db2/os/os_rw.c

   1 /*-
   2  * See the file LICENSE for redistribution information.
   3  *
   4  * Copyright (c) 1997, 1998
   5  *      Sleepycat Software.  All rights reserved.
   6  */
   7
   8 #include "config.h"
   9
  10 #ifndef lint
  11 static const char sccsid[] = "@(#)os_rw.c       10.7 (Sleepycat) 4/10/98";
  12 #endif /* not lint */
  13
  14 #ifndef NO_SYSTEM_INCLUDES
  15 #include <sys/types.h>
  16
  17 #include <errno.h>
  18 #include <unistd.h>
  19 #endif
  20
  21 #include "db_int.h"
  22
  23 /*
  24  * __db_read --
  25  *      Read from a file handle.
  26  *
  27  * PUBLIC: int __db_read __P((int, void *, size_t, ssize_t *));
  28  */
  29 int
  30 __db_read(fd, addr, len, nrp)
  31         int fd;
  32         void *addr;
  33         size_t len;
  34         ssize_t *nrp;
  35 {
  36         size_t offset;
  37         ssize_t nr;
  38         u_int8_t *taddr;
  39
  40         for (taddr = addr,
  41             offset = 0; offset < len; taddr += nr, offset += nr) {
  42                 if ((nr = __os_read(fd, taddr, len - offset)) < 0)
  43                         return (errno);
  44                 if (nr == 0)
  45                         break;
  46         }
  47         *nrp = taddr - (u_int8_t *)addr;
  48         return (0);
  49 }
  50
  51 /*
  52  * __db_write --
  53  *      Write to a file handle.
  54  *
  55  * PUBLIC: int __db_write __P((int, void *, size_t, ssize_t *));
  56  */
  57 int
  58 __db_write(fd, addr, len, nwp)
  59         int fd;
  60         void *addr;
  61         size_t len;
  62         ssize_t *nwp;
  63 {
  64         size_t offset;
  65         ssize_t nw;
  66         u_int8_t *taddr;
  67
  68         for (taddr = addr,
  69             offset = 0; offset < len; taddr += nw, offset += nw)
  70                 if ((nw = __os_write(fd, taddr, len - offset)) < 0)
  71                         return (errno);
  72         *nwp = len;
  73         return (0);
  74 }