1207753Smm/////////////////////////////////////////////////////////////////////////////// 2207753Smm// 3207753Smm/// \file lzma2_encoder.c 4207753Smm/// \brief LZMA2 encoder 5207753Smm/// 6207753Smm// Authors: Igor Pavlov 7207753Smm// Lasse Collin 8207753Smm// 9207753Smm// This file has been put into the public domain. 10207753Smm// You can do whatever you want with this file. 11207753Smm// 12207753Smm/////////////////////////////////////////////////////////////////////////////// 13207753Smm 14207753Smm#include "lz_encoder.h" 15207753Smm#include "lzma_encoder.h" 16207753Smm#include "fastpos.h" 17207753Smm#include "lzma2_encoder.h" 18207753Smm 19207753Smm 20207753Smmstruct lzma_coder_s { 21207753Smm enum { 22207753Smm SEQ_INIT, 23207753Smm SEQ_LZMA_ENCODE, 24207753Smm SEQ_LZMA_COPY, 25207753Smm SEQ_UNCOMPRESSED_HEADER, 26207753Smm SEQ_UNCOMPRESSED_COPY, 27207753Smm } sequence; 28207753Smm 29207753Smm /// LZMA encoder 30207753Smm lzma_coder *lzma; 31207753Smm 32207753Smm /// LZMA options currently in use. 33207753Smm lzma_options_lzma opt_cur; 34207753Smm 35207753Smm bool need_properties; 36207753Smm bool need_state_reset; 37207753Smm bool need_dictionary_reset; 38207753Smm 39207753Smm /// Uncompressed size of a chunk 40207753Smm size_t uncompressed_size; 41207753Smm 42207753Smm /// Compressed size of a chunk (excluding headers); this is also used 43207753Smm /// to indicate the end of buf[] in SEQ_LZMA_COPY. 44207753Smm size_t compressed_size; 45207753Smm 46207753Smm /// Read position in buf[] 47207753Smm size_t buf_pos; 48207753Smm 49207753Smm /// Buffer to hold the chunk header and LZMA compressed data 50207753Smm uint8_t buf[LZMA2_HEADER_MAX + LZMA2_CHUNK_MAX]; 51207753Smm}; 52207753Smm 53207753Smm 54207753Smmstatic void 55207753Smmlzma2_header_lzma(lzma_coder *coder) 56207753Smm{ 57207753Smm assert(coder->uncompressed_size > 0); 58207753Smm assert(coder->uncompressed_size <= LZMA2_UNCOMPRESSED_MAX); 59207753Smm assert(coder->compressed_size > 0); 60207753Smm assert(coder->compressed_size <= LZMA2_CHUNK_MAX); 61207753Smm 62207753Smm size_t pos; 63207753Smm 64207753Smm if (coder->need_properties) { 65207753Smm pos = 0; 66207753Smm 67207753Smm if (coder->need_dictionary_reset) 68207753Smm coder->buf[pos] = 0x80 + (3 << 5); 69207753Smm else 70207753Smm coder->buf[pos] = 0x80 + (2 << 5); 71207753Smm } else { 72207753Smm pos = 1; 73207753Smm 74207753Smm if (coder->need_state_reset) 75207753Smm coder->buf[pos] = 0x80 + (1 << 5); 76207753Smm else 77207753Smm coder->buf[pos] = 0x80; 78207753Smm } 79207753Smm 80207753Smm // Set the start position for copying. 81207753Smm coder->buf_pos = pos; 82207753Smm 83207753Smm // Uncompressed size 84207753Smm size_t size = coder->uncompressed_size - 1; 85207753Smm coder->buf[pos++] += size >> 16; 86207753Smm coder->buf[pos++] = (size >> 8) & 0xFF; 87207753Smm coder->buf[pos++] = size & 0xFF; 88207753Smm 89207753Smm // Compressed size 90207753Smm size = coder->compressed_size - 1; 91207753Smm coder->buf[pos++] = size >> 8; 92207753Smm coder->buf[pos++] = size & 0xFF; 93207753Smm 94207753Smm // Properties, if needed 95207753Smm if (coder->need_properties) 96207753Smm lzma_lzma_lclppb_encode(&coder->opt_cur, coder->buf + pos); 97207753Smm 98207753Smm coder->need_properties = false; 99207753Smm coder->need_state_reset = false; 100207753Smm coder->need_dictionary_reset = false; 101207753Smm 102207753Smm // The copying code uses coder->compressed_size to indicate the end 103207753Smm // of coder->buf[], so we need add the maximum size of the header here. 104207753Smm coder->compressed_size += LZMA2_HEADER_MAX; 105207753Smm 106207753Smm return; 107207753Smm} 108207753Smm 109207753Smm 110207753Smmstatic void 111207753Smmlzma2_header_uncompressed(lzma_coder *coder) 112207753Smm{ 113207753Smm assert(coder->uncompressed_size > 0); 114207753Smm assert(coder->uncompressed_size <= LZMA2_CHUNK_MAX); 115207753Smm 116207753Smm // If this is the first chunk, we need to include dictionary 117207753Smm // reset indicator. 