pd.if.org Git - zpackage/blob - lzma/lzma/lzma_encoder.c

   1 ///////////////////////////////////////////////////////////////////////////////
   2 //
   3 /// \file       lzma_encoder.c
   4 /// \brief      LZMA encoder
   5 ///
   6 //  Authors:    Igor Pavlov
   7 //              Lasse Collin
   8 //
   9 //  This file has been put into the public domain.
  10 //  You can do whatever you want with this file.
  11 //
  12 ///////////////////////////////////////////////////////////////////////////////
  13
  14 #include "lzma2_encoder.h"
  15 #include "lzma_encoder_private.h"
  16 #include "fastpos.h"
  17
  18
  19 /////////////
  20 // Literal //
  21 /////////////
  22
  23 static inline void
  24 literal_matched(lzma_range_encoder *rc, probability *subcoder,
  25                 uint32_t match_byte, uint32_t symbol)
  26 {
  27         uint32_t offset = 0x100;
  28         symbol += UINT32_C(1) << 8;
  29
  30         do {
  31                 match_byte <<= 1;
  32                 const uint32_t match_bit = match_byte & offset;
  33                 const uint32_t subcoder_index
  34                                 = offset + match_bit + (symbol >> 8);
  35                 const uint32_t bit = (symbol >> 7) & 1;
  36                 rc_bit(rc, &subcoder[subcoder_index], bit);
  37
  38                 symbol <<= 1;
  39                 offset &= ~(match_byte ^ symbol);
  40
  41         } while (symbol < (UINT32_C(1) << 16));
  42 }
  43
  44
  45 static inline void
  46 literal(lzma_coder *coder, lzma_mf *mf, uint32_t position)
  47 {
  48         // Locate the literal byte to be encoded and the subcoder.
  49         const uint8_t cur_byte = mf->buffer[
  50                         mf->read_pos - mf->read_ahead];
  51         probability *subcoder = literal_subcoder(coder->literal,
  52                         coder->literal_context_bits, coder->literal_pos_mask,
  53                         position, mf->buffer[mf->read_pos - mf->read_ahead - 1]);
  54
  55         if (is_literal_state(coder->state)) {
  56                 // Previous LZMA-symbol was a literal. Encode a normal
  57                 // literal without a match byte.
  58                 rc_bittree(&coder->rc, subcoder, 8, cur_byte);
  59         } else {
  60                 // Previous LZMA-symbol was a match. Use the last byte of
  61                 // the match as a "match byte". That is, compare the bits
  62                 // of the current literal and the match byte.
  63                 const uint8_t match_byte = mf->buffer[
  64                                 mf->read_pos - coder->reps[0] - 1
  65                                 - mf->read_ahead];
  66                 literal_matched(&coder->rc, subcoder, match_byte, cur_byte);
  67         }
  68
  69         update_literal(coder->state);
  70 }
  71
  72
  73 //////////////////
  74 // Match length //
  75 //////////////////
  76
  77 static void
  78 length_update_prices(lzma_length_encoder *lc, const uint32_t pos_state)
  79 {
  80         const uint32_t table_size = lc->table_size;
  81         lc->counters[pos_state] = table_size;
  82
  83         const uint32_t a0 = rc_bit_0_price(lc->choice);
  84         const uint32_t a1 = rc_bit_1_price(lc->choice);
