1 /* $NetBSD: hash.c,v 1.33 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 * 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 1.33 2013/12/01 00:22:48 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 = __dbopen(file, flags, mode, &statbuf)) == -1) 132 RETURN_ERROR(errno, error0); 133 new_table |= statbuf.st_size == 0; 134 } 135 if (new_table) { 136 if (!(hashp = init_hash(hashp, file, info))) 137 RETURN_ERROR(errno, error1); 138 } else { 139 /* Table already exists */ 140 if (info && info->hash) 141 hashp->hash = info->hash; 142 else 143 hashp->hash = __default_hash; 144 145 hdrsize = read(hashp->fp, &hashp->hdr, sizeof(HASHHDR)); 146 #if BYTE_ORDER == LITTLE_ENDIAN 147 swap_header(hashp); 148 #endif 149 if (hdrsize == -1) 150 RETURN_ERROR(errno, error1); 151 if (hdrsize != sizeof(HASHHDR)) 152 RETURN_ERROR(EFTYPE, error1); 153 /* Verify file type, versions and hash function */ 154 if (hashp->MAGIC != HASHMAGIC) 155 RETURN_ERROR(EFTYPE, error1); 156 #define OLDHASHVERSION 1 157 if (hashp->VERSION != HASHVERSION && 158 hashp->VERSION != OLDHASHVERSION) 159 RETURN_ERROR(EFTYPE, error1); 160 if (hashp->hash(CHARKEY, sizeof(CHARKEY)) != 161 (uint32_t)hashp->H_CHARKEY) 162 RETURN_ERROR(EFTYPE, error1); 163 /* 164 * Figure out how many segments we need. Max_Bucket is the 165 * maximum bucket number, so the number of buckets is 166 * max_bucket + 1. 167 */ 168 nsegs = (hashp->MAX_BUCKET + 1 + hashp->SGSIZE - 1) / 169 hashp->SGSIZE; 170 hashp->nsegs = 0; 171 if (alloc_segs(hashp, nsegs)) 172 /* 173 * If alloc_segs fails, table will have been destroyed 174 * and errno will have been set. 175 */ 176 return (NULL); 177 /* Read in bitmaps */ 178 bpages = (hashp->SPARES[hashp->OVFL_POINT] + 179 (unsigned int)(hashp->BSIZE << BYTE_SHIFT) - 1) >> 180 (hashp->BSHIFT + BYTE_SHIFT); 181 182 hashp->nmaps = bpages; 183 (void)memset(&hashp->mapp[0], 0, bpages * sizeof(uint32_t *)); 184 } 185 186 /* Initialize Buffer Manager */ 187 if (info && info->cachesize) 188 __buf_init(hashp, info->cachesize); 189 else 190 __buf_init(hashp, DEF_BUFSIZE); 191 192 hashp->new_file = new_table; 193 hashp->save_file = file && (hashp->flags & O_RDWR); 194 hashp->cbucket = -1; 195 if (!(dbp = malloc(sizeof(*dbp)))) { 196 save_errno = errno; 197 hdestroy(hashp); 198 errno = save_errno; 199 return (NULL); 200 } 201 dbp->internal = hashp; 202 dbp->close = hash_close; 203 dbp->del = hash_delete; 204 dbp->fd = hash_fd; 205 dbp->get = hash_get; 206 dbp->put = hash_put; 207 dbp->seq = hash_seq; 208 dbp->sync = hash_sync; 209 dbp->type = DB_HASH; 210 211 #ifdef DEBUG1 212 (void)fprintf(stderr, 213 "%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", 214 "init_htab:", 215 "TABLE POINTER ", hashp, 