1 /* $NetBSD: hash.c,v 1.32 2012/03/13 21:13:32 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 * Margo Seltzer. 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: hash.c,v 1.32 2012/03/13 21:13:32 christos Exp $"); 41 42 #include "namespace.h" 43 #include <sys/param.h> 44 #include <sys/stat.h> 45 46 #include <errno.h> 47 #include <fcntl.h> 48 #include <stdio.h> 49 #include <stdlib.h> 50 #include <string.h> 51 #include <unistd.h> 52 #include <assert.h> 53 54 #include <db.h> 55 #include "hash.h" 56 #include "page.h" 57 #include "extern.h" 58 59 static int alloc_segs(HTAB *, int); 60 static int flush_meta(HTAB *); 61 static int hash_access(HTAB *, ACTION, DBT *, DBT *); 62 static int hash_close(DB *); 63 static int hash_delete(const DB *, const DBT *, uint32_t); 64 static int hash_fd(const DB *); 65 static int hash_get(const DB *, const DBT *, DBT *, uint32_t); 66 static int hash_put(const DB *, DBT *, const DBT *, uint32_t); 67 static void *hash_realloc(SEGMENT **, size_t, size_t); 68 static int hash_seq(const DB *, DBT *, DBT *, uint32_t); 69 static int hash_sync(const DB *, uint32_t); 70 static int hdestroy(HTAB *); 71 static HTAB *init_hash(HTAB *, const char *, const HASHINFO *); 72 static int init_htab(HTAB *, size_t); 73 #if BYTE_ORDER == LITTLE_ENDIAN 74 static void swap_header(HTAB *); 75 static void swap_header_copy(HASHHDR *, HASHHDR *); 76 #endif 77 78 /* Fast arithmetic, relying on powers of 2, */ 79 #define MOD(x, y) ((x) & ((y) - 1)) 80 81 #define RETURN_ERROR(ERR, LOC) { save_errno = ERR; goto LOC; } 82 83 /* Return values */ 84 #define SUCCESS (0) 85 #define ERROR (-1) 86 #define ABNORMAL (1) 87 88 #ifdef HASH_STATISTICS 89 int hash_accesses, hash_collisions, hash_expansions, hash_overflows; 90 #endif 91 92 /************************** INTERFACE ROUTINES ***************************/ 93 /* OPEN/CLOSE */ 94 95 /* ARGSUSED */ 96 DB * 97 __hash_open(const char *file, int flags, mode_t mode, const HASHINFO *info, 98 int dflags) 99 { 100 HTAB *hashp; 101 struct stat statbuf; 102 DB *dbp; 103 int bpages, new_table, nsegs, save_errno; 104 ssize_t hdrsize; 105 106 if ((flags & O_ACCMODE) == O_WRONLY) { 107 errno = EINVAL; 108 return (NULL); 109 } 110 111 if (!(hashp = calloc(1, sizeof(HTAB)))) 112 return (NULL); 113 hashp->fp = -1; 114 115 /* 116 * Even if user wants write only, we need to be able to read 117 * the actual file, so we need to open it read/write. But, the 118 * field in the hashp structure needs to be accurate so that 119 * we can check accesses. 120 */ 121 hashp->flags = flags; 122 123 new_table = 0; 124 if (!file || (flags & O_TRUNC) || 125 (stat(file, &statbuf) && (errno == ENOENT))) { 126 if (errno == ENOENT) 127 errno = 0; /* Just in case someone looks at errno */ 128 new_table = 1; 129 } 130 if (file) { 131 if ((hashp->fp = open(file, flags, mode)) == -1) 132 RETURN_ERROR(errno, error0); 133 if (fcntl(hashp->fp, F_SETFD, FD_CLOEXEC) == -1) 134 RETURN_ERROR(errno, error1); 135 if (fstat(hashp->fp, &statbuf) == -1) 136 RETURN_ERROR(errno, error1); 137 new_table |= statbuf.st_size == 0; 138 } 139 if (new_table) { 140 if (!