ClickHouse/base/poco/Foundation/include/Poco/Base64Decoder.h

//
// Base64Decoder.h
//
// Library: Foundation
// Package: Streams
// Module:  Base64
//
// Definition of class Base64Decoder.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_Base64Decoder_INCLUDED
#define Foundation_Base64Decoder_INCLUDED


#include <istream>
#include "Poco/Foundation.h"
#include "Poco/UnbufferedStreamBuf.h"


namespace Poco
{


class Foundation_API Base64DecoderBuf : public UnbufferedStreamBuf
/// This streambuf base64-decodes all data read
/// from the istream connected to it.
///
/// Note: For performance reasons, the characters
/// are read directly from the given istream's
/// underlying streambuf, so the state
/// of the istream will not reflect that of
/// its streambuf.
{
public:
    Base64DecoderBuf(std::istream & istr, int options = 0);
    ~Base64DecoderBuf();

private:
    int readFromDevice();
    int readOne();

    int _options;
    unsigned char _group[3];
    int _groupLength;
    int _groupIndex;
    std::streambuf & _buf;
    const unsigned char * _pInEncoding;

    static unsigned char IN_ENCODING[256];
    static bool IN_ENCODING_INIT;
    static unsigned char IN_ENCODING_URL[256];
    static bool IN_ENCODING_URL_INIT;

private:
    Base64DecoderBuf(const Base64DecoderBuf &);
    Base64DecoderBuf & operator=(const Base64DecoderBuf &);
};


class Foundation_API Base64DecoderIOS : public virtual std::ios
/// The base class for Base64Decoder.
///
/// This class is needed to ensure the correct initialization
/// order of the stream buffer and base classes.
{
public:
    Base64DecoderIOS(std::istream & istr, int options = 0);
    ~Base64DecoderIOS();
    Base64DecoderBuf * rdbuf();

protected:
    Base64DecoderBuf _buf;

private:
    Base64DecoderIOS(const Base64DecoderIOS &);
    Base64DecoderIOS & operator=(const Base64DecoderIOS &);
};


class Foundation_API Base64Decoder : public Base64DecoderIOS, public std::istream
/// This istream base64-decodes all data
/// read from the istream connected to it.
///
/// Note: For performance reasons, the characters
/// are read directly from the given istream's
/// underlying streambuf, so the state
/// of the istream will not reflect that of
/// its streambuf.
{
public:
    Base64Decoder(std::istream & istr, int options = 0);
    ~Base64Decoder();

private:
    Base64Decoder(const Base64Decoder &);
    Base64Decoder & operator=(const Base64Decoder &);
};


} // namespace Poco


#endif // Foundation_Base64Decoder_INCLUDED