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618287b373
These affected only quality 11, and now it does not make sense to disable block splitting or context modeling because most of the time is spent in zopfli anyway. Now all speed vs size compromises are controlled by the quality param.
760 lines
28 KiB
C++
760 lines
28 KiB
C++
// Copyright 2013 Google Inc. All Rights Reserved.
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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//
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// Function to find backward reference copies.
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#include "./backward_references.h"
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#include <algorithm>
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#include <vector>
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#include "./command.h"
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namespace brotli {
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static const double kInfinity = 1.0 / 0.0;
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// Histogram based cost model for zopflification.
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class ZopfliCostModel {
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public:
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void SetFromCommands(size_t num_bytes,
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size_t position,
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const uint8_t* ringbuffer,
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size_t ringbuffer_mask,
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const Command* commands,
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int num_commands,
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int last_insert_len) {
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std::vector<int> histogram_literal(256, 0);
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std::vector<int> histogram_cmd(kNumCommandPrefixes, 0);
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std::vector<int> histogram_dist(kNumDistancePrefixes, 0);
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size_t pos = position - last_insert_len;
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for (int i = 0; i < num_commands; i++) {
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int inslength = commands[i].insert_len_;
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int copylength = commands[i].copy_len_;
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int distcode = commands[i].dist_prefix_;
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int cmdcode = commands[i].cmd_prefix_;
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histogram_cmd[cmdcode]++;
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if (cmdcode >= 128) histogram_dist[distcode]++;
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for (int j = 0; j < inslength; j++) {
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histogram_literal[ringbuffer[(pos + j) & ringbuffer_mask]]++;
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}
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pos += inslength + copylength;
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}
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std::vector<double> cost_literal;
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Set(histogram_literal, &cost_literal);
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Set(histogram_cmd, &cost_cmd_);
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Set(histogram_dist, &cost_dist_);
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min_cost_cmd_ = kInfinity;
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for (int i = 0; i < kNumCommandPrefixes; ++i) {
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min_cost_cmd_ = std::min(min_cost_cmd_, cost_cmd_[i]);
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}
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literal_costs_.resize(num_bytes + 1);
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literal_costs_[0] = 0.0;
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for (int i = 0; i < num_bytes; ++i) {
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literal_costs_[i + 1] = literal_costs_[i] +
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cost_literal[ringbuffer[(position + i) & ringbuffer_mask]];
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}
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}
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void SetFromLiteralCosts(size_t num_bytes,
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size_t position,
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const float* literal_cost,
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size_t literal_cost_mask) {
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literal_costs_.resize(num_bytes + 1);
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literal_costs_[0] = 0.0;
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if (literal_cost) {
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for (int i = 0; i < num_bytes; ++i) {
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literal_costs_[i + 1] = literal_costs_[i] +
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literal_cost[(position + i) & literal_cost_mask];
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}
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} else {
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for (int i = 1; i <= num_bytes; ++i) {
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literal_costs_[i] = i * 5.4;
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}
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}
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cost_cmd_.resize(kNumCommandPrefixes);
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cost_dist_.resize(kNumDistancePrefixes);
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for (int i = 0; i < kNumCommandPrefixes; ++i) {
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cost_cmd_[i] = FastLog2(11 + i);
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}
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for (int i = 0; i < kNumDistancePrefixes; ++i) {
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cost_dist_[i] = FastLog2(20 + i);
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}
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min_cost_cmd_ = FastLog2(11);
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}
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double GetCommandCost(
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int dist_code, int length_code, int insert_length) const {
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int inscode = GetInsertLengthCode(insert_length);
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int copycode = GetCopyLengthCode(length_code);
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uint16_t cmdcode = CombineLengthCodes(inscode, copycode, dist_code);
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uint64_t insnumextra = insextra[inscode];
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uint64_t copynumextra = copyextra[copycode];
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uint16_t dist_symbol;
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uint32_t distextra;
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GetDistCode(dist_code, &dist_symbol, &distextra);
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uint32_t distnumextra = distextra >> 24;
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double result = insnumextra + copynumextra + distnumextra;
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result += cost_cmd_[cmdcode];
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if (cmdcode >= 128) result += cost_dist_[dist_symbol];
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return result;
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}
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double GetLiteralCosts(int from, int to) const {
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return literal_costs_[to] - literal_costs_[from];
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}
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double GetMinCostCmd() const {
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return min_cost_cmd_;
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}
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private:
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void Set(const std::vector<int>& histogram, std::vector<double>* cost) {
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cost->resize(histogram.size());
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double sum = 0;
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for (size_t i = 0; i < histogram.size(); i++) {
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sum += histogram[i];
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}
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for (size_t i = 0; i < histogram.size(); i++) {
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if (histogram[i] == 0) {
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(*cost)[i] = -log2(0.25 / sum);
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continue;
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}
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// Shannon bits for this symbol.
