Hash :
35e69fc7
Author :
Date :
2018-02-26T09:04:36
New feature: "Large Window Brotli" (#640) * New feature: "Large Window Brotli" By setting special encoder/decoder flag it is now possible to extend LZ-window up to 30 bits; though produced stream will not be RFC7932 compliant. Added new dictionary generator - "DSH". It combines speed of "Sieve" and quality of "DM". Plus utilities to prepare train corpora (remove unique strings). Improved compression ratio: now two sub-blocks could be stitched: the last copy command could be extended to span the next sub-block. Fixed compression ineffectiveness caused by floating numbers rounding and wrong cost heuristic. Other C changes: - combined / moved `context.h` to `common` - moved transforms to `common` - unified some aspects of code formatting - added an abstraction for encoder (static) dictionary - moved default allocator/deallocator functions to `common` brotli CLI: - window size is auto-adjusted if not specified explicitly Java: - added "eager" decoding both to JNI wrapper and pure decoder - huge speed-up of `DictionaryData` initialization * Add dictionaryless compressed dictionary * Fix `sources.lst` * Fix `sources.lst` and add a note that `libtool` is also required. * Update setup.py * Fix `EagerStreamTest` * Fix BUILD file * Add missing `libdivsufsort` dependency * Fix "unused parameter" warning.
/* NOLINT(build/header_guard) */
/* Copyright 2014 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)
/* Creates entropy codes for all block types and stores them to the bit
stream. */
static void FN(BuildAndStoreEntropyCodes)(MemoryManager* m, BlockEncoder* self,
const HistogramType* histograms, const size_t histograms_size,
const size_t alphabet_size, HuffmanTree* tree,
size_t* storage_ix, uint8_t* storage) {
const size_t table_size = histograms_size * self->histogram_length_;
self->depths_ = BROTLI_ALLOC(m, uint8_t, table_size);
self->bits_ = BROTLI_ALLOC(m, uint16_t, table_size);
if (BROTLI_IS_OOM(m)) return;
{
size_t i;
for (i = 0; i < histograms_size; ++i) {
size_t ix = i * self->histogram_length_;
BuildAndStoreHuffmanTree(&histograms[i].data_[0], self->histogram_length_,
alphabet_size, tree, &self->depths_[ix], &self->bits_[ix],
storage_ix, storage);
}
}
}
#undef HistogramType