1 files changed, 105 insertions, 0 deletions
diff --git a/modules/brotli/enc/metablock.h b/modules/brotli/enc/metablock.h
new file mode 100644
index 0000000000..334a79a443
--- /dev/null
+++ b/modules/brotli/enc/metablock.h
@@ -0,0 +1,105 @@
+/* Copyright 2015 Google Inc. All Rights Reserved.
+
+   Distributed under MIT license.
+   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
+*/
+
+/* Algorithms for distributing the literals and commands of a metablock between
+   block types and contexts. */
+
+#ifndef BROTLI_ENC_METABLOCK_H_
+#define BROTLI_ENC_METABLOCK_H_
+
+#include "../common/context.h"
+#include "../common/platform.h"
+#include <brotli/types.h>
+#include "./block_splitter.h"
+#include "./command.h"
+#include "./histogram.h"
+#include "./memory.h"
+#include "./quality.h"
+
+#if defined(__cplusplus) || defined(c_plusplus)
+extern "C" {
+#endif
+
+typedef struct MetaBlockSplit {
+  BlockSplit literal_split;
+  BlockSplit command_split;
+  BlockSplit distance_split;
+  uint32_t* literal_context_map;
+  size_t literal_context_map_size;
+  uint32_t* distance_context_map;
+  size_t distance_context_map_size;
+  HistogramLiteral* literal_histograms;
+  size_t literal_histograms_size;
+  HistogramCommand* command_histograms;
+  size_t command_histograms_size;
+  HistogramDistance* distance_histograms;
+  size_t distance_histograms_size;
+} MetaBlockSplit;
+
+static BROTLI_INLINE void InitMetaBlockSplit(MetaBlockSplit* mb) {
+  BrotliInitBlockSplit(&mb->literal_split);
+  BrotliInitBlockSplit(&mb->command_split);
+  BrotliInitBlockSplit(&mb->distance_split);
+  mb->literal_context_map = 0;
+  mb->literal_context_map_size = 0;
+  mb->distance_context_map = 0;
+  mb->distance_context_map_size = 0;
+  mb->literal_histograms = 0;
+  mb->literal_histograms_size = 0;
+  mb->command_histograms = 0;
+  mb->command_histograms_size = 0;
+  mb->distance_histograms = 0;
+  mb->distance_histograms_size = 0;
+}
+
+static BROTLI_INLINE void DestroyMetaBlockSplit(
+    MemoryManager* m, MetaBlockSplit* mb) {
+  BrotliDestroyBlockSplit(m, &mb->literal_split);
+  BrotliDestroyBlockSplit(m, &mb->command_split);
+  BrotliDestroyBlockSplit(m, &mb->distance_split);
+  BROTLI_FREE(m, mb->literal_context_map);
+  BROTLI_FREE(m, mb->distance_context_map);
+  BROTLI_FREE(m, mb->literal_histograms);
+  BROTLI_FREE(m, mb->command_histograms);
+  BROTLI_FREE(m, mb->distance_histograms);
+}
+
+/* Uses the slow shortest-path block splitter and does context clustering.
+   The distance parameters are dynamically selected based on the commands
+   which get recomputed under the new distance parameters. The new distance
+   parameters are stored into *params. */
+BROTLI_INTERNAL void BrotliBuildMetaBlock(MemoryManager* m,
+                                          const uint8_t* ringbuffer,
+                                          const size_t pos,
+                                          const size_t mask,
+                                          BrotliEncoderParams* params,
+                                          uint8_t prev_byte,
+                                          uint8_t prev_byte2,
+                                          Command* cmds,
+                                          size_t num_commands,
+                                          ContextType literal_context_mode,
+                                          MetaBlockSplit* mb);
+
+/* Uses a fast greedy block splitter that tries to merge current block with the
+   last or the second last block and uses a static context clustering which
+   is the same for all block types. */
+BROTLI_INTERNAL void BrotliBuildMetaBlockGreedy(
+    MemoryManager* m, const uint8_t* ringbuffer, size_t pos, size_t mask,
+    uint8_t prev_byte, uint8_t prev_byte2, ContextLut literal_context_lut,
+    size_t num_contexts, const uint32_t* static_context_map,
+    const Command* commands, size_t n_commands, MetaBlockSplit* mb);
+
+BROTLI_INTERNAL void BrotliOptimizeHistograms(uint32_t num_distance_codes,
+                                              MetaBlockSplit* mb);
+
+BROTLI_INTERNAL void BrotliInitDistanceParams(BrotliEncoderParams* params,
+    uint32_t npostfix, uint32_t ndirect);
+
+#if defined(__cplusplus) || defined(c_plusplus)
+}  /* extern "C" */
+#endif
+
+#endif  /* BROTLI_ENC_METABLOCK_H_ */