diff options
author | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 03:10:08 +0000 |
---|---|---|
committer | Daniel Baumann <daniel.baumann@progress-linux.org> | 2024-04-19 03:10:08 +0000 |
commit | 5262a872f308b3b584c97d621992fb3877e392b8 (patch) | |
tree | b956c322376141abeafe639bd72cfecdf16954b5 /src/liblzma/lzma/lzma2_encoder.c | |
parent | Initial commit. (diff) | |
download | xz-utils-5262a872f308b3b584c97d621992fb3877e392b8.tar.xz xz-utils-5262a872f308b3b584c97d621992fb3877e392b8.zip |
Adding upstream version 5.6.1+really5.4.5.upstream/5.6.1+really5.4.5
Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>
Diffstat (limited to 'src/liblzma/lzma/lzma2_encoder.c')
-rw-r--r-- | src/liblzma/lzma/lzma2_encoder.c | 414 |
1 files changed, 414 insertions, 0 deletions
diff --git a/src/liblzma/lzma/lzma2_encoder.c b/src/liblzma/lzma/lzma2_encoder.c new file mode 100644 index 0000000..4b6b231 --- /dev/null +++ b/src/liblzma/lzma/lzma2_encoder.c @@ -0,0 +1,414 @@ +/////////////////////////////////////////////////////////////////////////////// +// +/// \file lzma2_encoder.c +/// \brief LZMA2 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 "lz_encoder.h" +#include "lzma_encoder.h" +#include "fastpos.h" +#include "lzma2_encoder.h" + + +typedef struct { + enum { + SEQ_INIT, + SEQ_LZMA_ENCODE, + SEQ_LZMA_COPY, + SEQ_UNCOMPRESSED_HEADER, + SEQ_UNCOMPRESSED_COPY, + } sequence; + + /// LZMA encoder + void *lzma; + + /// LZMA options currently in use. + lzma_options_lzma opt_cur; + + bool need_properties; + bool need_state_reset; + bool need_dictionary_reset; + + /// Uncompressed size of a chunk + size_t uncompressed_size; + + /// Compressed size of a chunk (excluding headers); this is also used + /// to indicate the end of buf[] in SEQ_LZMA_COPY. + size_t compressed_size; + + /// Read position in buf[] + size_t buf_pos; + + /// Buffer to hold the chunk header and LZMA compressed data + uint8_t buf[LZMA2_HEADER_MAX + LZMA2_CHUNK_MAX]; +} lzma_lzma2_coder; + + +static void +lzma2_header_lzma(lzma_lzma2_coder *coder) +{ + assert(coder->uncompressed_size > 0); + assert(coder->uncompressed_size <= LZMA2_UNCOMPRESSED_MAX); + assert(coder->compressed_size > 0); + assert(coder->compressed_size <= LZMA2_CHUNK_MAX); + + size_t pos; + + if (coder->need_properties) { + pos = 0; + + if (coder->need_dictionary_reset) + coder->buf[pos] = 0x80 + (3 << 5); + else + coder->buf[pos] = 0x80 + (2 << 5); + } else { + pos = 1; + + if (coder->need_state_reset) + coder->buf[pos] = 0x80 + (1 << 5); + else + coder->buf[pos] = 0x80; + } + + // Set the start position for copying. + coder->buf_pos = pos; + + // Uncompressed size + size_t size = coder->uncompressed_size - 1; + coder->buf[pos++] += size >> 16; + coder->buf[pos++] = (size >> 8) & 0xFF; + coder->buf[pos++] = size & 0xFF; + + // Compressed size + size = coder->compressed_size - 1; + coder->buf[pos++] = size >> 8; + coder->buf[pos++] = size & 0xFF; + + // Properties, if needed + if (coder->need_properties) + lzma_lzma_lclppb_encode(&coder->opt_cur, coder->buf + pos); + + coder->need_properties = false; + coder->need_state_reset = false; + coder->need_dictionary_reset = false; + + // The copying code uses coder->compressed_size to indicate the end + // of coder->buf[], so we need add the maximum size of the header here. + coder->compressed_size += LZMA2_HEADER_MAX; + + return; +} + + +static void +lzma2_header_uncompressed(lzma_lzma2_coder *coder) +{ + assert(coder->uncompressed_size > 0); + assert(coder->uncompressed_size <= LZMA2_CHUNK_MAX); + + // If this is the first chunk, we need to include dictionary + // reset indicator. + if (coder->need_dictionary_reset) + coder->buf[0] = 1; + else + coder->buf[0] = 2; + + coder->need_dictionary_reset = false; + + // "Compressed" size + coder->buf[1] = (coder->uncompressed_size - 1) >> 