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(*cost)[i] = -log2(histogram[i] / sum);
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// Cannot be coded with less than 1 bit
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if ((*cost)[i] < 1) (*cost)[i] = 1;
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}
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}
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std::vector<double> cost_cmd_; // The insert and copy length symbols.
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std::vector<double> cost_dist_;
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// Cumulative costs of literals per position in the stream.
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std::vector<double> literal_costs_;
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double min_cost_cmd_;
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};
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inline void SetDistanceCache(int distance,
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int distance_code,
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int max_distance,
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const int* dist_cache,
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int* result_dist_cache) {
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if (distance <= max_distance && distance_code > 0) {
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result_dist_cache[0] = distance;
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memcpy(&result_dist_cache[1], dist_cache, 3 * sizeof(dist_cache[0]));
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} else {
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memcpy(result_dist_cache, dist_cache, 4 * sizeof(dist_cache[0]));
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}
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}
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inline int ComputeDistanceCode(int distance,
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int max_distance,
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int quality,
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const int* dist_cache) {
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if (distance <= max_distance) {
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if (distance == dist_cache[0]) {
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return 0;
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} else if (distance == dist_cache[1]) {
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return 1;
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} else if (distance == dist_cache[2]) {
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return 2;
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} else if (distance == dist_cache[3]) {
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return 3;
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} else if (quality > 3 && distance >= 6) {
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for (int k = 4; k < kNumDistanceShortCodes; ++k) {
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int idx = kDistanceCacheIndex[k];
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int candidate = dist_cache[idx] + kDistanceCacheOffset[k];
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static const int kLimits[16] = { 0, 0, 0, 0,
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6, 6, 11, 11,
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11, 11, 11, 11,
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12, 12, 12, 12 };
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if (distance == candidate && distance >= kLimits[k]) {
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return k;
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}
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}
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}
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}
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return distance + 15;
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}
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struct ZopfliNode {
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ZopfliNode() : length(1),
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distance(0),
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distance_code(0),
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length_code(0),
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insert_length(0),
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cost(kInfinity) {}
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// best length to get up to this byte (not including this byte itself)
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int length;
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// distance associated with the length
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int distance;
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int distance_code;
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int distance_cache[4];
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// length code associated with the length - usually the same as length,
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// except in case of length-changing dictionary transformation.
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int length_code;
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// number of literal inserts before this copy
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int insert_length;
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// smallest cost to get to this byte from the beginning, as found so far
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double cost;
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};
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inline void UpdateZopfliNode(ZopfliNode* nodes, size_t pos, size_t start_pos,
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int len, int len_code, int dist, int dist_code,
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int max_dist, const int* dist_cache,
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double cost) {
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ZopfliNode& next = nodes[pos + len];
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next.length = len;
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next.length_code = len_code;
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next.distance = dist;
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next.distance_code = dist_code;
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next.insert_length = pos - start_pos;
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next.cost = cost;
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SetDistanceCache(dist, dist_code, max_dist, dist_cache,
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&next.distance_cache[0]);
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}
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// Maintains the smallest 2^k cost difference together with their positions
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class StartPosQueue {
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public:
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explicit StartPosQueue(int bits)
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: mask_((1 << bits) - 1), q_(1 << bits), idx_(0) {}
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void Clear() {
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idx_ = 0;
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}
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void Push(size_t pos, double costdiff) {
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q_[idx_ & mask_] = std::make_pair(pos, costdiff);
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// Restore the sorted order.