(hashp = init_hash(hashp, file, info))) 141 RETURN_ERROR(errno, error1); 142 } else { 143 /* Table already exists */ 144 if (info && info->hash) 145 hashp->hash = info->hash; 146 else 147 hashp->hash = __default_hash; 148 149 hdrsize = read(hashp->fp, &hashp->hdr, sizeof(HASHHDR)); 150 #if BYTE_ORDER == LITTLE_ENDIAN 151 swap_header(hashp); 152 #endif 153 if (hdrsize == -1) 154 RETURN_ERROR(errno, error1); 155 if (hdrsize != sizeof(HASHHDR)) 156 RETURN_ERROR(EFTYPE, error1); 157 /* Verify file type, versions and hash function */ 158 if (hashp->MAGIC != HASHMAGIC) 159 RETURN_ERROR(EFTYPE, error1); 160 #define OLDHASHVERSION 1 161 if (hashp->VERSION != HASHVERSION && 162 hashp->VERSION != OLDHASHVERSION) 163 RETURN_ERROR(EFTYPE, error1); 164 if (hashp->hash(CHARKEY, sizeof(CHARKEY)) != 165 (uint32_t)hashp->H_CHARKEY) 166 RETURN_ERROR(EFTYPE, error1); 167 /* 168 * Figure out how many segments we need. Max_Bucket is the 169 * maximum bucket number, so the number of buckets is 170 * max_bucket + 1. 171 */ 172 nsegs = (hashp->MAX_BUCKET + 1 + hashp->SGSIZE - 1) / 173 hashp->SGSIZE; 174 hashp->nsegs = 0; 175 if (alloc_segs(hashp, nsegs)) 176 /* 177 * If alloc_segs fails, table will have been destroyed 178 * and errno will have been set. 179 */ 180 return (NULL); 181 /* Read in bitmaps */ 182 bpages = (hashp->SPARES[hashp->OVFL_POINT] + 183 (unsigned int)(hashp->BSIZE << BYTE_SHIFT) - 1) >> 184 (hashp->BSHIFT + BYTE_SHIFT); 185 186 hashp->nmaps = bpages; 187 (void)memset(&hashp->mapp[0], 0, bpages * sizeof(uint32_t *)); 188 } 189 190 /* Initialize Buffer Manager */ 191 if (info && info->cachesize) 192 __buf_init(hashp, info->cachesize); 193 else 194 __buf_init(hashp, DEF_BUFSIZE); 195 196 hashp->new_file = new_table; 197 hashp->save_file = file && (hashp->flags & O_RDWR); 198 hashp->cbucket = -1; 199 if (!(dbp = malloc(sizeof(DB)))) { 200 save_errno = errno; 201 hdestroy(hashp); 202 errno = save_errno; 203 return (NULL); 204 } 205 dbp->internal = hashp; 206 dbp->close = hash_close; 207 dbp->del = hash_delete; 208 dbp->fd = hash_fd; 209 dbp->get = hash_get; 210 dbp->put = hash_put; 211 dbp->seq = hash_seq; 212 dbp->sync = hash_sync; 213 dbp->type = DB_HASH; 214 215 #ifdef DEBUG1 216 (void)fprintf(stderr, 217 "%s\n%s%p\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%d\n%s%x\n%s%x\n%s%d\n%s%d\n", 218 "init_htab:", 219 "TABLE POINTER ", hashp, 220 "BUCKET SIZE ", hashp->BSIZE, 221 "BUCKET SHIFT ", hashp->BSHIFT, 222 "DIRECTORY SIZE ", hashp->DSIZE, 223 "SEGMENT SIZE ", hashp->SGSIZE, 224 "SEGMENT SHIFT ", hashp->SSHIFT, 225 "FILL FACTOR ", hashp->FFACTOR, 226 "MAX BUCKET ", hashp->MAX_BUCKET, 227 "OVFL POINT ", hashp->OVFL_POINT, 228 "LAST FREED ", hashp->LAST_FREED, 229 "HIGH MASK ", hashp->HIGH_MASK, 230 "LOW MASK ", hashp->LOW_MASK, 231 "NSEGS ", hashp->nsegs, 232 "NKEYS ", hashp->NKEYS); 233 #endif 234 #ifdef HASH_STATISTICS 235 hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0; 236 #endif 237 return (dbp); 238 239 error1: 240 if (hashp != NULL) 241 (void)close(hashp->fp); 242 243 error0: 244 free(hashp); 245 errno = save_errno; 246 return (NULL); 247 } 248 249 static int 250 hash_close(DB *dbp) 251 { 252 HTAB *hashp; 253 int retval; 254 255 if (!dbp) 256 return (ERROR); 257 258 hashp = dbp->internal; 259 retval = hdestroy(hashp); 260 free(dbp); 261 return (retval); 262 } 263 264 static int 265 hash_fd(const DB *dbp) 266 { 267 HTAB *hashp; 268 269 if (!dbp) 270 return (ERROR); 271 272 hashp = dbp->internal; 273 if (hashp->fp == -1) { 274 errno = ENOENT; 275 return (-1); 276 } 277 return (hashp->fp); 278 } 279 280 /************************** LOCAL CREATION ROUTINES **********************/ 281 static HTAB * 282 init_hash(HTAB *hashp, const char *file, const HASHINFO *info) 283 { 284 struct stat statbuf; 285 int nelem; 286 287 nelem = 1; 288 hashp->NKEYS = 0; 289 hashp->LORDER = BYTE_ORDER; 290 hashp->BSIZE = DEF_BUCKET_SIZE; 291 hashp->BSHIFT = DEF_BUCKET_SHIFT; 292 hashp->SGSIZE = DEF_SEGSIZE; 293 hashp->SSHIFT = DEF_SEGSIZE_SHIFT; 294 hashp->DSIZE = DEF_DIRSIZE; 295 hashp->FFACTOR = DEF_FFACTOR; 296 hashp->hash = __default_hash; 297 memset(hashp->SPARES, 0, sizeof(hashp->SPARES)); 298 memset(hashp->BITMAPS, 0, sizeof (hashp->BITMAPS)); 299 300 /* Fix bucket size to be optimal for file system */ 301 if (file != NULL) { 302 if (stat(file, &statbuf)) 303 return (NULL); 304 hashp->BSIZE = MIN(statbuf.st_blksize, MAX_BSIZE); 305 hashp->BSHIFT = __log2((uint32_t)hashp->BSIZE); 306 } 307 308 if (info) { 309 if (info->bsize) { 310 /* Round pagesize up to power of 2 */ 311 hashp->BSHIFT = __log2(info->bsize); 312 hashp->BSIZE = 1 << hashp->BSHIFT; 313 if (hashp->BSIZE > MAX_BSIZE) { 314 errno = EINVAL; 315 return (NULL); 316 } 317 } 318 if (info->ffactor) 319 hashp->FFACTOR = info->ffactor; 320 if (info->hash) 321 hashp->hash = info->hash; 322 if (info->nelem) 323 nelem = info->nelem; 324 if (info->lorder) { 325 if (info->lorder != BIG_ENDIAN && 326 info->lorder != LITTLE_ENDIAN) { 327 errno = EINVAL; 328 return (NULL); 329 } 330 hashp->LORDER = info->lorder; 331 } 332 } 333 /* init_htab should destroy the table and set errno if it fails */ 334 if (init_htab(hashp, (size_t)nelem)) 335 return (NULL); 336 else 337 return (hashp); 338 } 339 /* 340 * This calls alloc_segs which may run out of memory. Alloc_segs will destroy 341 * the table and set errno, so we just pass the error information along. 342 * 343 * Returns 0 on No Error 344 */ 345 static int 346 init_htab(HTAB *hashp, size_t nelem) 347 { 348 int nbuckets; 349 uint32_t nsegs; 350 int l2; 351 352 /* 353 * Divide number of elements by the fill factor and determine a 354 * desired number of buckets. Allocate space for the next greater 355 * power of two number of buckets. 