8; + coder->buf[2] = (coder->uncompressed_size - 1) & 0xFF; + + // Set the start position for copying. + coder->buf_pos = 0; + return; +} + + +static lzma_ret +lzma2_encode(void *coder_ptr, lzma_mf *restrict mf, + uint8_t *restrict out, size_t *restrict out_pos, + size_t out_size) +{ + lzma_lzma2_coder *restrict coder = coder_ptr; + + while (*out_pos < out_size) + switch (coder->sequence) { + case SEQ_INIT: + // If there's no input left and we are flushing or finishing, + // don't start a new chunk. + if (mf_unencoded(mf) == 0) { + // Write end of payload marker if finishing. + if (mf->action == LZMA_FINISH) + out[(*out_pos)++] = 0; + + return mf->action == LZMA_RUN + ? LZMA_OK : LZMA_STREAM_END; + } + + if (coder->need_state_reset) + return_if_error(lzma_lzma_encoder_reset( + coder->lzma, &coder->opt_cur)); + + coder->uncompressed_size = 0; + coder->compressed_size = 0; + coder->sequence = SEQ_LZMA_ENCODE; + + // Fall through + + case SEQ_LZMA_ENCODE: { + // Calculate how much more uncompressed data this chunk + // could accept. + const uint32_t left = LZMA2_UNCOMPRESSED_MAX + - coder->uncompressed_size; + uint32_t limit; + + if (left < mf->match_len_max) { + // Must flush immediately since the next LZMA symbol + // could make the uncompressed size of the chunk too + // big. + limit = 0; + } else { + // Calculate maximum read_limit that is OK from point + // of view of LZMA2 chunk size. + limit = mf->read_pos - mf->read_ahead + + left - mf->match_len_max; + } + + // Save the start position so that we can update + // coder->uncompressed_size. + const uint32_t read_start = mf->read_pos - mf->read_ahead; + + // Call the LZMA encoder until the chunk is finished. + const lzma_ret ret = lzma_lzma_encode(coder->lzma, mf, + coder->buf + LZMA2_HEADER_MAX, + &coder->compressed_size, + LZMA2_CHUNK_MAX, limit); + + coder->uncompressed_size += mf->read_pos - mf->read_ahead + - read_start; + + assert(coder->compressed_size <= LZMA2_CHUNK_MAX); + assert(coder->uncompressed_size <= LZMA2_UNCOMPRESSED_MAX); + + if (ret != LZMA_STREAM_END) + return LZMA_OK; + + // See if the chunk compressed. If it didn't, we encode it + // as uncompressed chunk. This saves a few bytes of space + // and makes decoding faster. + if (coder->compressed_size >= coder->uncompressed_size) { + coder->uncompressed_size += mf->read_ahead; + assert(coder->uncompressed_size + <= LZMA2_UNCOMPRESSED_MAX); + mf->read_ahead = 0; + lzma2_header_uncompressed(coder); + coder->need_state_reset = true; + coder->sequence = SEQ_UNCOMPRESSED_HEADER; + break; + } + + // The chunk did compress at least by one byte, so we store + // the chunk as LZMA. + lzma2_header_lzma(coder); + + coder->sequence = SEQ_LZMA_COPY; + } + + // Fall through + + case SEQ_LZMA_COPY: + // Copy the compressed chunk along its headers to the + // output buffer. + lzma_bufcpy(coder->buf, &coder->buf_pos, + coder->compressed_size, + out, out_pos, out_size); + if (coder->buf_pos != coder->compressed_size) + return LZMA_OK; + + coder->sequence = SEQ_INIT; + break; + + case SEQ_UNCOMPRESSED_HEADER: + // Copy the three-byte header to indicate uncompressed chunk. + lzma_bufcpy(coder->buf, &coder->buf_pos, + LZMA2_HEADER_UNCOMPRESSED, + out, out_pos, out_size); + if (coder->buf_pos != LZMA2_HEADER_UNCOMPRESSED) + return LZMA_OK; + + coder->sequence = SEQ_UNCOMPRESSED_COPY; + + // Fall through + + case SEQ_UNCOMPRESSED_COPY: + // Copy the uncompressed data as is from the dictionary + // to the output buffer. + mf_read(mf, out, out_pos, out_size, &coder->uncompressed_size); + if (coder->uncompressed_size != 0) + return LZMA_OK; + + coder->sequence = SEQ_INIT; + break; + } + + return LZMA_OK; +} + + +static void +lzma2_encoder_end(void *coder_ptr, const lzma_allocator *allocator) +{ + lzma_lzma2_coder *coder = coder_ptr; + lzma_free(coder->lzma, allocator); + lzma_free(coder, allocator); + return; +} + + +static