--- /dev/null
+///////////////////////////////////////////////////////////////////////////////
+//
+/// \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, const 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, const 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, 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_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 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);
+}
projects / zpackage / blobdiff