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/* ScummVM - Scumm Interpreter
* Copyright (C) 2001/2002 The ScummVM project
*
* This program is free software; you can redistribute it and/or
* modify it under the terms of the GNU General Public License
* as published by the Free Software Foundation; either version 2
* of the License, or (at your option) any later version.
* This program 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 General Public License for more details.
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*
* $Header$
*
*/
#ifndef CHUNK_H
#define CHUNK_H
#include "config.h"
/*! @brief Interface for Chunk handling
This class is an interface for reading from a Chunk.
\todo handle big endian system.
*/
class Chunk {
public:
enum seek_type { seek_start, seek_end, seek_cur };
virtual ~Chunk() {};
typedef unsigned int type; //!< type of a Chunk (i.e. The first 4byte field of the Chunk structure).
/*! @brief convert a type to a string
Utility function that convert a type to a string.
@param t the type to convert to a string
@return the converted string
*/
static const char * ChunkString(type t);
virtual type getType() const = 0; //!< return the type of the Chunk
virtual unsigned int getSize() const = 0; //!< return the size of the Chunk
virtual Chunk * subBlock() = 0; //!< extract a subChunk from the current read position
virtual bool eof() const = 0; //!< is the Chunk completely read ?
virtual unsigned int tell() const = 0; //!< get the Chunk current read position
virtual bool seek(int delta, seek_type dir = seek_cur) = 0; //!< move the current read position inside the Chunk
virtual bool read(void * buffer, unsigned int size) = 0; //!< read some data for the current read position
virtual char getChar() = 0; //!< extract the character at the current read position
virtual unsigned char getByte() = 0; //!< extract the byte at the current read position
virtual short getShort() = 0; //!< extract the short at the current read position
virtual unsigned short getWord() = 0; //!< extract the word at the current read position
virtual unsigned int getDword()= 0; //!< extract the dword at the current read position
};
class FilePtr;
/*! @brief file based ::Chunk
This class is an implementation of ::Chunk that handles file.
*/
class FileChunk : public Chunk {
private:
FilePtr * _data;
type _type;
unsigned int _size;
unsigned int _offset;
unsigned int _curPos;
protected:
FileChunk();
public:
FileChunk(const char * fname);
virtual ~FileChunk();
type getType() const;
unsigned int getSize() const;
Chunk * subBlock();
bool eof() const;
unsigned int tell() const;
bool seek(int delta, seek_type dir = seek_cur);
bool read(void * buffer, unsigned int size);
char getChar();
unsigned char getByte();
short getShort();
unsigned short getWord();
unsigned int getDword();
};
/*! @brief memory based ::Chunk
This class is an implementation of ::Chunk that handles a memory buffer.
*/
class ContChunk : public Chunk {
private:
char * _data;
Chunk::type _type;
unsigned int _size;
unsigned int _curPos;
public:
ContChunk(char * data);
Chunk::type getType() const;
unsigned int getSize() const;
Chunk * subBlock();
bool eof() const;
unsigned int tell() const;
bool seek(int delta, seek_type dir = seek_cur);
bool read(void * buffer, unsigned int size);
char getChar();
unsigned char getByte();
short getShort();
unsigned short getWord();
unsigned int getDword();
};
#endif
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