lzma_ret +lzma2_encoder_options_update(void *coder_ptr, const lzma_filter *filter) +{ + lzma_lzma2_coder *coder = coder_ptr; + + // New options can be set only when there is no incomplete chunk. + // This is the case at the beginning of the raw stream and right + // after LZMA_SYNC_FLUSH. + if (filter->options == NULL || coder->sequence != SEQ_INIT) + return LZMA_PROG_ERROR; + + // Look if there are new options. At least for now, + // only lc/lp/pb can be changed. + const lzma_options_lzma *opt = filter->options; + if (coder->opt_cur.lc != opt->lc || coder->opt_cur.lp != opt->lp + || coder->opt_cur.pb != opt->pb) { + // Validate the options. + if (opt->lc > LZMA_LCLP_MAX || opt->lp > LZMA_LCLP_MAX + || opt->lc + opt->lp > LZMA_LCLP_MAX + || opt->pb > LZMA_PB_MAX) + return LZMA_OPTIONS_ERROR; + + // The new options will be used when the encoder starts + // a new LZMA2 chunk. + coder->opt_cur.lc = opt->lc; + coder->opt_cur.lp = opt->lp; + coder->opt_cur.pb = opt->pb; + coder->need_properties = true; + coder->need_state_reset = true; + } + + return LZMA_OK; +} + + +static lzma_ret +lzma2_encoder_init(lzma_lz_encoder *lz, const lzma_allocator *allocator, + lzma_vli id lzma_attribute((__unused__)), const void *options, + lzma_lz_options *lz_options) +{ + if (options == NULL) + return LZMA_PROG_ERROR; + + lzma_lzma2_coder *coder = lz->coder; + if (coder == NULL) { + coder = lzma_alloc(sizeof(lzma_lzma2_coder), allocator); + if (coder == NULL) + return LZMA_MEM_ERROR; + + lz->coder = coder; + lz->code = &lzma2_encode; + lz->end = &lzma2_encoder_end; + lz->options_update = &lzma2_encoder_options_update; + + coder->lzma = NULL; + } + + coder->opt_cur = *(const lzma_options_lzma *)(options); + + coder->sequence = SEQ_INIT; + coder->need_properties = true; + coder->need_state_reset = false; + coder->need_dictionary_reset + = coder->opt_cur.preset_dict == NULL + || coder->opt_cur.preset_dict_size == 0; + + // Initialize LZMA encoder + return_if_error(lzma_lzma_encoder_create(&coder->lzma, allocator, + LZMA_FILTER_LZMA2, &coder->opt_cur, lz_options)); + + // Make sure that we will always have enough history available in + // case we need to use uncompressed chunks. They are used when the + // compressed size of a chunk is not smaller than the uncompressed + // size, so we need to have at least LZMA2_COMPRESSED_MAX bytes + // history available. + if (lz_options->before_size + lz_options->dict_size < LZMA2_CHUNK_MAX) + lz_options->before_size + = LZMA2_CHUNK_MAX - lz_options->dict_size; + + return LZMA_OK; +} + + +extern lzma_ret +lzma_lzma2_encoder_init(lzma_next_coder *next, const lzma_allocator *allocator, + const lzma_filter_info *filters) +{ + return lzma_lz_encoder_init( + next, allocator, filters, &lzma2_encoder_init); +} + + +extern uint64_t +lzma_lzma2_encoder_memusage(const void *options) +{ + const uint64_t lzma_mem = lzma_lzma_encoder_memusage(options); + if (lzma_mem == UINT64_MAX) + return UINT64_MAX; + + return sizeof(lzma_lzma2_coder) + lzma_mem; +} + + +extern lzma_ret +lzma_lzma2_props_encode(const void *options, uint8_t *out) +{ + if (options == NULL) + return LZMA_PROG_ERROR; + + const lzma_options_lzma *const opt = options; + uint32_t d = my_max(opt->dict_size, LZMA_DICT_SIZE_MIN); + + // Round up to the next 2^n - 1 or 2^n + 2^(n - 1) - 1 depending + // on which one is the next: + --d; + d |= d >> 2; + d |= d >> 3; + d |= d >> 4; + d |= d >> 8; + d |= d >> 16; + + // Get the highest two bits using the proper encoding: + if (d == UINT32_MAX) + out[0] = 40; + else + out[0] = get_dist_slot(d + 1) - 24; + + return LZMA_OK; +} + + +extern uint64_t +lzma_lzma2_block_size(const void *options) +{ + const lzma_options_lzma *const opt = options; + + // Use at least 1 MiB to keep compression ratio better. + return my_max((uint64_t)(opt->dict_size) * 3, UINT64_C(1) << 20); +} |