diff options
Diffstat (limited to 'Build/source/texk/dvisvgm/dvisvgm-src/libs/brotli/enc/metablock_inc.h')
-rw-r--r-- | Build/source/texk/dvisvgm/dvisvgm-src/libs/brotli/enc/metablock_inc.h | 183 |
1 files changed, 0 insertions, 183 deletions
diff --git a/Build/source/texk/dvisvgm/dvisvgm-src/libs/brotli/enc/metablock_inc.h b/Build/source/texk/dvisvgm/dvisvgm-src/libs/brotli/enc/metablock_inc.h deleted file mode 100644 index ed507ef5ef4..00000000000 --- a/Build/source/texk/dvisvgm/dvisvgm-src/libs/brotli/enc/metablock_inc.h +++ /dev/null @@ -1,183 +0,0 @@ -/* NOLINT(build/header_guard) */ -/* Copyright 2015 Google Inc. All Rights Reserved. - - Distributed under MIT license. - See file LICENSE for detail or copy at https://opensource.org/licenses/MIT -*/ - -/* template parameters: FN */ - -#define HistogramType FN(Histogram) - -/* Greedy block splitter for one block category (literal, command or distance). -*/ -typedef struct FN(BlockSplitter) { - /* Alphabet size of particular block category. */ - size_t alphabet_size_; - /* We collect at least this many symbols for each block. */ - size_t min_block_size_; - /* We merge histograms A and B if - entropy(A+B) < entropy(A) + entropy(B) + split_threshold_, - where A is the current histogram and B is the histogram of the last or the - second last block type. */ - double split_threshold_; - - size_t num_blocks_; - BlockSplit* split_; /* not owned */ - HistogramType* histograms_; /* not owned */ - size_t* histograms_size_; /* not owned */ - - /* The number of symbols that we want to collect before deciding on whether - or not to merge the block with a previous one or emit a new block. */ - size_t target_block_size_; - /* The number of symbols in the current histogram. */ - size_t block_size_; - /* Offset of the current histogram. */ - size_t curr_histogram_ix_; - /* Offset of the histograms of the previous two block types. */ - size_t last_histogram_ix_[2]; - /* Entropy of the previous two block types. */ - double last_entropy_[2]; - /* The number of times we merged the current block with the last one. */ - size_t merge_last_count_; -} FN(BlockSplitter); - -static void FN(InitBlockSplitter)( - MemoryManager* m, FN(BlockSplitter)* self, size_t alphabet_size, - size_t min_block_size, double split_threshold, size_t num_symbols, - BlockSplit* split, HistogramType** histograms, size_t* histograms_size) { - size_t max_num_blocks = num_symbols / min_block_size + 1; - /* We have to allocate one more histogram than the maximum number of block - types for the current histogram when the meta-block is too big. */ - size_t max_num_types = - BROTLI_MIN(size_t, max_num_blocks, BROTLI_MAX_NUMBER_OF_BLOCK_TYPES + 1); - self->alphabet_size_ = alphabet_size; - self->min_block_size_ = min_block_size; - self->split_threshold_ = split_threshold; - self->num_blocks_ = 0; - self->split_ = split; - self->histograms_size_ = histograms_size; - self->target_block_size_ = min_block_size; - self->block_size_ = 0; - self->curr_histogram_ix_ = 0; - self->merge_last_count_ = 0; - BROTLI_ENSURE_CAPACITY(m, uint8_t, - split->types, split->types_alloc_size, max_num_blocks); - BROTLI_ENSURE_CAPACITY(m, uint32_t, - split->lengths, split->lengths_alloc_size, max_num_blocks); - if (BROTLI_IS_OOM(m)) return; - self->split_->num_blocks = max_num_blocks; - BROTLI_DCHECK(*histograms == 0); - *histograms_size = max_num_types; - *histograms = BROTLI_ALLOC(m, HistogramType, *histograms_size); - self->histograms_ = *histograms; - if (BROTLI_IS_OOM(m) || BROTLI_IS_NULL(*histograms)) return; - /* Clear only current histogram. */ - FN(HistogramClear)(&self->histograms_[0]); - self->last_histogram_ix_[0] = self->last_histogram_ix_[1] = 0; -} - -/* Does either of three things: - (1) emits the current block with a new block type; - (2) emits the current block with the type of the second last block; - (3) merges the current block with