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comparison nss/lib/dbm/src/hash.c @ 3:150b72113545

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Add DBM and legacydb support
author Andre Heinecke <andre.heinecke@intevation.de>
date Tue, 05 Aug 2014 18:32:02 +0200
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2:a945361df361 3:150b72113545
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 * Margo Seltzer.
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. ***REMOVED*** - see
17 * ftp://ftp.cs.berkeley.edu/pub/4bsd/README.Impt.License.Change
18 * 4. 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[] = "@(#)hash.c 8.9 (Berkeley) 6/16/94";
37 #endif /* LIBC_SCCS and not lint */
38
39 #if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)
40 #include <sys/param.h>
41 #endif
42
43 #if !defined(macintosh)
44 #ifdef XP_OS2
45 #include <sys/types.h>
46 #endif
47 #include <sys/stat.h>
48 #endif
49
50 #if defined(macintosh)
51 #include <unix.h>
52 #include <unistd.h>
53 #endif
54
55 #include <errno.h>
56 #include <fcntl.h>
57 #include <stdio.h>
58 #include <stdlib.h>
59 #include <string.h>
60
61 #if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh)
62 #include <unistd.h>
63 #endif
64 #if defined(_WIN32) || defined(_WINDOWS)
65 #include <windows.h>
66 #endif
67
68 #include <assert.h>
69
70 #include "mcom_db.h"
71 #include "hash.h"
72 #include "page.h"
73
74 /*
75 #include "extern.h"
76 */
77 static int alloc_segs __P((HTAB *, int));
78 static int flush_meta __P((HTAB *));
79 static int hash_access __P((HTAB *, ACTION, DBT *, DBT *));
80 static int hash_close __P((DB *));
81 static int hash_delete __P((const DB *, const DBT *, uint));
82 static int hash_fd __P((const DB *));
83 static int hash_get __P((const DB *, const DBT *, DBT *, uint));
84 static int hash_put __P((const DB *, DBT *, const DBT *, uint));
85 static void *hash_realloc __P((SEGMENT **, size_t, size_t));
86 static int hash_seq __P((const DB *, DBT *, DBT *, uint));
87 static int hash_sync __P((const DB *, uint));
88 static int hdestroy __P((HTAB *));
89 static HTAB *init_hash __P((HTAB *, const char *, HASHINFO *));
90 static int init_htab __P((HTAB *, int));
91 #if BYTE_ORDER == LITTLE_ENDIAN
92 static void swap_header __P((HTAB *));
93 static void swap_header_copy __P((HASHHDR *, HASHHDR *));
94 #endif
95
96 /* Fast arithmetic, relying on powers of 2, */
97 #define MOD(x, y) ((x) & ((y) - 1))
98
99 #define RETURN_ERROR(ERR, LOC) { save_errno = ERR; goto LOC; }
100
101 /* Return values */
102 #define SUCCESS (0)
103 #define DBM_ERROR (-1)
104 #define ABNORMAL (1)
105
106 #ifdef HASH_STATISTICS
107 int hash_accesses, hash_collisions, hash_expansions, hash_overflows;
108 #endif
109
110 /* A new Lou (montulli@mozilla.com) routine.
111 *
112 * The database is screwed.
113 *
114 * This closes the file, flushing buffers as appropriate.
115 */
116 static void
117 __remove_database(DB *dbp)
118 {
119 HTAB *hashp = (HTAB *)dbp->internal;
120
121 assert(0);
122
123 if (!hashp)
124 return;
125 hdestroy(hashp);
126 dbp->internal = NULL;
127 }
128
129 /************************** INTERFACE ROUTINES ***************************/
130 /* OPEN/CLOSE */
131
132
133 extern DB *
134 __hash_open(const char *file, int flags, int mode, const HASHINFO *info, int dflags)
135 {
136 HTAB *hashp=NULL;
137 struct stat statbuf;
138 DB *dbp;
139 int bpages, hdrsize, new_table, nsegs, save_errno;
140
141 if ((flags & O_ACCMODE) == O_WRONLY) {
142 errno = EINVAL;
143 return NULL;
144 }
145
146 /* zero the statbuffer so that
147 * we can check it for a non-zero
148 * date to see if stat succeeded
149 */
150 memset(&statbuf, 0, sizeof(struct stat));
151
152 if (!(hashp = (HTAB *)calloc(1, sizeof(HTAB)))) {
153 errno = ENOMEM;
154 return NULL;
155 }
156 hashp->fp = NO_FILE;
157 if(file)
158 hashp->filename = strdup(file);
159
160 /*
161 * Even if user wants write only, we need to be able to read
162 * the actual file, so we need to open it read/write. But, the
163 * field in the hashp structure needs to be accurate so that
164 * we can check accesses.
