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bt_open.c
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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)
38static char sccsid[] = "@(#)bt_open.c 8.10 (Berkeley) 8/17/94";
39#endif /* LIBC_SCCS and not lint */
40
41/*
42 * Implementation of btree access method for 4.4BSD.
43 *
44 * The design here was originally based on that of the btree access method
45 * used in the Postgres database system at UC Berkeley. This implementation
46 * is wholly independent of the Postgres code.
47 */
48
49#include <sys/param.h>
50#include <sys/stat.h>
51
52#include <errno.h>
53#include <fcntl.h>
54#include <limits.h>
55#include <signal.h>
56#include <stdio.h>
57#include <stdlib.h>
58#include <string.h>
59#include <unistd.h>
60
61#include "../include/db.h"
62#include "btree.h"
63
64#ifdef DEBUG
65#undef MINPSIZE
66#define MINPSIZE 128
67#endif
68
69static int byteorder __P((void));
70static int nroot __P((BTREE *));
71static int tmp __P((void));
72
73/*
74 * __BT_OPEN -- Open a btree.
75 *
76 * Creates and fills a DB struct, and calls the routine that actually
77 * opens the btree.
78 *
79 * Parameters:
80 * fname: filename (NULL for in-memory trees)
81 * flags: open flag bits
82 * mode: open permission bits
83 * b: BTREEINFO pointer
84 *
85 * Returns:
86 * NULL on failure, pointer to DB on success.
87 *
88 */
89DB *
90__bt_open(fname, flags, mode, openinfo, dflags)
91 const char *fname;
92 int flags, mode, dflags;
93 const BTREEINFO *openinfo;
94{
95 struct stat sb;
96 BTMETA m;
97 BTREE *t;
99 DB *dbp;
100 pgno_t ncache;
101 ssize_t nr;
102 int machine_lorder;
103
104 t = NULL;
105
106 /*
107 * Intention is to make sure all of the user's selections are okay
108 * here and then use them without checking. Can't be complete, since
109 * we don't know the right page size, lorder or flags until the backing
110 * file is opened. Also, the file's page size can cause the cachesize
111 * to change.
112 */
113 machine_lorder = byteorder();
114 if (openinfo) {
115 b = *openinfo;
116
117 /* Flags: R_DUP. */
118 if (b.flags & ~(R_DUP))
119 goto einval;
120
121 /*
122 * Page size must be indx_t aligned and >= MINPSIZE. Default
123 * page size is set farther on, based on the underlying file
124 * transfer size.
125 */
126 if (b.psize &&
127 (b.psize < MINPSIZE || b.psize > MAX_PAGE_OFFSET + 1 ||
128 b.psize & (sizeof(indx_t) - 1)))
129 goto einval;
130
131 /* Minimum number of keys per page; absolute minimum is 2. */
132 if (b.minkeypage) {
133 if (b.minkeypage < 2)
134 goto einval;
135 } else
136 b.minkeypage = DEFMINKEYPAGE;
137
138 /* If no comparison, use default comparison and prefix. */
139 if (b.compare == NULL) {
140 b.compare = __bt_defcmp;
141 if (b.prefix == NULL)
142 b.prefix = __bt_defpfx;
143 }
144
145 if (b.lorder == 0)
146 b.lorder = machine_lorder;
147 } else {
148 b.compare = __bt_defcmp;
149 b.cachesize = 0;