the last block. */ -static void FN(BlockSplitterFinishBlock)( - FN(BlockSplitter)* self, BROTLI_BOOL is_final) { - BlockSplit* split = self->split_; - double* last_entropy = self->last_entropy_; - HistogramType* histograms = self->histograms_; - self->block_size_ = - BROTLI_MAX(size_t, self->block_size_, self->min_block_size_); - if (self->num_blocks_ == 0) { - /* Create first block. */ - split->lengths[0] = (uint32_t)self->block_size_; - split->types[0] = 0; - last_entropy[0] = - BitsEntropy(histograms[0].data_, self->alphabet_size_); - last_entropy[1] = last_entropy[0]; - ++self->num_blocks_; - ++split->num_types; - ++self->curr_histogram_ix_; - if (self->curr_histogram_ix_ < *self->histograms_size_) - FN(HistogramClear)(&histograms[self->curr_histogram_ix_]); - self->block_size_ = 0; - } else if (self->block_size_ > 0) { - double entropy = BitsEntropy(histograms[self->curr_histogram_ix_].data_, - self->alphabet_size_); - HistogramType combined_histo[2]; - double combined_entropy[2]; - double diff[2]; - size_t j; - for (j = 0; j < 2; ++j) { - size_t last_histogram_ix = self->last_histogram_ix_[j]; - combined_histo[j] = histograms[self->curr_histogram_ix_]; - FN(HistogramAddHistogram)(&combined_histo[j], - &histograms[last_histogram_ix]); - combined_entropy[j] = BitsEntropy( - &combined_histo[j].data_[0], self->alphabet_size_); - diff[j] = combined_entropy[j] - entropy - last_entropy[j]; - } - - if (split->num_types < BROTLI_MAX_NUMBER_OF_BLOCK_TYPES && - diff[0] > self->split_threshold_ && - diff[1] > self->split_threshold_) { - /* Create new block. */ - split->lengths[self->num_blocks_] = (uint32_t)self->block_size_; - split->types[self->num_blocks_] = (uint8_t)split->num_types; - self->last_histogram_ix_[1] = self->last_histogram_ix_[0]; - self->last_histogram_ix_[0] = (uint8_t)split->num_types; - last_entropy[1] = last_entropy[0]; - last_entropy[0] = entropy; - ++self->num_blocks_; - ++split->num_types; - ++self->curr_histogram_ix_; - if (self->curr_histogram_ix_ < *self->histograms_size_) - FN(HistogramClear)(&histograms[self->curr_histogram_ix_]); - self->block_size_ = 0; - self->merge_last_count_ = 0; - self->target_block_size_ = self->min_block_size_; - } else if (diff[1] < diff[0] - 20.0) { - /* Combine this block with second last block. */ - split->lengths[self->num_blocks_] = (uint32_t)self->block_size_; - split->types[self->num_blocks_] = split->types[self->num_blocks_ - 2]; - BROTLI_SWAP(size_t, self->last_histogram_ix_, 0, 1); - histograms[self->last_histogram_ix_[0]] = combined_histo[1]; - last_entropy[1] = last_entropy[0]; - last_entropy[0] = combined_entropy[1]; - ++self->num_blocks_; - self->block_size_ = 0; - FN(HistogramClear)(&histograms[self->curr_histogram_ix_]); - self->merge_last_count_ = 0; - self->target_block_size_ = self->min_block_size_; - } else { - /* Combine this block with last block. */ - split->lengths[self->num_blocks_ - 1] += (uint32_t)self->block_size_; - histograms[self->last_histogram_ix_[0]] = combined_histo[0]; - last_entropy[0] = combined_entropy[0]; - if (split->num_types == 1) { - last_entropy[1] = last_entropy[0]; - } - self->block_size_ = 0; - FN(HistogramClear)(&histograms[self->curr_histogram_ix_]); - if (++self->merge_last_count_ > 1) { - self->target_block_size_ += self->min_block_size_; - } - } - } - if (is_final) { - *self->histograms_size_ = split->num_types; - split->num_blocks = self->num_blocks_; - } -} - -/* Adds the next symbol to the current histogram. When the current histogram - reaches the target size, decides on merging the block. */ -static void FN(BlockSplitterAddSymbol)(FN(BlockSplitter)* self, size_t symbol) { - FN(HistogramAdd)(&self->histograms_[self->curr_histogram_ix_], symbol); - ++self->block_size_; - if (self->block_size_ == self->target_block_size_) { - FN(BlockSplitterFinishBlock)(self, /* is_final = */ BROTLI_FALSE); - } -} - -#undef HistogramType |