165 */
166 hashp->flags = flags;
167
168 new_table = 0;
169 if (!file || (flags & O_TRUNC) || (stat(file, &statbuf) && (errno == ENOENT)))
170 {
171 if (errno == ENOENT)
172 errno = 0; /* Just in case someone looks at errno */
173 new_table = 1;
174 }
175 else if(statbuf.st_mtime && statbuf.st_size == 0)
176 {
177 /* check for a zero length file and delete it
178 * if it exists
179 */
180 new_table = 1;
181 }
182 hashp->file_size = statbuf.st_size;
183
184 if (file) {
185 #if defined(_WIN32) || defined(_WINDOWS) || defined (macintosh) || defined(XP_OS2)
186 if ((hashp->fp = DBFILE_OPEN(file, flags | O_BINARY, mode)) == -1)
187 RETURN_ERROR(errno, error1);
188 #else
189 if ((hashp->fp = open(file, flags, mode)) == -1)
190 RETURN_ERROR(errno, error1);
191 (void)fcntl(hashp->fp, F_SETFD, 1);
192 #endif
193 }
194 if (new_table) {
195 if (!init_hash(hashp, file, (HASHINFO *)info))
196 RETURN_ERROR(errno, error1);
197 } else {
198 /* Table already exists */
199 if (info && info->hash)
200 hashp->hash = info->hash;
201 else
202 hashp->hash = __default_hash;
203
204 hdrsize = read(hashp->fp, (char *)&hashp->hdr, sizeof(HASHHDR));
205 if (hdrsize == -1)
206 RETURN_ERROR(errno, error1);
207 if (hdrsize != sizeof(HASHHDR))
208 RETURN_ERROR(EFTYPE, error1);
209 #if BYTE_ORDER == LITTLE_ENDIAN
210 swap_header(hashp);
211 #endif
212 /* Verify file type, versions and hash function */
213 if (hashp->MAGIC != HASHMAGIC)
214 RETURN_ERROR(EFTYPE, error1);
215 #define OLDHASHVERSION 1
216 if (hashp->VERSION != HASHVERSION &&
217 hashp->VERSION != OLDHASHVERSION)
218 RETURN_ERROR(EFTYPE, error1);
219 if (hashp->hash(CHARKEY, sizeof(CHARKEY)) != hashp->H_CHARKEY)
220 RETURN_ERROR(EFTYPE, error1);
221 if (hashp->NKEYS < 0) /* Old bad database. */
222 RETURN_ERROR(EFTYPE, error1);
223
224 /*
225 * Figure out how many segments we need. Max_Bucket is the
226 * maximum bucket number, so the number of buckets is
227 * max_bucket + 1.
228 */
229 nsegs = (hashp->MAX_BUCKET + 1 + hashp->SGSIZE - 1) /
230 hashp->SGSIZE;
231 hashp->nsegs = 0;
232 if (alloc_segs(hashp, nsegs))
233 /* If alloc_segs fails, errno will have been set. */
234 RETURN_ERROR(errno, error1);
235 /* Read in bitmaps */
236 bpages = (hashp->SPARES[hashp->OVFL_POINT] +
237 (hashp->BSIZE << BYTE_SHIFT) - 1) >>
238 (hashp->BSHIFT + BYTE_SHIFT);
239
240 hashp->nmaps = bpages;
241 (void)memset(&hashp->mapp[0], 0, bpages * sizeof(uint32 *));
242 }
243
244 /* Initialize Buffer Manager */
245 if (info && info->cachesize)
246 __buf_init(hashp, (int32) info->cachesize);
247 else
248 __buf_init(hashp, DEF_BUFSIZE);
249
250 hashp->new_file = new_table;
251 #ifdef macintosh
252 hashp->save_file = file && !(hashp->flags & O_RDONLY);
253 #else
254 hashp->save_file = file && (hashp->flags & O_RDWR);
255 #endif
256 hashp->cbucket = -1;
257 if (!(dbp = (DB *)malloc(sizeof(DB)))) {
258 RETURN_ERROR(ENOMEM, error1);
259 }
260 dbp->internal = hashp;
261 dbp->close = hash_close;
262 dbp->del = hash_delete;
263 dbp->fd = hash_fd;
264 dbp->get = hash_get;
265 dbp->put = hash_put;
266 dbp->seq = hash_seq;
267 dbp->sync = hash_sync;
268 dbp->type = DB_HASH;
269
270 #ifdef HASH_STATISTICS
271 hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0;
272 #endif
273 return (dbp);
274
275 error1:
276 hdestroy(hashp);
277 errno = save_errno;
278 return (NULL);
279 }
280
281 static int
282 hash_close(DB *dbp)
283 {
284 HTAB *hashp;
285 int retval;
286
287 if (!dbp)
288 return (DBM_ERROR);
289
290 hashp = (HTAB *)dbp->internal;
291 if(!hashp)
292 return (DBM_ERROR);
293
294 retval = hdestroy(hashp);
295 free(dbp);
296 return (retval);
297 }
298
299 static int hash_fd(const DB *dbp)
300 {
301 HTAB *hashp;