  85         const uint32_t b0 = a1 + rc_bit_0_price(lc->choice2);
  86         const uint32_t b1 = a1 + rc_bit_1_price(lc->choice2);
  87         uint32_t *const prices = lc->prices[pos_state];
  88
  89         uint32_t i;
  90         for (i = 0; i < table_size && i < LEN_LOW_SYMBOLS; ++i)
  91                 prices[i] = a0 + rc_bittree_price(lc->low[pos_state],
  92                                 LEN_LOW_BITS, i);
  93
  94         for (; i < table_size && i < LEN_LOW_SYMBOLS + LEN_MID_SYMBOLS; ++i)
  95                 prices[i] = b0 + rc_bittree_price(lc->mid[pos_state],
  96                                 LEN_MID_BITS, i - LEN_LOW_SYMBOLS);
  97
  98         for (; i < table_size; ++i)
  99                 prices[i] = b1 + rc_bittree_price(lc->high, LEN_HIGH_BITS,
 100                                 i - LEN_LOW_SYMBOLS - LEN_MID_SYMBOLS);
 101
 102         return;
 103 }
 104
 105
 106 static inline void
 107 length(lzma_range_encoder *rc, lzma_length_encoder *lc,
 108                 const uint32_t pos_state, uint32_t len, const bool fast_mode)
 109 {
 110         assert(len <= MATCH_LEN_MAX);
 111         len -= MATCH_LEN_MIN;
 112
 113         if (len < LEN_LOW_SYMBOLS) {
 114                 rc_bit(rc, &lc->choice, 0);
 115                 rc_bittree(rc, lc->low[pos_state], LEN_LOW_BITS, len);
 116         } else {
 117                 rc_bit(rc, &lc->choice, 1);
 118                 len -= LEN_LOW_SYMBOLS;
 119
 120                 if (len < LEN_MID_SYMBOLS) {
 121                         rc_bit(rc, &lc->choice2, 0);
 122                         rc_bittree(rc, lc->mid[pos_state], LEN_MID_BITS, len);
 123                 } else {
 124                         rc_bit(rc, &lc->choice2, 1);
 125                         len -= LEN_MID_SYMBOLS;
 126                         rc_bittree(rc, lc->high, LEN_HIGH_BITS, len);
 127                 }
 128         }
 129
 130         // Only getoptimum uses the prices so don't update the table when
 131         // in fast mode.
 132         if (!fast_mode)
 133                 if (--lc->counters[pos_state] == 0)
 134                         length_update_prices(lc, pos_state);
 135 }
 136
 137
 138 ///////////
 139 // Match //
 140 ///////////
 141
 142 static inline void
 143 match(lzma_coder *coder, const uint32_t pos_state,
 144                 const uint32_t distance, const uint32_t len)
 145 {
 146         update_match(coder->state);
 147
 148         length(&coder->rc, &coder->match_len_encoder, pos_state, len,
 149                         coder->fast_mode);
 150
 151         const uint32_t dist_slot = get_dist_slot(distance);
 152         const uint32_t dist_state = get_dist_state(len);
 153         rc_bittree(&coder->rc, coder->dist_slot[dist_state],
 154                         DIST_SLOT_BITS, dist_slot);
 155
 156         if (dist_slot >= DIST_MODEL_START) {
 157                 const uint32_t footer_bits = (dist_slot >> 1) - 1;
 158                 const uint32_t base = (2 | (dist_slot & 1)) << footer_bits;
 159                 const uint32_t dist_reduced = distance - base;
 160
 161                 if (dist_slot < DIST_MODEL_END) {
 162                         // Careful here: base - dist_slot - 1 can be -1, but
 163                         // rc_bittree_reverse starts at probs[1], not probs[0].
