aboutsummaryrefslogtreecommitdiffstats
path: root/db1-ast/recno/rec_open.c
blob: cf9511e872ae9badb486977dc0aae6a89971ab38 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
/*-
 * Copyright (c) 1990, 1993, 1994
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * Mike Olson.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 */

#if defined(LIBC_SCCS) && !defined(lint)
static char sccsid[] = "@(#)rec_open.c	8.10 (Berkeley) 9/1/94";
#endif /* LIBC_SCCS and not lint */

#include <sys/types.h>
#include <sys/mman.h>
#include <sys/stat.h>

#include <errno.h>
#include <fcntl.h>
#include <limits.h>
#include <stddef.h>
#include <stdio.h>
#include <unistd.h>

#include <db.h>
#include "recno.h"

DB *
__rec_open(fname, flags, mode, openinfo, dflags)
	const char *fname;
	int flags, mode, dflags;
	const RECNOINFO *openinfo;
{
	BTREE *t;
	BTREEINFO btopeninfo;
	DB *dbp;
	PAGE *h;
	struct stat sb;
	int rfd = 0, sverrno;

	/* Open the user's file -- if this fails, we're done. */
	if (fname != NULL && (rfd = open(fname, flags, mode)) < 0)
		return (NULL);

	/* Create a btree in memory (backed by disk). */
	dbp = NULL;
	if (openinfo) {
		if (openinfo->flags & ~(R_FIXEDLEN | R_NOKEY | R_SNAPSHOT))
			goto einval;
		btopeninfo.flags = 0;
		btopeninfo.cachesize = openinfo->cachesize;
		btopeninfo.maxkeypage = 0;
		btopeninfo.minkeypage = 0;
		btopeninfo.psize = openinfo->psize;
		btopeninfo.compare = NULL;
		btopeninfo.prefix = NULL;
		btopeninfo.lorder = openinfo->lorder;
		dbp = __bt_open(openinfo->bfname,
		    O_RDWR, S_IRUSR | S_IWUSR, &btopeninfo, dflags);
	} else
		dbp = __bt_open(NULL, O_RDWR, S_IRUSR | S_IWUSR, NULL, dflags);
	if (dbp == NULL)
		goto err;

	/*
	 * Some fields in the tree structure are recno specific.  Fill them
	 * in and make the btree structure look like a recno structure.  We
	 * don't change the bt_ovflsize value, it's close enough and slightly
	 * bigger.
	 */
	t = dbp->internal;
	if (openinfo) {
		if (openinfo->flags & R_FIXEDLEN) {
			F_SET(t, R_FIXLEN);
			t->bt_reclen = openinfo->reclen;
			if (t->bt_reclen == 0)
				goto einval;
		}
		t->bt_bval = openinfo->bval;
	} else
		t->bt_bval = '\n';

	F_SET(t, R_RECNO);
	if (fname == NULL)
		F_SET(t, R_EOF | R_INMEM);
	else
		t->bt_rfd = rfd;

	if (fname != NULL) {
		/*
		 * In 4.4BSD, stat(2) returns true for ISSOCK on pipes.
		 * Unfortunately, that's not portable, so we use lseek
		 * and check the errno values.
		 */
		errno = 0;
		if (lseek(rfd, (off_t)0, SEEK_CUR) == -1 && errno == ESPIPE) {
			switch (flags & O_ACCMODE) {
			case O_RDONLY:
				F_SET(t, R_RDONLY);
				break;
			default:
				goto einval;
			}
slow:			if ((t->bt_rfp = fdopen(rfd, "r")) == NULL)
				goto err;
			F_SET(t, R_CLOSEFP);
			t->bt_irec =
			    F_ISSET(t, R_FIXLEN) ? __rec_fpipe : __rec_vpipe;
		} else {
			switch (flags & O_ACCMODE) {
			case O_RDONLY:
				F_SET(t, R_RDONLY);
				break;
			case O_RDWR:
				break;
			default:
				goto einval;
			}

			if (fstat(rfd, &sb))
				goto err;
			/*
			 * Kluge -- we'd like to test to see if the file is too
			 * big to mmap.  Since, we don't know what size or type
			 * off_t's or size_t's are, what the largest unsigned
			 * integral type is, or what random insanity the local
			 * C compiler will perpetrate, doing the comparison in
			 * a portable way is flatly impossible.  Hope that mmap
			 * fails if the file is too large.
			 */
			if (sb.st_size == 0)
				F_SET(t, R_EOF);
			else {
#ifdef MMAP_NOT_AVAILABLE
				/*
				 * XXX
				 * Mmap doesn't work correctly on many current
				 * systems.  In particular, it can fail subtly,
				 * with cache coherency problems.  Don't use it
				 * for now.
				 */
				t->bt_msize = sb.st_size;
				if ((t->bt_smap = mmap(NULL, t->bt_msize,
				    PROT_READ, MAP_PRIVATE, rfd,
				    (off_t)0)) == (caddr_t)-1)
					goto slow;
				t->bt_cmap = t->bt_smap;
				t->bt_emap = t->bt_smap + sb.st_size;
				t->bt_irec = F_ISSET(t, R_FIXLEN) ?
				    __rec_fmap : __rec_vmap;
				F_SET(t, R_MEMMAPPED);
#else
				goto slow;
#endif
			}
		}
	}

	/* Use the recno routines. */
	dbp->close = __rec_close;
	dbp->del = __rec_delete;
	dbp->fd = __rec_fd;
	dbp->get = __rec_get;
	dbp->put = __rec_put;
	dbp->seq = __rec_seq;
	dbp->sync = __rec_sync;

	/* If the root page was created, reset the flags. */
	if ((h = mpool_get(t->bt_mp, P_ROOT, 0)) == NULL)
		goto err;
	if ((h->flags & P_TYPE) == P_BLEAF) {
		F_CLR(h, P_TYPE);
		F_SET(h, P_RLEAF);
		mpool_put(t->bt_mp, h, MPOOL_DIRTY);
	} else
		mpool_put(t->bt_mp, h, 0);

	if (openinfo && openinfo->flags & R_SNAPSHOT &&
	    !F_ISSET(t, R_EOF | R_INMEM) &&
	    t->bt_irec(t, MAX_REC_NUMBER) == RET_ERROR)
                goto err;
	return (dbp);

einval:	errno = EINVAL;
err:	sverrno = errno;
	if (dbp != NULL)
		(void)__bt_close(dbp);
	if (fname != NULL)
		(void)close(rfd);
	errno = sverrno;
	return (NULL);
}

int
__rec_fd(dbp)
	const DB *dbp;
{
	BTREE *t;

	t = dbp->internal;

	/* Toss any page pinned across calls. */
	if (t->bt_pinned != NULL) {
		mpool_put(t->bt_mp, t->bt_pinned, 0);
		t->bt_pinned = NULL;
	}

	/* In-memory database can't have a file descriptor. */
	if (F_ISSET(t, R_INMEM)) {
		errno = ENOENT;
		return (-1);
	}
	return (t->bt_rfd);
}