302
303 if (!dbp)
304 return (DBM_ERROR);
305
306 hashp = (HTAB *)dbp->internal;
307 if(!hashp)
308 return (DBM_ERROR);
309
310 if (hashp->fp == -1) {
311 errno = ENOENT;
312 return (-1);
313 }
314 return (hashp->fp);
315 }
316
317 /************************** LOCAL CREATION ROUTINES **********************/
318 static HTAB *
319 init_hash(HTAB *hashp, const char *file, HASHINFO *info)
320 {
321 struct stat statbuf;
322 int nelem;
323
324 nelem = 1;
325 hashp->NKEYS = 0;
326 hashp->LORDER = BYTE_ORDER;
327 hashp->BSIZE = DEF_BUCKET_SIZE;
328 hashp->BSHIFT = DEF_BUCKET_SHIFT;
329 hashp->SGSIZE = DEF_SEGSIZE;
330 hashp->SSHIFT = DEF_SEGSIZE_SHIFT;
331 hashp->DSIZE = DEF_DIRSIZE;
332 hashp->FFACTOR = DEF_FFACTOR;
333 hashp->hash = __default_hash;
334 memset(hashp->SPARES, 0, sizeof(hashp->SPARES));
335 memset(hashp->BITMAPS, 0, sizeof (hashp->BITMAPS));
336
337 /* Fix bucket size to be optimal for file system */
338 if (file != NULL) {
339 if (stat(file, &statbuf))
340 return (NULL);
341
342 #if !defined(_WIN32) && !defined(_WINDOWS) && !defined(macintosh) && !defined(XP_OS2)
343 #if defined(__QNX__) && !defined(__QNXNTO__)
344 hashp->BSIZE = 512; /* preferred blk size on qnx4 */
345 #else
346 hashp->BSIZE = statbuf.st_blksize;
347 #endif
348
349 /* new code added by Lou to reduce block
350 * size down below MAX_BSIZE
351 */
352 if (hashp->BSIZE > MAX_BSIZE)
353 hashp->BSIZE = MAX_BSIZE;
354 #endif
355 hashp->BSHIFT = __log2((uint32)hashp->BSIZE);
356 }
357
358 if (info) {
359 if (info->bsize) {
360 /* Round pagesize up to power of 2 */
361 hashp->BSHIFT = __log2(info->bsize);
362 hashp->BSIZE = 1 << hashp->BSHIFT;
363 if (hashp->BSIZE > MAX_BSIZE) {
364 errno = EINVAL;
365 return (NULL);
366 }
367 }
368 if (info->ffactor)
369 hashp->FFACTOR = info->ffactor;
370 if (info->hash)
371 hashp->hash = info->hash;
372 if (info->nelem)
373 nelem = info->nelem;
374 if (info->lorder) {
375 if (info->lorder != BIG_ENDIAN &&
376 info->lorder != LITTLE_ENDIAN) {
377 errno = EINVAL;
378 return (NULL);
379 }
380 hashp->LORDER = info->lorder;
381 }
382 }
383 /* init_htab sets errno if it fails */
384 if (init_htab(hashp, nelem))
385 return (NULL);
386 else
387 return (hashp);
388 }
389 /*
390 * This calls alloc_segs which may run out of memory. Alloc_segs will
391 * set errno, so we just pass the error information along.
392 *
393 * Returns 0 on No Error
394 */
395 static int
396 init_htab(HTAB *hashp, int nelem)
397 {
398 register int nbuckets, nsegs;
399 int l2;
400
401 /*
402 * Divide number of elements by the fill factor and determine a
403 * desired number of buckets. Allocate space for the next greater
404 * power of two number of buckets.
405 */
406 nelem = (nelem - 1) / hashp->FFACTOR + 1;
407
408 l2 = __log2((uint32)PR_MAX(nelem, 2));
409 nbuckets = 1 << l2;
410
411 hashp->SPARES[l2] = l2 + 1;
412 hashp->SPARES[l2 + 1] = l2 + 1;
413 hashp->OVFL_POINT = l2;
414 hashp->LAST_FREED = 2;
415
416 /* First bitmap page is at: splitpoint l2 page offset 1 */
417 if (__ibitmap(hashp, (int)OADDR_OF(l2, 1), l2 + 1, 0))
418 return (-1);
419
420 hashp->MAX_BUCKET = hashp->LOW_MASK = nbuckets - 1;
421 hashp->HIGH_MASK = (nbuckets << 1) - 1;
422 hashp->HDRPAGES = ((PR_MAX(sizeof(HASHHDR), MINHDRSIZE) - 1) >>
423 hashp->BSHIFT) + 1;
424
425 nsegs = (nbuckets - 1) / hashp->SGSIZE + 1;
426 nsegs = 1 << __log2((uint32)nsegs);
427
428 if (nsegs > hashp->DSIZE)
429 hashp->DSIZE = nsegs;
430 return (alloc_segs(hashp, nsegs));
431 }
432
433 /********************** DESTROY/CLOSE ROUTINES ************************/
434
435 /*
436 * Flushes any changes to the file if necessary and destroys the hashp
437 * structure, freeing all allocated space.