216 "BUCKET SIZE ", hashp->BSIZE, 217 "BUCKET SHIFT ", hashp->BSHIFT, 218 "DIRECTORY SIZE ", hashp->DSIZE, 219 "SEGMENT SIZE ", hashp->SGSIZE, 220 "SEGMENT SHIFT ", hashp->SSHIFT, 221 "FILL FACTOR ", hashp->FFACTOR, 222 "MAX BUCKET ", hashp->MAX_BUCKET, 223 "OVFL POINT ", hashp->OVFL_POINT, 224 "LAST FREED ", hashp->LAST_FREED, 225 "HIGH MASK ", hashp->HIGH_MASK, 226 "LOW MASK ", hashp->LOW_MASK, 227 "NSEGS ", hashp->nsegs, 228 "NKEYS ", hashp->NKEYS); 229 #endif 230 #ifdef HASH_STATISTICS 231 hash_overflows = hash_accesses = hash_collisions = hash_expansions = 0; 232 #endif 233 return (dbp); 234 235 error1: 236 if (hashp != NULL) 237 (void)close(hashp->fp); 238 239 error0: 240 free(hashp); 241 errno = save_errno; 242 return (NULL); 243 } 244 245 static int 246 hash_close(DB *dbp) 247 { 248 HTAB *hashp; 249 int retval; 250 251 if (!dbp) 252 return (ERROR); 253 254 hashp = dbp->internal; 255 retval = hdestroy(hashp); 256 free(dbp); 257 return (retval); 258 } 259 260 static int 261 hash_fd(const DB *dbp) 262 { 263 HTAB *hashp; 264 265 if (!dbp) 266 return (ERROR); 267 268 hashp = dbp->internal; 269 if (hashp->fp == -1) { 270 errno = ENOENT; 271 return (-1); 272 } 273 return (hashp->fp); 274 } 275 276 /************************** LOCAL CREATION ROUTINES **********************/ 277 static HTAB * 278 init_hash(HTAB *hashp, const char *file, const HASHINFO *info) 279 { 280 struct stat statbuf; 281 int nelem; 282 283 nelem = 1; 284 hashp->NKEYS = 0; 285 hashp->LORDER = BYTE_ORDER; 286 hashp->BSIZE = DEF_BUCKET_SIZE; 287 hashp->BSHIFT = DEF_BUCKET_SHIFT; 288 hashp->SGSIZE = DEF_SEGSIZE; 289 hashp->SSHIFT = DEF_SEGSIZE_SHIFT; 290 hashp->DSIZE = DEF_DIRSIZE; 291 hashp->FFACTOR = DEF_FFACTOR; 292 hashp->hash = __default_hash; 293 memset(hashp->SPARES, 0, sizeof(hashp->SPARES)); 294 memset(hashp->BITMAPS, 0, sizeof (hashp->BITMAPS)); 295 296 /* Fix bucket size to be optimal for file system */ 297 if (file != NULL) { 298 if (stat(file, &statbuf)) 299 return (NULL); 300 hashp->BSIZE = MIN(statbuf.st_blksize, MAX_BSIZE); 301 hashp->BSHIFT = __log2((uint32_t)hashp->BSIZE); 302 } 303 304 if (info) { 305 if (info->bsize) { 306 /* Round pagesize up to power of 2 */ 307 hashp->BSHIFT = __log2(info->bsize); 308 hashp->BSIZE = 1 << hashp->BSHIFT; 309 if (hashp->BSIZE > MAX_BSIZE) { 310 errno = EINVAL; 311 return (NULL); 312 } 313 } 314 if (info->ffactor) 315 hashp->FFACTOR = info->ffactor; 316 if (info->hash) 317 hashp->hash = info->hash; 318 if (info->nelem) 319 nelem = info->nelem; 320 if (info->lorder) { 321 if (info->lorder != BIG_ENDIAN && 322 info->lorder != LITTLE_ENDIAN) { 323 errno = EINVAL; 324 return (NULL); 325 } 326 hashp->LORDER = info->lorder; 327 } 328 } 329 /* init_htab should destroy the table and set errno if it fails */ 330 if (init_htab(hashp, (size_t)nelem)) 331 return (NULL); 332 else 333 return (hashp); 334 } 335 /* 336 * This calls alloc_segs which may run out of memory. Alloc_segs will destroy 337 * the table and set errno, so we just pass the error information along. 