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for (int i = idx_; i > 0 && i > idx_ - mask_; --i) {
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if (q_[i & mask_].second > q_[(i - 1) & mask_].second) {
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std::swap(q_[i & mask_], q_[(i - 1) & mask_]);
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}
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}
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++idx_;
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}
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int size() const { return std::min<int>(idx_, mask_ + 1); }
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size_t GetStartPos(int k) const {
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return q_[(idx_ - k - 1) & mask_].first;
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}
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private:
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const int mask_;
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std::vector<std::pair<size_t, double> > q_;
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int idx_;
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};
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// Returns the minimum possible copy length that can improve the cost of any
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// future position.
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int ComputeMinimumCopyLength(const StartPosQueue& queue,
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const std::vector<ZopfliNode>& nodes,
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const ZopfliCostModel& model,
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size_t pos,
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double min_cost_cmd) {
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// Compute the minimum possible cost of reaching any future position.
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const size_t start0 = queue.GetStartPos(0);
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double min_cost = (nodes[start0].cost +
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model.GetLiteralCosts(start0, pos) +
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min_cost_cmd);
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int len = 2;
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int next_len_bucket = 4;
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int next_len_offset = 10;
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while (pos + len < nodes.size() && nodes[pos + len].cost <= min_cost) {
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// We already reached (pos + len) with no more cost than the minimum
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// possible cost of reaching anything from this pos, so there is no point in
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// looking for lengths <= len.
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++len;
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if (len == next_len_offset) {
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// We reached the next copy length code bucket, so we add one more
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// extra bit to the minimum cost.
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min_cost += 1.0;
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next_len_offset += next_len_bucket;
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next_len_bucket *= 2;
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}
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}
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return len;
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}
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void ZopfliIterate(size_t num_bytes,
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size_t position,
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const uint8_t* ringbuffer,
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size_t ringbuffer_mask,
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const size_t max_backward_limit,
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const ZopfliCostModel& model,
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const std::vector<int>& num_matches,
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const std::vector<BackwardMatch>& matches,
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int* dist_cache,
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int* last_insert_len,
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Command* commands,
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int* num_commands,
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int* num_literals) {
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const Command * const orig_commands = commands;
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std::vector<ZopfliNode> nodes(num_bytes + 1);
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nodes[0].length = 0;
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nodes[0].cost = 0;
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memcpy(nodes[0].distance_cache, dist_cache, 4 * sizeof(dist_cache[0]));
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StartPosQueue queue(3);
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const double min_cost_cmd = model.GetMinCostCmd();
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size_t cur_match_pos = 0;
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for (size_t i = 0; i + 3 < num_bytes; i++) {
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size_t cur_ix = position + i;
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size_t cur_ix_masked = cur_ix & ringbuffer_mask;
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size_t max_distance = std::min(cur_ix, max_backward_limit);
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int max_length = num_bytes - i;
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queue.Push(i, nodes[i].cost - model.GetLiteralCosts(0, i));
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const int min_len = ComputeMinimumCopyLength(queue, nodes, model,
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i, min_cost_cmd);
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// Go over the command starting positions in order of increasing cost
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// difference.
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for (size_t k = 0; k < 5 && k < queue.size(); ++k) {
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const size_t start = queue.GetStartPos(k);
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const double start_costdiff =
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nodes[start].cost - model.GetLiteralCosts(0, start);
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const int* dist_cache2 = &nodes[start].distance_cache[0];
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// Look for last distance matches using the distance cache from this
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// starting position.
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int best_len = min_len - 1;
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for (int j = 0; j < kNumDistanceShortCodes; ++j) {
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const int idx = kDistanceCacheIndex[j];
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const int backward = dist_cache2[idx] + kDistanceCacheOffset[j];
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size_t prev_ix = cur_ix - backward;
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if (prev_ix >= cur_ix) {
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continue;
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}
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if (PREDICT_FALSE(backward > max_distance)) {
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continue;
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}
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prev_ix &= ringbuffer_mask;
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if (cur_ix_masked + best_len > ringbuffer_mask ||
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prev_ix + best_len > ringbuffer_mask ||
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ringbuffer[cur_ix_masked + best_len] !=
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ringbuffer[prev_ix + best_len]) {
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continue;
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}
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const size_t len =
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FindMatchLengthWithLimit(&ringbuffer[prev_ix],
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&ringbuffer[cur_ix_masked],
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max_length);
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for (int l = best_len + 1; l <= len; ++l) {
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double cmd_cost = model.GetCommandCost(j, l, i - start);
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double cost = start_costdiff + cmd_cost + model.GetLiteralCosts(0, i);
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if (cost < nodes[i + l].cost) {
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UpdateZopfliNode(&nodes[0], i, start, l, l, backward, j,
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max_distance, dist_cache2, cost);
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}
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best_len = l;
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}
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}
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// At higher iterations look only for new last distance matches, since
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// looking only for new command start positions with the same distances
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// does not help much.
