCH_LEN_MAX]
+ uint32_t len;
+ uint32_t back;
+
+ if (coder->fast_mode)
+ lzma_lzma_optimum_fast(coder, mf, &back, &len);
+ else
+ lzma_lzma_optimum_normal(
+ coder, mf, &back, &len, position);
+
+ encode_symbol(coder, mf, back, len, position);
+
+ position += len;
+ }
+
+ if (!coder->is_flushed) {
+ coder->is_flushed = true;
+
+ // We don't support encoding plain LZMA streams without EOPM,
+ // and LZMA2 doesn't use EOPM at LZMA level.
+ if (limit == UINT32_MAX)
+ encode_eopm(coder, position);
+
+ // Flush the remaining bytes from the range encoder.
+ rc_flush(&coder->rc);
+
+ // Copy the remaining bytes to the output buffer. If there
+ // isn't enough output space, we will copy out the remaining
+ // bytes on the next call to this function by using
+ // the rc_encode() call in the encoding loop above.
+ if (rc_encode(&coder->rc, out, out_pos, out_size)) {
+ assert(limit == UINT32_MAX);
+ return LZMA_OK;
+ }
+ }
+
+ // Make it ready for the next LZMA2 chunk.
+ coder->is_flushed = false;
+
+ return LZMA_STREAM_END;
+}
+
+
+static lzma_ret
+lzma_encode(lzma_coder *restrict coder, lzma_mf *restrict mf,
+ uint8_t *restrict out, size_t *restrict out_pos,
+ size_t out_size)
+{
+ // Plain LZMA has no support for sync-flushing.
+ if (unlikely(mf->action == LZMA_SYNC_FLUSH))
+ return LZMA_OPTIONS_ERROR;
+
+ return lzma_lzma_encode(coder, mf, out, out_pos, out_size, UINT32_MAX);
+}
+
+
+////////////////////
+// Initialization //
+////////////////////
+
+static bool
+is_options_valid(const lzma_options_lzma *options)
+{
+ // Validate some of the options. LZ encoder validates nice_len too
+ // but we need a valid value here earlier.
+ return is_lclppb_valid(options)
+ && options->nice_len >= MATCH_LEN_MIN
+ && options->nice_len <= MATCH_LEN_MAX
+ && (options->mode == LZMA_MODE_FAST
+ || options->mode == LZMA_MODE_NORMAL);
+}
+
+
+static void
+set_lz_options(lzma_lz_options *lz_options, const lzma_options_lzma *options)
+{
+ // LZ encoder initialization does the validation for these so we
+ // don't need to validate here.
+ lz_options->before_size = OPTS;
+ lz_options->dict_size = options->dict_size;
+ lz_options->after_size = LOOP_INPUT_MAX;
+ lz_options->match_len_max = MATCH_LEN_MAX;
+ lz_options->nice_len = options->nice_len;
+ lz_options->match_finder = options->mf;
+ lz_options->depth = options->depth;
+ lz_options->preset_dict = options->preset_dict;
+ lz_options->preset_dict_size = options->preset_dict_size;
+ return;
+}
+
+
+static void
+length_encoder_reset(lzma_length_encoder *lencoder,
+ const uint32_t num_pos_states, const bool fast_mode)
+{
+ bit_reset(lencoder->choice);
+ bit_reset(lencoder->choice2);
+
+ for (size_t pos_state = 0; pos_state < num_pos_states; ++pos_state) {
+ bittree_reset(lencoder->low[pos_state], LEN_LOW_BITS);
+ bittree_reset(lencoder->mid[pos_state], LEN_MID_BITS);
+ }
+
+ bittree_reset(lencoder->high, LEN_HIGH_BITS);
+
+ if (!fast_mode)
+ for (uint32_t pos_state = 0; pos_state < num_pos_states;
+ ++pos_state)
+ length_update_prices(lencoder, pos_state);
+
+ return;
+}
+
+
+extern lzma_ret
+lzma_lzma_encoder_reset(lzma_coder *coder, const lzma_options_lzma *options)
+{
+ if (!is_options_valid(options))
+ return LZMA_OPTIONS_ERROR;
+
+ coder->pos_mask = (1U << options->pb) - 1;
+ coder->literal_context_bits = options->lc;
+ coder->literal_pos_mask = (1U << options->lp) - 1;
+
+ // Range coder
+ rc_reset(&coder->rc);
+
+ // State
+ coder->state = STATE_LIT_LIT;
+ for (size_t i = 0; i < REPS; ++i)
+ coder->reps[i] = 0;
+
+ literal_init(coder->literal, options->lc, options->lp);
+
+ // Bit encoders
+ for (size_t i = 0; i < STATES; ++i) {
+ for (size_t j = 0; j <= coder->pos_mask; ++j) {
+ bit_reset(coder->is_match[i][j]);
+ bit_reset(coder->is_rep0_long[i][j]);
+ }
+
+ bit_reset(coder->is_rep[i]);
+ bit_reset(coder->is_rep0[i]);
+ bit_reset(coder->is_rep1[i]);
+ bit_reset(coder->is_rep2[i]);
+ }
+
+ for (size_t i = 0; i < FULL_DISTANCES - DIST_MODEL_END; ++i)
+ bit_reset(coder->dist_special[i]);
+
+ // Bit tree encoders
+ for (size_t i = 0; i < DIST_STATES; ++i)
+ bittree_reset(coder->dist_slot[i], DIST_SLOT_BITS);
+
+ bittree_reset(coder->dist_align, ALIGN_BITS);
+
+ // Length encoders
+ length_encoder_reset(&coder->match_len_encoder,
+ 1U << options->pb, coder->fast_mode);
+
+ length_encoder_reset(&coder->rep_len_encoder,
+ 1U << options->pb, coder->fast_mode);
+
+ // Price counts are incremented every time appropriate probabilities
+ // are changed. price counts are set to zero when the price tables
+ // are updated, which is done when the appropriate price counts have
+ // big enough value, and lzma_mf.read_ahead == 0 which happens at
+ // least every OPTS (a few thousand) possible price count increments.
