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

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//
// FIFOBufferStream.h
//
// $Id: //poco/1.4/Foundation/include/Poco/FIFOBufferStream.h#1 $
//
// Library: Foundation
// Package: Streams
// Module: FIFOBufferStream
//
// Definition of the FIFOBufferStream class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// SPDX-License-Identifier: BSL-1.0
//
#ifndef Foundation_FIFOBufferStream_INCLUDED
#define Foundation_FIFOBufferStream_INCLUDED
#include "Poco/Foundation.h"
#include "Poco/FIFOBuffer.h"
#include "Poco/BufferedBidirectionalStreamBuf.h"
#include <istream>
#include <ostream>
namespace Poco {
class Foundation_API FIFOBufferStreamBuf: public BufferedBidirectionalStreamBuf
/// This is the streambuf class used for reading from and writing to a FIFOBuffer.
/// FIFOBuffer is enabled for emtpy/non-empty/full state transitions notifications.
{
public:
FIFOBufferStreamBuf();
/// Creates a FIFOBufferStreamBuf.
explicit FIFOBufferStreamBuf(FIFOBuffer& fifoBuffer);
/// Creates a FIFOBufferStreamBuf and assigns the given buffer to it.
FIFOBufferStreamBuf(char* pBuffer, std::size_t length);
/// Creates a FIFOBufferStreamBuf and assigns the given buffer to it.
FIFOBufferStreamBuf(const char* pBuffer, std::size_t length);
/// Creates a FIFOBufferStreamBuf and assigns the given buffer to it.
explicit FIFOBufferStreamBuf(std::size_t length);
/// Creates a FIFOBufferStreamBuf of the given length.
~FIFOBufferStreamBuf();
/// Destroys the FIFOBufferStreamBuf.
FIFOBuffer& fifoBuffer();
/// Returns the underlying FIFO buffer reference.
protected:
int readFromDevice(char* buffer, std::streamsize length);
int writeToDevice(const char* buffer, std::streamsize length);
private:
enum
{
STREAM_BUFFER_SIZE = 1024
};
FIFOBuffer* _pFIFOBuffer;
FIFOBuffer& _fifoBuffer;
};
class Foundation_API FIFOIOS: public virtual std::ios
/// The base class for FIFOBufferInputStream and
/// FIFOBufferStream.
///
/// This class is needed to ensure the correct initialization
/// order of the stream buffer and base classes.
{
public:
explicit FIFOIOS(FIFOBuffer& buffer);
/// Creates a FIFOIOS and assigns the given buffer to it.
FIFOIOS(char* pBuffer, std::size_t length);
/// Creates a FIFOIOS and assigns the given buffer to it.
FIFOIOS(const char* pBuffer, std::size_t length);
/// Creates a FIFOIOS and assigns the given buffer to it.
explicit FIFOIOS(std::size_t length);
/// Creates a FIFOIOS of the given length.
~FIFOIOS();
/// Destroys the FIFOIOS.
///
/// Flushes the buffer.
FIFOBufferStreamBuf* rdbuf();
/// Returns a pointer to the internal FIFOBufferStreamBuf.
void close();
/// Flushes the stream.
protected:
FIFOBufferStreamBuf _buf;
};
class Foundation_API FIFOBufferStream: public FIFOIOS, public std::iostream
/// An output stream for writing to a FIFO.
{
public:
Poco::BasicEvent<bool>& readable;
Poco::BasicEvent<bool>& writable;
explicit FIFOBufferStream(FIFOBuffer& buffer);
/// Creates the FIFOBufferStream with supplied buffer as initial value.
FIFOBufferStream(char* pBuffer, std::size_t length);
/// Creates a FIFOBufferStream and assigns the given buffer to it.
FIFOBufferStream(const char* pBuffer, std::size_t length);
/// Creates a FIFOBufferStream and assigns the given buffer to it.
explicit FIFOBufferStream(std::size_t length);
/// Creates a FIFOBufferStream of the given length.
~FIFOBufferStream();
/// Destroys the FIFOBufferStream.
///
/// Flushes the buffer.
private:
FIFOBufferStream();
FIFOBufferStream(const FIFOBufferStream& other);
FIFOBufferStream& operator =(const FIFOBufferStream& other);
};
///
/// inlines
///
inline FIFOBuffer& FIFOBufferStreamBuf::fifoBuffer()
{
return _fifoBuffer;
}
} // namespace Poco
#endif // Foundation_FIFOBufferStream_INCLUDED