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if (k >= 2) continue;
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// Loop through all possible copy lengths at this position.
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int len = min_len;
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for (int j = 0; j < num_matches[i]; ++j) {
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BackwardMatch match = matches[cur_match_pos + j];
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int dist = match.distance;
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bool is_dictionary_match = dist > max_distance;
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// We already tried all possible last distance matches, so we can use
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// normal distance code here.
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int dist_code = dist + 15;
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// Try all copy lengths up until the maximum copy length corresponding
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// to this distance. If the distance refers to the static dictionary, or
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// the maximum length is long enough, try only one maximum length.
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int max_len = match.length();
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if (len < max_len && (is_dictionary_match || max_len > kMaxZopfliLen)) {
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len = max_len;
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}
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for (; len <= max_len; ++len) {
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int len_code = is_dictionary_match ? match.length_code() : len;
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double cmd_cost =
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model.GetCommandCost(dist_code, len_code, i - start);
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double cost = start_costdiff + cmd_cost + model.GetLiteralCosts(0, i);
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if (cost < nodes[i + len].cost) {
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UpdateZopfliNode(&nodes[0], i, start, len, len_code, dist,
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dist_code, max_distance, dist_cache2, cost);
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}
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}
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}
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}
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cur_match_pos += num_matches[i];
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// The zopflification can be too slow in case of very long lengths, so in
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// such case skip it all, it does not cost a lot of compression ratio.
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if (num_matches[i] == 1 &&
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matches[cur_match_pos - 1].length() > kMaxZopfliLen) {
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i += matches[cur_match_pos - 1].length() - 1;
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queue.Clear();
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}
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}
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std::vector<int> backwards;
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size_t index = num_bytes;
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while (nodes[index].cost == kInfinity) --index;
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while (index > 0) {
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int len = nodes[index].length + nodes[index].insert_length;
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backwards.push_back(len);
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index -= len;
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}
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std::vector<int> path;
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for (size_t i = backwards.size(); i > 0; i--) {
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path.push_back(backwards[i - 1]);
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}
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size_t pos = 0;
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for (size_t i = 0; i < path.size(); i++) {
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const ZopfliNode& next = nodes[pos + path[i]];
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int copy_length = next.length;
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int insert_length = next.insert_length;
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pos += insert_length;
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if (i == 0) {
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insert_length += *last_insert_len;
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}
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int distance = next.distance;
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int len_code = next.length_code;
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size_t max_distance = std::min(position + pos, max_backward_limit);
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bool is_dictionary = (distance > max_distance);
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int dist_code = next.distance_code;
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Command cmd(insert_length, copy_length, len_code, dist_code);
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*commands++ = cmd;
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if (!is_dictionary && dist_code > 0) {
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dist_cache[3] = dist_cache[2];
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dist_cache[2] = dist_cache[1];
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dist_cache[1] = dist_cache[0];
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dist_cache[0] = distance;
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}
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*num_literals += insert_length;
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insert_length = 0;
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pos += copy_length;
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}
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*last_insert_len = num_bytes - pos;
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*num_commands += (commands - orig_commands);
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}
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template<typename Hasher>
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void CreateBackwardReferences(size_t num_bytes,
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size_t position,
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const uint8_t* ringbuffer,
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size_t ringbuffer_mask,
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const size_t max_backward_limit,
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const int quality,
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Hasher* hasher,
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int* dist_cache,
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int* last_insert_len,
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Command* commands,
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int* num_commands,
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int* num_literals) {
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if (num_bytes >= 3 && position >= 3) {
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// Prepare the hashes for three last bytes of the last write.
|
|
// These could not be calculated before, since they require knowledge
|
|
// of both the previous and the current block.
