Annotation of embedaddon/dhcp/omapip/hash.c, revision 1.1
1.1 ! misho 1: /* hash.c
! 2:
! 3: Routines for manipulating hash tables... */
! 4:
! 5: /*
! 6: * Copyright (c) 2009-2010 by Internet Systems Consortium, Inc. ("ISC")
! 7: * Copyright (c) 2004-2007 by Internet Systems Consortium, Inc. ("ISC")
! 8: * Copyright (c) 1995-2003 by Internet Software Consortium
! 9: *
! 10: * Permission to use, copy, modify, and distribute this software for any
! 11: * purpose with or without fee is hereby granted, provided that the above
! 12: * copyright notice and this permission notice appear in all copies.
! 13: *
! 14: * THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES
! 15: * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
! 16: * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR
! 17: * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
! 18: * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
! 19: * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT
! 20: * OF OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
! 21: *
! 22: * Internet Systems Consortium, Inc.
! 23: * 950 Charter Street
! 24: * Redwood City, CA 94063
! 25: * <info@isc.org>
! 26: * https://www.isc.org/
! 27: *
! 28: * This software has been written for Internet Systems Consortium
! 29: * by Ted Lemon in cooperation with Vixie Enterprises and Nominum, Inc.
! 30: * To learn more about Internet Systems Consortium, see
! 31: * ``https://www.isc.org/''. To learn more about Vixie Enterprises,
! 32: * see ``http://www.vix.com''. To learn more about Nominum, Inc., see
! 33: * ``http://www.nominum.com''.
! 34: */
! 35:
! 36: #include "dhcpd.h"
! 37:
! 38: #include <omapip/omapip_p.h>
! 39: #include <limits.h>
! 40: #include <ctype.h>
! 41:
! 42: static unsigned
! 43: find_length(const void *key,
! 44: unsigned (*do_hash)(const void *, unsigned, unsigned))
! 45: {
! 46: if (do_hash == do_case_hash || do_hash == do_string_hash)
! 47: return strlen((const char *)key);
! 48: if (do_hash == do_number_hash)
! 49: return sizeof(unsigned);
! 50: if (do_hash == do_ip4_hash)
! 51: return 4;
! 52:
! 53: log_debug("Unexpected hash function at %s:%d.", MDL);
! 54: /*
! 55: * If we get a hash function we don't specifically expect
! 56: * return a length of 0, this covers the case where a client
! 57: * id has a length of 0.
! 58: */
! 59: return 0;
! 60: }
! 61:
! 62: int new_hash_table (tp, count, file, line)
! 63: struct hash_table **tp;
! 64: unsigned count;
! 65: const char *file;
! 66: int line;
! 67: {
! 68: struct hash_table *rval;
! 69: unsigned extra;
! 70:
! 71: if (!tp) {
! 72: log_error ("%s(%d): new_hash_table called with null pointer.",
! 73: file, line);
! 74: #if defined (POINTER_DEBUG)
! 75: abort ();
! 76: #endif
! 77: return 0;
! 78: }
! 79: if (*tp) {
! 80: log_error ("%s(%d): non-null target for new_hash_table.",
! 81: file, line);
! 82: #if defined (POINTER_DEBUG)
! 83: abort ();
! 84: #endif
! 85: }
! 86:
! 87: /* There is one hash bucket in the structure. Allocate extra
! 88: * memory beyond the end of the structure to fulfill the requested
! 89: * count ("count - 1"). Do not let there be less than one.
