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

//
// TeeStream.h
//
// Library: Foundation
// Package: Streams
// Module:  TeeStream
//
// Definition of the TeeStream class.
//
// Copyright (c) 2005-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier:	BSL-1.0
//


#ifndef Foundation_TeeStream_INCLUDED
#define Foundation_TeeStream_INCLUDED


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


namespace Poco
{


class Foundation_API TeeStreamBuf : public UnbufferedStreamBuf
/// This stream buffer copies all data written to or
/// read from it to one or multiple output streams.
{
public:
    TeeStreamBuf();
    /// Creates an unconnected CountingStreamBuf.
    /// Use addStream() to attach output streams.

    TeeStreamBuf(std::istream & istr);
    /// Creates the CountingStreamBuf and connects it
    /// to the given input stream.

    TeeStreamBuf(std::ostream & ostr);
    /// Creates the CountingStreamBuf and connects it
    /// to the given output stream.

    ~TeeStreamBuf();
    /// Destroys the CountingStream.

    void addStream(std::ostream & ostr);
    /// Adds the given output stream.

protected:
    int readFromDevice();
    int writeToDevice(char c);

private:
    typedef std::vector<std::ostream *> StreamVec;

    std::istream * _pIstr;
    StreamVec _streams;
};


class Foundation_API TeeIOS : public virtual std::ios
/// The base class for TeeInputStream and TeeOutputStream.
///
/// This class is needed to ensure the correct initialization
/// order of the stream buffer and base classes.
{
public:
    TeeIOS();
    /// Creates the basic stream and leaves it unconnected.

    TeeIOS(std::istream & istr);
    /// Creates the basic stream and connects it
    /// to the given input stream.

    TeeIOS(std::ostream & ostr);
    /// Creates the basic stream and connects it
    /// to the given output stream.

    ~TeeIOS();
    /// Destroys the stream.

    void addStream(std::ostream & ostr);
    /// Adds the given output stream.

    TeeStreamBuf * rdbuf();
    /// Returns a pointer to the underlying streambuf.

protected:
    TeeStreamBuf _buf;
};


class Foundation_API TeeInputStream : public TeeIOS, public std::istream
/// This stream copies all characters read through it
/// to one or multiple output streams.
{
public:
    TeeInputStream(std::istream & istr);
    /// Creates the TeeInputStream and connects it
    /// to the given input stream.

    ~TeeInputStream();
    /// Destroys the TeeInputStream.
};


class Foundation_API TeeOutputStream : public TeeIOS, public std::ostream
/// This stream copies all characters written to it
/// to one or multiple output streams.
{
public:
    TeeOutputStream();
    /// Creates an unconnected TeeOutputStream.

    TeeOutputStream(std::ostream & ostr);
    /// Creates the TeeOutputStream and connects it
    /// to the given input stream.

    ~TeeOutputStream();
    /// Destroys the TeeOutputStream.
};


} // namespace Poco


#endif // Foundation_TeeStream_INCLUDED