Clean project structure.

src/base/compression/huffman/HuffmanEncoder.h

@@ -0,0 +1,57 @@
+#pragma once
+
+#include "RawTree.h"
+
+#include "HuffmanCodeLengthTable.h"
+#include "HuffmanFixedCodes.h"
+
+#include <vector>
+#include <tuple>
+#include <unordered_map>
+
+class PrefixCodeGenerator
+{
+public:
+    virtual ~PrefixCodeGenerator() = default;
+    virtual std::optional<PrefixCode> getLiteralValue(unsigned char symbol) const = 0;
+    virtual std::optional<PrefixCode> getLengthValue(unsigned length) const = 0;
+    virtual std::optional<PrefixCode> getDistanceValue(unsigned distance) const = 0;
+
+    virtual std::optional<PrefixCode> getEndOfStreamValue() const = 0;
+};
+
+class HuffmanEncoder : public PrefixCodeGenerator
+{
+    using CountPair = std::pair<unsigned, unsigned>;
+    using Hit = std::tuple<unsigned, unsigned, unsigned char>;
+
+public:
+    void encode(const std::vector<unsigned>& counts);
+    void encode(const std::unordered_map<unsigned char, unsigned>& counts);
+
+    uint32_t getLengthValue(unsigned length);
+
+    std::optional<PrefixCode> getLiteralValue(unsigned char symbol) const override;
+
+    std::optional<PrefixCode> getLengthValue(unsigned length) const override;
+
+    std::optional<PrefixCode> getDistanceValue(unsigned distance) const override;
+
+    std::optional<PrefixCode> getEndOfStreamValue() const override;
+
+    void initializeTrees(const std::vector<Hit>& hits);
+
+    void setUseFixedCode(bool useFixed);
+private:
+    void initializeLiteralLengthTable(const std::vector<Hit>& hits);
+
+    void dumpTree(const RawTree<CountPair>& tree) const;
+    void dumpNode(RawNode<CountPair>* node, unsigned depth) const;
+
+    bool mUseFixedCode{false};
+    bool mTableIsInitialized{false};
+
+    std::vector<unsigned char> mSymbolMapping;
+    HuffmanCodeLengthTable mLiteralLengthTable;
+    HuffmanCodeLengthTable mDistanceTable;
+};