db/recno/FreeBSD/rec_open.c

   1 /*-
   2  * Copyright (c) 1990, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * This code is derived from software contributed to Berkeley by
   6  * Mike Olson.
   7  *
   8  * Redistribution and use in source and binary forms, with or without
   9  * modification, are permitted provided that the following conditions
  10  * are met:
  11  * 1. Redistributions of source code must retain the above copyright
  12  *    notice, this list of conditions and the following disclaimer.
  13  * 2. Redistributions in binary form must reproduce the above copyright
  14  *    notice, this list of conditions and the following disclaimer in the
  15  *    documentation and/or other materials provided with the distribution.
  16  * 4. Neither the name of the University nor the names of its contributors
  17  *    may be used to endorse or promote products derived from this software
  18  *    without specific prior written permission.
  19  *
  20  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  21  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  23  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  24  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  25  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  26  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  27  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  28  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  29  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  30  * SUCH DAMAGE.
  31  */
  32
  33 #if defined(LIBC_SCCS) && !defined(lint)
  34 static char sccsid[] = "@(#)rec_open.c  8.10 (Berkeley) 9/1/94";
  35 #endif /* LIBC_SCCS and not lint */
  36 #include <sys/cdefs.h>
  37 __FBSDID("$FreeBSD: src/lib/libc/db/recno/rec_open.c,v 1.9 2009/03/04 00:58:04 delphij Exp $");
  38
  39 #include "namespace.h"
  40 #include <sys/types.h>
  41 #include <sys/mman.h>
  42 #include <sys/stat.h>
  43
  44 #include <errno.h>
  45 #include <fcntl.h>
  46 #include <limits.h>
  47 #include <stddef.h>
  48 #include <stdio.h>
  49 #include <unistd.h>
  50 #include "un-namespace.h"
  51
  52 #include <db.h>
  53 #include "recno.h"
  54
  55 DB *
  56 __rec_open(const char *fname, int flags, int mode, const RECNOINFO *openinfo,
  57     int dflags)
  58 {
  59         BTREE *t;
  60         BTREEINFO btopeninfo;
  61         DB *dbp;
  62         PAGE *h;
  63         struct stat sb;
  64         int rfd, sverrno;
  65
  66         /* Open the user's file -- if this fails, we're done. */
  67         if (fname != NULL && (rfd = _open(fname, flags, mode)) < 0)
  68                 return (NULL);
  69
  70         /* Create a btree in memory (backed by disk). */
  71         dbp = NULL;
  72         if (openinfo) {
  73                 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT))
  74                         goto einval;
  75                 btopeninfo.flags = 0;
  76                 btopeninfo.cachesize = openinfo->cachesize;
  77                 btopeninfo.maxkeypage = 0;
  78                 btopeninfo.minkeypage = 0;
  79                 btopeninfo.psize = openinfo->psize;
  80                 btopeninfo.compare = NULL;
  81                 btopeninfo.prefix = NULL;
  82                 btopeninfo.lorder = openinfo->lorder;
  83                 dbp = __bt_open(openinfo->bfname,
  84                     O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags);
  85         } else
  86                 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags);
  87         if (dbp == NULL)
  88                 goto err;
  89
  90         /*
  91          * Some fields in the tree structure are recno specific.  Fill them
  92          * in and make the btree structure look like a recno structure.  We
  93          * don't change the bt_ovflsize value, it's close enough and slightly
  94          * bigger.
  95          */
  96         t = dbp->internal;
  97         if (openinfo) {
  98                 if (openinfo->flags & R_FIXEDLEN) {
  99                         F_SET(t, R_FIXLEN);
 100                         t->bt_reclen = openinfo->reclen;
 101                         if (t->bt_reclen == 0)
 102                                 goto einval;
 103                 }
 104                 t->bt_bval = openinfo->bval;
 105         } else
 106                 t->bt_bval = '\n';
 107
 108         F_SET(t, R_RECNO);
 109         if (fname == NULL)
 110                 F_SET(t, R_EOF | R_INMEM);
 111         else
 112                 t->bt_rfd = rfd;
 113
 114         if (fname != NULL) {
 115                 /*
 116                  * In 4.4BSD, stat(2) returns true for ISSOCK on pipes.
 117                  * Unfortunately, that's not portable, so we use lseek
 118                  * and check the errno values.