! 90: */
! 91: if (count <= 1)
! 92: extra = 0;
! 93: else
! 94: extra = count - 1;
! 95:
! 96: rval = dmalloc(sizeof(struct hash_table) +
! 97: (extra * sizeof(struct hash_bucket *)), file, line);
! 98: if (!rval)
! 99: return 0;
! 100: rval -> hash_count = count;
! 101: *tp = rval;
! 102: return 1;
! 103: }
! 104:
! 105: void free_hash_table (tp, file, line)
! 106: struct hash_table **tp;
! 107: const char *file;
! 108: int line;
! 109: {
! 110: struct hash_table *ptr = *tp;
! 111:
! 112: #if defined (DEBUG_MEMORY_LEAKAGE) || \
! 113: defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
! 114: int i;
! 115: struct hash_bucket *hbc, *hbn = (struct hash_bucket *)0;
! 116:
! 117: for (i = 0; i < ptr -> hash_count; i++) {
! 118: for (hbc = ptr -> buckets [i]; hbc; hbc = hbn) {
! 119: hbn = hbc -> next;
! 120: if (ptr -> dereferencer && hbc -> value)
! 121: (*ptr -> dereferencer) (&hbc -> value, MDL);
! 122: }
! 123: for (hbc = ptr -> buckets [i]; hbc; hbc = hbn) {
! 124: hbn = hbc -> next;
! 125: free_hash_bucket (hbc, MDL);
! 126: }
! 127: ptr -> buckets [i] = (struct hash_bucket *)0;
! 128: }
! 129: #endif
! 130:
! 131: dfree((void *)ptr, MDL);
! 132: *tp = (struct hash_table *)0;
! 133: }
! 134:
! 135: struct hash_bucket *free_hash_buckets;
! 136:
! 137: #if defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
! 138: struct hash_bucket *hash_bucket_hunks;
! 139:
! 140: void relinquish_hash_bucket_hunks ()
! 141: {
! 142: struct hash_bucket *c, *n, **p;
! 143:
! 144: /* Account for all the hash buckets on the free list. */
! 145: p = &free_hash_buckets;
! 146: for (c = free_hash_buckets; c; c = c -> next) {
! 147: for (n = hash_bucket_hunks; n; n = n -> next) {
! 148: if (c > n && c < n + 127) {
! 149: *p = c -> next;
! 150: n -> len++;
! 151: break;
! 152: }
! 153: }
! 154: /* If we didn't delete the hash bucket from the free list,
! 155: advance the pointer. */
! 156: if (!n)
! 157: p = &c -> next;
! 158: }
! 159:
! 160: for (c = hash_bucket_hunks; c; c = n) {
! 161: n = c -> next;
! 162: if (c -> len != 126) {
! 163: log_info ("hashbucket %lx hash_buckets %d free %u",
! 164: (unsigned long)c, 127, c -> len);
! 165: }
! 166: dfree (c, MDL);
! 167: }
! 168: }
! 169: #endif
! 170:
! 171: struct hash_bucket *new_hash_bucket (file, line)
! 172: const char *file;
! 173: int line;
! 174: {
! 175: struct hash_bucket *rval;
! 176: int i = 0;
! 177: if (!free_hash_buckets) {
! 178: rval = dmalloc (127 * sizeof (struct hash_bucket),
! 179: file, line);
! 180: if (!rval)
! 181: return rval;
! 182: # if defined (DEBUG_MEMORY_LEAKAGE_ON_EXIT)
! 183: rval -> next = hash_bucket_hunks;
! 184: hash_bucket_hunks = rval;
! 185: hash_bucket_hunks -> len = 0;
! 186: i++;
! 187: rval++;
! 188: #endif
! 189: for (; i < 127; i++) {
! 190: rval -> next = free_hash_buckets;
! 191: free_hash_buckets = rval;
! 192: rval++;
! 193: }
! 194: }
! 195: rval = free_hash_buckets;
! 196: free_hash_buckets = rval -> next;
! 197: return rval;
! 198: }
! 199:
! 200: void free_hash_bucket (ptr, file, line)
! 201: struct hash_bucket *ptr;
! 202: const char *file;
! 203: int line;
! 204: {
! 205: #if defined (DEBUG_MALLOC_POOL)
! 206: struct hash_bucket *hp;