338 * 339 * Returns 0 on No Error 340 */ 341 static int 342 init_htab(HTAB *hashp, size_t nelem) 343 { 344 int nbuckets; 345 uint32_t nsegs; 346 int l2; 347 348 /* 349 * Divide number of elements by the fill factor and determine a 350 * desired number of buckets. Allocate space for the next greater 351 * power of two number of buckets. 352 */ 353 nelem = (nelem - 1) / hashp->FFACTOR + 1; 354 355 _DBFIT(nelem, uint32_t); 356 l2 = __log2(MAX((uint32_t)nelem, 2)); 357 nbuckets = 1 << l2; 358 359 hashp->SPARES[l2] = l2 + 1; 360 hashp->SPARES[l2 + 1] = l2 + 1; 361 hashp->OVFL_POINT = l2; 362 hashp->LAST_FREED = 2; 363 364 /* First bitmap page is at: splitpoint l2 page offset 1 */ 365 if (__ibitmap(hashp, (int)OADDR_OF(l2, 1), l2 + 1, 0)) 366 return (-1); 367 368 hashp->MAX_BUCKET = hashp->LOW_MASK = nbuckets - 1; 369 hashp->HIGH_MASK = (nbuckets << 1) - 1; 370 /* LINTED constant in conditional context */ 371 hashp->HDRPAGES = ((MAX(sizeof(HASHHDR), MINHDRSIZE) - 1) >> 372 hashp->BSHIFT) + 1; 373 374 nsegs = (nbuckets - 1) / hashp->SGSIZE + 1; 375 nsegs = 1 << __log2(nsegs); 376 377 if (nsegs > (uint32_t)hashp->DSIZE) 378 hashp->DSIZE = nsegs; 379 return (alloc_segs(hashp, (int)nsegs)); 380 } 381 382 /********************** DESTROY/CLOSE ROUTINES ************************/ 383 384 /* 385 * Flushes any changes to the file if necessary and destroys the hashp 386 * structure, freeing all allocated space. 387 */ 388 static int 389 hdestroy(HTAB *hashp) 390 { 391 int i, save_errno; 392 393 save_errno = 0; 394 395 #ifdef HASH_STATISTICS 396 (void)fprintf(stderr, "hdestroy: accesses %d collisions %d\n", 397 hash_accesses, hash_collisions); 398 (void)fprintf(stderr, "hdestroy: expansions %d\n", 399 hash_expansions); 400 (void)fprintf(stderr, "hdestroy: overflows %d\n", 401 hash_overflows); 402 (void)fprintf(stderr, "keys %d maxp %d segmentcount %d\n", 403 hashp->NKEYS, hashp->MAX_BUCKET, hashp->nsegs); 404 405 for (i = 0; i < NCACHED; i++) 406 (void)fprintf(stderr, 407 "spares[%d] = %d\n", i, hashp->SPARES[i]); 408 #endif 409 /* 410 * Call on buffer manager to free buffers, and if required, 411 * write them to disk. 412 */ 413 if (__buf_free(hashp, 1, hashp->save_file)) 414 save_errno = errno; 415 if (hashp->dir) { 416 free(*hashp->dir); /* Free initial segments */ 417 /* Free extra segments */ 418 while (hashp->exsegs--) 419 free(hashp->dir[--hashp->nsegs]); 420 free(hashp->dir); 