150 b.flags = 0;
151 b.lorder = machine_lorder;
152 b.minkeypage = DEFMINKEYPAGE;
153 b.prefix = __bt_defpfx;
154 b.psize = 0;
155 }
156
157 /* Check for the ubiquitous PDP-11. */
158 if (b.lorder != BIG_ENDIAN && b.lorder != LITTLE_ENDIAN)
159 goto einval;
160
161 /* Allocate and initialize DB and BTREE structures. */
162 if ((t = (BTREE *)malloc(sizeof(BTREE))) == NULL)
163 goto err;
164 memset(t, 0, sizeof(BTREE));
165 t->bt_fd = -1; /* Don't close unopened fd on error. */
166 t->bt_lorder = b.lorder;
167 t->bt_order = NOT;
168 t->bt_cmp = b.compare;
169 t->bt_pfx = b.prefix;
170 t->bt_rfd = -1;
171
172 if ((t->bt_dbp = dbp = (DB *)malloc(sizeof(DB))) == NULL)
173 goto err;
174 memset(t->bt_dbp, 0, sizeof(DB));
175 if (t->bt_lorder != machine_lorder)
176 F_SET(t, B_NEEDSWAP);
177
178 dbp->type = DB_BTREE;
179 dbp->internal = t;
180 dbp->close = __bt_close;
181 dbp->del = __bt_delete;
182 dbp->fd = __bt_fd;
183 dbp->get = __bt_get;
184 dbp->put = __bt_put;
185 dbp->seq = __bt_seq;
186 dbp->sync = __bt_sync;
187
188 /*
189 * If no file name was supplied, this is an in-memory btree and we
190 * open a backing temporary file. Otherwise, it's a disk-based tree.
191 */
192 if (fname) {
193 switch (flags & O_ACCMODE) {
194 case O_RDONLY:
195 F_SET(t, B_RDONLY);
196 break;
197 case O_RDWR:
198 break;
199 case O_WRONLY:
200 default:
201 goto einval;
202 }
203
204 if ((t->bt_fd = open(fname, flags, mode)) < 0)
205 goto err;
206
207 } else {
208 if ((flags & O_ACCMODE) != O_RDWR)
209 goto einval;
210 if ((t->bt_fd = tmp()) == -1)
211 goto err;
212 F_SET(t, B_INMEM);
213 }
214
215 if (fcntl(t->bt_fd, F_SETFD, 1) == -1)
216 goto err;
217
218 if (fstat(t->bt_fd, &sb))
219 goto err;
220 if (sb.st_size) {
221 if ((nr = read(t->bt_fd, &m, sizeof(BTMETA))) < 0)
222 goto err;
223 if (nr != sizeof(BTMETA))
224 goto eftype;
225
226 /*
227 * Read in the meta-data. This can change the notion of what
228 * the lorder, page size and flags are, and, when the page size
229 * changes, the cachesize value can change too. If the user
230 * specified the wrong byte order for an existing database, we
231 * don't bother to return an error, we just clear the NEEDSWAP
232 * bit.
233 */
234 if (m.magic == BTREEMAGIC)
235 F_CLR(t, B_NEEDSWAP);
236 else {
237 F_SET(t, B_NEEDSWAP);
238 M_32_SWAP(m.magic);
239 M_32_SWAP(m.version);
240 M_32_SWAP(m.psize);
241 M_32_SWAP(m.free);
242 M_32_SWAP(m.nrecs);
243 M_32_SWAP(m.flags);
244 }
245 if (m.magic != BTREEMAGIC || m.version != BTREEVERSION)
246 goto eftype;
247 if (m.psize < MINPSIZE || m.psize > MAX_PAGE_OFFSET + 1 ||
248 m.psize & (sizeof(indx_t) - 1))
249 goto eftype;
250 if (m.flags & ~SAVEMETA)
251 goto eftype;
252 b.psize = m.psize;
253 F_SET(t, m.flags);
254 t->bt_free = m.free;
255 t->bt_nrecs = m.nrecs;
256 } else {
257 /*
258 * Set the page size to the best value for I/O to this file.
259 * Don't overflow the page offset type.
