campo-sirio/arch/cmpengn.h

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4.6 KiB
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/*
* CPMENGN.H
*
* Header file for ArchiveLib 1.0
*
* Copyright (c) 1994 Greenleaf Software, Inc.
* All Rights Reserved
*
* DESCRIPTION
*
* This header file contains the class declaration for ALCompressionEngine,
* the base class used by all ArchiveLib compression engines.
*
* CLASS DEFINITIONS:
*
* ALCompressionEngine
*
* REVISION HISTORY
*
* May 26, 1994 1.0A : First release
*
*/
#ifndef _CMPENGN_H
#define _CMPENGN_H
#if defined( __cplusplus )
/*
* class ALOpenInputFile
*
* DESCRIPTION
*
* This header file defines the ALCompressionEngine class. It is a base
* class with pure virtual functions, so it cannot be instantiated.
* The two derived classes supplied with Archive Library at this time are
* ALGreenleafEngine, which implements a Greenleaf proprietary compression
* engine, and ALCopyEngine, which just performs straight copying.
*
* ALCompressionEngine has two public virtual functions, Compress()
* and Decompress(), which are pure here. It also provides two
* virtual protected functions which are used to store configuration
* in the archive directory.
*
* DATA MEMBERS
*
* miCompressionType : The compression type integer is what gets stored
* in the archive directory, and what the archive
* class looks at when extracting so it can figure
* out what type of compression engine to construct
* for a specific type of object.
*
* mszCompressionType : This string just describes the compression type
* in ASCII format suitable for printing or display.
*
* mStatus : A standard ArchiveLib status object, stored
* with the compression engine. Check this after
* completing a compression or decompression to
* see how things went.
*
* MEMBER FUNCTIONS
*
* ALCompressionEngine() : The constructor. Only called by the ctors for
* derived classes.
* ~ALCompressionEngine() : The virtual destructor.
* operator new() : Memory allocation operator, only gets used
* when the library is in a DLL.
* WriteEngineData() : Private virtual function used to store engine
* specific data.
* ReadEngineData() : Private virtual function used to read back
* engine specific data.
* Compress() : The compression routine. Derived classes
* have to provide their own versions of this
* function. Wouldn't be much good without it.
* Decompress() : The inverse, has to know how to undo the
* Compress() output.
*
* REVISION HISTORY
*
* May 26, 1994 1.0A : First release
*
*/
class AL_CLASS_TYPE ALCompressionEngine {
/*
* Constructors, destructors, declarations, and friends
*/
friend class AL_CLASS_TYPE ALArchiveBase;
public :
AL_PROTO ALCompressionEngine( ALCompressionType compression_type_int,
const char AL_DLL_FAR *compression_type_string );
virtual AL_PROTO ~ALCompressionEngine();
#if defined( AL_USING_DLL ) || defined( AL_BUILDING_DLL )
void AL_DLL_FAR * AL_PROTO operator new( size_t size );
#endif
/*
* The copy constructor and assignment operator do not exist. I define
* them here to prevent the compiler from creating default versions.
*/
protected :
AL_PROTO ALCompressionEngine( ALCompressionEngine AL_DLL_FAR & );
ALCompressionEngine AL_DLL_FAR & AL_PROTO operator=( ALCompressionEngine AL_DLL_FAR & rhs );
/*
* Member functions
*/
protected :
virtual int AL_PROTO WriteEngineData( ALStorage AL_DLL_FAR * archive );
virtual int AL_PROTO ReadEngineData( ALStorage AL_DLL_FAR * archive );
public :
virtual int AL_PROTO Compress( ALStorage AL_DLL_FAR &input_object,
ALStorage AL_DLL_FAR &output_object ) = 0;
virtual int AL_PROTO Decompress( ALStorage AL_DLL_FAR &input_object,
ALStorage AL_DLL_FAR &output_object,
long compressed_length = -1 ) = 0;
/*
* Data members
*/
public :
const ALCompressionType miCompressionType;
const char AL_DLL_FAR *mszCompressionType;
ALStatus mStatus;
AL_CLASS_TAG( _ALCompressionEngineTag );
};
#endif /* #if defined( __cplusplus ) */
#endif /* #ifndef _CMPENGN_H */