67 lines
2.2 KiB
C++
67 lines
2.2 KiB
C++
/* Copyright 2018 Dirk Steinke
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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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http://www.apache.org/licenses/LICENSE-2.0
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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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#include "pch.h"
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#include <algorithm>
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#include "preflate_block_trees.h"
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#include "support/bit_helper.h"
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static HuffmanDecoder* staticLitLenDecoder;
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static HuffmanDecoder* staticDistDecoder;
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static HuffmanEncoder* staticLitLenEncoder;
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static HuffmanEncoder* staticDistEncoder;
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static void setLitLenBitLengths(unsigned char(&a)[288]) {
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std::fill(a + 0, a + 144, 8);
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std::fill(a + 144, a + 256, 9);
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std::fill(a + 256, a + 280, 7);
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std::fill(a + 280, a + 288, 8);
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}
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static void setDistBitLengths(unsigned char(&a)[32]) {
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std::fill(a, a + 32, 5);
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}
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const HuffmanDecoder* PreflateBlockTrees::staticLitLenTreeDecoder() {
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if (!staticLitLenDecoder) {
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unsigned char l_lengths[288];
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setLitLenBitLengths(l_lengths);
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staticLitLenDecoder = new HuffmanDecoder(l_lengths, 288, true, 15);
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}
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return staticLitLenDecoder;
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}
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const HuffmanDecoder* PreflateBlockTrees::staticDistTreeDecoder() {
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if (!staticDistDecoder) {
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unsigned char d_lengths[32];
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setDistBitLengths(d_lengths);
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staticDistDecoder = new HuffmanDecoder(d_lengths, 32, true, 15);
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}
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return staticDistDecoder;
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}
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const HuffmanEncoder* PreflateBlockTrees::staticLitLenTreeEncoder() {
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if (!staticLitLenEncoder) {
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unsigned char l_lengths[288];
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setLitLenBitLengths(l_lengths);
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staticLitLenEncoder = new HuffmanEncoder(l_lengths, 288, true);
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}
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return staticLitLenEncoder;
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}
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const HuffmanEncoder* PreflateBlockTrees::staticDistTreeEncoder() {
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if (!staticDistEncoder) {
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unsigned char d_lengths[32];
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setDistBitLengths(d_lengths);
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staticDistEncoder = new HuffmanEncoder(d_lengths, 32, true);
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}
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return staticDistEncoder;
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}
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