421 } 422 if (flush_meta(hashp) && !save_errno) 423 save_errno = errno; 424 /* Free Bigmaps */ 425 for (i = 0; i < hashp->nmaps; i++) 426 if (hashp->mapp[i]) 427 free(hashp->mapp[i]); 428 429 if (hashp->fp != -1) 430 (void)close(hashp->fp); 431 432 free(hashp); 433 434 if (save_errno) { 435 errno = save_errno; 436 return (ERROR); 437 } 438 return (SUCCESS); 439 } 440 /* 441 * Write modified pages to disk 442 * 443 * Returns: 444 * 0 == OK 445 * -1 ERROR 446 */ 447 static int 448 hash_sync(const DB *dbp, uint32_t flags) 449 { 450 HTAB *hashp; 451 452 if (flags != 0) { 453 errno = EINVAL; 454 return (ERROR); 455 } 456 457 if (!dbp) 458 return (ERROR); 459 460 hashp = dbp->internal; 461 if (!hashp->save_file) 462 return (0); 463 if (__buf_free(hashp, 0, 1) || flush_meta(hashp)) 464 return (ERROR); 465 hashp->new_file = 0; 466 return (0); 467 } 468 469 /* 470 * Returns: 471 * 0 == OK 472 * -1 indicates that errno should be set 473 */ 474 static int 475 flush_meta(HTAB *hashp) 476 { 477 HASHHDR *whdrp; 478 #if BYTE_ORDER == LITTLE_ENDIAN 479 HASHHDR whdr; 480 #endif 481 int fp, i; 482 ssize_t wsize; 483 484 if (!hashp->save_file) 485 return (0); 486 hashp->MAGIC = HASHMAGIC; 487 hashp->VERSION = HASHVERSION; 488 hashp->H_CHARKEY = hashp->hash(CHARKEY, sizeof(CHARKEY)); 489 490 fp = hashp->fp; 491 whdrp = &hashp->hdr; 492 #if BYTE_ORDER == LITTLE_ENDIAN 493 whdrp = &whdr; 494 swap_header_copy(&hashp->hdr, whdrp); 495 #endif 496 if ((wsize = pwrite(fp, whdrp, sizeof(HASHHDR), (off_t)0)) == -1) 497 return (-1); 498 else 499 if (wsize != sizeof(HASHHDR)) { 500 errno = EFTYPE; 501 hashp->err = errno; 502 return (-1); 503 } 504 for (i = 0; i < NCACHED; i++) 505 if (hashp->mapp[i]) 506 if (__put_page(hashp, (char *)(void *)hashp->mapp[i], 507 (u_int)hashp->BITMAPS[i], 0, 1)) 508 return (-1); 509 return (0); 510 } 511 512 /*******************************SEARCH ROUTINES *****************************/ 513 /* 514 * All the access routines return 515 * 516 * Returns: 517 * 0 on SUCCESS 518 * 1 to indicate an external ERROR (i.e. key not found, etc) 519 * -1 to indicate an internal ERROR (i.e. out of memory, etc) 520 */ 521 static int 522 hash_get(const DB *dbp, const DBT *key, DBT *data, uint32_t flag) 523 { 524 HTAB *hashp; 525 526 hashp = dbp->internal; 527 if (flag) { 528 hashp->err = errno = EINVAL; 529 return (ERROR); 530 } 531 return (hash_access(hashp, HASH_GET, __UNCONST(key), data)); 532 } 533 534 static int 535 hash_put(const DB *dbp, DBT *key, const DBT *data, uint32_t flag) 536 { 537 HTAB *hashp; 538 539 hashp = dbp->internal; 540 if (flag && flag != R_NOOVERWRITE) { 541 hashp->err = errno = EINVAL; 542 return (ERROR); 543 } 544 if ((hashp->flags & O_ACCMODE) == O_RDONLY) { 545 hashp->err = errno = EPERM; 546 return (ERROR); 547 } 548 /* LINTED const castaway */ 549 return (hash_access(hashp, flag == R_NOOVERWRITE ? 