! 207:
! 208: for (hp = free_hash_buckets; hp; hp = hp -> next) {
! 209: if (hp == ptr) {
! 210: log_error ("hash bucket freed twice!");
! 211: abort ();
! 212: }
! 213: }
! 214: #endif
! 215: ptr -> next = free_hash_buckets;
! 216: free_hash_buckets = ptr;
! 217: }
! 218:
! 219: int new_hash(struct hash_table **rp,
! 220: hash_reference referencer,
! 221: hash_dereference dereferencer,
! 222: unsigned hsize,
! 223: unsigned (*hasher)(const void *, unsigned, unsigned),
! 224: const char *file, int line)
! 225: {
! 226: if (hsize == 0)
! 227: hsize = DEFAULT_HASH_SIZE;
! 228:
! 229: if (!new_hash_table (rp, hsize, file, line))
! 230: return 0;
! 231:
! 232: memset ((*rp)->buckets, 0, hsize * sizeof(struct hash_bucket *));
! 233:
! 234: (*rp)->referencer = referencer;
! 235: (*rp)->dereferencer = dereferencer;
! 236: (*rp)->do_hash = hasher;
! 237:
! 238: if (hasher == do_case_hash)
! 239: (*rp)->cmp = casecmp;
! 240: else
! 241: (*rp)->cmp = memcmp;
! 242:
! 243: return 1;
! 244: }
! 245:
! 246: unsigned
! 247: do_case_hash(const void *name, unsigned len, unsigned size)
! 248: {
! 249: register unsigned accum = 0;
! 250: register const unsigned char *s = name;
! 251: int i = len;
! 252: register unsigned c;
! 253:
! 254: while (i--) {
! 255: /* Make the hash case-insensitive. */
! 256: c = *s++;
! 257: if (isascii(c))
! 258: c = tolower(c);
! 259:
! 260: /* Add the character in... */
! 261: accum = (accum << 1) + c;
! 262:
! 263: /* Add carry back in... */
! 264: while (accum > 65535) {
! 265: accum = (accum & 65535) + (accum >> 16);
! 266: }
! 267:
! 268: }
! 269: return accum % size;
! 270: }
! 271:
! 272: unsigned
! 273: do_string_hash(const void *name, unsigned len, unsigned size)
! 274: {
! 275: register unsigned accum = 0;
! 276: register const unsigned char *s = (const unsigned char *)name;
! 277: int i = len;
! 278:
! 279: while (i--) {
! 280: /* Add the character in... */
! 281: accum = (accum << 1) + *s++;
! 282:
! 283: /* Add carry back in... */
! 284: while (accum > 65535) {
! 285: accum = (accum & 65535) + (accum >> 16);
! 286: }
! 287: }
! 288: return accum % size;
! 289: }
! 290:
! 291: /* Client identifiers are generally 32-bits of ordinary
! 292: * non-randomness followed by 24-bits of unordinary randomness.
! 293: * So, end-align in 24-bit chunks, and xor any preceding data
! 294: * just to mix it up a little.
! 295: */
! 296: unsigned
! 297: do_id_hash(const void *name, unsigned len, unsigned size)
! 298: {
! 299: register unsigned accum = 0;
! 300: register const unsigned char *s = (const unsigned char *)name;
! 301: const unsigned char *end = s + len;
! 302:
! 303: if (len == 0)
! 304: return 0;
! 305:
! 306: /*
! 307: * The switch handles our starting conditions, then we hash the
! 308: * remaining bytes in groups of 3
! 309: */
! 310:
! 311: switch (len % 3) {
! 312: case 0:
! 313: break;
! 314: case 2:
! 315: accum ^= *s++ << 8;
! 316: case 1:
! 317: accum ^= *s++;
! 318: break;
! 319: }
! 320:
! 321: while (s < end) {
! 322: accum ^= *s++ << 16;
! 323: accum ^= *s++ << 8;
! 324: accum ^= *s++;
! 325: }
! 326:
! 327: return accum % size;
! 328: }
! 329:
! 330: unsigned
