Encoder.h

#pragma once


#include <libutl/CRC32.h>
#include <libutl/BufferedStream.h>


UTL_NS_BEGIN;



class Encoder : public BufferedStream
{
    UTL_CLASS_DECL_ABC(Encoder, BufferedStream);
    UTL_CLASS_NO_COPY;

public:
    Encoder(uint_t mode, Stream* stream, bool owner = true)
    {
        set(mode, stream, owner);
    }


    virtual void close();



    uint32_t
    getCRC() const
    {
        return isCRC() ? _crc.get() : _lastCRC;
    }

    uint32_t
    getLastCRC() const
    {
        return _lastCRC;
    }

    bool
    isCRC() const
    {
        return getFlag(flg_crc);
    }

    void
    setCRC(bool crc)
    {
        setFlag(flg_crc, crc);
    }

    virtual size_t decode(byte_t* block, size_t num) = 0;

    virtual size_t encode(const byte_t* block, size_t num) = 0;

    void set(uint_t mode, Stream* stream, bool owner = true, size_t bufSize = KB(16));

protected:
    virtual void clear();



    bool
    isLastBlock() const
    {
        return getFlag(flg_lastBlock);
    }

    void
    setLastBlock(bool lastBlock)
    {
        setFlag(flg_lastBlock, lastBlock);
    }

    virtual void overflow();

    virtual void underflow();

    virtual void finishEncoding();

    virtual size_t finishDecoding();

private:
    void
    init()
    {
        _lastCRC = 0;
    }
    void
    deInit()
    {
    }

private:
    enum flg_t
    {
        flg_lastBlock = 8,
        flg_crc
    };

private:
    CRC32 _crc;
    uint32_t _lastCRC;
};


UTL_NS_END;