118207753Smm if (coder->need_dictionary_reset) 119207753Smm coder->buf[0] = 1; 120207753Smm else 121207753Smm coder->buf[0] = 2; 122207753Smm 123207753Smm coder->need_dictionary_reset = false; 124207753Smm 125207753Smm // "Compressed" size 126207753Smm coder->buf[1] = (coder->uncompressed_size - 1) >> 8; 127207753Smm coder->buf[2] = (coder->uncompressed_size - 1) & 0xFF; 128207753Smm 129207753Smm // Set the start position for copying. 130207753Smm coder->buf_pos = 0; 131207753Smm return; 132207753Smm} 133207753Smm 134207753Smm 135207753Smmstatic lzma_ret 136207753Smmlzma2_encode(lzma_coder *restrict coder, lzma_mf *restrict mf, 137207753Smm uint8_t *restrict out, size_t *restrict out_pos, 138207753Smm size_t out_size) 139207753Smm{ 140207753Smm while (*out_pos < out_size) 141207753Smm switch (coder->sequence) { 142207753Smm case SEQ_INIT: 143207753Smm // If there's no input left and we are flushing or finishing, 144207753Smm // don't start a new chunk. 145207753Smm if (mf_unencoded(mf) == 0) { 146207753Smm // Write end of payload marker if finishing. 147207753Smm if (mf->action == LZMA_FINISH) 148207753Smm out[(*out_pos)++] = 0; 149207753Smm 150207753Smm return mf->action == LZMA_RUN 151207753Smm ? LZMA_OK : LZMA_STREAM_END; 152207753Smm } 153207753Smm 154207753Smm if (coder->need_state_reset) 155207753Smm return_if_error(lzma_lzma_encoder_reset( 156207753Smm coder->lzma, &coder->opt_cur)); 157207753Smm 158207753Smm coder->uncompressed_size = 0; 159207753Smm coder->compressed_size = 0; 160207753Smm coder->sequence = SEQ_LZMA_ENCODE; 161207753Smm 162207753Smm // Fall through 163207753Smm 164207753Smm case SEQ_LZMA_ENCODE: { 165207753Smm // Calculate how much more uncompressed data this chunk 166207753Smm // could accept. 167207753Smm const uint32_t left = LZMA2_UNCOMPRESSED_MAX 168207753Smm - coder->uncompressed_size; 169207753Smm uint32_t limit; 170207753Smm 171207753Smm if (left < mf->match_len_max) { 172207753Smm // Must flush immediately since the next LZMA symbol 173207753Smm // could make the uncompressed size of the chunk too 174207753Smm // big. 175207753Smm limit = 0; 176207753Smm } else { 177207753Smm // Calculate maximum read_limit that is OK from point 178207753Smm // of view of LZMA2 chunk size. 179207753Smm limit = mf->read_pos - mf->read_ahead 180207753Smm + left - mf->match_len_max; 181207753Smm } 182207753Smm 183207753Smm // Save the start position so that we can update 184207753Smm // coder->uncompressed_size. 185207753Smm const uint32_t read_start = mf->read_pos - mf->read_ahead; 186207753Smm 187207753Smm // Call the LZMA encoder until the chunk is finished. 188207753Smm const lzma_ret ret = lzma_lzma_encode(coder->lzma, mf, 189207753Smm coder->buf + LZMA2_HEADER_MAX, 190207753Smm &coder->compressed_size, 191207753Smm LZMA2_CHUNK_MAX, limit); 192207753Smm 193207753Smm coder->uncompressed_size += mf->read_pos - mf->read_ahead 194207753Smm - read_start; 195207753Smm 196207753Smm assert(coder->compressed_size <= LZMA2_CHUNK_MAX); 197207753Smm assert(coder->uncompressed_size <= LZMA2_UNCOMPRESSED_MAX); 198207753Smm 199207753Smm if (ret != LZMA_STREAM_END) 200207753Smm return LZMA_OK; 201207753Smm 202207753Smm // See if the chunk compressed. If it didn't, we encode it 203207753Smm // as uncompressed chunk. This saves a few bytes of space 204207753Smm // and makes decoding faster. 