550 HASH_PUTNEW : HASH_PUT, __UNCONST(key), __UNCONST(data))); 551 } 552 553 static int 554 hash_delete(const DB *dbp, const DBT *key, uint32_t flag) 555 { 556 HTAB *hashp; 557 558 hashp = dbp->internal; 559 if (flag && flag != R_CURSOR) { 560 hashp->err = errno = EINVAL; 561 return (ERROR); 562 } 563 if ((hashp->flags & O_ACCMODE) == O_RDONLY) { 564 hashp->err = errno = EPERM; 565 return (ERROR); 566 } 567 return hash_access(hashp, HASH_DELETE, __UNCONST(key), NULL); 568 } 569 570 /* 571 * Assume that hashp has been set in wrapper routine. 572 */ 573 static int 574 hash_access(HTAB *hashp, ACTION action, DBT *key, DBT *val) 575 { 576 BUFHEAD *rbufp; 577 BUFHEAD *bufp, *save_bufp; 578 uint16_t *bp; 579 int n, ndx, off; 580 size_t size; 581 char *kp; 582 uint16_t pageno; 583 584 #ifdef HASH_STATISTICS 585 hash_accesses++; 586 #endif 587 588 off = hashp->BSIZE; 589 size = key->size; 590 kp = (char *)key->data; 591 rbufp = __get_buf(hashp, __call_hash(hashp, kp, (int)size), NULL, 0); 592 if (!rbufp) 593 return (ERROR); 594 save_bufp = rbufp; 595 596 /* Pin the bucket chain */ 597 rbufp->flags |= BUF_PIN; 598 for (bp = (uint16_t *)(void *)rbufp->page, n = *bp++, ndx = 1; ndx < n;) 599 if (bp[1] >= REAL_KEY) { 600 /* Real key/data pair */ 601 if (size == (size_t)(off - *bp) && 602 memcmp(kp, rbufp->page + *bp, size) == 0) 603 goto found; 604 off = bp[1]; 605 #ifdef HASH_STATISTICS 606 hash_collisions++; 607 #endif 608 bp += 2; 609 ndx += 2; 610 } else if (bp[1] == OVFLPAGE) { 611 rbufp = __get_buf(hashp, (uint32_t)*bp, rbufp, 0); 612 if (!rbufp) { 613 save_bufp->flags &= ~BUF_PIN; 614 return (ERROR); 615 } 616 /* FOR LOOP INIT */ 617 bp = (uint16_t *)(void *)rbufp->page; 618 n = *bp++; 619 ndx = 1; 620 off = hashp->BSIZE; 621 } else if (bp[1] < REAL_KEY) { 622 if ((ndx = 623 __find_bigpair(hashp, rbufp, ndx, kp, (int)size)) > 0) 624 goto found; 625 if (ndx == -2) { 626 bufp = rbufp; 627 if (!(pageno = 628 __find_last_page(hashp, &bufp))) { 629 ndx = 0; 630 rbufp = bufp; 631 break; /* FOR */ 632 } 633 rbufp = __get_buf(hashp, (uint32_t)pageno, 634 bufp, 0); 635 if (!rbufp) { 636 save_bufp->flags &= ~BUF_PIN; 637 return (ERROR); 638 } 639 /* FOR LOOP INIT */ 640 bp = (uint16_t *)(void *)rbufp->page; 641 n = *bp++; 642 ndx = 1; 643 off = hashp->BSIZE; 644 } else { 645 save_bufp->flags &= ~BUF_PIN; 646 return (ERROR); 647 } 648 } 649 650 /* Not found */ 651 switch (action) { 652 case HASH_PUT: 653 case HASH_PUTNEW: 654 if (__addel(hashp, rbufp, key, val)) { 655 save_bufp->flags &= ~BUF_PIN; 656 return (ERROR); 657 } else { 658 