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// -*- C++ -*-
// $Id: reader.h,v 1.13 2002/07/02 22:10:57 t1mpy Exp $
// id3lib: a software library for creating and manipulating id3v1/v2 tags
// Copyright 1999, 2000 Scott Thomas Haug
// This library is free software; you can redistribute it and/or modify it
// under the terms of the GNU Library General Public License as published by
// the Free Software Foundation; either version 2 of the License, or (at your
// option) any later version.
//
// This library is distributed in the hope that it will be useful, but WITHOUT
// ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
// FITNESS FOR A PARTICULAR PURPOSE. See the GNU Library General Public
// License for more details.
//
// You should have received a copy of the GNU Library General Public License
// along with this library; if not, write to the Free Software Foundation,
// Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
// The id3lib authors encourage improvements and optimisations to be sent to
// the id3lib coordinator. Please see the README file for details on where to
// send such submissions. See the AUTHORS file for a list of people who have
// contributed to id3lib. See the ChangeLog file for a list of changes to
// id3lib. These files are distributed with id3lib at
// http://download.sourceforge.net/id3lib/
#ifndef _ID3LIB_READER_H_
#define _ID3LIB_READER_H_
#include "id3/globals.h" //has <stdlib.h> "id3/sized_types.h"
class ID3_CPP_EXPORT ID3_Reader
{
public:
typedef uint32 size_type;
typedef uint8 char_type;
typedef uint32 pos_type;
typedef int32 off_type;
typedef int16 int_type;
static const int_type END_OF_READER;
/** Close the reader. Any further actions on the reader should fail.
**/
virtual void close() = 0;
/** Return the beginning position in the reader */
virtual pos_type getBeg() { return static_cast<pos_type>(0); }
/** Return the ending position in the reader */
virtual pos_type getEnd() { return static_cast<pos_type>(-1); }
/** Return the current position in the reader */
virtual pos_type getCur() = 0;
/** Set the value of the current position for reading.
**/
virtual pos_type setCur(pos_type pos) = 0;
/**
** Read a single character and advance the internal position. Note that the
** interal position may advance more than one byte for a single character
** read. Returns END_OF_READER if there isn't a character to read.
**/
virtual int_type readChar()
{
if (this->atEnd())
{
return END_OF_READER;
}
char_type ch;
this->readChars(&ch, 1);
return ch;
}
/**
** Return the next character to be read without advancing the internal
** position. Returns END_OF_READER if there isn't a character to read.
**/
virtual int_type peekChar() = 0;
/** Read up to \c len characters into buf and advance the internal position
** accordingly. Returns the number of characters read into buf. Note that
** the value returned may be less than the number of bytes that the internal
** position advances, due to multi-byte characters.
**/
virtual size_type readChars(char_type buf[], size_type len) = 0;
virtual size_type readChars(char buf[], size_type len)
{
return this->readChars(reinterpret_cast<char_type *>(buf), len);
}
/** Skip up to \c len chars in the stream and advance the internal position
** accordingly. Returns the number of characters actually skipped (may be
** less than requested).
**/
virtual size_type skipChars(size_type len)
{
const size_type SIZE = 1024;
char_type bytes[SIZE];
size_type remaining = len;
while (!this->atEnd() && remaining > 0)
{
remaining -= this->readChars(bytes, (remaining < SIZE ? remaining : SIZE));
}
return len - remaining;
}
virtual size_type remainingBytes()
{
pos_type end = this->getEnd(), cur = this->getCur();
if (end == pos_type(-1))
{
return size_type(-1);
}
if (end >= cur)
{
return end - cur;
}
return 0;
}
virtual bool atEnd() { return this->getCur() >= this->getEnd(); }
};
#endif /* _ID3LIB_READER_H_ */
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