 119                  */
 120                 errno = 0;
 121                 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) {
 122                         switch (flags & O_ACCMODE) {
 123                         case O_RDONLY:
 124                                 F_SET(t, R_RDONLY);
 125                                 break;
 126                         default:
 127                                 goto einval;
 128                         }
 129 slow:                   if ((t->bt_rfp = fdopen(rfd, "r")) == NULL)
 130                                 goto err;
 131                         F_SET(t, R_CLOSEFP);
 132                         t->bt_irec =
 133                             F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
 134                 } else {
 135                         switch (flags & O_ACCMODE) {
 136                         case O_RDONLY:
 137                                 F_SET(t, R_RDONLY);
 138                                 break;
 139                         case O_RDWR:
 140                                 break;
 141                         default:
 142                                 goto einval;
 143                         }
 144
 145                         if (_fstat(rfd, &sb))
 146                                 goto err;
 147                         /*
 148                          * Kluge -- we'd like to test to see if the file is too
 149                          * big to mmap.  Since, we don't know what size or type
 150                          * off_t's or size_t's are, what the largest unsigned
 151                          * integral type is, or what random insanity the local
 152                          * C compiler will perpetrate, doing the comparison in
 153                          * a portable way is flatly impossible.  Hope that mmap
 154                          * fails if the file is too large.
 155                          */
 156                         if (sb.st_size == 0)
 157                                 F_SET(t, R_EOF);
 158                         else {
 159 #ifdef MMAP_NOT_AVAILABLE
 160                                 /*
 161                                  * XXX
 162                                  * Mmap doesn't work correctly on many current
 163                                  * systems.  In particular, it can fail subtly,
 164                                  * with cache coherency problems.  Don't use it
 165                                  * for now.
 166                                  */
 167                                 t->bt_msize = sb.st_size;
 168                                 if ((t->bt_smap = mmap(NULL, t->bt_msize,
 169                                     PROT_READ, MAP_PRIVATE, rfd,
 170                                     (off_t)0)) == MAP_FAILED)
 171                                         goto slow;
 172                                 t->bt_cmap = t->bt_smap;
 173                                 t->bt_emap = t->bt_smap + sb.st_size;
 174                                 t->bt_irec = F_ISSET(t, R_FIXLEN) ?
 175                                     __rec_fmap : __rec_vmap;
 176                                 F_SET(t, R_MEMMAPPED);
 177 #else
 178                                 goto slow;
 179 #endif
 180                         }
 181                 }
 182         }
 183
 184         /* Use the recno routines. */
 185         dbp->close = __rec_close;
 186         dbp->del = __rec_delete;
 187         dbp->fd = __rec_fd;
 188         dbp->get = __rec_get;
 189         dbp->put = __rec_put;
 190         dbp->seq = __rec_seq;
 191         dbp->sync = __rec_sync;
 192
 193         /* If the root page was created, reset the flags. */
 194         if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
 195                 goto err;
 196         if ((h->flags & P_TYPE) == P_BLEAF) {
 197                 F_CLR(h, P_TYPE);
 198                 F_SET(h, P_RLEAF);
 199                 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
 200         } else
 201                 mpool_put(t->bt_mp, h, 0);
 202
 203         if (openinfo && openinfo->flags & R_SNAPSHOT &&
 204             !F_ISSET(t, R_EOF | R_INMEM) &&
 205             t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
 206                 goto err;
 207         return (dbp);
 208
 209 einval: errno = EINVAL;
 210 err:    sverrno = errno;
 211         if (dbp != NULL)
 212                 (void)__bt_close(dbp);
 213         if (fname != NULL)
 214                 (void)_close(rfd);
 215         errno = sverrno;
 216         return (NULL);
 217 }
 218
 219 int
 220 __rec_fd(const DB *dbp)
 221 {
 222         BTREE *t;
 223
 224         t = dbp->internal;
 225
 226         /* Toss any page pinned across calls. */
 227         if (t->bt_pinned != NULL) {
 228                 mpool_put(t->bt_mp, t->bt_pinned, 0);
 229                 t->bt_pinned = NULL;
 230         }
 231
 232         /* In-memory database can't have a file descriptor. */
 233         if (F_ISSET(t, R_INMEM)) {
 234                 errno = ENOENT;
 235                 return (-1);
 236         }
 237         return (t->bt_rfd);
 238 }