save_bufp->flags &= ~BUF_PIN; 659 return (SUCCESS); 660 } 661 case HASH_GET: 662 case HASH_DELETE: 663 default: 664 save_bufp->flags &= ~BUF_PIN; 665 return (ABNORMAL); 666 } 667 668 found: 669 switch (action) { 670 case HASH_PUTNEW: 671 save_bufp->flags &= ~BUF_PIN; 672 return (ABNORMAL); 673 case HASH_GET: 674 bp = (uint16_t *)(void *)rbufp->page; 675 if (bp[ndx + 1] < REAL_KEY) { 676 if (__big_return(hashp, rbufp, ndx, val, 0)) 677 return (ERROR); 678 } else { 679 val->data = (uint8_t *)rbufp->page + (int)bp[ndx + 1]; 680 val->size = bp[ndx] - bp[ndx + 1]; 681 } 682 break; 683 case HASH_PUT: 684 if ((__delpair(hashp, rbufp, ndx)) || 685 (__addel(hashp, rbufp, key, val))) { 686 save_bufp->flags &= ~BUF_PIN; 687 return (ERROR); 688 } 689 break; 690 case HASH_DELETE: 691 if (__delpair(hashp, rbufp, ndx)) 692 return (ERROR); 693 break; 694 default: 695 abort(); 696 } 697 save_bufp->flags &= ~BUF_PIN; 698 return (SUCCESS); 699 } 700 701 static int 702 hash_seq(const DB *dbp, DBT *key, DBT *data, uint32_t flag) 703 { 704 uint32_t bucket; 705 BUFHEAD *bufp = NULL; /* XXX: gcc */ 706 HTAB *hashp; 707 uint16_t *bp, ndx; 708 709 hashp = dbp->internal; 710 if (flag && flag != R_FIRST && flag != R_NEXT) { 711 hashp->err = errno = EINVAL; 712 return (ERROR); 713 } 714 #ifdef HASH_STATISTICS 715 hash_accesses++; 716 #endif 717 if ((hashp->cbucket < 0) || (flag == R_FIRST)) { 718 hashp->cbucket = 0; 719 hashp->cndx = 1; 720 hashp->cpage = NULL; 721 } 722 723 for (bp = NULL; !bp || !bp[0]; ) { 724 if (!(bufp = hashp->cpage)) { 725 for (bucket = hashp->cbucket; 726 bucket <= (uint32_t)hashp->MAX_BUCKET; 727 bucket++, hashp->cndx = 1) { 728 bufp = __get_buf(hashp, bucket, NULL, 0); 729 if (!bufp) 730 return (ERROR); 731 hashp->cpage = bufp; 732 bp = (uint16_t *)(void *)bufp->page; 733 if (bp[0]) 734 break; 735 } 736 hashp->cbucket = bucket; 737 if (hashp->cbucket > hashp->MAX_BUCKET) { 738 hashp->cbucket = -1; 739 return (ABNORMAL); 740 } 741 } else 742 bp = (uint16_t *)(void *)hashp->cpage->page; 743 744 _DIAGASSERT(bp != NULL); 745 _DIAGASSERT(bufp != NULL); 746 while (bp[hashp->cndx + 1] == OVFLPAGE) { 747 bufp = hashp->cpage = 748 __get_buf(hashp, (uint32_t)bp[hashp->cndx], bufp, 749 0); 750 if (!bufp) 751 return (ERROR); 752 bp = (uint16_t *)(void *)(bufp->page); 753 hashp->cndx = 1; 754 } 755 if (!bp[0]) { 756 hashp->cpage = NULL; 757 ++hashp->cbucket; 758 } 759 } 760 ndx = hashp->cndx; 761 if (bp[ndx + 1] < REAL_KEY) { 762 if (__big_keydata(hashp, bufp, key, data, 1)) 763 return (ERROR); 764 } else { 765 if (hashp->cpage == NULL) 766 return (ERROR); 767 key->data = (uint8_t *)hashp->cpage->page + bp[ndx]; 768 key->size = (ndx > 1 ? bp[ndx - 1] : hashp->BSIZE) - bp[ndx]; 769 