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 * 3. 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 * @(#)rec_open.c 8.10 (Berkeley) 9/1/94
33 * $FreeBSD: head/lib/libc/db/recno/rec_open.c 189327 2009-03-04 00:58:04Z delphij $
34 */
35
36 #include "namespace.h"
37 #include <sys/types.h>
38 #include <sys/mman.h>
39 #include <sys/stat.h>
40
41 #include <errno.h>
42 #include <fcntl.h>
43 #include <limits.h>
44 #include <stddef.h>
45 #include <stdio.h>
46 #include <unistd.h>
47 #include "un-namespace.h"
48
49 #include <db.h>
50 #include "recno.h"
51
52 DB *
__rec_open(const char * fname,int flags,mode_t mode,const RECNOINFO * openinfo,int dflags)53 __rec_open(const char *fname, int flags, mode_t mode, const RECNOINFO *openinfo,
54 int dflags)
55 {
56 BTREE *t;
57 BTREEINFO btopeninfo;
58 DB *dbp;
59 PAGE *h;
60 struct stat sb;
61 int rfd, sverrno;
62
63 /* Open the user's file -- if this fails, we're done. */
64 if (fname != NULL && (rfd = _open(fname, flags | O_CLOEXEC, mode)) < 0)
65 return (NULL);
66
67 /* Create a btree in memory (backed by disk). */
68 dbp = NULL;
69 if (openinfo) {
70 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT))
71 goto einval;
72 btopeninfo.flags = 0;
73 btopeninfo.cachesize = openinfo->cachesize;
74 btopeninfo.maxkeypage = 0;
75 btopeninfo.minkeypage = 0;
76 btopeninfo.psize = openinfo->psize;
77 btopeninfo.compare = NULL;
78 btopeninfo.prefix = NULL;
79 btopeninfo.lorder = openinfo->lorder;
80 dbp = __bt_open(openinfo->bfname,
81 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags);
82 } else
83 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags);
84 if (dbp == NULL)
85 goto err;
86
87 /*
88 * Some fields in the tree structure are recno specific. Fill them
89 * in and make the btree structure look like a recno structure. We
90 * don't change the bt_ovflsize value, it's close enough and slightly
91 * bigger.
92 */
93 t = dbp->internal;
94 if (openinfo) {
95 if (openinfo->flags & R_FIXEDLEN) {
96 F_SET(t, R_FIXLEN);
97 t->bt_reclen = openinfo->reclen;
98 if (t->bt_reclen == 0)
99 goto einval;
100 }
101 t->bt_bval = openinfo->bval;
102 } else
103 t->bt_bval = '\n';
104
105 F_SET(t, R_RECNO);
106 if (fname == NULL)
107 F_SET(t, R_EOF | R_INMEM);
108 else
109 t->bt_rfd = rfd;
110
111 if (fname != NULL) {
112 /*
113 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes.
114 * Unfortunately, that's not portable, so we use lseek
115 * and check the errno values.
116 */
117 errno = 0;
118 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) {
119 switch (flags & O_ACCMODE) {
120 case O_RDONLY:
121 F_SET(t, R_RDONLY);
122 break;
123 default:
124 goto einval;
125 }
126 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL)
127 goto err;
128 F_SET(t, R_CLOSEFP);
129 t->bt_irec =
130 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
131 } else {
132 switch (flags & O_ACCMODE) {
133 case O_RDONLY:
134 F_SET(t, R_RDONLY);
135 break;
136 case O_RDWR:
137 break;
138 default:
139 goto einval;
140 }
141
142 if (_fstat(rfd, &sb))
143 goto err;
144 /*
145 * Kluge -- we'd like to test to see if the file is too
146 * big to mmap. Since, we don't know what size or type
147 * off_t's or size_t's are, what the largest unsigned
148 * integral type is, or what random insanity the local
149 * C compiler will perpetrate, doing the comparison in
150 * a portable way is flatly impossible. Hope that mmap
151 * fails if the file is too large.
152 */
153 if (sb.st_size == 0)
154 F_SET(t, R_EOF);
155 else {
156 #ifdef MMAP_NOT_AVAILABLE
157 /*
158 * XXX
159 * Mmap doesn't work correctly on many current
160 * systems. In particular, it can fail subtly,
161 * with cache coherency problems. Don't use it
162 * for now.
163 */
164 t->bt_msize = sb.st_size;
165 if ((t->bt_smap = mmap(NULL, t->bt_msize,
166 PROT_READ, MAP_PRIVATE, rfd,
167 (off_t)0)) == MAP_FAILED)
168 goto slow;
169 t->bt_cmap = t->bt_smap;
170 t->bt_emap = t->bt_smap + sb.st_size;
171 t->bt_irec = F_ISSET(t, R_FIXLEN) ?
172 __rec_fmap : __rec_vmap;
173 F_SET(t, R_MEMMAPPED);
174 #else
175 goto slow;
176 #endif
177 }
178 }
179 }
180
181 /* Use the recno routines. */
182 dbp->close = __rec_close;
183 dbp->del = __rec_delete;
184 dbp->fd = __rec_fd;
185 dbp->get = __rec_get;
186 dbp->put = __rec_put;
187 dbp->seq = __rec_seq;
188 dbp->sync = __rec_sync;
189
190 /* If the root page was created, reset the flags. */
191 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
192 goto err;
193 if ((h->flags & P_TYPE) == P_BLEAF) {
194 F_CLR(h, P_TYPE);
195 F_SET(h, P_RLEAF);
196 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
197 } else
198 mpool_put(t->bt_mp, h, 0);
199
200 if (openinfo && openinfo->flags & R_SNAPSHOT &&
201 !F_ISSET(t, R_EOF | R_INMEM) &&
202 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
203 goto err;
204 return (dbp);
205
206 einval: errno = EINVAL;
207 err: sverrno = errno;
208 if (dbp != NULL)
209 __bt_close(dbp);
210 if (fname != NULL)
211 _close(rfd);
212 errno = sverrno;
213 return (NULL);
214 }
215
216 int
__rec_fd(const DB * dbp)217 __rec_fd(const DB *dbp)
218 {
219 BTREE *t;
220
221 t = dbp->internal;
222
223 /* Toss any page pinned across calls. */
224 if (t->bt_pinned != NULL) {
225 mpool_put(t->bt_mp, t->bt_pinned, 0);
226 t->bt_pinned = NULL;
227 }
228
229 /* In-memory database can't have a file descriptor. */
230 if (F_ISSET(t, R_INMEM)) {
231 errno = ENOENT;
232 return (-1);
233 }
234 return (t->bt_rfd);
235 }
236