438 */
439 static int
440 hdestroy(HTAB *hashp)
441 {
442 int i, save_errno;
443
444 save_errno = 0;
445
446 #ifdef HASH_STATISTICS
447 (void)fprintf(stderr, "hdestroy: accesses %ld collisions %ld\n",
448 hash_accesses, hash_collisions);
449 (void)fprintf(stderr, "hdestroy: expansions %ld\n",
450 hash_expansions);
451 (void)fprintf(stderr, "hdestroy: overflows %ld\n",
452 hash_overflows);
453 (void)fprintf(stderr, "keys %ld maxp %d segmentcount %d\n",
454 hashp->NKEYS, hashp->MAX_BUCKET, hashp->nsegs);
455
456 for (i = 0; i < NCACHED; i++)
457 (void)fprintf(stderr,
458 "spares[%d] = %d\n", i, hashp->SPARES[i]);
459 #endif
460 /*
461 * Call on buffer manager to free buffers, and if required,
462 * write them to disk.
463 */
464 if (__buf_free(hashp, 1, hashp->save_file))
465 save_errno = errno;
466 if (hashp->dir) {
467 free(*hashp->dir); /* Free initial segments */
468 /* Free extra segments */
469 while (hashp->exsegs--)
470 free(hashp->dir[--hashp->nsegs]);
471 free(hashp->dir);
472 }
473 if (flush_meta(hashp) && !save_errno)
474 save_errno = errno;
475 /* Free Bigmaps */
476 for (i = 0; i < hashp->nmaps; i++)
477 if (hashp->mapp[i])
478 free(hashp->mapp[i]);
479
480 if (hashp->fp != -1)
481 (void)close(hashp->fp);
482
483 if(hashp->filename) {
484 #if defined(_WIN32) || defined(_WINDOWS) || defined(XP_OS2)
485 if (hashp->is_temp)
486 (void)unlink(hashp->filename);
487 #endif
488 free(hashp->filename);
489 }
490 if (hashp->tmp_buf)
491 free(hashp->tmp_buf);
492 if (hashp->tmp_key)
493 free(hashp->tmp_key);
494 free(hashp);
495 if (save_errno) {
496 errno = save_errno;
497 return (DBM_ERROR);
498 }
499 return (SUCCESS);
500 }
501
502 #if defined(_WIN32) || defined(_WINDOWS)
503 /*
504 * Close and reopen file to force file length update on windows.
505 *
506 * Returns:
507 * 0 == OK
508 * -1 DBM_ERROR
509 */
510 static int
511 update_EOF(HTAB *hashp)
512 {
513 #if defined(DBM_REOPEN_ON_FLUSH)
514 char * file = hashp->filename;
515 off_t file_size;
516 int flags;
517 int mode = -1;
518 struct stat statbuf;
519
520 memset(&statbuf, 0, sizeof statbuf);
521
522 /* make sure we won't lose the file by closing it. */
523 if (!file || (stat(file, &statbuf) && (errno == ENOENT))) {
524 /* pretend we did it. */
525 return 0;
526 }
527
528 (void)close(hashp->fp);
529
530 flags = hashp->flags & ~(O_TRUNC | O_CREAT | O_EXCL);
531
532 if ((hashp->fp = DBFILE_OPEN(file, flags | O_BINARY, mode)) == -1)
533 return -1;
534 file_size = lseek(hashp->fp, (off_t)0, SEEK_END);
535 if (file_size == -1)
536 return -1;
537 hashp->file_size = file_size;
538 return 0;
539 #else
540 int fd = hashp->fp;
541 off_t file_size = lseek(fd, (off_t)0, SEEK_END);
542 HANDLE handle = (HANDLE)_get_osfhandle(fd);
543 BOOL cool = FlushFileBuffers(handle);
544 #ifdef DEBUG3
545 if (!cool) {
546 DWORD err = GetLastError();
547 (void)fprintf(stderr,
548 "FlushFileBuffers failed, last error = %d, 0x%08x\n",
549 err, err);
550 }
551 #endif
552 if (file_size == -1)
553 return -1;
554 hashp->file_size = file_size;
555 return cool ? 0 : -1;
556 #endif
557 }
558 #endif
559
560 /*
561 * Write modified pages to disk
562 *
563 * Returns:
564 * 0 == OK
565 * -1 DBM_ERROR
566 */
567 static int
568 hash_sync(const DB *dbp, uint flags)
569 {
570 HTAB *hashp;
571
572 if (flags != 0) {
573 errno = EINVAL;
574 return (DBM_ERROR);
575 }
576
577 if (!dbp)
578 return (DBM_ERROR);
579
580 hashp = (HTAB *)dbp->internal;
581 if(!hashp)
582 return (DBM_ERROR);
583
584 if (!hashp->save_file)
585 return (0);
586 if (__buf_free(hashp, 0, 1) || flush_meta(hashp))
587 return (DBM_ERROR);
588 #if defined(_WIN32) || defined(_WINDOWS)
589 if (hashp->updateEOF && hashp->filename && !hashp->is_temp) {