205207753Smm if (coder->compressed_size >= coder->uncompressed_size) { 206207753Smm coder->uncompressed_size += mf->read_ahead; 207207753Smm assert(coder->uncompressed_size 208207753Smm <= LZMA2_UNCOMPRESSED_MAX); 209207753Smm mf->read_ahead = 0; 210207753Smm lzma2_header_uncompressed(coder); 211207753Smm coder->need_state_reset = true; 212207753Smm coder->sequence = SEQ_UNCOMPRESSED_HEADER; 213207753Smm break; 214207753Smm } 215207753Smm 216207753Smm // The chunk did compress at least by one byte, so we store 217207753Smm // the chunk as LZMA. 218207753Smm lzma2_header_lzma(coder); 219207753Smm 220207753Smm coder->sequence = SEQ_LZMA_COPY; 221207753Smm } 222207753Smm 223207753Smm // Fall through 224207753Smm 225207753Smm case SEQ_LZMA_COPY: 226207753Smm // Copy the compressed chunk along its headers to the 227207753Smm // output buffer. 228207753Smm lzma_bufcpy(coder->buf, &coder->buf_pos, 229207753Smm coder->compressed_size, 230207753Smm out, out_pos, out_size); 231207753Smm if (coder->buf_pos != coder->compressed_size) 232207753Smm return LZMA_OK; 233207753Smm 234207753Smm coder->sequence = SEQ_INIT; 235207753Smm break; 236207753Smm 237207753Smm case SEQ_UNCOMPRESSED_HEADER: 238207753Smm // Copy the three-byte header to indicate uncompressed chunk. 239207753Smm lzma_bufcpy(coder->buf, &coder->buf_pos, 240207753Smm LZMA2_HEADER_UNCOMPRESSED, 241207753Smm out, out_pos, out_size); 242207753Smm if (coder->buf_pos != LZMA2_HEADER_UNCOMPRESSED) 243207753Smm return LZMA_OK; 244207753Smm 245207753Smm coder->sequence = SEQ_UNCOMPRESSED_COPY; 246207753Smm 247207753Smm // Fall through 248207753Smm 249207753Smm case SEQ_UNCOMPRESSED_COPY: 250207753Smm // Copy the uncompressed data as is from the dictionary 251207753Smm // to the output buffer. 252207753Smm mf_read(mf, out, out_pos, out_size, &coder->uncompressed_size); 253207753Smm if (coder->uncompressed_size != 0) 254207753Smm return LZMA_OK; 255207753Smm 256207753Smm coder->sequence = SEQ_INIT; 257207753Smm break; 258207753Smm } 259207753Smm 260207753Smm return LZMA_OK; 261207753Smm} 262207753Smm 263207753Smm 264207753Smmstatic void 265207753Smmlzma2_encoder_end(lzma_coder *coder, lzma_allocator *allocator) 266207753Smm{ 267207753Smm lzma_free(coder->lzma, allocator); 268207753Smm lzma_free(coder, allocator); 269207753Smm return; 270207753Smm} 271207753Smm 272207753Smm 273207753Smmstatic lzma_ret 274207753Smmlzma2_encoder_options_update(lzma_coder *coder, const lzma_filter *filter) 275207753Smm{ 276207753Smm // New options can be set only when there is no incomplete chunk. 277207753Smm // This is the case at the beginning of the raw stream and right 278207753Smm // after LZMA_SYNC_FLUSH. 279207753Smm if (filter->options == NULL || coder->sequence != SEQ_INIT) 280207753Smm return LZMA_PROG_ERROR; 281207753Smm 282207753Smm // Look if there are new options. At least for now, 283207753Smm // only lc/lp/pb can be changed. 284207753Smm const lzma_options_lzma *opt = filter->options; 285207753Smm if (coder->opt_cur.lc != opt->lc || coder->opt_cur.lp != opt->lp 286207753Smm || coder->opt_cur.pb != opt->pb) { 287207753Smm // Validate the options. 288207753Smm if (opt->lc > LZMA_LCLP_MAX || opt->lp > LZMA_LCLP_MAX 289207753Smm || opt->lc + opt->lp > LZMA_LCLP_MAX 290207753Smm || opt->pb > LZMA_PB_MAX) 291207753Smm return LZMA_OPTIONS_ERROR; 292207753Smm 293207753Smm // The new options will be used when the encoder starts 294207753Smm // a new LZMA2 chunk. 