68 lines
1.6 KiB
C
68 lines
1.6 KiB
C
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#pragma once
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#include "RawTree.h"
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#include "HuffmanCodeLengthTable.h"
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#include "HuffmanFixedCodes.h"
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#include <vector>
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#include <unordered_map>
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class PrefixCodeGenerator
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{
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public:
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virtual ~PrefixCodeGenerator() = default;
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virtual const PrefixCode& getLiteralValue(unsigned char value) const = 0;
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virtual const PrefixCode& getEndOfStreamValue() const = 0;
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};
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class HuffmanEncoder : public PrefixCodeGenerator
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{
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using DataStream = std::vector<unsigned char>;
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using CountPair = std::pair<unsigned char, unsigned>;
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public:
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void encode(const DataStream& stream);
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void encode(const std::unordered_map<unsigned char, unsigned>& counts);
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void setUseFixedCode(bool useFixed)
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{
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mUseFixedCode = useFixed;
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}
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uint32_t getLengthValue(unsigned length)
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{
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return 0;
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}
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const PrefixCode& getLiteralValue(unsigned char value) const override
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{
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return mLiteralLengthTable.getCode(value);
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}
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const PrefixCode& getEndOfStreamValue() const override
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{
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return mLiteralLengthTable.getCode(256);
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}
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void initializeLiteralLengthTable()
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{
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if(mUseFixedCode)
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{
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mLiteralLengthTable.setInputLengthSequence(HuffmanFixedCodes::getDeflateFixedHuffmanCodes(), false);
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mLiteralLengthTable.buildPrefixCodes();
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}
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}
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private:
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void dumpTree(const RawTree<CountPair>& tree) const;
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void dumpNode(RawNode<CountPair>* node, unsigned depth) const;
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bool mUseFixedCode{false};
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bool mTableIsInitialized{false};
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HuffmanCodeLengthTable mLiteralLengthTable;
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HuffmanCodeLengthTable mDistanceTable;
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};
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