260 */
261 if (b.psize == 0) {
262#ifdef _STATBUF_ST_BLKSIZE
263 b.psize = sb.st_blksize;
264#endif
265 if (b.psize < MINPSIZE)
266 b.psize = MINPSIZE;
267 if (b.psize > MAX_PAGE_OFFSET + 1)
268 b.psize = MAX_PAGE_OFFSET + 1;
269 }
270
271 /* Set flag if duplicates permitted. */
272 if (!(b.flags & R_DUP))
273 F_SET(t, B_NODUPS);
274
275 t->bt_free = P_INVALID;
276 t->bt_nrecs = 0;
277 F_SET(t, B_METADIRTY);
278 }
279
280 t->bt_psize = b.psize;
281
282 /* Set the cache size; must be a multiple of the page size. */
283 if (b.cachesize && b.cachesize & (b.psize - 1))
284 b.cachesize += (~b.cachesize & (b.psize - 1)) + 1;
285 if (b.cachesize < b.psize * MINCACHE)
286 b.cachesize = b.psize * MINCACHE;
287
288 /* Calculate number of pages to cache. */
289 ncache = (b.cachesize + t->bt_psize - 1) / t->bt_psize;
290
291 /*
292 * The btree data structure requires that at least two keys can fit on
293 * a page, but other than that there's no fixed requirement. The user
294 * specified a minimum number per page, and we translated that into the
295 * number of bytes a key/data pair can use before being placed on an
296 * overflow page. This calculation includes the page header, the size
297 * of the index referencing the leaf item and the size of the leaf item
298 * structure. Also, don't let the user specify a minkeypage such that
299 * a key/data pair won't fit even if both key and data are on overflow
300 * pages.
301 */
302 t->bt_ovflsize = (t->bt_psize - BTDATAOFF) / b.minkeypage -
303 (sizeof(indx_t) + NBLEAFDBT(0, 0));
304 if (t->bt_ovflsize < NBLEAFDBT(NOVFLSIZE, NOVFLSIZE) + sizeof(indx_t))
305 t->bt_ovflsize =
307
308 /* Initialize the buffer pool. */
309 if ((t->bt_mp =
310 mpool_open(NULL, t->bt_fd, t->bt_psize, ncache)) == NULL)
311 goto err;
312 if (!F_ISSET(t, B_INMEM))
314
315 /* Create a root page if new tree. */
316 if (nroot(t) == RET_ERROR)
317 goto err;
318
319 /* Global flags. */
320 if (dflags & DB_LOCK)
321 F_SET(t, B_DB_LOCK);
322 if (dflags & DB_SHMEM)
323 F_SET(t, B_DB_SHMEM);
324 if (dflags & DB_TXN)
325 F_SET(t, B_DB_TXN);
326
327 return (dbp);
328
329einval: errno = EINVAL;
330 goto err;
331
332eftype: errno = EFTYPE;
333 goto err;
334
335err: if (t) {
336 if (t->bt_dbp)
337 free(t->bt_dbp);
338 if (t->bt_fd != -1)
339 (void)close(t->bt_fd);
340 free(t);
341 }
342 return (NULL);
343}
344
345/*
346 * NROOT -- Create the root of a new tree.
