usr/src/cmd/sendmail/db/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       10.11 (Sleepycat) 10/12/98";
  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 #include "os_jump.h"
  23
  24 /*
  25  * __os_io --
  26  *      Do an I/O.
  27  *
  28  * PUBLIC: int __os_io __P((DB_IO *, int, ssize_t *));
  29  */
  30 int
  31 __os_io(db_iop, op, niop)
  32         DB_IO *db_iop;
  33         int op;
  34         ssize_t *niop;
  35 {
  36         int ret;
  37
  38 #ifdef HAVE_PREAD
  39         switch (op) {
  40         case DB_IO_READ:
  41                 if (__db_jump.j_read != NULL)
  42                         goto slow;
  43                 *niop = pread(db_iop->fd_io, db_iop->buf,
  44                     db_iop->bytes, (off_t)db_iop->pgno * db_iop->pagesize);
  45                 break;
  46         case DB_IO_WRITE:
  47                 if (__db_jump.j_write != NULL)
  48                         goto slow;
  49                 *niop = pwrite(db_iop->fd_io, db_iop->buf,
  50                     db_iop->bytes, (off_t)db_iop->pgno * db_iop->pagesize);
  51                 break;
  52         }
  53         if (*niop == db_iop->bytes)
  54                 return (0);
  55 slow:
  56 #endif
  57         if (db_iop->mutexp != NULL)
  58                 (void)__db_mutex_lock(db_iop->mutexp, db_iop->fd_lock);
  59
  60         if ((ret = __os_seek(db_iop->fd_io,
  61             db_iop->pagesize, db_iop->pgno, 0, 0, SEEK_SET)) != 0)
  62                 goto err;
  63         switch (op) {
  64         case DB_IO_READ:
  65                 ret =
  66                     __os_read(db_iop->fd_io, db_iop->buf, db_iop->bytes, niop);
  67                 break;
  68         case DB_IO_WRITE:
  69                 ret =
  70                     __os_write(db_iop->fd_io, db_iop->buf, db_iop->bytes, niop);
  71                 break;
  72         }
  73
  74 err:    if (db_iop->mutexp != NULL)
  75                 (void)__db_mutex_unlock(db_iop->mutexp, db_iop->fd_lock);
  76
  77         return (ret);
  78
  79 }
  80
  81 /*
  82  * __os_read --
  83  *      Read from a file handle.
  84  *
  85  * PUBLIC: int __os_read __P((int, void *, size_t, ssize_t *));
  86  */
  87 int
  88 __os_read(fd, addr, len, nrp)
  89         int fd;
  90         void *addr;
  91         size_t len;
  92         ssize_t *nrp;
  93 {
  94         size_t offset;
  95         ssize_t nr;
  96         u_int8_t *taddr;
  97
  98         for (taddr = addr,
  99             offset = 0; offset < len; taddr += nr, offset += nr) {
 100                 if ((nr = __db_jump.j_read != NULL ?
 101                     __db_jump.j_read(fd, taddr, len - offset) :
 102                     read(fd, taddr, len - offset)) < 0)
 103                         return (errno);
 104                 if (nr == 0)
 105                         break;
 106         }
 107         *nrp = taddr - (u_int8_t *)addr;
 108         return (0);
 109 }
 110
 111 /*
 112  * __os_write --
 113  *      Write to a file handle.
 114  *
 115  * PUBLIC: int __os_write __P((int, void *, size_t, ssize_t *));
 116  */
 117 int
 118 __os_write(fd, addr, len, nwp)
 119         int fd;
 120         void *addr;
 121         size_t len;
 122         ssize_t *nwp;
 123 {
 124         size_t offset;
 125         ssize_t nw;
 126         u_int8_t *taddr;
 127
 128         for (taddr = addr,
 129             offset = 0; offset < len; taddr += nw, offset += nw)
 130                 if ((nw = __db_jump.j_write != NULL ?
 131                     __db_jump.j_write(fd, taddr, len - offset) :
 132                     write(fd, taddr, len - offset)) < 0)
 133                         return (errno);
 134         *nwp = len;
 135         return (0);
 136 }