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