ClickHouse/contrib/libpoco/Foundation/include/Poco/PipeStream.h

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//
// PipeStream.h
//
// $Id: //poco/1.4/Foundation/include/Poco/PipeStream.h#1 $
//
// Library: Foundation
// Package: Processes
// Module: PipeStream
//
// Definition of the PipeStream class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_PipeStream_INCLUDED
#define Foundation_PipeStream_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/Pipe.h"
#include "Poco/BufferedStreamBuf.h"
#include <istream>
#include <ostream>
namespace Poco {
class Foundation_API PipeStreamBuf: public BufferedStreamBuf
/// This is the streambuf class used for reading from and writing to a Pipe.
{
public:
typedef BufferedStreamBuf::openmode openmode;
PipeStreamBuf(const Pipe& pipe, openmode mode);
/// Creates a PipeStreamBuf with the given Pipe.
~PipeStreamBuf();
/// Destroys the PipeStreamBuf.
void close();
/// Closes the pipe.
protected:
int readFromDevice(char* buffer, std::streamsize length);
int writeToDevice(const char* buffer, std::streamsize length);
private:
enum
{
STREAM_BUFFER_SIZE = 1024
};
Pipe _pipe;
};
class Foundation_API PipeIOS: public virtual std::ios
/// The base class for PipeInputStream and
/// PipeOutputStream.
///
/// This class is needed to ensure the correct initialization
/// order of the stream buffer and base classes.
{
public:
PipeIOS(const Pipe& pipe, openmode mode);
/// Creates the PipeIOS with the given Pipe.
~PipeIOS();
/// Destroys the PipeIOS.
///
/// Flushes the buffer, but does not close the pipe.
PipeStreamBuf* rdbuf();
/// Returns a pointer to the internal PipeStreamBuf.
void close();
/// Flushes the stream and closes the pipe.
protected:
PipeStreamBuf _buf;
};
class Foundation_API PipeOutputStream: public PipeIOS, public std::ostream
/// An output stream for writing to a Pipe.
{
public:
PipeOutputStream(const Pipe& pipe);
/// Creates the PipeOutputStream with the given Pipe.
~PipeOutputStream();
/// Destroys the PipeOutputStream.
///
/// Flushes the buffer, but does not close the pipe.
};
class Foundation_API PipeInputStream: public PipeIOS, public std::istream
/// An input stream for reading from a Pipe.
///
/// Using formatted input from a PipeInputStream
/// is not recommended, due to the read-ahead behavior of
/// istream with formatted reads.
{
public:
PipeInputStream(const Pipe& pipe);
/// Creates the PipeInputStream with the given Pipe.
~PipeInputStream();
/// Destroys the PipeInputStream.
};
} // namespace Poco
#endif // Foundation_PipeStream_INCLUDED