590 int status = update_EOF(hashp);
591 hashp->updateEOF = 0;
592 if (status)
593 return status;
594 }
595 #endif
596 hashp->new_file = 0;
597 return (0);
598 }
599
600 /*
601 * Returns:
602 * 0 == OK
603 * -1 indicates that errno should be set
604 */
605 static int
606 flush_meta(HTAB *hashp)
607 {
608 HASHHDR *whdrp;
609 #if BYTE_ORDER == LITTLE_ENDIAN
610 HASHHDR whdr;
611 #endif
612 int fp, i, wsize;
613
614 if (!hashp->save_file)
615 return (0);
616 hashp->MAGIC = HASHMAGIC;
617 hashp->VERSION = HASHVERSION;
618 hashp->H_CHARKEY = hashp->hash(CHARKEY, sizeof(CHARKEY));
619
620 fp = hashp->fp;
621 whdrp = &hashp->hdr;
622 #if BYTE_ORDER == LITTLE_ENDIAN
623 whdrp = &whdr;
624 swap_header_copy(&hashp->hdr, whdrp);
625 #endif
626 if ((lseek(fp, (off_t)0, SEEK_SET) == -1) ||
627 ((wsize = write(fp, (char*)whdrp, sizeof(HASHHDR))) == -1))
628 return (-1);
629 else
630 if (wsize != sizeof(HASHHDR)) {
631 errno = EFTYPE;
632 hashp->dbmerrno = errno;
633 return (-1);
634 }
635 for (i = 0; i < NCACHED; i++)
636 if (hashp->mapp[i])
637 if (__put_page(hashp, (char *)hashp->mapp[i],
638 hashp->BITMAPS[i], 0, 1))
639 return (-1);
640 return (0);
641 }
642
643 /*******************************SEARCH ROUTINES *****************************/
644 /*
645 * All the access routines return
646 *
647 * Returns:
648 * 0 on SUCCESS
649 * 1 to indicate an external DBM_ERROR (i.e. key not found, etc)
650 * -1 to indicate an internal DBM_ERROR (i.e. out of memory, etc)
651 */
652 static int
653 hash_get(
654 const DB *dbp,
655 const DBT *key,
656 DBT *data,
657 uint flag)
658 {
659 HTAB *hashp;
660 int rv;
661
662 hashp = (HTAB *)dbp->internal;
663 if (!hashp)
664 return (DBM_ERROR);
665
666 if (flag) {
667 hashp->dbmerrno = errno = EINVAL;
668 return (DBM_ERROR);
669 }
670
671 rv = hash_access(hashp, HASH_GET, (DBT *)key, data);
672
673 if(rv == DATABASE_CORRUPTED_ERROR)
674 {
675 #if defined(unix) && defined(DEBUG)
676 printf("\n\nDBM Database has been corrupted, tell Lou...\n\n");
677 #endif
678 __remove_database((DB *)dbp);
679 }
680
681 return(rv);
682 }
683
684 static int
685 hash_put(
686 const DB *dbp,
687 DBT *key,
688 const DBT *data,
689 uint flag)
690 {
691 HTAB *hashp;
692 int rv;
693
694 hashp = (HTAB *)dbp->internal;
695 if (!hashp)
696 return (DBM_ERROR);
697
698 if (flag && flag != R_NOOVERWRITE) {
699 hashp->dbmerrno = errno = EINVAL;
700 return (DBM_ERROR);
701 }
702 if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
703 hashp->dbmerrno = errno = EPERM;
704 return (DBM_ERROR);
705 }
706
707 rv = hash_access(hashp, flag == R_NOOVERWRITE ?
708 HASH_PUTNEW : HASH_PUT, (DBT *)key, (DBT *)data);
709
710 if(rv == DATABASE_CORRUPTED_ERROR)
711 {
712 #if defined(unix) && defined(DEBUG)
713 printf("\n\nDBM Database has been corrupted, tell Lou...\n\n");
714 #endif
715 __remove_database((DB *)dbp);
716 }
717
718 return(rv);
719 }
720
721 static int
722 hash_delete(
723 const DB *dbp,
724 const DBT *key,
725 uint flag) /* Ignored */
726 {
727 HTAB *hashp;
728 int rv;
729
730 hashp = (HTAB *)dbp->internal;
731 if (!hashp)
732 return (DBM_ERROR);
733
734 if (flag && flag != R_CURSOR) {
735 hashp->dbmerrno = errno = EINVAL;
736 return (DBM_ERROR);
737 }
738 if ((hashp->flags & O_ACCMODE) == O_RDONLY) {
739 hashp->dbmerrno = errno = EPERM;
740 return (DBM_ERROR);
741 }
742 rv = hash_access(hashp, HASH_DELETE, (DBT *)key, NULL);
743
744 if(rv == DATABASE_CORRUPTED_ERROR)
745 {
746 #if defined(unix) && defined(DEBUG)
747 printf("\n\nDBM Database has been corrupted, tell Lou...\n\n");
748 #endif
749 __remove_database((DB *)dbp);
750 }
751
752 return(rv);
753 }
754
755 #define MAX_OVERFLOW_HASH_ACCESS_LOOPS 2000
756 /*
757 * Assume that hashp has been set in wrapper routine.
