57 lines
1.7 KiB
C++
57 lines
1.7 KiB
C++
#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 <tuple>
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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 std::optional<PrefixCode> getLiteralValue(unsigned char symbol) const = 0;
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virtual std::optional<PrefixCode> getLengthValue(unsigned length) const = 0;
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virtual std::optional<PrefixCode> getDistanceValue(unsigned distance) const = 0;
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virtual std::optional<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 CountPair = std::pair<unsigned, unsigned>;
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using Hit = std::tuple<unsigned, unsigned, unsigned char>;
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public:
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void encode(const std::vector<unsigned>& counts);
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void encode(const std::unordered_map<unsigned char, unsigned>& counts);
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uint32_t getLengthValue(unsigned length);
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std::optional<PrefixCode> getLiteralValue(unsigned char symbol) const override;
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std::optional<PrefixCode> getLengthValue(unsigned length) const override;
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std::optional<PrefixCode> getDistanceValue(unsigned distance) const override;
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std::optional<PrefixCode> getEndOfStreamValue() const override;
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void initializeTrees(const std::vector<Hit>& hits);
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void setUseFixedCode(bool useFixed);
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private:
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void initializeLiteralLengthTable(const std::vector<Hit>& hits);
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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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std::vector<unsigned char> mSymbolMapping;
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HuffmanCodeLengthTable mLiteralLengthTable;
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HuffmanCodeLengthTable mDistanceTable;
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};
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