|
|
hasher->Store(&ringbuffer[(position - 3) & ringbuffer_mask],
|
|
position - 3);
|
|
hasher->Store(&ringbuffer[(position - 2) & ringbuffer_mask],
|
|
position - 2);
|
|
hasher->Store(&ringbuffer[(position - 1) & ringbuffer_mask],
|
|
position - 1);
|
|
}
|
|
const Command * const orig_commands = commands;
|
|
int insert_length = *last_insert_len;
|
|
size_t i = position & ringbuffer_mask;
|
|
const int i_diff = position - i;
|
|
const size_t i_end = i + num_bytes;
|
|
|
|
// For speed up heuristics for random data.
|
|
const int random_heuristics_window_size = quality < 9 ? 64 : 512;
|
|
int apply_random_heuristics = i + random_heuristics_window_size;
|
|
|
|
// Minimum score to accept a backward reference.
|
|
const int kMinScore = 4.0;
|
|
|
|
while (i + 3 < i_end) {
|
|
int max_length = i_end - i;
|
|
size_t max_distance = std::min(i + i_diff, max_backward_limit);
|
|
int best_len = 0;
|
|
int best_len_code = 0;
|
|
int best_dist = 0;
|
|
double best_score = kMinScore;
|
|
bool match_found = hasher->FindLongestMatch(
|
|
ringbuffer, ringbuffer_mask,
|
|
dist_cache, i + i_diff, max_length, max_distance,
|
|
&best_len, &best_len_code, &best_dist, &best_score);
|
|
if (match_found) {
|
|
// Found a match. Let's look for something even better ahead.
|
|
int delayed_backward_references_in_row = 0;
|
|
for (;;) {
|
|
--max_length;
|
|
int best_len_2 = quality < 5 ? std::min(best_len - 1, max_length) : 0;
|
|
int best_len_code_2 = 0;
|
|
int best_dist_2 = 0;
|
|
double best_score_2 = kMinScore;
|
|
max_distance = std::min(i + i_diff + 1, max_backward_limit);
|
|
hasher->Store(ringbuffer + i, i + i_diff);
|
|
match_found = hasher->FindLongestMatch(
|
|
ringbuffer, ringbuffer_mask,
|
|
dist_cache, i + i_diff + 1, max_length, max_distance,
|
|
&best_len_2, &best_len_code_2, &best_dist_2, &best_score_2);
|
|
double cost_diff_lazy = 7.0;
|
|
if (match_found && best_score_2 >= best_score + cost_diff_lazy) {
|
|
// Ok, let's just write one byte for now and start a match from the
|
|
// next byte.
|
|
++i;
|
|
++insert_length;
|
|
best_len = best_len_2;
|
|
best_len_code = best_len_code_2;
|
|
best_dist = best_dist_2;
|
|
best_score = best_score_2;
|
|
if (++delayed_backward_references_in_row < 4) {
|
|
continue;
|
|
}
|
|
}
|
|
break;
|
|
}
|
|
apply_random_heuristics =
|
|
i + 2 * best_len + random_heuristics_window_size;
|
|
max_distance = std::min(i + i_diff, max_backward_limit);
|
|
// The first 16 codes are special shortcodes, and the minimum offset is 1.
|
|
int distance_code =
|
|
ComputeDistanceCode(best_dist, max_distance, quality, dist_cache);
|
|
if (best_dist <= max_distance && distance_code > 0) {
|
|
dist_cache[3] = dist_cache[2];
|
|
dist_cache[2] = dist_cache[1];
|
|
dist_cache[1] = dist_cache[0];
|
|
dist_cache[0] = best_dist;
|
|
}
|
|
Command cmd(insert_length, best_len, best_len_code, distance_code);
|
|
*commands++ = cmd;
|
|
*num_literals += insert_length;
|
|
insert_length = 0;
|
|
// Put the hash keys into the table, if there are enough
|
|
// bytes left.
|
|
for (int j = 1; j < best_len; ++j) {
|
|
hasher->Store(&ringbuffer[i + j], i + i_diff + j);
|
|
}
|
|
i += best_len;
|
|
} else {
|
|
++insert_length;
|
|
hasher->Store(ringbuffer + i, i + i_diff);
|
|
++i;
|
|
// If we have not seen matches for a long time, we can skip some
|
|
// match lookups. Unsuccessful match lookups are very very expensive
|
|
// and this kind of a heuristic speeds up compression quite
|
|
// a lot.