! 331: do_number_hash(const void *key, unsigned len, unsigned size)
! 332: {
! 333: register unsigned number = *((const unsigned *)key);
! 334:
! 335: return number % size;
! 336: }
! 337:
! 338: unsigned
! 339: do_ip4_hash(const void *key, unsigned len, unsigned size)
! 340: {
! 341: u_int32_t number;
! 342:
! 343: memcpy(&number, key, 4);
! 344:
! 345: number = ntohl(number);
! 346:
! 347: return number % size;
! 348: }
! 349:
! 350: unsigned char *
! 351: hash_report(struct hash_table *table)
! 352: {
! 353: static unsigned char retbuf[sizeof("Contents/Size (%): "
! 354: "2147483647/2147483647 "
! 355: "(2147483647%). "
! 356: "Min/max: 2147483647/2147483647")];
! 357: unsigned curlen, pct, contents=0, minlen=UINT_MAX, maxlen=0;
! 358: unsigned i;
! 359: struct hash_bucket *bp;
! 360:
! 361: if (table == NULL)
! 362: return (unsigned char *) "No table.";
! 363:
! 364: if (table->hash_count == 0)
! 365: return (unsigned char *) "Invalid hash table.";
! 366:
! 367: for (i = 0 ; i < table->hash_count ; i++) {
! 368: curlen = 0;
! 369:
! 370: bp = table->buckets[i];
! 371: while (bp != NULL) {
! 372: curlen++;
! 373: bp = bp->next;
! 374: }
! 375:
! 376: if (curlen < minlen)
! 377: minlen = curlen;
! 378: if (curlen > maxlen)
! 379: maxlen = curlen;
! 380:
! 381: contents += curlen;
! 382: }
! 383:
! 384: if (contents >= (UINT_MAX / 100))
! 385: pct = contents / ((table->hash_count / 100) + 1);
! 386: else
! 387: pct = (contents * 100) / table->hash_count;
! 388:
! 389: if (contents > 2147483647 ||
! 390: table->hash_count > 2147483647 ||
! 391: pct > 2147483647 ||
! 392: minlen > 2147483647 ||
! 393: maxlen > 2147483647)
! 394: return (unsigned char *) "Report out of range for display.";
! 395:
! 396: sprintf((char *)retbuf,
! 397: "Contents/Size (%%): %u/%u (%u%%). Min/max: %u/%u",
! 398: contents, table->hash_count, pct, minlen, maxlen);
! 399:
! 400: return retbuf;
! 401: }
! 402:
! 403: void add_hash (table, key, len, pointer, file, line)
! 404: struct hash_table *table;
! 405: unsigned len;
! 406: const void *key;
! 407: hashed_object_t *pointer;
! 408: const char *file;
! 409: int line;
! 410: {
! 411: int hashno;
! 412: struct hash_bucket *bp;
! 413: void *foo;
! 414:
! 415: if (!table)
! 416: return;
! 417:
! 418: if (!len)
! 419: len = find_length(key, table->do_hash);
! 420:
! 421: hashno = (*table->do_hash)(key, len, table->hash_count);
! 422: bp = new_hash_bucket (file, line);
! 423:
! 424: if (!bp) {
! 425: log_error ("Can't add entry to hash table: no memory.");
! 426: return;
! 427: }
! 428: bp -> name = key;
! 429: if (table -> referencer) {
! 430: foo = &bp -> value;
! 431: (*(table -> referencer)) (foo, pointer, file, line);
! 432: } else
! 433: bp -> value = pointer;
! 434: bp -> next = table -> buckets [hashno];
! 435: bp -> len = len;
! 436: table -> buckets [hashno] = bp;
! 437: }
! 438:
! 439: void delete_hash_entry (table, key, len, file, line)
! 440: struct hash_table *table;
! 441: unsigned len;
! 442: const void *key;
! 443: const char *file;
! 444: int line;
! 445: {
! 446: int hashno;
! 447: struct hash_bucket *bp, *pbp = (struct hash_bucket *)0;
! 448: void *foo;
! 449:
! 450: if (!table)
