/*
* MEMSTORE.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 ALMemory.
*
* CLASS DEFINITIONS:
*
* ALMemory
*
* REVISION HISTORY
*
* May 26, 1994 1.0A : First release
*
*/
#ifndef _MEMSTORE_H
#define _MEMSTORE_H
#include "arclib.h"
#if defined( __cplusplus )
/*
* class ALMemory : public ALStorage
*
* DESCRIPTION
*
* Class ALMemory is an ALStorage class that stores its data in memory
* buffers. Under real mode MS-DOS, buffers are limited to 64Kbytes.
* Under Windows, they can get a lot bigger. There are slight
* differences in operations between the the Windows and MS-DOS
* versions, so you will see some #ifdefs here and there.
*
* You can use ALMemory to work with a buffer of your own, or you
* can ask the class to allocate the memory for you. You can
* also change the ownership of the buffer in midstream, allowing
* you to take control of a buffer that the class has generated.
*
* DATA MEMBERS
*
* mfUserOwnsBuffer : If this flag is set, it indicates that the user
* owns the buffer, not the class. This means
* the class can't grow the buffer if it runs out
* of space, and it can't delete it in the
* ALMemory destructor.
*
* mhUserMemoryHandle : Under Windows, this member contains the handle
* of the Windows memory block that has been
* allocated
*
* muUserBufferSize : The actual size of the buffer, whether it is
* owned by the user or not. This is a size_t
* member under real mode DOS, and a long under
* Windows.
*
* mpcUserBuffer : A pointer to the buffer the class is presently
* using. The name User Buffer was probably a bad
* choice, because this is the pointer we use
* regardless of whether or not the user owns the
* buffer.
*
* MEMBER FUNCTIONS
*
* ALMemory() : The constructor, slightly different between DOS
* and Windows.
* ~ALMemory() : The virtual destructor.
* operator new() : Memory allocation operator, only used when the
* library is in a DLL. Note that this isn't the
* operator used to allocate the buffer, just the
* one to allocate a class object.
* Open() : Open the storage object for reading and writing.
* Create() : Create a new buffer to write to.
* Close() : Close the existing memory object.
* LoadBuffer() : Load a new block from the memory object into
* the I/O buffer.
* FlushBuffer() : Flush the contents of the I/O buffer, sending
* the contents into the memory object.
* Seek() : Seek to a new location in the memory object.
* Rename() : Give the object a new name. Names are pretty
* irrelevant for memory objects, feel free to use
* whatever you want here.
* UnRename() : Restore the old name.
* Delete() : Delete the memory object. It is gone forever.
* RenameToBackup() : Give the memory object an arbitrary new name.
* GrowUserBuffer() : A private function used to give us more space
* when the memory object is owner of the buffer.
*
* REVISION HISTORY
*
* May 26, 1994 1.0A : First release
*
*/
class AL_CLASS_TYPE ALMemory : public ALStorage {
/*
* Constructors, destructors, assignment operator, friends, declarations
*/
public :
#ifdef AL_WINDOWS_MEMORY
AL_PROTO ALMemory( const char AL_DLL_FAR *buffer_name = "",
char AL_HUGE *user_buffer = 0,
DWORD user_buffer_size = 0,
ALCase name_case = AL_MIXED );
#else
AL_PROTO ALMemory( const char AL_DLL_FAR *buffer_name = "",
char AL_DLL_FAR *user_buffer = 0,
int user_buffer_size = 0,
ALCase name_case = AL_MIXED );
#endif
virtual AL_PROTO ~ALMemory();
#if defined( AL_USING_DLL ) || defined( AL_BUILDING_DLL )
void AL_DLL_FAR * AL_PROTO operator new( size_t size );
#endif
/*
* As usual, I don't want the compiler to generate a default copy constructor,
* or an assignment operator here. I force it to back off by declaring them
* here. They do not exist!
*/
protected :
AL_PROTO ALMemory( ALMemory AL_DLL_FAR & );
ALMemory AL_DLL_FAR & AL_PROTO operator=( const ALMemory AL_DLL_FAR & );
/*
* Member functions, grouped by category.
*
*
* Protected member manipulation, used inside library, not for public use.
*/
protected :
/*
* The file I/O access public interface
*/
public :
virtual int AL_PROTO Open();
virtual int AL_PROTO Create();
virtual int AL_PROTO Close();
virtual int AL_PROTO LoadBuffer( long address );
virtual int AL_PROTO FlushBuffer();
virtual int AL_PROTO Seek( long address );
/*
* File name and underlying object manipulation public interface
*/
public :
virtual int AL_PROTO Rename( const char AL_DLL_FAR *new_name = 0,
int delete_on_clash = 1 );
virtual int AL_PROTO UnRename( int delete_on_clash = 1 );
virtual int AL_PROTO Delete();
virtual int AL_PROTO RenameToBackup( int delete_on_clash = 1 );
/*
* Unique to this class
*/
protected :
int AL_PROTO GrowUserBuffer( long minimum_new_size );
/*
* Data members
*/
protected :
public : /* Should some of these might be better off private */
int mfUserOwnsBuffer;
#ifdef AL_WINDOWS_MEMORY
HGLOBAL mhUserMemoryHandle;
long muUserBufferSize;
char AL_HUGE *mpcUserBuffer;
#else
size_t muUserBufferSize;
char AL_DLL_FAR *mpcUserBuffer;
#endif
AL_CLASS_TAG( _ALMemoryTag );
};
#endif /* #if defined( __cplusplus ) */
#endif /* #ifndef _MEMSTORE_H */