+ //
+ // By resetting price counts to UINT32_MAX / 2, we make sure that the
+ // price tables will be initialized before they will be used (since
+ // the value is definitely big enough), and that it is OK to increment
+ // price counts without risk of integer overflow (since UINT32_MAX / 2
+ // is small enough). The current code doesn't increment price counts
+ // before initializing price tables, but it maybe done in future if
+ // we add support for saving the state between LZMA2 chunks.
+ coder->match_price_count = UINT32_MAX / 2;
+ coder->align_price_count = UINT32_MAX / 2;
+
+ coder->opts_end_index = 0;
+ coder->opts_current_index = 0;
+
+ return LZMA_OK;
+}
+
+
+extern lzma_ret
+lzma_lzma_encoder_create(lzma_coder **coder_ptr,
+ const lzma_allocator *allocator,
+ const lzma_options_lzma *options, lzma_lz_options *lz_options)
+{
+ // Allocate lzma_coder if it wasn't already allocated.
+ if (*coder_ptr == NULL) {
+ *coder_ptr = lzma_alloc(sizeof(lzma_coder), allocator);
+ if (*coder_ptr == NULL)
+ return LZMA_MEM_ERROR;
+ }
+
+ lzma_coder *coder = *coder_ptr;
+
+ // Set compression mode. We haven't validates the options yet,
+ // but it's OK here, since nothing bad happens with invalid
+ // options in the code below, and they will get rejected by
+ // lzma_lzma_encoder_reset() call at the end of this function.
+ switch (options->mode) {
+ case LZMA_MODE_FAST:
+ coder->fast_mode = true;
+ break;
+
+ case LZMA_MODE_NORMAL: {
+ coder->fast_mode = false;
+
+ // Set dist_table_size.
+ // Round the dictionary size up to next 2^n.
+ uint32_t log_size = 0;
+ while ((UINT32_C(1) << log_size) < options->dict_size)
+ ++log_size;
+
+ coder->dist_table_size = log_size * 2;
+
+ // Length encoders' price table size
+ coder->match_len_encoder.table_size
+ = options->nice_len + 1 - MATCH_LEN_MIN;
+ coder->rep_len_encoder.table_size
+ = options->nice_len + 1 - MATCH_LEN_MIN;
+ break;
+ }
+
+ default:
+ return LZMA_OPTIONS_ERROR;
+ }
+
+ // We don't need to write the first byte as literal if there is
+ // a non-empty preset dictionary. encode_init() wouldn't even work
+ // if there is a non-empty preset dictionary, because encode_init()
+ // assumes that position is zero and previous byte is also zero.
+ coder->is_initialized = options->preset_dict != NULL
+ && options->preset_dict_size > 0;
+ coder->is_flushed = false;
+
+ set_lz_options(lz_options, options);
+
+ return lzma_lzma_encoder_reset(coder, options);
+}
+
+
+static lzma_ret
+lzma_encoder_init(lzma_lz_encoder *lz, const lzma_allocator *allocator,
+ const void *options, lzma_lz_options *lz_options)
+{
+ lz->code = &lzma_encode;
+ return lzma_lzma_encoder_create(
+ &lz->coder, allocator, options, lz_options);
+}
+
+
+extern lzma_ret
+lzma_lzma_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
+ const lzma_filter_info *filters)
+{
+ return lzma_lz_encoder_init(
+ next, allocator, filters, &lzma_encoder_init);
+}
+
+
+extern uint64_t
+lzma_lzma_encoder_memusage(const void *options)
+{
+ if (!is_options_valid(options))
+ return UINT64_MAX;
+
+ lzma_lz_options lz_options;
+ set_lz_options(&lz_options, options);
+
+ const uint64_t lz_memusage = lzma_lz_encoder_memusage(&lz_options);
+ if (lz_memusage == UINT64_MAX)
+ return UINT64_MAX;
+
+ return (uint64_t)(sizeof(lzma_coder)) + lz_memusage;
+}
+
+
+extern bool
+lzma_lzma_lclppb_encode(const lzma_options_lzma *options, uint8_t *byte)
+{
+ if (!is_lclppb_valid(options))
+ return true;
+
+ *byte = (options->pb * 5 + options->lp) * 9 + options->lc;
+ assert(*byte <= (4 * 5 + 4) * 9 + 8);
+
+ return false;
+}
+
+
+#ifdef HAVE_ENCODER_LZMA1
+extern lzma_ret
+lzma_lzma_props_encode(const void *options, uint8_t *out)
+{
+ const lzma_options_lzma *const opt = options;
+
+ if (lzma_lzma_lclppb_encode(opt, out))
+ return LZMA_PROG_ERROR;
+
+ unaligned_write32le(out + 1, opt->dict_size);
+
+ return LZMA_OK;
+}
+#endif
+
+
+extern LZMA_API(lzma_bool)
+lzma_mode_is_supported(lzma_mode mode)
+{
+ return mode == LZMA_MODE_FAST || mode == LZMA_MODE_NORMAL;
+}
projects / zpackage / blobdiff