! 451: return;
! 452:
! 453: if (!len)
! 454: len = find_length(key, table->do_hash);
! 455:
! 456: hashno = (*table->do_hash)(key, len, table->hash_count);
! 457:
! 458: /* Go through the list looking for an entry that matches;
! 459: if we find it, delete it. */
! 460: for (bp = table -> buckets [hashno]; bp; bp = bp -> next) {
! 461: if ((!bp -> len &&
! 462: !strcmp ((const char *)bp->name, key)) ||
! 463: (bp -> len == len &&
! 464: !(table -> cmp)(bp->name, key, len))) {
! 465: if (pbp) {
! 466: pbp -> next = bp -> next;
! 467: } else {
! 468: table -> buckets [hashno] = bp -> next;
! 469: }
! 470: if (bp -> value && table -> dereferencer) {
! 471: foo = &bp -> value;
! 472: (*(table -> dereferencer)) (foo, file, line);
! 473: }
! 474: free_hash_bucket (bp, file, line);
! 475: break;
! 476: }
! 477: pbp = bp; /* jwg, 9/6/96 - nice catch! */
! 478: }
! 479: }
! 480:
! 481: int hash_lookup (vp, table, key, len, file, line)
! 482: hashed_object_t **vp;
! 483: struct hash_table *table;
! 484: const void *key;
! 485: unsigned len;
! 486: const char *file;
! 487: int line;
! 488: {
! 489: int hashno;
! 490: struct hash_bucket *bp;
! 491:
! 492: if (!table)
! 493: return 0;
! 494: if (!len)
! 495: len = find_length(key, table->do_hash);
! 496:
! 497: if (*vp != NULL) {
! 498: log_fatal("Internal inconsistency: storage value has not been "
! 499: "initialized to zero (from %s:%d).", file, line);
! 500: }
! 501:
! 502: hashno = (*table->do_hash)(key, len, table->hash_count);
! 503:
! 504: for (bp = table -> buckets [hashno]; bp; bp = bp -> next) {
! 505: if (len == bp -> len
! 506: && !(*table->cmp)(bp->name, key, len)) {
! 507: if (table -> referencer)
! 508: (*table -> referencer) (vp, bp -> value,
! 509: file, line);
! 510: else
! 511: *vp = bp -> value;
! 512: return 1;
! 513: }
! 514: }
! 515: return 0;
! 516: }
! 517:
! 518: int hash_foreach (struct hash_table *table, hash_foreach_func func)
! 519: {
! 520: int i;
! 521: struct hash_bucket *bp, *next;
! 522: int count = 0;
! 523:
! 524: if (!table)
! 525: return 0;
! 526:
! 527: for (i = 0; i < table -> hash_count; i++) {
! 528: bp = table -> buckets [i];
! 529: while (bp) {
! 530: next = bp -> next;
! 531: if ((*func)(bp->name, bp->len, bp->value)
! 532: != ISC_R_SUCCESS)
! 533: return count;
! 534: bp = next;
! 535: count++;
! 536: }
! 537: }
! 538: return count;
! 539: }
! 540:
! 541: int casecmp (const void *v1, const void *v2, size_t len)
! 542: {
! 543: size_t i;
! 544: const unsigned char *s = v1;
! 545: const unsigned char *t = v2;
! 546:
! 547: for (i = 0; i < len; i++)
! 548: {
! 549: int c1, c2;
! 550: if (isascii(s[i]))
! 551: c1 = tolower(s[i]);
! 552: else
! 553: c1 = s[i];
! 554:
! 555: if (isascii(t[i]))
! 556: c2 = tolower(t[i]);
! 557: else
! 558: c2 = t[i];
! 559:
! 560: if (c1 < c2)
! 561: return -1;
! 562: if (c1 > c2)
! 563: return 1;
! 564: }
! 565: return 0;
! 566: }
FreeBSD-CVSweb <freebsd-cvsweb@FreeBSD.org>
![[BACK]](/icons/cvsweb/back.gif){kind=icon}
Return to hash.c CVS log ![[TXT]](/icons/cvsweb/text.gif){kind=icon}
![[DIR]](/icons/cvsweb/dir.gif){kind=icon}
Up to [ELWIX - Embedded LightWeight unIX -] / embedaddon / dhcp / omapip