 164                         rc_bittree_reverse(&coder->rc,
 165                                 coder->dist_special + base - dist_slot - 1,
 166                                 footer_bits, dist_reduced);
 167                 } else {
 168                         rc_direct(&coder->rc, dist_reduced >> ALIGN_BITS,
 169                                         footer_bits - ALIGN_BITS);
 170                         rc_bittree_reverse(
 171                                         &coder->rc, coder->dist_align,
 172                                         ALIGN_BITS, dist_reduced & ALIGN_MASK);
 173                         ++coder->align_price_count;
 174                 }
 175         }
 176
 177         coder->reps[3] = coder->reps[2];
 178         coder->reps[2] = coder->reps[1];
 179         coder->reps[1] = coder->reps[0];
 180         coder->reps[0] = distance;
 181         ++coder->match_price_count;
 182 }
 183
 184
 185 ////////////////////
 186 // Repeated match //
 187 ////////////////////
 188
 189 static inline void
 190 rep_match(lzma_coder *coder, const uint32_t pos_state,
 191                 const uint32_t rep, const uint32_t len)
 192 {
 193         if (rep == 0) {
 194                 rc_bit(&coder->rc, &coder->is_rep0[coder->state], 0);
 195                 rc_bit(&coder->rc,
 196                                 &coder->is_rep0_long[coder->state][pos_state],
 197                                 len != 1);
 198         } else {
 199                 const uint32_t distance = coder->reps[rep];
 200                 rc_bit(&coder->rc, &coder->is_rep0[coder->state], 1);
 201
 202                 if (rep == 1) {
 203                         rc_bit(&coder->rc, &coder->is_rep1[coder->state], 0);
 204                 } else {
 205                         rc_bit(&coder->rc, &coder->is_rep1[coder->state], 1);
 206                         rc_bit(&coder->rc, &coder->is_rep2[coder->state],
 207                                         rep - 2);
 208
 209                         if (rep == 3)
 210                                 coder->reps[3] = coder->reps[2];
 211
 212                         coder->reps[2] = coder->reps[1];
 213                 }
 214
 215                 coder->reps[1] = coder->reps[0];
 216                 coder->reps[0] = distance;
 217         }
 218
 219         if (len == 1) {
 220                 update_short_rep(coder->state);
 221         } else {
 222                 length(&coder->rc, &coder->rep_len_encoder, pos_state, len,
 223                                 coder->fast_mode);
 224                 update_long_rep(coder->state);
 225         }
 226 }
 227
 228
 229 //////////
 230 // Main //
 231 //////////
 232
 233 static void
 234 encode_symbol(lzma_coder *coder, lzma_mf *mf,
 235                 uint32_t back, uint32_t len, uint32_t position)
 236 {
 237         const uint32_t pos_state = position & coder->pos_mask;
 238
 239         if (back == UINT32_MAX) {
 240                 // Literal i.e. eight-bit byte
 241                 assert(len == 1);
 242                 rc_bit(&coder->rc,
 243                                 &coder->is_match[coder->state][pos_state], 0);
 244                 literal(coder, mf, position);
 245         } else {
 246                 // Some type of match
 247                 rc_bit(&coder->rc,
 248                         &coder->is_match[coder->state][pos_state], 1);
 249
 250                 if (back < REPS) {
 251                         // It's a repeated match i.e. the same distance
 252                         // has been used earlier.
 253                         rc_bit(&coder->rc, &coder->is_rep[coder->state], 1);
 254                         rep_match(coder, pos_state, back, len);
 255                 } else {
 256                         // Normal match
 257                         rc_bit(&coder->rc, &coder->is_rep[coder->state], 0);
 258                         match(coder, pos_state, back - REPS, len);
 259                 }
 260         }
 261
 262         assert(mf->read_ahead >= len);
 263         mf->read_ahead -= len;
 264 }
 265
 266
 267 static bool
 268 encode_init(lzma_coder *coder, lzma_mf *mf)
 269 {
 270         assert(mf_position(mf) == 0);
 271
 272         if (mf->read_pos == mf->read_limit) {
 273                 if (mf->action == LZMA_RUN)
 274                         return false; // We cannot do anything.
 275
 276                 // We are finishing (we cannot get here when flushing).
 277                 assert(mf->write_pos == mf->read_pos);
 278                 assert(mf->action == LZMA_FINISH);
 279         } else {
 280                 // Do the actual initialization. The first LZMA symbol must
 281                 // always be a literal.
 282                 mf_skip(mf, 1);
 283                 mf->read_ahead = 0;
 284                 rc_bit(&coder->rc, &coder->is_match[0][0], 0);
 285                 rc_bittree(&coder->rc, coder->literal[0], 8, mf->buffer[0]);
 286         }
 287
 288         // Initialization is done (except if empty file).
