ClickHouse/base/poco/Foundation/include/Poco/Base64Encoder.h

//
// Base64Encoder.h
//
// Library: Foundation
// Package: Streams
// Module:  Base64
//
// Definition of class Base64Encoder.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_Base64Encoder_INCLUDED
#define Foundation_Base64Encoder_INCLUDED


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


namespace Poco
{


enum Base64EncodingOptions
{
    BASE64_URL_ENCODING = 0x01,
    /// Use the URL and filename-safe alphabet,
    /// replacing '+' with '-' and '/' with '_'.
    ///
    /// Will also set line length to unlimited.

    BASE64_NO_PADDING = 0x02
    /// Do not append padding characters ('=') at end.
};


class Foundation_API Base64EncoderBuf : public UnbufferedStreamBuf
/// This streambuf base64-encodes all data written
/// to it and forwards it to a connected
/// ostream.
///
/// Note: The characters are directly written
/// to the ostream's streambuf, thus bypassing
/// the ostream. The ostream's state is therefore
/// not updated to match the buffer's state.
{
public:
    Base64EncoderBuf(std::ostream & ostr, int options = 0);
    ~Base64EncoderBuf();

    int close();
    /// Closes the stream buffer.

    void setLineLength(int lineLength);
    /// Specify the line length.
    ///
    /// After the given number of characters have been written,
    /// a newline character will be written.
    ///
    /// Specify 0 for an unlimited line length.

    int getLineLength() const;
    /// Returns the currently set line length.

private:
    int writeToDevice(char c);

    int _options;
    unsigned char _group[3];
    int _groupLength;
    int _pos;
    int _lineLength;
    std::streambuf & _buf;
    const unsigned char * _pOutEncoding;

    static const unsigned char OUT_ENCODING[64];
    static const unsigned char OUT_ENCODING_URL[64];

    friend class Base64DecoderBuf;

    Base64EncoderBuf(const Base64EncoderBuf &);
    Base64EncoderBuf & operator=(const Base64EncoderBuf &);
};


class Foundation_API Base64EncoderIOS : public virtual std::ios
/// The base class for Base64Encoder.
///
/// This class is needed to ensure the correct initialization
/// order of the stream buffer and base classes.
{
public:
    Base64EncoderIOS(std::ostream & ostr, int options = 0);
    ~Base64EncoderIOS();
    int close();
    Base64EncoderBuf * rdbuf();

protected:
    Base64EncoderBuf _buf;

private:
    Base64EncoderIOS(const Base64EncoderIOS &);
    Base64EncoderIOS & operator=(const Base64EncoderIOS &);
};


class Foundation_API Base64Encoder : public Base64EncoderIOS, public std::ostream
/// This ostream base64-encodes all data
/// written to it and forwards it to
/// a connected ostream.
/// Always call close() when done
/// writing data, to ensure proper
/// completion of the encoding operation.
///
/// Note: The characters are directly written
/// to the ostream's streambuf, thus bypassing
/// the ostream. The ostream's state is therefore
/// not updated to match the buffer's state.
{
public:
    Base64Encoder(std::ostream & ostr, int options = 0);
    ~Base64Encoder();

private:
    Base64Encoder(const Base64Encoder &);
    Base64Encoder & operator=(const Base64Encoder &);
};


} // namespace Poco


#endif // Foundation_Base64Encoder_INCLUDED