libspclient/read.c

   1 /*
   2  * Copyright (C) 2006 by Latchesar Ionkov <lucho@ionkov.net>
   3  *
   4  * Permission is hereby granted, free of charge, to any person obtaining a
   5  * copy of this software and associated documentation files (the "Software"),
   6  * to deal in the Software without restriction, including without limitation
   7  * the rights to use, copy, modify, merge, publish, distribute, sublicense,
   8  * and/or sell copies of the Software, and to permit persons to whom the
   9  * Software is furnished to do so, subject to the following conditions:
  10  *
  11  * The above copyright notice and this permission notice (including the next
  12  * paragraph) shall be included in all copies or substantial portions of the
  13  * Software.
  14  *
  15  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
  16  * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
  17  * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.  IN NO EVENT SHALL
  18  * LATCHESAR IONKOV AND/OR ITS SUPPLIERS BE LIABLE FOR ANY CLAIM, DAMAGES OR
  19  * OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE,
  20  * ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
  21  * DEALINGS IN THE SOFTWARE.
  22  */
  23 #include <stdlib.h>
  24 #include <stdio.h>
  25 #include <string.h>
  26 #include <unistd.h>
  27 #include <errno.h>
  28 #include "spfs.h"
  29 #include "spclient.h"
  30 #include "spcimpl.h"
  31
  32 int
  33 spc_read(Spcfid *fid, u8 *buf, u32 count, u64 offset)
  34 {
  35         int i, n, l;
  36         Spfcall *tc, *rc;
  37
  38         n = 0;
  39         while (n < count) {
  40                 i = count - n;
  41                 if (i > (fid->fsys->msize - IOHDRSZ))
  42                         i = fid->fsys->msize - IOHDRSZ;
  43
  44                 tc = sp_create_tread(fid->fid, offset + n, i);
  45                 if (spc_rpc(fid->fsys, tc, &rc) < 0) {
  46                         free(tc);
  47                         return -1;
  48                 }
  49
  50                 l = rc->count;
  51                 if (l > count)
  52                         l = count;
  53                 memmove(buf + n, rc->data, l);
  54                 free(rc);
  55
  56                 if (l == 0)
  57                         break;
  58
  59                 n += l;
  60         }
  61
  62         return n;
  63 }