poco/Foundation/include/Poco/BinaryReader.h

//
// BinaryReader.h
//
// $Id: //poco/svn/Foundation/include/Poco/BinaryReader.h#2 $
//
// Library: Foundation
// Package: Streams
// Module:  BinaryReaderWriter
//
// Definition of the BinaryReader class.
//
// Copyright (c) 2004-2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef Foundation_BinaryReader_INCLUDED
#define Foundation_BinaryReader_INCLUDED


#include "Poco/Foundation.h"
#include <vector>
#include <istream>


namespace Poco {


class TextEncoding;
class TextConverter;


class Foundation_API BinaryReader
        /// This class reads basic types (and std::vectors thereof)
        /// 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        = 1,  /// the host's native byte-order
		BIG_ENDIAN_BYTE_ORDER    = 2,  /// big-endian (network) byte-order
		NETWORK_BYTE_ORDER       = 2,  /// big-endian (network) byte-order
		LITTLE_ENDIAN_BYTE_ORDER = 3,  /// little-endian byte-order
		UNSPECIFIED_BYTE_ORDER   = 4   /// unknown, byte-order will be determined by reading the byte-order mark
	};

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

        BinaryReader(std::istream& istr, TextEncoding& encoding, StreamByteOrder byteOrder = NATIVE_BYTE_ORDER);
                /// Creates the BinaryReader using the given TextEncoding.
                ///
                /// Strings will be converted from the specified encoding
                /// to the currently set global encoding (see Poco::TextEncoding::global()).

        ~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);

        template <typename T>
        BinaryReader& operator >> (std::vector<T>& value)
        {
                Poco::UInt32 size(0);
                T elem;

                *this >> size;
                if (!good()) return *this;
                value.reserve(size);
                while (this->good() && size-- > 0)
                {
                        *this >> elem;
                        value.push_back(elem);
                }
                return *this;
        }

        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 readRaw(std::streamsize length, std::string& value);
                /// Reads length bytes of raw data into value.

        void readRaw(char* buffer, std::streamsize length);
                /// Reads length bytes of raw data into buffer.

        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; 
        TextConverter* _pTextConverter;
};


//
// 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
}


} // namespace Poco


#endif // Foundation_BinaryReader_INCLUDED