347 *
348 * Parameters:
349 * t: tree
350 *
351 * Returns:
352 * RET_ERROR, RET_SUCCESS
353 */
354static int
356 BTREE *t;
357{
358 PAGE *meta, *root;
359 pgno_t npg;
360
361 if ((meta = mpool_get(t->bt_mp, 0, 0)) != NULL) {
362 mpool_put(t->bt_mp, meta, 0);
363 return (RET_SUCCESS);
364 }
365 if (errno != EINVAL) /* It's OK to not exist. */
366 return (RET_ERROR);
367 errno = 0;
368
369 if ((meta = mpool_new(t->bt_mp, &npg)) == NULL)
370 return (RET_ERROR);
371
372 if ((root = mpool_new(t->bt_mp, &npg)) == NULL)
373 return (RET_ERROR);
374
375 if (npg != P_ROOT)
376 return (RET_ERROR);
377 root->pgno = npg;
378 root->prevpg = root->nextpg = P_INVALID;
379 root->lower = BTDATAOFF;
380 root->upper = t->bt_psize;
381 root->flags = P_BLEAF;
382 memset(meta, 0, t->bt_psize);
384 mpool_put(t->bt_mp, root, MPOOL_DIRTY);
385 return (RET_SUCCESS);
386}
387
388static int
390{
391 sigset_t set, oset;
392 int fd;
393 const char *envtmp;
394 char *path;
395 static const char fmt[] = "%s/bt.XXXXXX";
396 size_t n;
397
398 envtmp = getenv("TMPDIR");
399 if (!envtmp)
400 envtmp = "/tmp";
401 n = strlen (envtmp) + sizeof fmt;
402#ifdef __GNUC__
403 path = __builtin_alloca(n);
404#else
405 path = malloc(n);
406#endif
407 (void)snprintf(path, n, fmt, envtmp ? envtmp : "/tmp");
408
409 (void)sigfillset(&set);
410 (void)sigprocmask(SIG_BLOCK, &set, &oset);
411 if ((fd = mkstemp(path)) != -1)
412 (void)unlink(path);
413 (void)sigprocmask(SIG_SETMASK, &oset, NULL);
414#ifndef __GNUC__
415 free(path);
416#endif
417 return(fd);
418}
419
420static int
422{
423 u_int32_t x;
424 u_char *p;
425
426 x = 0x01020304;
427 p = (u_char *)&x;
428 switch (*p) {
429 case 1:
430 return (BIG_ENDIAN);
431 case 4:
432 return (LITTLE_ENDIAN);
433 default:
434 return (0);
435 }
436}
437
438int
440 const DB *dbp;
441{
442 BTREE *t;
443
444 t = dbp->internal;
445
446 /* Toss any page pinned across calls. */
447 if (t->bt_pinned != NULL) {
448 mpool_put(t->bt_mp, t->bt_pinned, 0);
449 t->bt_pinned = NULL;
450 }
451
452 /* In-memory database can't have a file descriptor. */
453 if (F_ISSET(t, B_INMEM)) {
454 errno = ENOENT;
455 return (-1);
456 }
457 return (t->bt_fd);
458}
dflags
Definition: app_dictate.c:63
int __bt_sync(DB *dbp, u_int flags) const
Definition: bt_close.c:119
int __bt_close(DB *dbp)
Definition: bt_close.c:64
void __bt_pgin(void *t, pgno_t pg, void *pp)
Definition: bt_conv.c:61
void __bt_pgout(void *t, pgno_t pg, void *pp)
Definition: bt_conv.c:129
int __bt_delete(DB *dbp, const DBT *key, u_int flags) const
Definition: bt_delete.c:63
int __bt_get(DB *dbp, const DBT *key, DBT *data, u_int flags) const
Definition: bt_get.c:63
static int tmp()
Definition: bt_open.c:389
static int byteorder()
Definition: bt_open.c:421
static int byteorder __P((void))
static int nroot(BTREE *t)
Definition: bt_open.c:355
int __bt_fd(DB *dbp) const
Definition: bt_open.c:439
DB * __bt_open(char *fname, int flags, int mode, const BTREEINFO *openinfo, int dflags) const
Definition: bt_open.c:90
int __bt_put(DB *dbp, DBT *key, const DBT *data, u_int flags) const
Definition: bt_put.c:67
int __bt_seq(DB *dbp, DBT *key, DBT *data, u_int flags) const
Definition: bt_seq.c:77