758 */
759 static int
760 hash_access(
761 HTAB *hashp,
762 ACTION action,
763 DBT *key, DBT *val)
764 {
765 register BUFHEAD *rbufp;
766 BUFHEAD *bufp, *save_bufp;
767 register uint16 *bp;
768 register long n, ndx, off;
769 register size_t size;
770 register char *kp;
771 uint16 pageno;
772 uint32 ovfl_loop_count=0;
773 int32 last_overflow_page_no = -1;
774
775 #ifdef HASH_STATISTICS
776 hash_accesses++;
777 #endif
778
779 off = hashp->BSIZE;
780 size = key->size;
781 kp = (char *)key->data;
782 rbufp = __get_buf(hashp, __call_hash(hashp, kp, size), NULL, 0);
783 if (!rbufp)
784 return (DATABASE_CORRUPTED_ERROR);
785 save_bufp = rbufp;
786
787 /* Pin the bucket chain */
788 rbufp->flags |= BUF_PIN;
789 for (bp = (uint16 *)rbufp->page, n = *bp++, ndx = 1; ndx < n;)
790 {
791
792 if (bp[1] >= REAL_KEY) {
793 /* Real key/data pair */
794 if (size == (unsigned long)(off - *bp) &&
795 memcmp(kp, rbufp->page + *bp, size) == 0)
796 goto found;
797 off = bp[1];
798 #ifdef HASH_STATISTICS
799 hash_collisions++;
800 #endif
801 bp += 2;
802 ndx += 2;
803 } else if (bp[1] == OVFLPAGE) {
804
805 /* database corruption: overflow loop detection */
806 if(last_overflow_page_no == (int32)*bp)
807 return (DATABASE_CORRUPTED_ERROR);
808
809 last_overflow_page_no = *bp;
810
811 rbufp = __get_buf(hashp, *bp, rbufp, 0);
812 if (!rbufp) {
813 save_bufp->flags &= ~BUF_PIN;
814 return (DBM_ERROR);
815 }
816
817 ovfl_loop_count++;
818 if(ovfl_loop_count > MAX_OVERFLOW_HASH_ACCESS_LOOPS)
819 return (DATABASE_CORRUPTED_ERROR);
820
821 /* FOR LOOP INIT */
822 bp = (uint16 *)rbufp->page;
823 n = *bp++;
824 ndx = 1;
825 off = hashp->BSIZE;
826 } else if (bp[1] < REAL_KEY) {
827 if ((ndx =
828 __find_bigpair(hashp, rbufp, ndx, kp, (int)size)) > 0)
829 goto found;
830 if (ndx == -2) {
831 bufp = rbufp;
832 if (!(pageno =
833 __find_last_page(hashp, &bufp))) {
834 ndx = 0;
835 rbufp = bufp;
836 break; /* FOR */
837 }
838 rbufp = __get_buf(hashp, pageno, bufp, 0);
839 if (!rbufp) {
840 save_bufp->flags &= ~BUF_PIN;
841 return (DBM_ERROR);
842 }
843 /* FOR LOOP INIT */
844 bp = (uint16 *)rbufp->page;
845 n = *bp++;
846 ndx = 1;
847 off = hashp->BSIZE;
848 } else {
849 save_bufp->flags &= ~BUF_PIN;
850 return (DBM_ERROR);
851
852 }
853 }
854 }
855
856 /* Not found */
857 switch (action) {
858 case HASH_PUT:
859 case HASH_PUTNEW:
860 if (__addel(hashp, rbufp, key, val)) {
861 save_bufp->flags &= ~BUF_PIN;
862 return (DBM_ERROR);
863 } else {
864 save_bufp->flags &= ~BUF_PIN;
865 return (SUCCESS);
866 }
867 case HASH_GET:
868 case HASH_DELETE:
869 default:
870 save_bufp->flags &= ~BUF_PIN;
871 return (ABNORMAL);
872 }
873
874 found:
875 switch (action) {
876 case HASH_PUTNEW:
877 save_bufp->flags &= ~BUF_PIN;
878 return (ABNORMAL);
879 case HASH_GET:
880 bp = (uint16 *)rbufp->page;
881 if (bp[ndx + 1] < REAL_KEY) {
882 if (__big_return(hashp, rbufp, ndx, val, 0))
883 return (DBM_ERROR);
884 } else {
885 val->data = (uint8 *)rbufp->page + (int)bp[ndx + 1];
886 val->size = bp[ndx] - bp[ndx + 1];
887 }
888 break;
889 case HASH_PUT:
890 if ((__delpair(hashp, rbufp, ndx)) ||
891 (__addel(hashp, rbufp, key, val))) {
892 save_bufp->flags &= ~BUF_PIN;
893 return (DBM_ERROR);
894 }
895 break;
896 case HASH_DELETE:
897 if (__delpair(hashp, rbufp, ndx))
898 return (DBM_ERROR);
899 break;
900 default:
901 abort();
902 }
903 save_bufp->flags &= ~BUF_PIN;
904 return (SUCCESS);
905 }
906
907 static int
908 hash_seq(
909 const DB *dbp,
910 DBT *key, DBT *data,
911 uint flag)
912 {
913 register uint32 bucket;
914 register BUFHEAD *bufp;
915 HTAB *hashp;
916 uint16 *bp, ndx;
917
918 hashp = (HTAB *)dbp->internal;
919 if (!hashp)
920 return (DBM_ERROR);