data->data = (uint8_t *)hashp->cpage->page + bp[ndx + 1]; 770 data->size = bp[ndx] - bp[ndx + 1]; 771 ndx += 2; 772 if (ndx > bp[0]) { 773 hashp->cpage = NULL; 774 hashp->cbucket++; 775 hashp->cndx = 1; 776 } else 777 hashp->cndx = ndx; 778 } 779 return (SUCCESS); 780 } 781 782 /********************************* UTILITIES ************************/ 783 784 /* 785 * Returns: 786 * 0 ==> OK 787 * -1 ==> Error 788 */ 789 int 790 __expand_table(HTAB *hashp) 791 { 792 uint32_t old_bucket, new_bucket; 793 int new_segnum, spare_ndx; 794 size_t dirsize; 795 796 #ifdef HASH_STATISTICS 797 hash_expansions++; 798 #endif 799 new_bucket = ++hashp->MAX_BUCKET; 800 old_bucket = (hashp->MAX_BUCKET & hashp->LOW_MASK); 801 802 new_segnum = new_bucket >> hashp->SSHIFT; 803 804 /* Check if we need a new segment */ 805 if (new_segnum >= hashp->nsegs) { 806 /* Check if we need to expand directory */ 807 if (new_segnum >= hashp->DSIZE) { 808 /* Reallocate directory */ 809 dirsize = hashp->DSIZE * sizeof(SEGMENT *); 810 if (!hash_realloc(&hashp->dir, dirsize, dirsize << 1)) 811 return (-1); 812 dirsize <<= 1; 813 _DBFIT(dirsize, uint32_t); 814 hashp->DSIZE = (uint32_t)dirsize; 815 } 816 if ((hashp->dir[new_segnum] = 817 calloc((size_t)hashp->SGSIZE, sizeof(SEGMENT))) == NULL) 818 return (-1); 819 hashp->exsegs++; 820 hashp->nsegs++; 821 } 822 /* 823 * If the split point is increasing (MAX_BUCKET's log base 2 824 * * increases), we need to copy the current contents of the spare 825 * split bucket to the next bucket. 826 */ 827 spare_ndx = __log2((uint32_t)(hashp->MAX_BUCKET + 1)); 828 if (spare_ndx > hashp->OVFL_POINT) { 829 hashp->SPARES[spare_ndx] = hashp->SPARES[hashp->OVFL_POINT]; 830 hashp->OVFL_POINT = spare_ndx; 831 } 832 833 if (new_bucket > (uint32_t)hashp->HIGH_MASK) { 834 /* Starting a new doubling */ 835 hashp->LOW_MASK = hashp->HIGH_MASK; 836 hashp->HIGH_MASK = new_bucket | hashp->LOW_MASK; 837 } 838 /* Relocate records to the new bucket */ 839 return (__split_page(hashp, old_bucket, new_bucket)); 840 } 841 842 /* 843 * If realloc guarantees that the pointer is not destroyed if the realloc 844 * fails, then this routine can go away. 845 */ 846 static void * 847 hash_realloc(SEGMENT **p_ptr, size_t oldsize, size_t newsize) 848 { 849 void *p; 850 851 if ((p = malloc(newsize)) != NULL) { 852 memmove(p, *p_ptr, oldsize); 853 memset((char *)p + oldsize, 0, newsize - oldsize); 854 free(*p_ptr); 855 *p_ptr = p; 856 } 857 return (p); 858 } 859 860 uint32_t 861 __call_hash(HTAB *hashp, char *k, int len) 862 { 863 int n, bucket; 864 865 n = hashp->hash(k, (size_t)len); 866 bucket = n & hashp->HIGH_MASK; 867 if (bucket > hashp->MAX_BUCKET) 868 bucket = bucket & hashp->LOW_MASK; 869 return (bucket); 870 } 871 872 /* 873 * Allocate segment table. On error, destroy the table and set errno. 