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. All advertising materials mentioning features or use of this software
17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
23 *
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
28 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
34 * SUCH DAMAGE.
35 */
36
37 #if defined(LIBC_SCCS) && !defined(lint)
38 static char sccsid[] = "@(#)rec_open.c 8.12 (Berkeley) 11/18/94";
39 #endif /* LIBC_SCCS and not lint */
40
41 #include <sys/types.h>
42 #ifdef RECNO_USE_MMAP
43 #include <sys/mman.h>
44 #endif
45 #include <sys/stat.h>
46
47 #include <errno.h>
48 #include <fcntl.h>
49 #include <limits.h>
50 #include <stddef.h>
51 #include <stdio.h>
52 #include <unistd.h>
53
54 #include "db-int.h"
55 #include "recno.h"
56
57 DB *
__rec_open(fname,flags,mode,openinfo,dflags)58 __rec_open(fname, flags, mode, openinfo, dflags)
59 const char *fname;
60 int flags, mode, dflags;
61 const RECNOINFO *openinfo;
62 {
63 BTREE *t;
64 BTREEINFO btopeninfo;
65 DB *dbp;
66 PAGE *h;
67 struct stat sb;
68 int rfd, sverrno;
69
70 /* Open the user's file -- if this fails, we're done. */
71 if (fname != NULL && (rfd = open(fname, flags | O_BINARY, mode)) < 0)
72 return (NULL);
73
74 /* Create a btree in memory (backed by disk). */
75 dbp = NULL;
76 if (openinfo) {
77 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT))
78 goto einval;
79 btopeninfo.flags = 0;
80 btopeninfo.cachesize = openinfo->cachesize;
81 btopeninfo.maxkeypage = 0;
82 btopeninfo.minkeypage = 0;
83 btopeninfo.psize = openinfo->psize;
84 btopeninfo.compare = NULL;
85 btopeninfo.prefix = NULL;
86 btopeninfo.lorder = openinfo->lorder;
87 dbp = __bt_open(openinfo->bfname,
88 O_RDWR | O_BINARY, S_IRUSR | S_IWUSR, &btopeninfo, dflags);
89 } else
90 dbp = __bt_open(NULL, O_RDWR | O_BINARY, S_IRUSR | S_IWUSR, NULL, dflags);
91 if (dbp == NULL)
92 goto err;
93
94 /*
95 * Some fields in the tree structure are recno specific. Fill them
96 * in and make the btree structure look like a recno structure. We
97 * don't change the bt_ovflsize value, it's close enough and slightly
98 * bigger.
99 */
100 t = dbp->internal;
101 if (openinfo) {
102 if (openinfo->flags & R_FIXEDLEN) {
103 F_SET(t, R_FIXLEN);
104 t->bt_reclen = openinfo->reclen;
105 if (t->bt_reclen == 0)
106 goto einval;
107 }
108 t->bt_bval = openinfo->bval;
109 } else
110 t->bt_bval = '\n';
111
112 F_SET(t, R_RECNO);
113 if (fname == NULL)
114 F_SET(t, R_EOF | R_INMEM);
115 else
116 t->bt_rfd = rfd;
117
118 if (fname != NULL) {
119 /*
120 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes.
121 * Unfortunately, that's not portable, so we use lseek
122 * and check the errno values.
123 */
124 errno = 0;
125 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) {
126 switch (flags & O_ACCMODE) {
127 case O_RDONLY:
128 F_SET(t, R_RDONLY);
129 break;
130 default:
131 goto einval;
132 }
133 slow: if ((t->bt_rfp = fdopen(rfd, "rb")) == NULL)
134 goto err;
135 F_SET(t, R_CLOSEFP);
136 t->bt_irec =
137 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
138 } else {
139 switch (flags & O_ACCMODE) {
140 case O_RDONLY:
141 F_SET(t, R_RDONLY);
142 break;
143 case O_RDWR:
144 break;
145 default:
146 goto einval;
147 }
148
149 if (fstat(rfd, &sb))
150 goto err;
151 /*
152 * Kluge -- we'd like to test to see if the file is too
153 * big to mmap. Since, we don't know what size or type
154 * off_t's or size_t's are, what the largest unsigned
155 * integral type is, or what random insanity the local
156 * C compiler will perpetrate, doing the comparison in
157 * a portable way is flatly impossible. Hope that mmap
158 * fails if the file is too large.
159 */
160 if (sb.st_size == 0)
161 F_SET(t, R_EOF);
162 else {
163 #ifdef RECNO_USE_MMAP
164 /*
165 * XXX
166 * Mmap doesn't work correctly on many current
167 * systems. In particular, it can fail subtly,
168 * with cache coherency problems. Don't use it
169 * for now.
170 */
171 t->bt_msize = sb.st_size;
172 if ((t->bt_smap = mmap(NULL, t->bt_msize,
173 PROT_READ, MAP_PRIVATE, rfd,
174 (off_t)0)) == (caddr_t)-1)
175 goto slow;
176 t->bt_cmap = t->bt_smap;
177 t->bt_emap = t->bt_smap + sb.st_size;
178 t->bt_irec = F_ISSET(t, R_FIXLEN) ?
179 __rec_fmap : __rec_vmap;
180 F_SET(t, R_MEMMAPPED);
181 #else
182 goto slow;
183 #endif
184 }
185 }
186 }
187
188 /* Use the recno routines. */
189 dbp->close = __rec_close;
190 dbp->del = __rec_delete;
191 dbp->fd = __rec_fd;
192 dbp->get = __rec_get;
193 dbp->put = __rec_put;
194 dbp->seq = __rec_seq;
195 dbp->sync = __rec_sync;
196
197 /* If the root page was created, reset the flags. */
198 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
199 goto err;
200 if ((h->flags & P_TYPE) == P_BLEAF) {
201 F_CLR(h, P_TYPE);
202 F_SET(h, P_RLEAF);
203 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
204 } else
205 mpool_put(t->bt_mp, h, 0);
206
207 if (openinfo && openinfo->flags & R_SNAPSHOT &&
208 !F_ISSET(t, R_EOF | R_INMEM) &&
209 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
210 goto err;
211 return (dbp);
212
213 einval: errno = EINVAL;
214 err: sverrno = errno;
215 if (dbp != NULL)
216 (void)__bt_close(dbp);
217 if (fname != NULL)
218 (void)close(rfd);
219 errno = sverrno;
220 return (NULL);
221 }
222
223 int
__rec_fd(dbp)224 __rec_fd(dbp)
225 const DB *dbp;
226 {
227 BTREE *t;
228
229 t = dbp->internal;
230
231 /* Toss any page pinned across calls. */
232 if (t->bt_pinned != NULL) {
233 mpool_put(t->bt_mp, t->bt_pinned, 0);
234 t->bt_pinned = NULL;
235 }
236
237 /* In-memory database can't have a file descriptor. */
238 if (F_ISSET(t, R_INMEM)) {
239 errno = ENOENT;
240 return (-1);
241 }
242 return (t->bt_rfd);
243 }
244