AOO410/main/cosv/inc/cosv/bstream.hxx

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 * 
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF licenses this file
 * to you under the Apache License, Version 2.0 (the
 * "License"); you may not use this file except in compliance
 * with the License.  You may obtain a copy of the License at
 * 
 *   http://www.apache.org/licenses/LICENSE-2.0
 * 
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 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
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 *************************************************************/



#ifndef CSV_BSTREAM_HXX
#define CSV_BSTREAM_HXX

#include <string.h>
#include <cosv/string.hxx>


namespace csv
{


enum seek_dir
{
    beg = 0,
    cur = 1,
    end = 2
};


class bistream
{
  public:
	// LIFECYCLE
	virtual				~bistream() {}

	//	OPERATIONS
		/// @return Number of actually read bytes.
	uintt 		        read(
							void *	        out_pDest,
							uintt           i_nNrofBytes);
	// INQUIRY
		/**  @return True, if already one try to read had failed.
			 There is no guarantee, that it returns true, if end of data
			 is just reached.
			 Though it will return false, if there is still somemething
			 to read.
		*/
	bool		        eod() const;

  private:
	virtual uintt 		do_read(
							void *	        out_pDest,
							uintt           i_nNrofBytes) = 0;
	virtual bool		inq_eod() const = 0;
};


class bostream
{
  public:
	// LIFECYCLE
	virtual				~bostream() {}

	//	OPERATIONS
		/// @return Number of actually written bytes.
	uintt 		        write(
							const void *   	i_pSrc,
							uintt           i_nNrofBytes);
		/// @return Number of actually written bytes.
	uintt 				write(
							const char *   	i_pSrc );
		/// @return Number of actually written bytes.
	uintt 				write(
							const String &	i_pSrc );
  private:
	virtual uintt 		do_write(
							const void *   	i_pSrc,
							uintt           i_nNrofBytes) = 0;
};


class bstream : public bistream,
				public bostream
{
  public:
	uintt 		        seek(
							intt 			i_nDistanceFromBegin,
                            seek_dir        i_eStartPoint = ::csv::beg );
	uintt 		        position() const;

  private:
	virtual uintt 		do_seek(
							intt 			i_nDistance,
                            seek_dir        i_eStartPoint = ::csv::beg ) = 0;
	virtual uintt 		inq_position() const = 0;
};


// IMPLEMENTATION
inline uintt 
bistream::read( void *	       o_pDest,
			   uintt           i_nNrofBytes)
    { return do_read(o_pDest, i_nNrofBytes); }
inline bool
bistream::eod() const
    { return inq_eod(); }

inline uintt 
bostream::write( const void *   i_pSrc,
				 uintt          i_nNrofBytes)
    { return do_write( i_pSrc, i_nNrofBytes ); }
inline uintt 
bostream::write( const char * i_sSrc )
    { return write( i_sSrc, strlen(i_sSrc) ); }
inline uintt 
bostream::write( const String &	i_sSrc )
    { return write( i_sSrc.c_str(), i_sSrc.length() ); }

inline uintt 
bstream::seek( intt     i_nDistance,
               seek_dir i_eStartPoint )
    { return do_seek( i_nDistance, i_eStartPoint ); }
inline uintt 
bstream::position() const
    { return inq_position(); }



}   // namespace csv


#endif