356 */ 357 nelem = (nelem - 1) / hashp->FFACTOR + 1; 358 359 _DBFIT(nelem, uint32_t); 360 l2 = __log2(MAX((uint32_t)nelem, 2)); 361 nbuckets = 1 << l2; 362 363 hashp->SPARES[l2] = l2 + 1; 364 hashp->SPARES[l2 + 1] = l2 + 1; 365 hashp->OVFL_POINT = l2; 366 hashp->LAST_FREED = 2; 367 368 /* First bitmap page is at: splitpoint l2 page offset 1 */ 369 if (__ibitmap(hashp, (int)OADDR_OF(l2, 1), l2 + 1, 0)) 370 return (-1); 371 372 hashp->MAX_BUCKET = hashp->LOW_MASK = nbuckets - 1; 373 hashp->HIGH_MASK = (nbuckets << 1) - 1; 374 /* LINTED constant in conditional context */ 375 hashp->HDRPAGES = ((MAX(sizeof(HASHHDR), MINHDRSIZE) - 1) >> 376 hashp->BSHIFT) + 1; 377 378 nsegs = (nbuckets - 1) / hashp->SGSIZE + 1; 379 nsegs = 1 << __log2(nsegs); 380 381 if (nsegs > (uint32_t)hashp->DSIZE) 382 hashp->DSIZE = nsegs; 383 return (alloc_segs(hashp, (int)nsegs)); 384 } 385 386 /********************** DESTROY/CLOSE ROUTINES ************************/ 387 388 /* 389 * Flushes any changes to the file if necessary and destroys the hashp 390 * structure, freeing all allocated space. 391 */ 392 static int 393 hdestroy(HTAB *hashp) 394 { 395 int i, save_errno; 396 397 save_errno = 0; 398 399 #ifdef HASH_STATISTICS 400 (void)fprintf(stderr, "hdestroy: accesses %d collisions %d\n", 401 hash_accesses, hash_collisions); 402 (void)fprintf(stderr, "hdestroy: expansions %d\n", 403 hash_expansions); 404 (void)fprintf(stderr, "hdestroy: overflows %d\n", 405 hash_overflows); 406 (void)fprintf(stderr, "keys %d maxp %d segmentcount %d\n", 407 hashp->NKEYS, hashp->MAX_BUCKET, hashp->nsegs); 408 409 for (i = 0; i < NCACHED; i++) 410 (void)fprintf(stderr, 411 "spares[%d] = %d\n", i, hashp->SPARES[i]); 412 #endif 413 /* 414 * Call on buffer manager to free buffers, and if required, 415 * write them to disk. 416 */ 417 if (__buf_free(hashp, 1, hashp->save_file)) 418 save_errno = errno; 419 if (hashp->dir) { 420 free(*hashp->dir); /* Free initial segments */ 421 /* Free extra segments */ 422 while (hashp->exsegs--) 423 free(hashp->dir[--hashp->nsegs]); 424 free(hashp->dir); 425 } 426 if (flush_meta(hashp) && !save_errno) 427 save_errno = errno; 428 /* Free Bigmaps */ 429 for (i = 0; i < hashp->nmaps; i++) 430 if (hashp->mapp[i]) 431 free(hashp->mapp[i]); 432 433 if (hashp->fp != -1) 434 (void)close(hashp->fp); 435 436 free(hashp); 437 438 if (save_errno) { 439 errno = save_errno; 440 return (ERROR); 441 } 442 return (SUCCESS); 443 } 444 /* 445 * Write modified pages to disk 446 * 447 * Returns: 448 * 0 == OK 449 * -1 ERROR 450 */ 451 static int 452 hash_sync(const DB *dbp, uint32_t flags) 453 { 454 HTAB *hashp; 455 456 if (flags != 0) { 457 errno = EINVAL; 458 return (ERROR); 459 } 460 461 if (!dbp) 462 return (ERROR); 463 464 hashp = dbp->internal; 465 if (!hashp->save_file) 466 return (0); 467 if (__buf_free(hashp, 0, 1) || flush_meta(hashp)) 468 return (ERROR); 469 hashp->new_file = 0; 470 return (0); 471 } 472 473 /* 474 * Returns: 475 * 0 == OK 476 * -1 indicates that errno should be set 477 */ 478 static int 479 flush_meta(HTAB *hashp) 480 { 481 HASHHDR *whdrp; 482 #if BYTE_ORDER == LITTLE_ENDIAN 483 HASHHDR whdr; 484 #endif 485 int fp, i; 486 ssize_t wsize; 487 488 if (!hashp->save_file) 489 return (0); 490 hashp->MAGIC = HASHMAGIC; 491 hashp->VERSION = HASHVERSION; 492 hashp->H_CHARKEY = hashp->hash(CHARKEY, sizeof(CHARKEY)); 493 494 fp = hashp->fp; 495 whdrp = &hashp->hdr; 