Update brotli to v1.0.0-snapshot.

third_party/brotli/enc/encode_parallel.cc

Index: third_party/brotli/enc/encode_parallel.cc
diff --git a/third_party/brotli/enc/encode_parallel.cc b/third_party/brotli/enc/encode_parallel.cc
deleted file mode 100644
index cbad975415dacfdcfd571c429d4fd528777721e9..0000000000000000000000000000000000000000
--- a/third_party/brotli/enc/encode_parallel.cc
+++ /dev/null
@@ -1,279 +0,0 @@
-/* Copyright 2013 Google Inc. All Rights Reserved.
-
-   Distributed under MIT license.
-   See file LICENSE for detail or copy at https://opensource.org/licenses/MIT
-*/
-
-// Implementation of parallel Brotli compressor.
-
-#include "./encode_parallel.h"
-
-#include <algorithm>
-#include <limits>
-
-#include "./backward_references.h"
-#include "./bit_cost.h"
-#include "./block_splitter.h"
-#include "./brotli_bit_stream.h"
-#include "./cluster.h"
-#include "./context.h"
-#include "./metablock.h"
-#include "./transform.h"
-#include "./entropy_encode.h"
-#include "./fast_log.h"
-#include "./hash.h"
-#include "./histogram.h"
-#include "./prefix.h"
-#include "./utf8_util.h"
-#include "./write_bits.h"
-
-namespace brotli {
-
-namespace {
-
-void RecomputeDistancePrefixes(Command* cmds, size_t num_commands,
-                               uint32_t num_direct_distance_codes,
-                               uint32_t distance_postfix_bits) {
-  if (num_direct_distance_codes == 0 &&
-      distance_postfix_bits == 0) {
-    return;
-  }
-  for (size_t i = 0; i < num_commands; ++i) {
-    Command* cmd = &cmds[i];
-    if (cmd->copy_len() && cmd->cmd_prefix_ >= 128) {
-      PrefixEncodeCopyDistance(cmd->DistanceCode(),
-                               num_direct_distance_codes,
-                               distance_postfix_bits,
-                               &cmd->dist_prefix_,
-                               &cmd->dist_extra_);
-    }
-  }
-}
-
-bool WriteMetaBlockParallel(const BrotliParams& params,
-                            const uint32_t input_size,
-                            const uint8_t* input_buffer,
-                            const uint32_t prefix_size,
-                            const uint8_t* prefix_buffer,
-                            const bool is_first,
-                            const bool is_last,
-                            size_t* encoded_size,
-                            uint8_t* encoded_buffer) {
-  if (input_size == 0) {
-    return false;
-  }
-
-  // Copy prefix + next input block into a continuous area.
-  uint32_t input_pos = prefix_size;
-  // CreateBackwardReferences reads up to 3 bytes past the end of input if the
-  // mask points past the end of input.
-  // FindMatchLengthWithLimit could do another 8 bytes look-forward.
-  std::vector<uint8_t> input(prefix_size + input_size + 4 + 8);
-  memcpy(&input[0], prefix_buffer, prefix_size);
-  memcpy(&input[input_pos], input_buffer, input_size);
-  // Since we don't have a ringbuffer, masking is a no-op.
-  // We use one less bit than the full range because some of the code uses
-  // mask + 1 as the size of the ringbuffer.
-  const uint32_t mask = std::numeric_limits<uint32_t>::max() >> 1;
-
-  uint8_t prev_byte = input_pos > 0 ? input[(input_pos - 1) & mask] : 0;
-  uint8_t prev_byte2 = input_pos > 1 ? input[(input_pos - 2) & mask] : 0;
-
-  // Decide about UTF8 mode.
-  static const double kMinUTF8Ratio = 0.75;
-  bool utf8_mode = IsMostlyUTF8(&input[0], input_pos, mask, input_size,
-                                kMinUTF8Ratio);
-
-  // Initialize hashers.
-  int hash_type = std::min(10, params.quality);
-  Hashers* hashers = new Hashers();
-  hashers->Init(hash_type);
-
-  // Compute backward references.
-  size_t last_insert_len = 0;
-  size_t num_commands = 0;
-  size_t num_literals = 0;
-  int dist_cache[4] = { -4, -4, -4, -4 };
-  Command* commands = static_cast<Command*>(
-      malloc(sizeof(Command) * ((input_size + 1) >> 1)));
-  if (commands == 0) {
-    delete hashers;
-    return false;
-  }
-  CreateBackwardReferences(
-      input_size, input_pos, is_last,
-      &input[0], mask,
-      params.quality,
-      params.lgwin,
-      hashers,
-      hash_type,
-      dist_cache,
-      &last_insert_len,
-      commands,
-      &num_commands,
-      &num_literals);
-  delete hashers;
-  if (last_insert_len > 0) {
-    commands[num_commands++] = Command(last_insert_len);
-    num_literals += last_insert_len;
-  }
-  assert(num_commands != 0);
-
-  // Build the meta-block.
