apps/iso9660/sector.c

   1 /*
   2     iso9660 - An iso9660 CDI driver with Rockridge support
   3     Copyright (C) 2008  Janosch Gräf <janosch.graef@gmx.net>
   4
   5     This program is free software: you can redistribute it and/or modify
   6     it under the terms of the GNU Lesser General Public License as published by
   7     the Free Software Foundation, either version 3 of the License, or
   8     (at your option) any later version.
   9
  10     This program is distributed in the hope that it will be useful,
  11     but WITHOUT ANY WARRANTY; without even the implied warranty of
  12     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13     GNU Lesser General Public License for more details.
  14
  15     You should have received a copy of the GNU Lesser General Public License
  16     along with this program.  If not, see <http://www.gnu.org/licenses/>.
  17 */
  18
  19 #include <stdint.h>
  20
  21 #include "cdi/fs.h"
  22 #include "cdi/cache.h"
  23
  24 #include "iso9660def.h"
  25
  26 #include "iso9660_cdi.h"
  27
  28 /**
  29  * Reads data from device for cache
  30  *  @param cache CDI cache
  31  *  @param block Block to read
  32  *  @param count How many blocks to read
  33  *  @param dest Buffer to store data in
  34  *  @param prv Private data (CDI filesystem)
  35  */
  36 int iso9660_sector_read_cache(struct cdi_cache *cache,uint64_t block,size_t count,void *dest,void *prv) {
  37   debug("iso9660_sector_read_cache(0x%x,0x%x,0x%x,0x%x,0x%x,0x%x)\n",cache,block,count,dest,prv);
  38   uint64_t start = ((uint64_t)block)*ISO9660_DEFAULT_SECTOR_SIZE;
  39   size_t size = count*ISO9660_DEFAULT_SECTOR_SIZE;
  40   return iso9660_sector_read(prv,start,size,dest)/ISO9660_DEFAULT_SECTOR_SIZE;
  41 }
  42
  43 /**
  44  * Read data from resource
  45  *  @param res Resource to read data from
  46  *  @param pos Position in resource
  47  *  @param size How many bytes to read
  48  *  @param Buffer Buffer to store data in
  49  *  @return How many bytes read
  50  */
  51 size_t iso9660_read(struct iso9660_fs_res *res,size_t pos,size_t size,void *buffer) {
  52   size_t block = pos/res->voldesc->sector_size;
  53   size_t offset = pos%res->voldesc->sector_size;
  54   size_t rem_size = size;
  55
  56   while (rem_size>0) {
  57     //debug("Block: 0x%x\n",res->data_sector+block++);
  58     struct cdi_cache_block *cache_block = cdi_cache_block_get(res->cache,res->data_sector+block++);
  59     size_t cur_size = rem_size>res->voldesc->sector_size?res->voldesc->sector_size:rem_size;
  60     memcpy(buffer,cache_block->data+offset,cur_size);
  61     cdi_cache_block_release(res->cache,cache_block);
  62     buffer += cur_size;
  63     rem_size -= cur_size;
  64     offset = 0;
  65   }
  66
  67   return size;
  68 }
  69