 289         coder->is_initialized = true;
 290
 291         return true;
 292 }
 293
 294
 295 static void
 296 encode_eopm(lzma_coder *coder, uint32_t position)
 297 {
 298         const uint32_t pos_state = position & coder->pos_mask;
 299         rc_bit(&coder->rc, &coder->is_match[coder->state][pos_state], 1);
 300         rc_bit(&coder->rc, &coder->is_rep[coder->state], 0);
 301         match(coder, pos_state, UINT32_MAX, MATCH_LEN_MIN);
 302 }
 303
 304
 305 /// Number of bytes that a single encoding loop in lzma_lzma_encode() can
 306 /// consume from the dictionary. This limit comes from lzma_lzma_optimum()
 307 /// and may need to be updated if that function is significantly modified.
 308 #define LOOP_INPUT_MAX (OPTS + 1)
 309
 310
 311 extern lzma_ret
 312 lzma_lzma_encode(lzma_coder *restrict coder, lzma_mf *restrict mf,
 313                 uint8_t *restrict out, size_t *restrict out_pos,
 314                 size_t out_size, uint32_t limit)
 315 {
 316         // Initialize the stream if no data has been encoded yet.
 317         if (!coder->is_initialized && !encode_init(coder, mf))
 318                 return LZMA_OK;
 319
 320         // Get the lowest bits of the uncompressed offset from the LZ layer.
 321         uint32_t position = mf_position(mf);
 322
 323         while (true) {
 324                 // Encode pending bits, if any. Calling this before encoding
 325                 // the next symbol is needed only with plain LZMA, since
 326                 // LZMA2 always provides big enough buffer to flush
 327                 // everything out from the range encoder. For the same reason,
 328                 // rc_encode() never returns true when this function is used
 329                 // as part of LZMA2 encoder.
 330                 if (rc_encode(&coder->rc, out, out_pos, out_size)) {
 331                         assert(limit == UINT32_MAX);
 332                         return LZMA_OK;
 333                 }
 334
 335                 // With LZMA2 we need to take care that compressed size of
 336                 // a chunk doesn't get too big.
 337                 // FIXME? Check if this could be improved.
 338                 if (limit != UINT32_MAX
 339                                 && (mf->read_pos - mf->read_ahead >= limit
 340                                         || *out_pos + rc_pending(&coder->rc)
 341                                                 >= LZMA2_CHUNK_MAX
 342                                                         - LOOP_INPUT_MAX))
 343                         break;
 344
 345                 // Check that there is some input to process.
 346                 if (mf->read_pos >= mf->read_limit) {
 347                         if (mf->action == LZMA_RUN)
 348                                 return LZMA_OK;
 349
 350                         if (mf->read_ahead == 0)
 351                                 break;
 352                 }
 353
 354                 // Get optimal match (repeat position and length).
 355                 // Value ranges for pos:
 356                 //   - [0, REPS): repeated match
 357                 //   - [REPS, UINT32_MAX):
 358                 //     match at (pos - REPS)
 359                 //   - UINT32_MAX: not a match but a literal
 360                 // Value ranges for len:
 361                 //   - [MATCH_LEN_MIN, MATCH_LEN_MAX]
 362                 uint32_t len;
 363                 uint32_t back;
 364
 365                 if (coder->fast_mode)
 366                         lzma_lzma_optimum_fast(coder, mf, &back, &len);
 367                 else
 368                         lzma_lzma_optimum_normal(
 369                                         coder, mf, &back, &len, position);
 370
 371                 encode_symbol(coder, mf, back, len, position);
 372
 373                 position += len;
 374         }
 375
 376         if (!coder->is_flushed) {
 377                 coder->is_flushed = true;
 378
 379                 // We don't support encoding plain LZMA streams without EOPM,
 380                 // and LZMA2 doesn't use EOPM at LZMA level.