496 #if BYTE_ORDER == LITTLE_ENDIAN 497 whdrp = &whdr; 498 swap_header_copy(&hashp->hdr, whdrp); 499 #endif 500 if ((wsize = pwrite(fp, whdrp, sizeof(HASHHDR), (off_t)0)) == -1) 501 return (-1); 502 else 503 if (wsize != sizeof(HASHHDR)) { 504 errno = EFTYPE; 505 hashp->err = errno; 506 return (-1); 507 } 508 for (i = 0; i < NCACHED; i++) 509 if (hashp->mapp[i]) 510 if (__put_page(hashp, (char *)(void *)hashp->mapp[i], 511 (u_int)hashp->BITMAPS[i], 0, 1)) 512 return (-1); 513 return (0); 514 } 515 516 /*******************************SEARCH ROUTINES *****************************/ 517 /* 518 * All the access routines return 519 * 520 * Returns: 521 * 0 on SUCCESS 522 * 1 to indicate an external ERROR (i.e. key not found, etc) 523 * -1 to indicate an internal ERROR (i.e. out of memory, etc) 524 */ 525 static int 526 hash_get(const DB *dbp, const DBT *key, DBT *data, uint32_t flag) 527 { 528 HTAB *hashp; 529 530 hashp = dbp->internal; 531 if (flag) { 532 hashp->err = errno = EINVAL; 533 return (ERROR); 534 } 535 return (hash_access(hashp, HASH_GET, __UNCONST(key), data)); 536 } 537 538 static int 539 hash_put(const DB *dbp, DBT *key, const DBT *data, uint32_t flag) 540 { 541 HTAB *hashp; 542 543 hashp = dbp->internal; 544 if (flag && flag != R_NOOVERWRITE) { 545 hashp->err = errno = EINVAL; 546 return (ERROR); 547 } 548 if ((hashp->flags & O_ACCMODE) == O_RDONLY) { 549 hashp->err = errno = EPERM; 550 return (ERROR); 551 } 552 /* LINTED const castaway */ 553 return (hash_access(hashp, flag == R_NOOVERWRITE ? 554 HASH_PUTNEW : HASH_PUT, __UNCONST(key), __UNCONST(data))); 555 } 556 557 static int 558 hash_delete(const DB *dbp, const DBT *key, uint32_t flag) 559 { 560 HTAB *hashp; 561 562 hashp = dbp->internal; 563 if (flag && flag != R_CURSOR) { 564 hashp->err = errno = EINVAL; 565 return (ERROR); 566 } 567 if ((hashp->flags & O_ACCMODE) == O_RDONLY) { 568 hashp->err = errno = EPERM; 569 return (ERROR); 570 } 571 return hash_access(hashp, HASH_DELETE, __UNCONST(key), NULL); 572 } 573 574 /* 575 * Assume that hashp has been set in wrapper routine. 576 */ 577 static int 578 hash_access(HTAB *hashp, ACTION action, DBT *key, DBT *val) 579 { 580 BUFHEAD *rbufp; 581 BUFHEAD *bufp, *save_bufp; 582 uint16_t *bp; 583 int n, ndx, off; 584 size_t size; 585 char *kp; 586 uint16_t pageno; 587 588 #ifdef HASH_STATISTICS 589 hash_accesses++; 590 #endif 591 592 off = hashp->BSIZE; 593 size = key->size; 594 kp = (char *)key->data; 595 rbufp = __get_buf(hashp, __call_hash(hashp, kp, (int)size), NULL, 0); 596 if (!rbufp) 597 return (ERROR); 598 save_bufp = rbufp; 599 600 /* Pin the bucket chain */ 601 rbufp->flags |= BUF_PIN; 602 for (bp = (uint16_t *)(void *)rbufp->page, n = *bp++, ndx = 1; ndx < n;) 603 if (bp[1] >= REAL_KEY) { 604 /* Real key/data pair */ 605 if (size == (size_t)(off - *bp) && 606 memcmp(kp, rbufp->page + *bp, size) == 0) 607 goto found; 608 off = bp[1]; 609 #ifdef HASH_STATISTICS 610 hash_collisions++; 611 #endif 612 bp += 2; 613 ndx += 2; 614 } else if (bp[1] == OVFLPAGE) { 615 rbufp = __get_buf(hashp, (uint32_t)*bp, rbufp, 0); 616 if (!rbufp) { 617 save_bufp->flags &= ~BUF_PIN; 618 return (ERROR); 619 } 620 /* FOR LOOP INIT */ 621 bp = (uint16_t *)(void *)rbufp->page; 622 n = *bp++; 623 ndx = 1; 624 off = hashp->BSIZE; 625 } else if (bp[1] < REAL_KEY) { 626 if ((ndx = 627 __find_bigpair(hashp, rbufp, ndx, kp, (int)size)) > 0) 628 goto found; 629 if (ndx == -2) { 630 bufp = rbufp; 631 if (!