921
922 if (flag && flag != R_FIRST && flag != R_NEXT) {
923 hashp->dbmerrno = errno = EINVAL;
924 return (DBM_ERROR);
925 }
926 #ifdef HASH_STATISTICS
927 hash_accesses++;
928 #endif
929 if ((hashp->cbucket < 0) || (flag == R_FIRST)) {
930 hashp->cbucket = 0;
931 hashp->cndx = 1;
932 hashp->cpage = NULL;
933 }
934
935 for (bp = NULL; !bp || !bp[0]; ) {
936 if (!(bufp = hashp->cpage)) {
937 for (bucket = hashp->cbucket;
938 bucket <= (uint32)hashp->MAX_BUCKET;
939 bucket++, hashp->cndx = 1) {
940 bufp = __get_buf(hashp, bucket, NULL, 0);
941 if (!bufp)
942 return (DBM_ERROR);
943 hashp->cpage = bufp;
944 bp = (uint16 *)bufp->page;
945 if (bp[0])
946 break;
947 }
948 hashp->cbucket = bucket;
949 if (hashp->cbucket > hashp->MAX_BUCKET) {
950 hashp->cbucket = -1;
951 return (ABNORMAL);
952 }
953 } else
954 bp = (uint16 *)hashp->cpage->page;
955
956 #ifdef DEBUG
957 assert(bp);
958 assert(bufp);
959 #endif
960 while (bp[hashp->cndx + 1] == OVFLPAGE) {
961 bufp = hashp->cpage =
962 __get_buf(hashp, bp[hashp->cndx], bufp, 0);
963 if (!bufp)
964 return (DBM_ERROR);
965 bp = (uint16 *)(bufp->page);
966 hashp->cndx = 1;
967 }
968 if (!bp[0]) {
969 hashp->cpage = NULL;
970 ++hashp->cbucket;
971 }
972 }
973 ndx = hashp->cndx;
974 if (bp[ndx + 1] < REAL_KEY) {
975 if (__big_keydata(hashp, bufp, key, data, 1))
976 return (DBM_ERROR);
977 } else {
978 key->data = (uint8 *)hashp->cpage->page + bp[ndx];
979 key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx];
980 data->data = (uint8 *)hashp->cpage->page + bp[ndx + 1];
981 data->size = bp[ndx] - bp[ndx + 1];
982 ndx += 2;
983 if (ndx > bp[0]) {
984 hashp->cpage = NULL;
985 hashp->cbucket++;
986 hashp->cndx = 1;
987 } else
988 hashp->cndx = ndx;
989 }
990 return (SUCCESS);
991 }
992
993 /********************************* UTILITIES ************************/
994
995 /*
996 * Returns:
997 * 0 ==> OK
998 * -1 ==> Error
999 */
1000 extern int
1001 __expand_table(HTAB *hashp)
1002 {
1003 uint32 old_bucket, new_bucket;
1004 int new_segnum, spare_ndx;
1005 size_t dirsize;
1006
1007 #ifdef HASH_STATISTICS
1008 hash_expansions++;
1009 #endif
1010 new_bucket = ++hashp->MAX_BUCKET;
1011 old_bucket = (hashp->MAX_BUCKET & hashp->LOW_MASK);
1012
1013 new_segnum = new_bucket >> hashp->SSHIFT;
1014
1015 /* Check if we need a new segment */
1016 if (new_segnum >= hashp->nsegs) {
1017 /* Check if we need to expand directory */
1018 if (new_segnum >= hashp->DSIZE) {
1019 /* Reallocate directory */
1020 dirsize = hashp->DSIZE * sizeof(SEGMENT *);
1021 if (!hash_realloc(&hashp->dir, dirsize, dirsize << 1))
1022 return (-1);
1023 hashp->DSIZE = dirsize << 1;
1024 }
1025 if ((hashp->dir[new_segnum] =
1026 (SEGMENT)calloc((size_t)hashp->SGSIZE, sizeof(SEGMENT))) == NULL)
1027 return (-1);
1028 hashp->exsegs++;
1029 hashp->nsegs++;
1030 }
1031 /*
1032 * If the split point is increasing (MAX_BUCKET's log base 2
1033 * * increases), we need to copy the current contents of the spare
1034 * split bucket to the next bucket.
1035 */
1036 spare_ndx = __log2((uint32)(hashp->MAX_BUCKET + 1));
1037 if (spare_ndx > hashp->OVFL_POINT) {
1038 hashp->SPARES[spare_ndx] = hashp->SPARES[hashp->OVFL_POINT];
1039 hashp->OVFL_POINT = spare_ndx;
1040 }
1041
1042 if (new_bucket > (uint32)hashp->HIGH_MASK) {
1043 /* Starting a new doubling */
1044 hashp->LOW_MASK = hashp->HIGH_MASK;
1045 hashp->HIGH_MASK = new_bucket | hashp->LOW_MASK;
1046 }
1047 /* Relocate records to the new bucket */
1048 return (__split_page(hashp, old_bucket, new_bucket));
1049 }
1050
1051 /*
1052 * If realloc guarantees that the pointer is not destroyed if the realloc
1053 * fails, then this routine can go away.