874 * 875 * Returns 0 on success 876 */ 877 static int 878 alloc_segs(HTAB *hashp, int nsegs) 879 { 880 int i; 881 SEGMENT store; 882 883 int save_errno; 884 885 hashp->dir = calloc((size_t)hashp->DSIZE, sizeof(SEGMENT *)); 886 if (hashp->dir == NULL) { 887 save_errno = errno; 888 (void)hdestroy(hashp); 889 errno = save_errno; 890 return (-1); 891 } 892 hashp->nsegs = nsegs; 893 if (nsegs == 0) 894 return 0; 895 /* Allocate segments */ 896 store = calloc((size_t)(nsegs << hashp->SSHIFT), sizeof(SEGMENT)); 897 if (store == NULL) { 898 save_errno = errno; 899 (void)hdestroy(hashp); 900 errno = save_errno; 901 return (-1); 902 } 903 for (i = 0; i < nsegs; i++) 904 hashp->dir[i] = &store[i << hashp->SSHIFT]; 905 return (0); 906 } 907 908 #if BYTE_ORDER == LITTLE_ENDIAN 909 /* 910 * Hashp->hdr needs to be byteswapped. 911 */ 912 static void 913 swap_header_copy(HASHHDR *srcp, HASHHDR *destp) 914 { 915 size_t i; 916 917 P_32_COPY(srcp->magic, destp->magic); 918 P_32_COPY(srcp->version, destp->version); 919 P_32_COPY(srcp->lorder, destp->lorder); 920 P_32_COPY(srcp->bsize, destp->bsize); 921 P_32_COPY(srcp->bshift, destp->bshift); 922 P_32_COPY(srcp->dsize, destp->dsize); 923 P_32_COPY(srcp->ssize, destp->ssize); 924 P_32_COPY(srcp->sshift, destp->sshift); 925 P_32_COPY(srcp->ovfl_point, destp->ovfl_point); 926 P_32_COPY(srcp->last_freed, destp->last_freed); 927 P_32_COPY(srcp->max_bucket, destp->max_bucket); 928 P_32_COPY(srcp->high_mask, destp->high_mask); 929 P_32_COPY(srcp->low_mask, destp->low_mask); 930 P_32_COPY(srcp->ffactor, destp->ffactor); 931 P_32_COPY(srcp->nkeys, destp->nkeys); 932 P_32_COPY(srcp->hdrpages, destp->hdrpages); 933 P_32_COPY(srcp->h_charkey, destp->h_charkey); 934 for (i = 0; i < NCACHED; i++) { 935 P_32_COPY(srcp->spares[i], destp->spares[i]); 936 P_16_COPY(srcp->bitmaps[i], destp->bitmaps[i]); 937 } 938 } 939 940 static void 941 swap_header(HTAB *hashp) 942 { 943 HASHHDR *hdrp; 944 size_t i; 945 946 hdrp = &hashp->hdr; 947 948 M_32_SWAP(hdrp->magic); 949 M_32_SWAP(hdrp->version); 950 M_32_SWAP(hdrp->lorder); 951 M_32_SWAP(hdrp->bsize); 952 M_32_SWAP(hdrp->bshift); 953 M_32_SWAP(hdrp->dsize); 954 M_32_SWAP(hdrp->ssize); 955 M_32_SWAP(hdrp->sshift); 956 M_32_SWAP(hdrp->ovfl_point); 957 M_32_SWAP(hdrp->last_freed); 958 M_32_SWAP(hdrp->max_bucket); 959 M_32_SWAP(hdrp->high_mask); 960 M_32_SWAP(hdrp->low_mask); 961 M_32_SWAP(hdrp->ffactor); 962 M_32_SWAP(hdrp->nkeys); 963 M_32_SWAP(hdrp->hdrpages); 964 M_32_SWAP(hdrp->h_charkey); 965 for (i = 0; i < NCACHED; i++) { 966 M_32_SWAP(hdrp->spares[i]); 967 M_16_SWAP(hdrp->bitmaps[i]); 968 } 969 } 970 #endif 971