(pageno = 632 __find_last_page(hashp, &bufp))) { 633 ndx = 0; 634 rbufp = bufp; 635 break; /* FOR */ 636 } 637 rbufp = __get_buf(hashp, (uint32_t)pageno, 638 bufp, 0); 639 if (!rbufp) { 640 save_bufp->flags &= ~BUF_PIN; 641 return (ERROR); 642 } 643 /* FOR LOOP INIT */ 644 bp = (uint16_t *)(void *)rbufp->page; 645 n = *bp++; 646 ndx = 1; 647 off = hashp->BSIZE; 648 } else { 649 save_bufp->flags &= ~BUF_PIN; 650 return (ERROR); 651 } 652 } 653 654 /* Not found */ 655 switch (action) { 656 case HASH_PUT: 657 case HASH_PUTNEW: 658 if (__addel(hashp, rbufp, key, val)) { 659 save_bufp->flags &= ~BUF_PIN; 660 return (ERROR); 661 } else { 662 save_bufp->flags &= ~BUF_PIN; 663 return (SUCCESS); 664 } 665 case HASH_GET: 666 case HASH_DELETE: 667 default: 668 save_bufp->flags &= ~BUF_PIN; 669 return (ABNORMAL); 670 } 671 672 found: 673 switch (action) { 674 case HASH_PUTNEW: 675 save_bufp->flags &= ~BUF_PIN; 676 return (ABNORMAL); 677 case HASH_GET: 678 bp = (uint16_t *)(void *)rbufp->page; 679 if (bp[ndx + 1] < REAL_KEY) { 680 if (__big_return(hashp, rbufp, ndx, val, 0)) 681 return (ERROR); 682 } else { 683 val->data = (uint8_t *)rbufp->page + (int)bp[ndx + 1]; 684 val->size = bp[ndx] - bp[ndx + 1]; 685 } 686 break; 687 case HASH_PUT: 688 if ((__delpair(hashp, rbufp, ndx)) || 689 (__addel(hashp, rbufp, key, val))) { 690 save_bufp->flags &= ~BUF_PIN; 691 return (ERROR); 692 } 693 break; 694 case HASH_DELETE: 695 if (__delpair(hashp, rbufp, ndx)) 696 return (ERROR); 697 break; 698 default: 699 abort(); 700 } 701 save_bufp->flags &= ~BUF_PIN; 702 return (SUCCESS); 703 } 704 705 static int 706 hash_seq(const DB *dbp, DBT *key, DBT *data, uint32_t flag) 707 { 708 uint32_t bucket; 709 BUFHEAD *bufp = NULL; /* XXX: gcc */ 710 HTAB *hashp; 711 uint16_t *bp, ndx; 712 713 hashp = dbp->internal; 714 if (flag && flag != R_FIRST && flag != R_NEXT) { 715 hashp->err = errno = EINVAL; 716 return (ERROR); 717 } 718 #ifdef HASH_STATISTICS 719 hash_accesses++; 720 #endif 721 if ((hashp->cbucket < 0) || (flag == R_FIRST)) { 722 hashp->cbucket = 0; 723 hashp->cndx = 1; 724 hashp->cpage = NULL; 725 } 726 727 for (bp = NULL; !bp || !bp[0]; ) { 728 if (!(bufp = hashp->cpage)) { 729 for (bucket = hashp->cbucket; 730 bucket <= (uint32_t)hashp->MAX_BUCKET; 731 bucket++, hashp->cndx = 1) { 732 bufp = __get_buf(hashp, bucket, NULL, 0); 733 if (!bufp) 734 return (ERROR); 735 hashp->cpage = bufp; 736 bp = (uint16_t *)(void *)bufp->page; 737 if (bp[0]) 738 break; 739 } 740 hashp->cbucket = bucket; 741 if (hashp->cbucket > hashp->MAX_BUCKET) { 742 hashp->cbucket = -1; 743 return (ABNORMAL); 744 } 745 } else 746 bp = (uint16_t *)(void *)hashp->cpage->page; 747 748 _DIAGASSERT(bp != NULL); 749 _DIAGASSERT(bufp != NULL); 750 while (bp[hashp->cndx + 1] == OVFLPAGE) { 751 bufp = hashp->cpage = 752 __get_buf(hashp, (uint32_t)bp[hashp->cndx], bufp, 753 0); 754 if (!bufp) 755 return (ERROR); 756 bp = (uint16_t *)(void *)(bufp->page); 757 hashp->cndx = 1; 758 } 759 if (!bp[0]) { 760 hashp->cpage = NULL; 761 ++hashp->cbucket; 762 } 763 } 764 ndx = hashp->cndx; 765 if (bp[ndx + 1] < REAL_KEY) { 766 if (__big_keydata(hashp, bufp, key, data, 1)) 767 return (ERROR); 768 } else { 769 if (hashp->cpage == NULL) 770 return (ERROR); 771 key->data = (uint8_t *)hashp->cpage->page + bp[ndx]; 772 key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx]; 773 data->data = (uint8_t *)hashp->cpage->page + bp[ndx + 1]; 774 data->size = bp[ndx] - bp[ndx + 1]; 775 ndx += 2; 776 if (ndx > bp[0]) { 777 hashp->cpage = NULL; 778 hashp->cbucket++; 779 hashp->cndx = 1; 780 } else 781 hashp->cndx = ndx; 782 } 783 return (SUCCESS); 784 } 785 786 /********************************* UTILITIES ************************/ 787 788 /* 789 * Returns: 790 * 0 ==> OK 791 * -1 ==> Error 792 */ 793 int 794 __expand_table(HTAB *hashp) 795 { 796 uint32_t old_bucket, new_bucket; 797 int new_segnum, spare_ndx; 798 size_t dirsize; 799 800 #ifdef HASH_STATISTICS 801 hash_expansions++; 802 #endif 803 new_bucket = ++hashp->MAX_BUCKET; 804 old_bucket = (hashp->MAX_BUCKET & hashp->LOW_MASK); 805 806 new_segnum = new_bucket >> hashp->SSHIFT; 807 808 /* Check if we need a new segment */ 809 if (new_segnum >= hashp->nsegs) { 810 /* Check if we need to expand directory */ 811 if (new_segnum >= hashp->DSIZE) { 812 /* Reallocate directory */ 813 dirsize = hashp->DSIZE * sizeof(SEGMENT *); 814 if (!hash_realloc(&hashp->dir, dirsize, dirsize << 1)) 815 return (-1); 816 dirsize <<= 1; 817 _DBFIT(dirsize, uint32_t); 818 hashp->DSIZE = (uint32_t)dirsize; 819 } 820 if ((hashp->dir[new_segnum] = 821 calloc((size_t)hashp->SGSIZE, sizeof(SEGMENT))) == NULL) 822 return (-1); 823 hashp->exsegs++; 824 hashp->nsegs++; 825 } 826 /* 827 * If the split point is increasing (MAX_BUCKET's log base 2 828 * * increases), we need to copy the current contents of the spare 829 * split bucket to the next bucket. 830 */ 831 spare_ndx = __log2((uint32_t)(hashp->MAX_BUCKET + 1)); 832 if (spare_ndx > hashp->OVFL_POINT) { 833 hashp->SPARES[spare_ndx] = hashp->SPARES[hashp->OVFL_POINT]; 834 hashp->OVFL_POINT = spare_ndx; 835 } 836 837 if (new_bucket > (uint32_t)hashp->HIGH_MASK) { 838 /* Starting a new doubling */ 839 hashp->LOW_MASK = hashp->HIGH_MASK; 840 hashp->HIGH_MASK = new_bucket | hashp->LOW_MASK; 841 } 842 /* Relocate records to the new bucket */ 843 return (__split_page(hashp, old_bucket, new_bucket)); 844 } 845 846 /* 847 * If realloc guarantees that the pointer is not destroyed if the realloc 848 * fails, then this routine can go away. 849 */ 850 static void * 851 hash_realloc(SEGMENT **p_ptr, size_t oldsize, size_t newsize) 852 { 853 void *p; 854 855 if ((p = malloc(newsize)) != NULL) { 856 memmove(p, *p_ptr, oldsize); 857 memset((char *)p + oldsize, 0, newsize - oldsize); 858 free(*p_ptr); 859 *p_ptr = p; 860 } 861 return (p); 862 } 863 864 uint32_t 865 __call_hash(HTAB *hashp, char *k, int len) 866 { 867 int n, bucket; 868 869 n = hashp->hash(k, (size_t)len); 870 bucket = n & hashp->HIGH_MASK; 871 if (bucket > hashp->MAX_BUCKET) 872 bucket = bucket & hashp->LOW_MASK; 873 return (bucket); 874 } 875 876 /* 877 * Allocate segment table. On error, destroy the table and set errno. 