1054 */
1055 static void *
1056 hash_realloc(
1057 SEGMENT **p_ptr,
1058 size_t oldsize, size_t newsize)
1059 {
1060 register void *p;
1061
1062 if ((p = malloc(newsize))) {
1063 memmove(p, *p_ptr, oldsize);
1064 memset((char *)p + oldsize, 0, newsize - oldsize);
1065 free(*p_ptr);
1066 *p_ptr = (SEGMENT *)p;
1067 }
1068 return (p);
1069 }
1070
1071 extern uint32
1072 __call_hash(HTAB *hashp, char *k, size_t len)
1073 {
1074 uint32 n, bucket;
1075
1076 n = hashp->hash(k, len);
1077 bucket = n & hashp->HIGH_MASK;
1078 if (bucket > (uint32)hashp->MAX_BUCKET)
1079 bucket = bucket & hashp->LOW_MASK;
1080 return (bucket);
1081 }
1082
1083 /*
1084 * Allocate segment table. On error, set errno.
1085 *
1086 * Returns 0 on success
1087 */
1088 static int
1089 alloc_segs(
1090 HTAB *hashp,
1091 int nsegs)
1092 {
1093 register int i;
1094 register SEGMENT store;
1095
1096 if ((hashp->dir =
1097 (SEGMENT *)calloc((size_t)hashp->DSIZE, sizeof(SEGMENT *))) == NULL) {
1098 errno = ENOMEM;
1099 return (-1);
1100 }
1101 /* Allocate segments */
1102 if ((store =
1103 (SEGMENT)calloc((size_t)nsegs << hashp->SSHIFT, sizeof(SEGMENT))) == NULL) {
1104 errno = ENOMEM;
1105 return (-1);
1106 }
1107 for (i = 0; i < nsegs; i++, hashp->nsegs++)
1108 hashp->dir[i] = &store[i << hashp->SSHIFT];
1109 return (0);
1110 }
1111
1112 #if BYTE_ORDER == LITTLE_ENDIAN
1113 /*
1114 * Hashp->hdr needs to be byteswapped.
1115 */
1116 static void
1117 swap_header_copy(
1118 HASHHDR *srcp, HASHHDR *destp)
1119 {
1120 int i;
1121
1122 P_32_COPY(srcp->magic, destp->magic);
1123 P_32_COPY(srcp->version, destp->version);
1124 P_32_COPY(srcp->lorder, destp->lorder);
1125 P_32_COPY(srcp->bsize, destp->bsize);
1126 P_32_COPY(srcp->bshift, destp->bshift);
1127 P_32_COPY(srcp->dsize, destp->dsize);
1128 P_32_COPY(srcp->ssize, destp->ssize);
1129 P_32_COPY(srcp->sshift, destp->sshift);
1130 P_32_COPY(srcp->ovfl_point, destp->ovfl_point);
1131 P_32_COPY(srcp->last_freed, destp->last_freed);
1132 P_32_COPY(srcp->max_bucket, destp->max_bucket);
1133 P_32_COPY(srcp->high_mask, destp->high_mask);
1134 P_32_COPY(srcp->low_mask, destp->low_mask);
1135 P_32_COPY(srcp->ffactor, destp->ffactor);
1136 P_32_COPY(srcp->nkeys, destp->nkeys);
1137 P_32_COPY(srcp->hdrpages, destp->hdrpages);
1138 P_32_COPY(srcp->h_charkey, destp->h_charkey);
1139 for (i = 0; i < NCACHED; i++) {
1140 P_32_COPY(srcp->spares[i], destp->spares[i]);
1141 P_16_COPY(srcp->bitmaps[i], destp->bitmaps[i]);
1142 }
1143 }
1144
1145 static void
1146 swap_header(HTAB *hashp)
1147 {
1148 HASHHDR *hdrp;
1149 int i;
1150
1151 hdrp = &hashp->hdr;
1152
1153 M_32_SWAP(hdrp->magic);
1154 M_32_SWAP(hdrp->version);
1155 M_32_SWAP(hdrp->lorder);
1156 M_32_SWAP(hdrp->bsize);
1157 M_32_SWAP(hdrp->bshift);
1158 M_32_SWAP(hdrp->dsize);
1159 M_32_SWAP(hdrp->ssize);
1160 M_32_SWAP(hdrp->sshift);
1161 M_32_SWAP(hdrp->ovfl_point);
1162 M_32_SWAP(hdrp->last_freed);
1163 M_32_SWAP(hdrp->max_bucket);
1164 M_32_SWAP(hdrp->high_mask);
1165 M_32_SWAP(hdrp->low_mask);
1166 M_32_SWAP(hdrp->ffactor);
1167 M_32_SWAP(hdrp->nkeys);
1168 M_32_SWAP(hdrp->hdrpages);
1169 M_32_SWAP(hdrp->h_charkey);
1170 for (i = 0; i < NCACHED; i++) {
1171 M_32_SWAP(hdrp->spares[i]);
1172 M_16_SWAP(hdrp->bitmaps[i]);
1173 }
1174 }
1175 #endif
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