size_t __bt_defpfx(DBT *a, DBT *b) const
Definition: bt_utils.c:246
int __bt_defcmp(DBT *a, DBT *b) const
Definition: bt_utils.c:216
#define DEFMINKEYPAGE
Definition: btree.h:54
#define MINCACHE
Definition: btree.h:55
#define F_ISSET(p, f)
Definition: btree.h:42
#define B_DB_TXN
Definition: btree.h:387
#define B_METADIRTY
Definition: btree.h:369
#define MINPSIZE
Definition: btree.h:56
#define B_NODUPS
Definition: btree.h:374
#define B_DB_SHMEM
Definition: btree.h:386
#define B_NEEDSWAP
Definition: btree.h:371
#define SAVEMETA
Definition: btree.h:307
#define NOVFLSIZE
Definition: btree.h:117
#define B_RDONLY
Definition: btree.h:372
#define F_SET(p, f)
Definition: btree.h:40
#define P_INVALID
Definition: btree.h:63
#define F_CLR(p, f)
Definition: btree.h:41
#define P_BLEAF
Definition: btree.h:81
#define B_DB_LOCK
Definition: btree.h:385
#define B_INMEM
Definition: btree.h:368
#define NBLEAFDBT(ksize, dsize)
Definition: btree.h:195
#define BTDATAOFF
Definition: btree.h:95
#define P_ROOT
Definition: btree.h:65
#define DB_LOCK
Definition: db.h:123
u_int16_t indx_t
Definition: db.h:80
#define R_DUP
Definition: db.h:146
#define BTREEVERSION
Definition: db.h:142
@ DB_BTREE
Definition: db.h:103
#define MAX_PAGE_OFFSET
Definition: db.h:79
#define DB_SHMEM
Definition: db.h:124
#define RET_SUCCESS
Definition: db.h:52
#define RET_ERROR
Definition: db.h:51
#define DB_TXN
Definition: db.h:125
u_int32_t pgno_t
Definition: db.h:78
#define BTREEMAGIC
Definition: db.h:141
static int set(struct ast_channel *chan, const char *cmd, char *data, char *buf, size_t len)
Definition: func_logic.c:238
char * malloc()
void free()
static DB * dbp
Definition: hsearch.c:49
unsigned int u_int32_t
#define BIG_ENDIAN
#define LITTLE_ENDIAN
int errno
void * mpool_get(MPOOL *mp, pgno_t pgno, u_int flags)
Definition: mpool.c:165
void * mpool_new(MPOOL *mp, pgno_t *pgnoaddr)
Definition: mpool.c:130
int mpool_put(MPOOL *mp, void *page, u_int flags)
Definition: mpool.c:251
void mpool_filter(MPOOL *mp, void *pgin, void *pgout, void *pgcookie)
Definition: mpool.c:114
MPOOL * mpool_open(void *key, int fd, pgno_t pagesize, pgno_t maxcache)
Definition: mpool.c:74
#define MPOOL_DIRTY
Definition: mpool.h:61
meta
below block is needed for mssql
Definition: cdr/env.py:22
#define NULL
Definition: resample.c:96
Definition: db.h:145
Definition: db.h:129
DBTYPE type
Definition: db.h:130
void * internal
Definition: db.h:137
Definition: btree.h:300
Definition: btree.h:312
int bt_fd
Definition: btree.h:335
u_int32_t bt_psize
Definition: btree.h:338
u_int32_t flags
Definition: btree.h:388
MPOOL * bt_mp
Definition: btree.h:313
PAGE * bt_pinned
Definition: btree.h:318
indx_t bt_ovflsize
Definition: btree.h:339
int bt_lorder
Definition: btree.h:340
enum _btree::@506 bt_order
pgno_t bt_free
Definition: btree.h:337
DB * bt_dbp
Definition: btree.h:315
recno_t bt_nrecs
Definition: btree.h:360
int bt_rfd
Definition: btree.h:353
Definition: btree.h:75
pgno_t prevpg
Definition: btree.h:77
indx_t lower
Definition: btree.h:89
indx_t upper
Definition: btree.h:90
u_int32_t flags
Definition: btree.h:87
pgno_t pgno
Definition: btree.h:76
pgno_t nextpg
Definition: btree.h:78
static struct test_val b
#define EFTYPE