streamconverter.h

来自「This software aims to create an applet a」· C头文件 代码 · 共 172 行

//
// StreamConverter.h
//
// $Id: //poco/Main/Foundation/include/Foundation/StreamConverter.h#5 $
//
// Definition of the StreamConverter class.
//
// Copyright (c) 2004, Guenter Obiltschnig/Applied Informatics.
// All rights reserved.
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions
// are met:
//
// 1. Redistributions of source code must retain the above copyright
//    notice, this list of conditions and the following disclaimer.
//
// 2. Redistributions in binary form must reproduce the above copyright
//    notice, this list of conditions and the following disclaimer in the
//    documentation and/or other materials provided with the distribution.
//
// 3. Redistributions in any form must be accompanied by information on
//    how to obtain complete source code for this software and any
//    accompanying software that uses this software.  The source code
//    must either be included in the distribution or be available for no
//    more than the cost of distribution plus a nominal fee, and must be
//    freely redistributable under reasonable conditions.  For an
//    executable file, complete source code means the source code for all
//    modules it contains.  It does not include source code for modules or
//    files that typically accompany the major components of the operating
//    system on which the executable file runs.
//
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
// FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
// COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
// INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
// BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
// LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
// CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
// LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
// ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
// POSSIBILITY OF SUCH DAMAGE.
//


#ifndef Foundation_StreamConverter_INCLUDED
#define Foundation_StreamConverter_INCLUDED


#ifndef Foundation_Foundation_INCLUDED
#include "Foundation/Foundation.h"
#endif
#ifndef Foundation_TextEncoding_INCLUDED
#include "Foundation/TextEncoding.h"
#endif
#ifndef Foundation_UnbufferedStreamBuf_INCLUDED
#include "Foundation/UnbufferedStreamBuf.h"
#endif
#ifndef STD_ISTREAM_INCLUDED
#include <istream>
#define STD_ISTREAM_INCLUDED
#endif
#ifndef STD_OSTREAM_INCLUDED
#include <ostream>
#define STD_OSTREAM_INCLUDED
#endif


Foundation_BEGIN


class Foundation_API StreamConverterBuf: public UnbufferedStreamBuf
	/// A StreamConverter converts streams from one encoding (inEncoding)
	/// into another (outEncoding).
	/// If a character cannot be represented in outEncoding, defaultChar
	/// is used instead.
	/// If a byte sequence is not valid in inEncoding, defaultChar is used
	/// instead and the encoding error count is incremented.
{
public:
	StreamConverterBuf(std::istream& istr, const TextEncoding& inEncoding, const TextEncoding& outEncoding, int defaultChar = '?');
		/// Creates the StreamConverterBuf and connects it
		/// to the given input stream.

	StreamConverterBuf(std::ostream& ostr, const TextEncoding& inEncoding, const TextEncoding& outEncoding, int defaultChar = '?');
		/// Creates the StreamConverterBuf and connects it
		/// to the given output stream.

	~StreamConverterBuf();
		/// Destroys the StreamConverterBuf.

	int errors() const;
		/// Returns the number of encoding errors encountered.

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

private:
	std::istream*       _pIstr;
	std::ostream*       _pOstr;
	const TextEncoding& _inEncoding;
	const TextEncoding& _outEncoding;
	int                 _defaultChar;
	unsigned char       _buffer[TextEncoding::MAX_SEQUENCE_LENGTH];
	int                 _sequenceLength;
	int                 _pos;
	int                 _errors;
};


class Foundation_API StreamConverterIOS: public virtual std::ios
	/// The base class for InputStreamConverter and OutputStreamConverter.
	///
	/// This class is needed to ensure the correct initialization
	/// order of the stream buffer and base classes.
{
public:
	StreamConverterIOS(std::istream& istr, const TextEncoding& inEncoding, const TextEncoding& outEncoding, int defaultChar = '?');
	StreamConverterIOS(std::ostream& ostr, const TextEncoding& inEncoding, const TextEncoding& outEncoding, int defaultChar = '?');
	~StreamConverterIOS();
	StreamConverterBuf* rdbuf();
	int errors() const;

protected:
	StreamConverterBuf _buf;
};


class Foundation_API InputStreamConverter: public StreamConverterIOS, public std::istream
	/// This stream converts all characters read from the
	/// underlying istream from one character encoding into another.
	/// If a character cannot be represented in outEncoding, defaultChar
	/// is used instead.
	/// If a byte sequence read from the underlying stream is not valid in inEncoding, 
	/// defaultChar is used instead and the encoding error count is incremented.
{
public:
	InputStreamConverter(std::istream& istr, const TextEncoding& inEncoding, const TextEncoding& outEncoding, int defaultChar = '?');
		/// Creates the InputStreamConverter and connects it
		/// to the given input stream.

	~InputStreamConverter();
		/// Destroys the stream.
};


class Foundation_API OutputStreamConverter: public StreamConverterIOS, public std::ostream
	/// This stream converts all characters written to the
	/// underlying ostream from one character encoding into another.
	/// If a character cannot be represented in outEncoding, defaultChar
	/// is used instead.
	/// If a byte sequence written to the stream is not valid in inEncoding, 
	/// defaultChar is used instead and the encoding error count is incremented.
{
public:
	OutputStreamConverter(std::ostream& ostr, const TextEncoding& inEncoding, const TextEncoding& outEncoding, int defaultChar = '?');
		/// Creates the OutputStreamConverter and connects it
		/// to the given input stream.

	~OutputStreamConverter();
		/// Destroys the CountingOutputStream.
};


Foundation_END


#endif // Foundation_StreamConverter_INCLUDED