 381                 if (limit == UINT32_MAX)
 382                         encode_eopm(coder, position);
 383
 384                 // Flush the remaining bytes from the range encoder.
 385                 rc_flush(&coder->rc);
 386
 387                 // Copy the remaining bytes to the output buffer. If there
 388                 // isn't enough output space, we will copy out the remaining
 389                 // bytes on the next call to this function by using
 390                 // the rc_encode() call in the encoding loop above.
 391                 if (rc_encode(&coder->rc, out, out_pos, out_size)) {
 392                         assert(limit == UINT32_MAX);
 393                         return LZMA_OK;
 394                 }
 395         }
 396
 397         // Make it ready for the next LZMA2 chunk.
 398         coder->is_flushed = false;
 399
 400         return LZMA_STREAM_END;
 401 }
 402
 403
 404 static lzma_ret
 405 lzma_encode(lzma_coder *restrict coder, lzma_mf *restrict mf,
 406                 uint8_t *restrict out, size_t *restrict out_pos,
 407                 size_t out_size)
 408 {
 409         // Plain LZMA has no support for sync-flushing.
 410         if (unlikely(mf->action == LZMA_SYNC_FLUSH))
 411                 return LZMA_OPTIONS_ERROR;
 412
 413         return lzma_lzma_encode(coder, mf, out, out_pos, out_size, UINT32_MAX);
 414 }
 415
 416
 417 ////////////////////
 418 // Initialization //
 419 ////////////////////
 420
 421 static bool
 422 is_options_valid(const lzma_options_lzma *options)
 423 {
 424         // Validate some of the options. LZ encoder validates nice_len too
 425         // but we need a valid value here earlier.
 426         return is_lclppb_valid(options)
 427                         && options->nice_len >= MATCH_LEN_MIN
 428                         && options->nice_len <= MATCH_LEN_MAX
 429                         && (options->mode == LZMA_MODE_FAST
 430                                 || options->mode == LZMA_MODE_NORMAL);
 431 }
 432
 433
 434 static void
 435 set_lz_options(lzma_lz_options *lz_options, const lzma_options_lzma *options)
 436 {
 437         // LZ encoder initialization does the validation for these so we
 438         // don't need to validate here.
 439         lz_options->before_size = OPTS;
 440         lz_options->dict_size = options->dict_size;
 441         lz_options->after_size = LOOP_INPUT_MAX;
 442         lz_options->match_len_max = MATCH_LEN_MAX;
 443         lz_options->nice_len = options->nice_len;
 444         lz_options->match_finder = options->mf;
 445         lz_options->depth = options->depth;
 446         lz_options->preset_dict = options->preset_dict;
 447         lz_options->preset_dict_size = options->preset_dict_size;
 448         return;
 449 }
 450
 451
 452 static void
 453 length_encoder_reset(lzma_length_encoder *lencoder,
 454                 const uint32_t num_pos_states, const bool fast_mode)
 455 {
 456         bit_reset(lencoder->choice);
 457         bit_reset(lencoder->choice2);
 458
 459         for (size_t pos_state = 0; pos_state < num_pos_states; ++pos_state) {
 460                 bittree_reset(lencoder->low[pos_state], LEN_LOW_BITS);
 461                 bittree_reset(lencoder->mid[pos_state], LEN_MID_BITS);
 462         }
 463
 464         bittree_reset(lencoder->high, LEN_HIGH_BITS);
 465
 466         if (!fast_mode)
 467                 for (uint32_t pos_state = 0; pos_state < num_pos_states;
 468                                 ++pos_state)
 469                         length_update_prices(lencoder, pos_state);
 470
 471         return;
 472 }
 473
 474
 475 extern lzma_ret
 476 lzma_lzma_encoder_reset(lzma_coder *coder, const lzma_options_lzma *options)
 477 {
 478         if (!is_options_valid(options))
 479                 return LZMA_OPTIONS_ERROR;