-  MetaBlockSplit mb;
-  uint32_t num_direct_distance_codes =
-      params.mode == BrotliParams::MODE_FONT ? 12 : 0;
-  uint32_t distance_postfix_bits =
-      params.mode == BrotliParams::MODE_FONT ? 1 : 0;
-  ContextType literal_context_mode = utf8_mode ? CONTEXT_UTF8 : CONTEXT_SIGNED;
-  RecomputeDistancePrefixes(commands, num_commands,
-                            num_direct_distance_codes,
-                            distance_postfix_bits);
-  if (params.quality <= 9) {
-    BuildMetaBlockGreedy(&input[0], input_pos, mask,
-                         commands, num_commands,
-                         &mb);
-  } else {
-    BuildMetaBlock(&input[0], input_pos, mask,
-                   prev_byte, prev_byte2,
-                   commands, num_commands,
-                   literal_context_mode,
-                   &mb);
-  }
-
-  // Set up the temporary output storage.
-  const size_t max_out_size = 2 * input_size + 500;
-  std::vector<uint8_t> storage(max_out_size);
-  uint8_t first_byte = 0;
-  size_t first_byte_bits = 0;
-  if (is_first) {
-    if (params.lgwin == 16) {
-      first_byte = 0;
-      first_byte_bits = 1;
-    } else if (params.lgwin == 17) {
-      first_byte = 1;
-      first_byte_bits = 7;
-    } else {
-      first_byte = static_cast<uint8_t>(((params.lgwin - 17) << 1) | 1);
-      first_byte_bits = 4;
-    }
-  }
-  storage[0] = static_cast<uint8_t>(first_byte);
-  size_t storage_ix = first_byte_bits;
-
-  // Store the meta-block to the temporary output.
-  StoreMetaBlock(&input[0], input_pos, input_size, mask,
-                 prev_byte, prev_byte2,
-                 is_last,
-                 num_direct_distance_codes,
-                 distance_postfix_bits,
-                 literal_context_mode,
-                 commands, num_commands,
-                 mb,
-                 &storage_ix, &storage[0]);
-  free(commands);
-
-  // If this is not the last meta-block, store an empty metadata
-  // meta-block so that the meta-block will end at a byte boundary.
-  if (!is_last) {
-    StoreSyncMetaBlock(&storage_ix, &storage[0]);
-  }
-
-  // If the compressed data is too large, fall back to an uncompressed
-  // meta-block.
-  size_t output_size = storage_ix >> 3;
-  if (input_size + 4 < output_size) {
-    storage[0] = static_cast<uint8_t>(first_byte);
-    storage_ix = first_byte_bits;
-    StoreUncompressedMetaBlock(is_last, &input[0], input_pos, mask,
-                               input_size,
-                               &storage_ix, &storage[0]);
-    output_size = storage_ix >> 3;
-  }
-
-  // Copy the temporary output with size-check to the output.
-  if (output_size > *encoded_size) {
-    return false;
-  }
-  memcpy(encoded_buffer, &storage[0], output_size);
-  *encoded_size = output_size;
-  return true;
-}
-
-}  // namespace
-
-int BrotliCompressBufferParallel(BrotliParams params,
-                                 size_t input_size,
-                                 const uint8_t* input_buffer,
-                                 size_t* encoded_size,
-                                 uint8_t* encoded_buffer) {
-  if (*encoded_size == 0) {
-    // Output buffer needs at least one byte.
-    return 0;
-  } else  if (input_size == 0) {
-    encoded_buffer[0] = 6;
-    *encoded_size = 1;
-    return 1;
-  }
-
-  // Sanitize params.
-  if (params.lgwin < kMinWindowBits) {
-    params.lgwin = kMinWindowBits;
-  } else if (params.lgwin > kMaxWindowBits) {
-    params.lgwin = kMaxWindowBits;
-  }
-  if (params.lgblock == 0) {
-    params.lgblock = 16;
-    if (params.quality >= 9 && params.lgwin > params.lgblock) {
-      params.lgblock = std::min(21, params.lgwin);
-    }
-  } else if (params.lgblock < kMinInputBlockBits) {
-    params.lgblock = kMinInputBlockBits;
-  } else if (params.lgblock > kMaxInputBlockBits) {
-    params.lgblock = kMaxInputBlockBits;
-  }
-  size_t max_input_block_size = 1 << params.lgblock;
-  size_t max_prefix_size = 1u << params.lgwin;
-
-  std::vector<std::vector<uint8_t> > compressed_pieces;
-
-  // Compress block-by-block independently.
-  for (size_t pos = 0; pos < input_size; ) {
-    uint32_t input_block_size =
-        static_cast<uint32_t>(std::min(max_input_block_size, input_size - pos));
-    uint32_t prefix_size =
-        static_cast<uint32_t>(std::min(max_prefix_size, pos));
-    size_t out_size = input_block_size + (input_block_size >> 3) + 1024;
-    std::vector<uint8_t> out(out_size);
-    if (!WriteMetaBlockParallel(params,
-                                input_block_size,
-                                &input_buffer[pos],
-                                prefix_size,
-                                &input_buffer[pos - prefix_size],
-                                pos == 0,
-                                pos + input_block_size == input_size,
-                                &out_size,
-                                &out[0])) {
-      return false;
-    }
-    out.resize(out_size);
-    compressed_pieces.push_back(out);
-    pos += input_block_size;
-  }
-
-  // Piece together the output.
-  size_t out_pos = 0;
-  for (size_t i = 0; i < compressed_pieces.size(); ++i) {
-    const std::vector<uint8_t>& out = compressed_pieces[i];
-    if (out_pos + out.size() > *encoded_size) {
-      return false;
-    }
-    memcpy(&encoded_buffer[out_pos], &out[0], out.size());
-    out_pos += out.size();
-  }
-  *encoded_size = out_pos;
-
-  return true;
-}
-
-}  // namespace brotli