Index: xz/src/liblzma/lzma/lzma2_encoder.c |
=================================================================== |
--- xz/src/liblzma/lzma/lzma2_encoder.c (revision 0) |
+++ xz/src/liblzma/lzma/lzma2_encoder.c (revision 0) |
@@ -0,0 +1,393 @@ |
+/////////////////////////////////////////////////////////////////////////////// |
+// |
+/// \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" |
+ |
+ |
+struct lzma_coder_s { |
+ enum { |
+ SEQ_INIT, |
+ SEQ_LZMA_ENCODE, |
+ SEQ_LZMA_COPY, |
+ SEQ_UNCOMPRESSED_HEADER, |
+ SEQ_UNCOMPRESSED_COPY, |
+ } sequence; |
+ |
+ /// LZMA encoder |
+ lzma_coder *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]; |
+}; |
+ |
+ |
+static void |
+lzma2_header_lzma(lzma_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_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(lzma_coder *restrict coder, lzma_mf *restrict mf, |
+ uint8_t *restrict out, size_t *restrict out_pos, |
+ size_t out_size) |
+{ |
+ 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(lzma_coder *coder, lzma_allocator *allocator) |
+{ |
+ lzma_free(coder->lzma, allocator); |
+ lzma_free(coder, allocator); |
+ return; |
+} |
+ |
+ |
+static lzma_ret |
+lzma2_encoder_options_update(lzma_coder *coder, const lzma_filter *filter) |
+{ |
+ // 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, lzma_allocator *allocator, |
+ const void *options, lzma_lz_options *lz_options) |
+{ |
+ if (options == NULL) |
+ return LZMA_PROG_ERROR; |
+ |
+ if (lz->coder == NULL) { |
+ lz->coder = lzma_alloc(sizeof(lzma_coder), allocator); |
+ if (lz->coder == NULL) |
+ return LZMA_MEM_ERROR; |
+ |
+ lz->code = &lzma2_encode; |
+ lz->end = &lzma2_encoder_end; |
+ lz->options_update = &lzma2_encoder_options_update; |
+ |
+ lz->coder->lzma = NULL; |
+ } |
+ |
+ lz->coder->opt_cur = *(const lzma_options_lzma *)(options); |
+ |
+ lz->coder->sequence = SEQ_INIT; |
+ lz->coder->need_properties = true; |
+ lz->coder->need_state_reset = false; |
+ lz->coder->need_dictionary_reset |
+ = lz->coder->opt_cur.preset_dict == NULL |
+ || lz->coder->opt_cur.preset_dict_size == 0; |
+ |
+ // Initialize LZMA encoder |
+ return_if_error(lzma_lzma_encoder_create(&lz->coder->lzma, allocator, |
+ &lz->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, 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_coder) + lzma_mem; |
+} |
+ |
+ |
+extern lzma_ret |
+lzma_lzma2_props_encode(const void *options, uint8_t *out) |
+{ |
+ const lzma_options_lzma *const opt = options; |
+ uint32_t d = my_max(opt->dict_size, LZMA_DICT_SIZE_MIN); |
+ |
+ // Round up to 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_pos_slot(d + 1) - 24; |
+ |
+ return LZMA_OK; |
+} |
Property changes on: xz/src/liblzma/lzma/lzma2_encoder.c |
___________________________________________________________________ |
Added: svn:eol-style |
+ LF |