 480
 481         coder->pos_mask = (1U << options->pb) - 1;
 482         coder->literal_context_bits = options->lc;
 483         coder->literal_pos_mask = (1U << options->lp) - 1;
 484
 485         // Range coder
 486         rc_reset(&coder->rc);
 487
 488         // State
 489         coder->state = STATE_LIT_LIT;
 490         for (size_t i = 0; i < REPS; ++i)
 491                 coder->reps[i] = 0;
 492
 493         literal_init(coder->literal, options->lc, options->lp);
 494
 495         // Bit encoders
 496         for (size_t i = 0; i < STATES; ++i) {
 497                 for (size_t j = 0; j <= coder->pos_mask; ++j) {
 498                         bit_reset(coder->is_match[i][j]);
 499                         bit_reset(coder->is_rep0_long[i][j]);
 500                 }
 501
 502                 bit_reset(coder->is_rep[i]);
 503                 bit_reset(coder->is_rep0[i]);
 504                 bit_reset(coder->is_rep1[i]);
 505                 bit_reset(coder->is_rep2[i]);
 506         }
 507
 508         for (size_t i = 0; i < FULL_DISTANCES - DIST_MODEL_END; ++i)
 509                 bit_reset(coder->dist_special[i]);
 510
 511         // Bit tree encoders
 512         for (size_t i = 0; i < DIST_STATES; ++i)
 513                 bittree_reset(coder->dist_slot[i], DIST_SLOT_BITS);
 514
 515         bittree_reset(coder->dist_align, ALIGN_BITS);
 516
 517         // Length encoders
 518         length_encoder_reset(&coder->match_len_encoder,
 519                         1U << options->pb, coder->fast_mode);
 520
 521         length_encoder_reset(&coder->rep_len_encoder,
 522                         1U << options->pb, coder->fast_mode);
 523
 524         // Price counts are incremented every time appropriate probabilities
 525         // are changed. price counts are set to zero when the price tables
 526         // are updated, which is done when the appropriate price counts have
 527         // big enough value, and lzma_mf.read_ahead == 0 which happens at
 528         // least every OPTS (a few thousand) possible price count increments.
 529         //
 530         // By resetting price counts to UINT32_MAX / 2, we make sure that the
 531         // price tables will be initialized before they will be used (since
 532         // the value is definitely big enough), and that it is OK to increment
 533         // price counts without risk of integer overflow (since UINT32_MAX / 2
 534         // is small enough). The current code doesn't increment price counts
 535         // before initializing price tables, but it maybe done in future if
 536         // we add support for saving the state between LZMA2 chunks.
 537         coder->match_price_count = UINT32_MAX / 2;
 538         coder->align_price_count = UINT32_MAX / 2;
 539
 540         coder->opts_end_index = 0;
 541         coder->opts_current_index = 0;
 542
 543         return LZMA_OK;
 544 }
 545
 546
 547 extern lzma_ret
 548 lzma_lzma_encoder_create(lzma_coder **coder_ptr,
 549                 const lzma_allocator *allocator,
 550                 const lzma_options_lzma *options, lzma_lz_options *lz_options)
 551 {
 552         // Allocate lzma_coder if it wasn't already allocated.
 553         if (*coder_ptr == NULL) {
 554                 *coder_ptr = lzma_alloc(sizeof(lzma_coder), allocator);
 555                 if (*coder_ptr == NULL)
 556                         return LZMA_MEM_ERROR;
 557         }
 558
 559         lzma_coder *coder = *coder_ptr;
 560
 561         // Set compression mode. We haven't validates the options yet,
 562         // but it's OK here, since nothing bad happens with invalid
 563         // options in the code below, and they will get rejected by
 564         // lzma_lzma_encoder_reset() call at the end of this function.