|
|
if (i > apply_random_heuristics) {
|
|
// Going through uncompressible data, jump.
|
|
if (i > apply_random_heuristics + 4 * random_heuristics_window_size) {
|
|
// It is quite a long time since we saw a copy, so we assume
|
|
// that this data is not compressible, and store hashes less
|
|
// often. Hashes of non compressible data are less likely to
|
|
// turn out to be useful in the future, too, so we store less of
|
|
// them to not to flood out the hash table of good compressible
|
|
// data.
|
|
int i_jump = std::min(i + 16, i_end - 4);
|
|
for (; i < i_jump; i += 4) {
|
|
hasher->Store(ringbuffer + i, i + i_diff);
|
|
insert_length += 4;
|
|
}
|
|
} else {
|
|
int i_jump = std::min(i + 8, i_end - 3);
|
|
for (; i < i_jump; i += 2) {
|
|
hasher->Store(ringbuffer + i, i + i_diff);
|
|
insert_length += 2;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
insert_length += (i_end - i);
|
|
*last_insert_len = insert_length;
|
|
*num_commands += (commands - orig_commands);
|
|
}
|
|
|
|
void CreateBackwardReferences(size_t num_bytes,
|
|
size_t position,
|
|
const uint8_t* ringbuffer,
|
|
size_t ringbuffer_mask,
|
|
const float* literal_cost,
|
|
size_t literal_cost_mask,
|
|
const size_t max_backward_limit,
|
|
const int quality,
|
|
Hashers* hashers,
|
|
int hash_type,
|
|
int* dist_cache,
|
|
int* last_insert_len,
|
|
Command* commands,
|
|
int* num_commands,
|
|
int* num_literals) {
|
|
bool zopflify = quality > 9;
|
|
if (zopflify) {
|
|
Hashers::H9* hasher = hashers->hash_h9.get();
|
|
if (num_bytes >= 3 && position >= 3) {
|
|
// Prepare the hashes for three last bytes of the last write.
|
|
// These could not be calculated before, since they require knowledge
|
|
// of both the previous and the current block.
|
|
hasher->Store(&ringbuffer[(position - 3) & ringbuffer_mask],
|
|
position - 3);
|
|
hasher->Store(&ringbuffer[(position - 2) & ringbuffer_mask],
|
|
position - 2);
|
|
hasher->Store(&ringbuffer[(position - 1) & ringbuffer_mask],
|
|
position - 1);
|
|
}
|
|
std::vector<int> num_matches(num_bytes);
|
|
std::vector<BackwardMatch> matches(3 * num_bytes);
|
|
size_t cur_match_pos = 0;
|
|
for (size_t i = 0; i + 3 < num_bytes; ++i) {
|
|
size_t max_distance = std::min(position + i, max_backward_limit);
|
|
int max_length = num_bytes - i;
|
|
// Ensure that we have at least kMaxZopfliLen free slots.
