1 /* 2 * media.h - 3 * 4 * Written by Eryk Vershen 5 */ 6 7 /* 8 * Copyright 1997,1998 by Apple Computer, Inc. 9 * All Rights Reserved 10 * 11 * Permission to use, copy, modify, and distribute this software and 12 * its documentation for any purpose and without fee is hereby granted, 13 * provided that the above copyright notice appears in all copies and 14 * that both the copyright notice and this permission notice appear in 15 * supporting documentation. 16 * 17 * APPLE COMPUTER DISCLAIMS ALL WARRANTIES WITH REGARD TO THIS SOFTWARE 18 * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS 19 * FOR A PARTICULAR PURPOSE. 20 * 21 * IN NO EVENT SHALL APPLE COMPUTER BE LIABLE FOR ANY SPECIAL, INDIRECT, OR 22 * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM 23 * LOSS OF USE, DATA OR PROFITS, WHETHER IN ACTION OF CONTRACT, 24 * NEGLIGENCE, OR OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION 25 * WITH THE USE OR PERFORMANCE OF THIS SOFTWARE. 26 */ 27 28 #ifndef __media__ 29 #define __media__ 30 31 32 /* 33 * Media is an abstraction of a disk device. 34 * 35 * A media object has the following visible attributes: 36 * 37 * a granularity (e.g. 512, 1024, 1, etc.) 38 * a total size in bytes 39 * 40 * And the following operations are available: 41 * 42 * open 43 * read @ byte offset for size in bytes 44 * write @ byte offset for size in bytes 45 * close 46 * 47 * XXX Should really split public media interface from "protected" interface. 48 */ 49 50 51 /* 52 * Defines 53 */ 54 55 56 /* 57 * Types 58 */ 59 /* those whose use media objects need just the pointer type */ 60 typedef struct media *MEDIA; 61 62 /* those who define media objects need the struct and internal routine types */ 63 typedef long (*media_read)(MEDIA m, long long offset, uint32_t count, void *address); 64 typedef long (*media_write)(MEDIA m, long long offset, uint32_t count, void *address); 65 typedef long (*media_close)(MEDIA m); 66 typedef long (*media_os_reload)(MEDIA m); 67 68 struct media { 69 long kind; /* kind of media - SCSI, IDE, etc. */ 70 uint32_t grain; /* granularity (offset & size) */ 71 long long size_in_bytes; /* offset granularity */ 72 media_read do_read; /* device specific routines */ 73 media_write do_write; 74 media_close do_close; 75 media_os_reload do_os_reload; 76 /* specific media kinds will add extra info */ 77 }; 78 79 /* those whose use media object iterators need just the pointer type */ 80 typedef struct media_iterator *MEDIA_ITERATOR; 81 82 /* those who define media object iterators need the struct and internal routine types */ 83 typedef void (*media_iterator_reset)(MEDIA_ITERATOR m); 84 typedef char* (*media_iterator_step)(MEDIA_ITERATOR m); 85 typedef void (*media_iterator_delete)(MEDIA_ITERATOR m); 86 87 typedef enum { 88 kInit, 89 kReset, 90 kIterating, 91 kEnd 92 } media_iterator_state; 93 94 struct media_iterator { 95 long kind; /* kind of media - SCSI, IDE, etc. */ 96 media_iterator_state state; /* init, reset, iterating, at_end */ 97 media_iterator_reset do_reset; /* device specific routines */ 98 media_iterator_step do_step; 99 media_iterator_delete do_delete; 100 /* specific media kinds will add extra info */ 101 }; 102 103 104 /* 105 * Global Constants 106 */ 107 108 109 /* 110 * Global Variables 111 */ 112 113 114 /* 115 * Forward declarations 116 */ 117 /* those whose use media objects need these routines */ 118 uint32_t media_granularity(MEDIA m); 119 long long media_total_size(MEDIA m); 120 long read_media(MEDIA m, long long offset, uint32_t count, void *address); 121 long write_media(MEDIA m, long long offset, uint32_t count, void *address); 122 void close_media(MEDIA m); 123 void os_reload_media(MEDIA m); 124 125 /* those who define media objects need these routines also */ 126 long allocate_media_kind(void); 127 MEDIA new_media(long size); 128 void delete_media(MEDIA m); 129 130 /* those whose use media object iterators need these routines */ 131 void reset_media_iterator(MEDIA_ITERATOR m); 132 char *step_media_iterator(MEDIA_ITERATOR m); 133 void delete_media_iterator(MEDIA_ITERATOR m); 134 135 /* those who define media object iterators need these routines also */ 136 MEDIA_ITERATOR new_media_iterator(long size); 137 void private_delete_media_iterator(MEDIA_ITERATOR m); 138 139 #endif /* __media__ */ 140