878 * 879 * Returns 0 on success 880 */ 881 static int 882 alloc_segs(HTAB *hashp, int nsegs) 883 { 884 int i; 885 SEGMENT store; 886 887 int save_errno; 888 889 hashp->dir = calloc((size_t)hashp->DSIZE, sizeof(SEGMENT *)); 890 if (hashp->dir == NULL) { 891 save_errno = errno; 892 (void)hdestroy(hashp); 893 errno = save_errno; 894 return (-1); 895 } 896 hashp->nsegs = nsegs; 897 if (nsegs == 0) 898 return 0; 899 /* Allocate segments */ 900 store = calloc((size_t)(nsegs << hashp->SSHIFT), sizeof(SEGMENT)); 901 if (store == NULL) { 902 save_errno = errno; 903 (void)hdestroy(hashp); 904 errno = save_errno; 905 return (-1); 906 } 907 for (i = 0; i < nsegs; i++) 908 hashp->dir[i] = &store[i << hashp->SSHIFT]; 909 return (0); 910 } 911 912 #if BYTE_ORDER == LITTLE_ENDIAN 913 /* 914 * Hashp->hdr needs to be byteswapped. 915 */ 916 static void 917 swap_header_copy(HASHHDR *srcp, HASHHDR *destp) 918 { 919 size_t i; 920 921 P_32_COPY(srcp->magic, destp->magic); 922 P_32_COPY(srcp->version, destp->version); 923 P_32_COPY(srcp->lorder, destp->lorder); 924 P_32_COPY(srcp->bsize, destp->bsize); 925 P_32_COPY(srcp->bshift, destp->bshift); 926 P_32_COPY(srcp->dsize, destp->dsize); 927 P_32_COPY(srcp->ssize, destp->ssize); 928 P_32_COPY(srcp->sshift, destp->sshift); 929 P_32_COPY(srcp->ovfl_point, destp->ovfl_point); 930 P_32_COPY(srcp->last_freed, destp->last_freed); 931 P_32_COPY(srcp->max_bucket, destp->max_bucket); 932 P_32_COPY(srcp->high_mask, destp->high_mask); 933 P_32_COPY(srcp->low_mask, destp->low_mask); 934 P_32_COPY(srcp->ffactor, destp->ffactor); 935 P_32_COPY(srcp->nkeys, destp->nkeys); 936 P_32_COPY(srcp->hdrpages, destp->hdrpages); 937 P_32_COPY(srcp->h_charkey, destp->h_charkey); 938 for (i = 0; i < NCACHED; i++) { 939 P_32_COPY(srcp->spares[i], destp->spares[i]); 940 P_16_COPY(srcp->bitmaps[i], destp->bitmaps[i]); 941 } 942 } 943 944 static void 945 swap_header(HTAB *hashp) 946 { 947 HASHHDR *hdrp; 948 size_t i; 949 950 hdrp = &hashp->hdr; 951 952 M_32_SWAP(hdrp->magic); 953 M_32_SWAP(hdrp->version); 954 M_32_SWAP(hdrp->lorder); 955 M_32_SWAP(hdrp->bsize); 956 M_32_SWAP(hdrp->bshift); 957 M_32_SWAP(hdrp->dsize); 958 M_32_SWAP(hdrp->ssize); 959 M_32_SWAP(hdrp->sshift); 960 M_32_SWAP(hdrp->ovfl_point); 961 M_32_SWAP(hdrp->last_freed); 962 M_32_SWAP(hdrp->max_bucket); 963 M_32_SWAP(hdrp->high_mask); 964 M_32_SWAP(hdrp->low_mask); 965 M_32_SWAP(hdrp->ffactor); 966 M_32_SWAP(hdrp->nkeys); 967 M_32_SWAP(hdrp->hdrpages); 968 M_32_SWAP(hdrp->h_charkey); 969 for (i = 0; i < NCACHED; i++) { 970 M_32_SWAP(hdrp->spares[i]); 971 M_16_SWAP(hdrp->bitmaps[i]); 972 } 973 } 974 #endif 975