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media.h
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media.h
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/*
* media.h -
*
* Written by Eryk Vershen
*/
/*
* Copyright 1997,1998 by Apple Computer, Inc.
* All Rights Reserved
*
* Permission to use, copy, modify, and distribute this software and
* its documentation for any purpose and without fee is hereby granted,
* provided that the above copyright notice appears in all copies and
* that both the copyright notice and this permission notice appear in
* supporting documentation.
*
* APPLE COMPUTER DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE
* INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
* FOR A PARTICULAR PURPOSE.
*
* IN NO EVENT SHALL APPLE COMPUTER BE LIABLE FOR ANY SPECIAL, INDIRECT, OR
* CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
* LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT,
* NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION
* WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
#ifndef __media__
#define __media__
/*
* Media is an abstraction of a disk device.
*
* A media object has the following visible attributes:
*
* a granularity (e.g. 512, 1024, 1, etc.)
* a total size in bytes
*
* And the following operations are available:
*
* open
* read @ byte offset for size in bytes
* write @ byte offset for size in bytes
* close
*
* XXX Should really split public media interface from "protected" interface.
*/
/*
* Defines
*/
/*
* Types
*/
/* those whose use media objects need just the pointer type */
typedef struct media *MEDIA;
/* those who define media objects need the struct and internal routine types */
typedef long (*media_read)(MEDIA m, long long offset, unsigned long count, void *address);
typedef long (*media_write)(MEDIA m, long long offset, unsigned long count, void *address);
typedef long (*media_close)(MEDIA m);
typedef long (*media_os_reload)(MEDIA m);
struct media {
long kind; /* kind of media - SCSI, IDE, etc. */
unsigned long grain; /* granularity (offset & size) */
long long size_in_bytes; /* offset granularity */
media_read do_read; /* device specific routines */
media_write do_write;
media_close do_close;
media_os_reload do_os_reload;
/* specific media kinds will add extra info */
};
/* those whose use media object iterators need just the pointer type */
typedef struct media_iterator *MEDIA_ITERATOR;
/* those who define media object iterators need the struct and internal routine types */
typedef void (*media_iterator_reset)(MEDIA_ITERATOR m);
typedef char* (*media_iterator_step)(MEDIA_ITERATOR m);
typedef void (*media_iterator_delete)(MEDIA_ITERATOR m);
typedef enum {
kInit,
kReset,
kIterating,
kEnd
} media_iterator_state;
struct media_iterator {
long kind; /* kind of media - SCSI, IDE, etc. */
media_iterator_state state; /* init, reset, iterating, at_end */
media_iterator_reset do_reset; /* device specific routines */
media_iterator_step do_step;
media_iterator_delete do_delete;
/* specific media kinds will add extra info */
};
/*
* Global Constants
*/
/*
* Global Variables
*/
/*
* Forward declarations
*/
/* those whose use media objects need these routines */
unsigned long media_granularity(MEDIA m);
long long media_total_size(MEDIA m);
long read_media(MEDIA m, long long offset, unsigned long count, void *address);
long write_media(MEDIA m, long long offset, unsigned long count, void *address);
void close_media(MEDIA m);
void os_reload_media(MEDIA m);
/* those who define media objects need these routines also */
long allocate_media_kind(void);
MEDIA new_media(long size);
void delete_media(MEDIA m);
/* those whose use media object iterators need these routines */
void reset_media_iterator(MEDIA_ITERATOR m);
char *step_media_iterator(MEDIA_ITERATOR m);
void delete_media_iterator(MEDIA_ITERATOR m);
/* those who define media object iterators need these routines also */
MEDIA_ITERATOR new_media_iterator(long size);
void private_delete_media_iterator(MEDIA_ITERATOR m);
#endif /* __media__ */