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92 lines
1.8 KiB
C++
92 lines
1.8 KiB
C++
//
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// NullStream.h
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//
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// Library: Foundation
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// Package: Streams
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// Module: NullStream
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//
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// Definition of the NullStreamBuf, NullInputStream and NullOutputStream classes.
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//
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// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
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// and Contributors.
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//
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// SPDX-License-Identifier: BSL-1.0
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//
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#ifndef Foundation_NullStream_INCLUDED
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#define Foundation_NullStream_INCLUDED
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#include <istream>
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#include <ostream>
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#include "Poco/Foundation.h"
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#include "Poco/UnbufferedStreamBuf.h"
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namespace Poco
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{
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class Foundation_API NullStreamBuf : public UnbufferedStreamBuf
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/// This stream buffer discards all characters written to it.
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/// Any read operation immediately yields EOF.
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{
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public:
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NullStreamBuf();
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/// Creates a NullStreamBuf.
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~NullStreamBuf();
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/// Destroys the NullStreamBuf.
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protected:
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int readFromDevice();
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int writeToDevice(char c);
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};
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class Foundation_API NullIOS : public virtual std::ios
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/// The base class for NullInputStream and NullOutputStream.
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///
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/// This class is needed to ensure the correct initialization
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/// order of the stream buffer and base classes.
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{
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public:
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NullIOS();
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~NullIOS();
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protected:
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NullStreamBuf _buf;
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};
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class Foundation_API NullInputStream : public NullIOS, public std::istream
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/// Any read operation from this stream immediately
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/// yields EOF.
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{
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public:
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NullInputStream();
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/// Creates the NullInputStream.
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~NullInputStream();
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/// Destroys the NullInputStream.
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};
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class Foundation_API NullOutputStream : public NullIOS, public std::ostream
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/// This stream discards all characters written to it.
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{
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public:
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NullOutputStream();
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/// Creates the NullOutputStream.
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~NullOutputStream();
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/// Destroys the NullOutputStream.
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};
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} // namespace Poco
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#endif // Foundation_NullStream_INCLUDED
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