dist/pdisk/media.c

   1 /*
   2  * media.c -
   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
  29 // for printf()
  30 #include <stdio.h>
  31 // for malloc() & free()
  32 #include <stdlib.h>
  33
  34 #include "media.h"
  35
  36
  37 /*
  38  * Defines
  39  */
  40
  41
  42 /*
  43  * Types
  44  */
  45
  46
  47 /*
  48  * Global Constants
  49  */
  50
  51
  52 /*
  53  * Global Variables
  54  */
  55 static long media_kind = 0;
  56
  57 /*
  58  * Forward declarations
  59  */
  60
  61
  62 /*
  63  * Routines
  64  */
  65 long
  66 allocate_media_kind(void)
  67 {
  68     media_kind++;
  69     return media_kind;
  70 }
  71
  72
  73 MEDIA
  74 new_media(long size)
  75 {
  76     return (MEDIA) malloc(size);
  77 }
  78
  79
  80 void
  81 delete_media(MEDIA m)
  82 {
  83     if (m == 0) {
  84         return;
  85     }
  86     free(m);
  87 }
  88
  89
  90 unsigned long
  91 media_granularity(MEDIA m)
  92 {
  93     if (m == 0) {
  94         return 0;
  95     } else {
  96         return m->grain;
  97     }
  98 }
  99
 100
 101 long long
 102 media_total_size(MEDIA m)
 103 {
 104     if (m == 0) {
 105         return 0;
 106     } else {
 107         return m->size_in_bytes;
 108     }
 109 }
 110
 111
 112 long
 113 read_media(MEDIA m, long long offset, unsigned long count, void *address)
 114 {
 115     long result;
 116
 117     if (m != 0 && m->do_read != 0) {
 118         //printf("media: read type %d, offset %Ld, count %d\n\t", m->kind, offset, count);
 119         result = (*m->do_read)(m, offset, count, address);
 120         //printf(" - returns %d\n", result);
 121         return result;
 122     } else {
 123         return 0;
 124     }
 125 }
 126
 127
 128 long
 129 write_media(MEDIA m, long long offset, unsigned long count, void *address)
 130 {
 131     long result;
 132
 133     if (m != 0 && m->do_write != 0) {
 134         //printf("media: write type %d, offset %Ld, count %d\n\t", m->kind, offset, count);
 135         result = (*m->do_write)(m, offset, count, address);
 136         //printf(" - returns %d\n", result);
 137         return result;
 138     } else {
 139         return 0;
 140     }
 141 }
 142
 143
 144 void
 145 close_media(MEDIA m)
 146 {
 147     if (m == 0) {
 148         return;
 149     }
 150     if (m->kind != 0) {
 151         if (m->do_close != 0) {
 152             (*m->do_close)(m);
 153         }
 154         m->kind = 0;
 155         delete_media(m);
 156     }
 157 }
 158
 159
 160 void
 161 os_reload_media(MEDIA m)
 162 {
 163     if (m != 0 && m->do_os_reload != 0) {
 164         (*m->do_os_reload)(m);
 165     }
 166 }
 167
 168
 169 #if !defined(__linux__) && !defined(__unix__)
 170 #pragma mark -
 171 #endif
 172
 173
 174
 175 MEDIA_ITERATOR
 176 new_media_iterator(long size)
 177 {
 178     return (MEDIA_ITERATOR) malloc(size);
 179 }
 180
 181
 182 void
 183 private_delete_media_iterator(MEDIA_ITERATOR m)
 184 {
 185     if (m == 0) {
 186         return;
 187     }
 188     free(m);
 189 }
 190
 191
 192 void
 193 reset_media_iterator(MEDIA_ITERATOR m)
 194 {
 195     if (m != 0 && m->do_reset != 0) {
 196         (*m->do_reset)(m);
 197     }
 198 }
 199
 200
 201 char *
 202 step_media_iterator(MEDIA_ITERATOR m)
 203 {
 204     char *result;
 205
 206     if (m != 0 && m->do_step != 0) {
 207         result = (*m->do_step)(m);
 208     } else {
 209         result = 0;
 210     }
 211     return result;
 212 }
 213
 214
 215 void
 216 delete_media_iterator(MEDIA_ITERATOR m)
 217 {
 218     if (m == 0) {
 219         return;
 220     }
 221     if (m->kind != 0) {
 222         if (m->do_delete != 0) {
 223             (*m->do_delete)(m);
 224         }
 225         m->kind = 0;
 226         private_delete_media_iterator(m);
 227     }
 228 }