binaryreader.h

来自「This software aims to create an applet a」· C头文件 代码 · 共 201 行

//
// BinaryReader.h
//
// $Id: //poco/Main/Foundation/include/Foundation/BinaryReader.h#5 $
//
// Definition of the BinaryReader 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_BinaryReader_INCLUDED
#define Foundation_BinaryReader_INCLUDED


#ifndef Foundation_Foundation_INCLUDED
#include "Foundation/Foundation.h"
#endif
#ifndef STD_ISTREAM_INCLUDED
#include <istream>
#define STD_ISTREAM_INCLUDED
#endif


Foundation_BEGIN


class Foundation_API BinaryReader
	/// This class reads basic types in binary form into an input stream.
	/// It provides an extractor-based interface similar to istream.
	/// The reader also supports automatic conversion from big-endian
	/// (network byte order) to little-endian and vice-versa.
	/// Use a BinaryWriter to create a stream suitable for a BinaryReader.
{
public:
	enum StreamByteOrder
	{
		NATIVE_BYTE_ORDER,        /// the host's native byte-order
		UNSPECIFIED_BYTE_ORDER,   /// unknown, byte-order will be determined by reading the byte-order mark
		BIG_ENDIAN_BYTE_ORDER,    /// big-endian (network) byte-order
		LITTLE_ENDIAN_BYTE_ORDER  /// little-endian byte-order
	};

	BinaryReader(std::istream& istr, StreamByteOrder byteOrder = NATIVE_BYTE_ORDER);
		/// Creates the BinaryReader.

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

	BinaryReader& operator >> (bool& value);
	BinaryReader& operator >> (char& value);
	BinaryReader& operator >> (unsigned char& value);
	BinaryReader& operator >> (signed char& value);
	BinaryReader& operator >> (short& value);
	BinaryReader& operator >> (unsigned short& value);
	BinaryReader& operator >> (int& value);
	BinaryReader& operator >> (unsigned int& value);
	BinaryReader& operator >> (long& value);
	BinaryReader& operator >> (unsigned long& value);
	BinaryReader& operator >> (float& value);
	BinaryReader& operator >> (double& value);

#if defined(POCO_HAVE_INT64) && !defined(POCO_LONG_IS_64_BIT)
	BinaryReader& operator >> (Int64& value);
	BinaryReader& operator >> (UInt64& value);
#endif

	BinaryReader& operator >> (std::string& value);

	void read7BitEncoded(UInt32& value);
		/// Reads a 32-bit unsigned integer in compressed format.
		/// See BinaryWriter::write7BitEncoded() for a description
		/// of the compression algorithm.

#if defined(POCO_HAVE_INT64)
	void read7BitEncoded(UInt64& value);
		/// Reads a 64-bit unsigned integer in compressed format.
		/// See BinaryWriter::write7BitEncoded() for a description
		/// of the compression algorithm.
#endif

	void readRawData(int length, std::string& value);
		/// Reads length bytes of raw data into value.

	void readBOM();
		/// Reads a byte-order mark from the stream and configures
		/// the reader for the encountered byte order.
		/// A byte-order mark is a 16-bit integer with a value of 0xFEFF,
		/// written in host byte order.
		
	bool good();
		/// Returns _istr.good();
		
	bool fail();
		/// Returns _istr.fail();

	bool bad();
		/// Returns _istr.bad();
	
	bool eof();
		/// Returns _istr.eof();

	std::istream& stream() const;
		/// Returns the underlying stream.
		
	StreamByteOrder byteOrder() const;
		/// Returns the byte-order used by the reader, which is
		/// either BIG_ENDIAN_BYTE_ORDER or LITTLE_ENDIAN_BYTE_ORDER.

private:
	std::istream& _istr;
	bool          _flipBytes; 
};


//
// inlines
//


inline bool BinaryReader::good()
{
	return _istr.good();
}

	
inline bool BinaryReader::fail()
{
	return _istr.fail();
}


inline bool BinaryReader::bad()
{
	return _istr.bad();
}


inline bool BinaryReader::eof()
{
	return _istr.eof();
}


inline std::istream& BinaryReader::stream() const
{
	return _istr;
}

	
inline BinaryReader::StreamByteOrder BinaryReader::byteOrder() const
{
#if defined(POCO_ARCH_BIG_ENDIAN)
	return _flipBytes ? LITTLE_ENDIAN_BYTE_ORDER : BIG_ENDIAN_BYTE_ORDER;
#else
	return _flipBytes ? BIG_ENDIAN_BYTE_ORDER : LITTLE_ENDIAN_BYTE_ORDER;
#endif
}


Foundation_END


#endif // Foundation_BinaryReader_INCLUDED