1 /* $NetBSD: rec_open.c,v 1.20 2013/12/01 00:22:48 christos Exp $ */
2
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 HAVE_NBTOOL_CONFIG_H
36 #include "nbtool_config.h"
37 #endif
38
39 #include <sys/cdefs.h>
40 __RCSID("$NetBSD: rec_open.c,v 1.20 2013/12/01 00:22:48 christos Exp $");
41
42 #include "namespace.h"
43 #include <sys/types.h>
44 #include <sys/mman.h>
45 #include <sys/stat.h>
46
47 #include <assert.h>
48 #include <errno.h>
49 #include <fcntl.h>
50 #include <limits.h>
51 #include <stddef.h>
52 #include <stdio.h>
53 #include <unistd.h>
54
55 #include <db.h>
56 #include "recno.h"
57
58 DB *
__rec_open(const char * fname,int flags,mode_t mode,const RECNOINFO * openinfo,int dflags)59 __rec_open(const char *fname, int flags, mode_t mode, const RECNOINFO *openinfo,
60 int dflags)
61 {
62 BTREE *t;
63 BTREEINFO btopeninfo;
64 DB *dbp;
65 PAGE *h;
66 struct stat sb;
67 int rfd = -1; /* pacify gcc */
68 int sverrno;
69
70 dbp = NULL;
71 /* Open the user's file -- if this fails, we're done. */
72 if (fname != NULL) {
73 if ((rfd = __dbopen(fname, flags, mode, NULL)) == -1)
74 return NULL;
75 }
76
77 /* Create a btree in memory (backed by disk). */
78 if (openinfo) {
79 if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT))
80 goto einval;
81 btopeninfo.flags = 0;
82 btopeninfo.cachesize = openinfo->cachesize;
83 btopeninfo.maxkeypage = 0;
84 btopeninfo.minkeypage = 0;
85 btopeninfo.psize = openinfo->psize;
86 btopeninfo.compare = NULL;
87 btopeninfo.prefix = NULL;
88 btopeninfo.lorder = openinfo->lorder;
89 dbp = __bt_open(openinfo->bfname,
90 O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags);
91 } else
92 dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags);
93 if (dbp == NULL)
94 goto err;
95
96 /*
97 * Some fields in the tree structure are recno specific. Fill them
98 * in and make the btree structure look like a recno structure. We
99 * don't change the bt_ovflsize value, it's close enough and slightly
100 * bigger.
101 */
102 t = dbp->internal;
103 if (openinfo) {
104 if (openinfo->flags & R_FIXEDLEN) {
105 F_SET(t, R_FIXLEN);
106 t->bt_reclen = openinfo->reclen;
107 if (t->bt_reclen == 0)
108 goto einval;
109 }
110 t->bt_bval = openinfo->bval;
111 } else
112 t->bt_bval = '\n';
113
114 F_SET(t, R_RECNO);
115 if (fname == NULL)
116 F_SET(t, R_EOF | R_INMEM);
117 else
118 t->bt_rfd = rfd;
119
120 if (fname != NULL) {
121 /*
122 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes.
123 * Unfortunately, that's not portable, so we use lseek
124 * and check the errno values.
125 */
126 errno = 0;
127 if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) {
128 switch (flags & O_ACCMODE) {
129 case O_RDONLY:
130 F_SET(t, R_RDONLY);
131 break;
132 default:
133 goto einval;
134 }
135 slow: if ((t->bt_rfp = fdopen(rfd, "r")) == NULL)
136 goto err;
137 F_SET(t, R_CLOSEFP);
138 t->bt_irec =
139 F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
140 } else {
141 switch (flags & O_ACCMODE) {
142 case O_RDONLY:
143 F_SET(t, R_RDONLY);
144 break;
145 case O_RDWR:
146 break;
147 default:
148 goto einval;
149 }
150
151 if (fstat(rfd, &sb))
152 goto err;
153 /*
154 * Kluge -- we'd like to test to see if the file is too
155 * big to mmap. Since, we don't know what size or type
156 * off_t's or size_t's are, what the largest unsigned
157 * integral type is, or what random insanity the local
158 * C compiler will perpetrate, doing the comparison in
159 * a portable way is flatly impossible. Hope that mmap
160 * fails if the file is too large.
161 */
162 if (sb.st_size == 0)
163 F_SET(t, R_EOF);
164 else {
165 #ifdef MMAP_NOT_AVAILABLE
166 /*
167 * XXX
168 * Mmap doesn't work correctly on many current
169 * systems. In particular, it can fail subtly,
170 * with cache coherency problems. Don't use it
171 * for now.
172 */
173 t->bt_msize = sb.st_size;
174 if ((t->bt_smap = mmap(NULL, t->bt_msize,
175 PROT_READ, MAP_FILE | MAP_PRIVATE, rfd,
176 (off_t)0)) == (caddr_t)-1)
177 goto slow;
178 t->bt_cmap = t->bt_smap;
179 t->bt_emap = t->bt_smap + sb.st_size;
180 t->bt_irec = F_ISSET(t, R_FIXLEN) ?
181 __rec_fmap : __rec_vmap;
182 F_SET(t, R_MEMMAPPED);
183 #else
184 goto slow;
185 #endif
186 }
187 }
188 }
189
190 /* Use the recno routines. */
191 dbp->close = __rec_close;
192 dbp->del = __rec_delete;
193 dbp->fd = __rec_fd;
194 dbp->get = __rec_get;
195 dbp->put = __rec_put;
196 dbp->seq = __rec_seq;
197 dbp->sync = __rec_sync;
198
199 /* If the root page was created, reset the flags. */
200 if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
201 goto err;
202 if ((h->flags & P_TYPE) == P_BLEAF) {
203 F_CLR(h, P_TYPE);
204 F_SET(h, P_RLEAF);
205 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
206 } else
207 mpool_put(t->bt_mp, h, 0);
208
209 if (openinfo && openinfo->flags & R_SNAPSHOT &&
210 !F_ISSET(t, R_EOF | R_INMEM) &&
211 t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
212 goto err;
213 return (dbp);
214
215 einval: errno = EINVAL;
216 err: sverrno = errno;
217 if (dbp != NULL)
218 (void)__bt_close(dbp);
219 if (fname != NULL)
220 (void)close(rfd);
221 errno = sverrno;
222 return (NULL);
223 }
224
225 int
__rec_fd(const DB * dbp)226 __rec_fd(const DB *dbp)
227 {
228 BTREE *t;
229
230 t = dbp->internal;
231
232 /* Toss any page pinned across calls. */
233 if (t->bt_pinned != NULL) {
234 mpool_put(t->bt_mp, t->bt_pinned, 0);
235 t->bt_pinned = NULL;
236 }
237
238 /* In-memory database can't have a file descriptor. */
239 if (F_ISSET(t, R_INMEM)) {
240 errno = ENOENT;
241 return (-1);
242 }
243 return (t->bt_rfd);
244 }
245