295207753Smm coder->opt_cur.lc = opt->lc; 296207753Smm coder->opt_cur.lp = opt->lp; 297207753Smm coder->opt_cur.pb = opt->pb; 298207753Smm coder->need_properties = true; 299207753Smm coder->need_state_reset = true; 300207753Smm } 301207753Smm 302207753Smm return LZMA_OK; 303207753Smm} 304207753Smm 305207753Smm 306207753Smmstatic lzma_ret 307207753Smmlzma2_encoder_init(lzma_lz_encoder *lz, lzma_allocator *allocator, 308207753Smm const void *options, lzma_lz_options *lz_options) 309207753Smm{ 310207753Smm if (options == NULL) 311207753Smm return LZMA_PROG_ERROR; 312207753Smm 313207753Smm if (lz->coder == NULL) { 314207753Smm lz->coder = lzma_alloc(sizeof(lzma_coder), allocator); 315207753Smm if (lz->coder == NULL) 316207753Smm return LZMA_MEM_ERROR; 317207753Smm 318207753Smm lz->code = &lzma2_encode; 319207753Smm lz->end = &lzma2_encoder_end; 320207753Smm lz->options_update = &lzma2_encoder_options_update; 321207753Smm 322207753Smm lz->coder->lzma = NULL; 323207753Smm } 324207753Smm 325207753Smm lz->coder->opt_cur = *(const lzma_options_lzma *)(options); 326207753Smm 327207753Smm lz->coder->sequence = SEQ_INIT; 328207753Smm lz->coder->need_properties = true; 329207753Smm lz->coder->need_state_reset = false; 330207753Smm lz->coder->need_dictionary_reset 331207753Smm = lz->coder->opt_cur.preset_dict == NULL 332207753Smm || lz->coder->opt_cur.preset_dict_size == 0; 333207753Smm 334207753Smm // Initialize LZMA encoder 335207753Smm return_if_error(lzma_lzma_encoder_create(&lz->coder->lzma, allocator, 336207753Smm &lz->coder->opt_cur, lz_options)); 337207753Smm 338207753Smm // Make sure that we will always have enough history available in 339207753Smm // case we need to use uncompressed chunks. They are used when the 340207753Smm // compressed size of a chunk is not smaller than the uncompressed 341207753Smm // size, so we need to have at least LZMA2_COMPRESSED_MAX bytes 342207753Smm // history available. 343207753Smm if (lz_options->before_size + lz_options->dict_size < LZMA2_CHUNK_MAX) 344207753Smm lz_options->before_size 345207753Smm = LZMA2_CHUNK_MAX - lz_options->dict_size; 346207753Smm 347207753Smm return LZMA_OK; 348207753Smm} 349207753Smm 350207753Smm 351207753Smmextern lzma_ret 352207753Smmlzma_lzma2_encoder_init(lzma_next_coder *next, lzma_allocator *allocator, 353207753Smm const lzma_filter_info *filters) 354207753Smm{ 355207753Smm return lzma_lz_encoder_init( 356207753Smm next, allocator, filters, &lzma2_encoder_init); 357207753Smm} 358207753Smm 359207753Smm 360207753Smmextern uint64_t 361207753Smmlzma_lzma2_encoder_memusage(const void *options) 362207753Smm{ 363207753Smm const uint64_t lzma_mem = lzma_lzma_encoder_memusage(options); 364207753Smm if (lzma_mem == UINT64_MAX) 365207753Smm return UINT64_MAX; 366207753Smm 367207753Smm return sizeof(lzma_coder) + lzma_mem; 368207753Smm} 369207753Smm 370207753Smm 371207753Smmextern lzma_ret 372207753Smmlzma_lzma2_props_encode(const void *options, uint8_t *out) 373207753Smm{ 374207753Smm const lzma_options_lzma *const opt = options; 375213700Smm uint32_t d = my_max(opt->dict_size, LZMA_DICT_SIZE_MIN); 376207753Smm 377223935Smm // Round up to the next 2^n - 1 or 2^n + 2^(n - 1) - 1 depending 378207753Smm // on which one is the next: 379207753Smm --d; 380207753Smm d |= d >> 2; 381207753Smm d |= d >> 3; 382207753Smm d |= d >> 4; 383207753Smm d |= d >> 8; 384207753Smm d |= d >> 16; 385207753Smm 386207753Smm // Get the highest two bits using the proper encoding: 387207753Smm if (d == UINT32_MAX) 388207753Smm out[0] = 40; 389207753Smm else 390207753Smm out[0] = get_pos_slot(d + 1) - 24; 391207753Smm 392207753Smm return LZMA_OK; 393207753Smm} 394