 565         switch (options->mode) {
 566                 case LZMA_MODE_FAST:
 567                         coder->fast_mode = true;
 568                         break;
 569
 570                 case LZMA_MODE_NORMAL: {
 571                         coder->fast_mode = false;
 572
 573                         // Set dist_table_size.
 574                         // Round the dictionary size up to next 2^n.
 575                         uint32_t log_size = 0;
 576                         while ((UINT32_C(1) << log_size) < options->dict_size)
 577                                 ++log_size;
 578
 579                         coder->dist_table_size = log_size * 2;
 580
 581                         // Length encoders' price table size
 582                         coder->match_len_encoder.table_size
 583                                 = options->nice_len + 1 - MATCH_LEN_MIN;
 584                         coder->rep_len_encoder.table_size
 585                                 = options->nice_len + 1 - MATCH_LEN_MIN;
 586                         break;
 587                 }
 588
 589                 default:
 590                         return LZMA_OPTIONS_ERROR;
 591         }
 592
 593         // We don't need to write the first byte as literal if there is
 594         // a non-empty preset dictionary. encode_init() wouldn't even work
 595         // if there is a non-empty preset dictionary, because encode_init()
 596         // assumes that position is zero and previous byte is also zero.
 597         coder->is_initialized = options->preset_dict != NULL
 598                         && options->preset_dict_size > 0;
 599         coder->is_flushed = false;
 600
 601         set_lz_options(lz_options, options);
 602
 603         return lzma_lzma_encoder_reset(coder, options);
 604 }
 605
 606
 607 static lzma_ret
 608 lzma_encoder_init(lzma_lz_encoder *lz, const lzma_allocator *allocator,
 609                 const void *options, lzma_lz_options *lz_options)
 610 {
 611         lz->code = &lzma_encode;
 612         return lzma_lzma_encoder_create(
 613                         &lz->coder, allocator, options, lz_options);
 614 }
 615
 616
 617 extern lzma_ret
 618 lzma_lzma_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator,
 619                 const lzma_filter_info *filters)
 620 {
 621         return lzma_lz_encoder_init(
 622                         next, allocator, filters, &lzma_encoder_init);
 623 }
 624
 625
 626 extern uint64_t
 627 lzma_lzma_encoder_memusage(const void *options)
 628 {
 629         if (!is_options_valid(options))
 630                 return UINT64_MAX;
 631
 632         lzma_lz_options lz_options;
 633         set_lz_options(&lz_options, options);
 634
 635         const uint64_t lz_memusage = lzma_lz_encoder_memusage(&lz_options);
 636         if (lz_memusage == UINT64_MAX)
 637                 return UINT64_MAX;
 638
 639         return (uint64_t)(sizeof(lzma_coder)) + lz_memusage;
 640 }
 641
 642
 643 extern bool
 644 lzma_lzma_lclppb_encode(const lzma_options_lzma *options, uint8_t *byte)
 645 {
 646         if (!is_lclppb_valid(options))
 647                 return true;
 648
 649         *byte = (options->pb * 5 + options->lp) * 9 + options->lc;
 650         assert(*byte <= (4 * 5 + 4) * 9 + 8);
 651
 652         return false;
 653 }
 654
 655
 656 #ifdef HAVE_ENCODER_LZMA1
 657 extern lzma_ret
 658 lzma_lzma_props_encode(const void *options, uint8_t *out)
 659 {
 660         const lzma_options_lzma *const opt = options;
 661
 662         if (lzma_lzma_lclppb_encode(opt, out))
 663                 return LZMA_PROG_ERROR;
 664
 665         unaligned_write32le(out + 1, opt->dict_size);
 666
 667         return LZMA_OK;
 668 }
 669 #endif
 670
 671
 672 extern LZMA_API(lzma_bool)
 673 lzma_mode_is_supported(lzma_mode mode)
 674 {
 675         return mode == LZMA_MODE_FAST || mode == LZMA_MODE_NORMAL;
 676 }