|
|
if (matches.size() < cur_match_pos + kMaxZopfliLen) {
|
|
matches.resize(cur_match_pos + kMaxZopfliLen);
|
|
}
|
|
hasher->FindAllMatches(
|
|
ringbuffer, ringbuffer_mask,
|
|
position + i, max_length, max_distance,
|
|
&num_matches[i], &matches[cur_match_pos]);
|
|
hasher->Store(&ringbuffer[(position + i) & ringbuffer_mask],
|
|
position + i);
|
|
cur_match_pos += num_matches[i];
|
|
if (num_matches[i] == 1) {
|
|
const int match_len = matches[cur_match_pos - 1].length();
|
|
if (match_len > kMaxZopfliLen) {
|
|
for (int j = 1; j < match_len; ++j) {
|
|
++i;
|
|
hasher->Store(
|
|
&ringbuffer[(position + i) & ringbuffer_mask], position + i);
|
|
num_matches[i] = 0;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
int orig_num_literals = *num_literals;
|
|
int orig_last_insert_len = *last_insert_len;
|
|
int orig_dist_cache[4] = {
|
|
dist_cache[0], dist_cache[1], dist_cache[2], dist_cache[3]
|
|
};
|
|
int orig_num_commands = *num_commands;
|
|
static const int kIterations = 2;
|
|
for (int i = 0; i < kIterations; i++) {
|
|
ZopfliCostModel model;
|
|
if (i == 0) {
|
|
model.SetFromLiteralCosts(num_bytes, position,
|
|
literal_cost, literal_cost_mask);
|
|
} else {
|
|
model.SetFromCommands(num_bytes, position,
|
|
ringbuffer, ringbuffer_mask,
|
|
commands, *num_commands - orig_num_commands,
|
|
orig_last_insert_len);
|
|
}
|
|
*num_commands = orig_num_commands;
|
|
*num_literals = orig_num_literals;
|
|
*last_insert_len = orig_last_insert_len;
|
|
memcpy(dist_cache, orig_dist_cache, 4 * sizeof(dist_cache[0]));
|
|
ZopfliIterate(num_bytes, position, ringbuffer, ringbuffer_mask,
|
|
max_backward_limit, model, num_matches, matches, dist_cache,
|
|
last_insert_len, commands, num_commands, num_literals);
|
|
}
|
|
return;
|
|
}
|
|
|
|
switch (hash_type) {
|
|
case 1:
|
|
CreateBackwardReferences<Hashers::H1>(
|
|
num_bytes, position, ringbuffer, ringbuffer_mask, max_backward_limit,
|
|
quality, hashers->hash_h1.get(), dist_cache, last_insert_len,
|
|
commands, num_commands, num_literals);
|
|
break;
|
|
case 2:
|
|
CreateBackwardReferences<Hashers::H2>(
|
|
num_bytes, position, ringbuffer, ringbuffer_mask, max_backward_limit,
|
|
quality, hashers->hash_h2.get(), dist_cache, last_insert_len,
|
|
commands, num_commands, num_literals);
|
|
break;
|
|
case 3:
|
|
CreateBackwardReferences<Hashers::H3>(
|
|
num_bytes, position, ringbuffer, ringbuffer_mask, max_backward_limit,
|
|
quality, hashers->hash_h3.get(), dist_cache, last_insert_len,
|
|
commands, num_commands, num_literals);
|
|
break;
|
|
case 4:
|
|
CreateBackwardReferences<Hashers::H4>(
|
|
num_bytes, position, ringbuffer, ringbuffer_mask, max_backward_limit,
|
|
quality, hashers->hash_h4.get(), dist_cache, last_insert_len,
|
|
commands, num_commands, num_literals);
|
|
break;
|
|
case 5:
|
|
CreateBackwardReferences<Hashers::H5>(
|
|
num_bytes, position, ringbuffer, ringbuffer_mask, max_backward_limit,
|
|
quality, hashers->hash_h5.get(), dist_cache, last_insert_len,
|
|
commands, num_commands, num_literals);
|
|
break;
|
|
case 6:
|
|
CreateBackwardReferences<Hashers::H6>(
|
|
num_bytes, position, ringbuffer, ringbuffer_mask, max_backward_limit,
|
|
quality, hashers->hash_h6.get(), dist_cache, last_insert_len,
|
|
commands, num_commands, num_literals);
|
|
break;
|
|
case 7:
|
|
CreateBackwardReferences<Hashers::H7>(
|
|
num_bytes, position, ringbuffer, ringbuffer_mask, max_backward_limit,
|
|
quality, hashers->hash_h7.get(), dist_cache, last_insert_len,
|
|
commands, num_commands, num_literals);
|
|
break;
|
|
case 8:
|
|
CreateBackwardReferences<Hashers::H8>(
|
|
num_bytes, position, ringbuffer, ringbuffer_mask, max_backward_limit,
|
|
quality, hashers->hash_h8.get(), dist_cache, last_insert_len,
|
|
commands, num_commands, num_literals);
|
|
break;
|
|
case 9:
|
|
CreateBackwardReferences<Hashers::H9>(
|
|
num_bytes, position, ringbuffer, ringbuffer_mask, max_backward_limit,
|
|
quality, hashers->hash_h9.get(), dist_cache, last_insert_len,
|
|
commands, num_commands, num_literals);
|
|
break;
|
|
default:
|
|
break;
|
|
}
|
|
}
|
|
|
|
} // namespace brotli
|