crypto/lhash/lhash.c

   1 /* crypto/lhash/lhash.c */
   2 /* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
   3  * All rights reserved.
   4  *
   5  * This package is an SSL implementation written
   6  * by Eric Young (eay@cryptsoft.com).
   7  * The implementation was written so as to conform with Netscapes SSL.
   8  *
   9  * This library is free for commercial and non-commercial use as long as
  10  * the following conditions are aheared to.  The following conditions
  11  * apply to all code found in this distribution, be it the RC4, RSA,
  12  * lhash, DES, etc., code; not just the SSL code.  The SSL documentation
  13  * included with this distribution is covered by the same copyright terms
  14  * except that the holder is Tim Hudson (tjh@cryptsoft.com).
  15  *
  16  * Copyright remains Eric Young's, and as such any Copyright notices in
  17  * the code are not to be removed.
  18  * If this package is used in a product, Eric Young should be given attribution
  19  * as the author of the parts of the library used.
  20  * This can be in the form of a textual message at program startup or
  21  * in documentation (online or textual) provided with the package.
  22  *
  23  * Redistribution and use in source and binary forms, with or without
  24  * modification, are permitted provided that the following conditions
  25  * are met:
  26  * 1. Redistributions of source code must retain the copyright
  27  *    notice, this list of conditions and the following disclaimer.
  28  * 2. Redistributions in binary form must reproduce the above copyright
  29  *    notice, this list of conditions and the following disclaimer in the
  30  *    documentation and/or other materials provided with the distribution.
  31  * 3. All advertising materials mentioning features or use of this software
  32  *    must display the following acknowledgement:
  33  *    "This product includes cryptographic software written by
  34  *     Eric Young (eay@cryptsoft.com)"
  35  *    The word 'cryptographic' can be left out if the rouines from the library
  36  *    being used are not cryptographic related :-).
  37  * 4. If you include any Windows specific code (or a derivative thereof) from
  38  *    the apps directory (application code) you must include an acknowledgement:
  39  *    "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
  40  *
  41  * THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
  42  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  43  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  44  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  45  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  46  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  47  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  48  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  49  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  50  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  51  * SUCH DAMAGE.
  52  *
  53  * The licence and distribution terms for any publically available version or
  54  * derivative of this code cannot be changed.  i.e. this code cannot simply be
  55  * copied and put under another distribution licence
  56  * [including the GNU Public Licence.]
  57  */
  58
  59 char *lh_version="lhash part of OpenSSL 0.9.1c 23-Dec-1998";
  60
  61 /* Code for dynamic hash table routines
  62  * Author - Eric Young v 2.0
  63  *
  64  * 2.2 eay - added #include "crypto.h" so the memory leak checking code is
  65  *           present. eay 18-Jun-98
  66  *
  67  * 2.1 eay - Added an 'error in last operation' flag. eay 6-May-98
  68  *
  69  * 2.0 eay - Fixed a bug that occured when using lh_delete
  70  *           from inside lh_doall().  As entries were deleted,
  71  *           the 'table' was 'contract()ed', making some entries
  72  *           jump from the end of the table to the start, there by
  73  *           skiping the lh_doall() processing. eay - 4/12/95
  74  *
  75  * 1.9 eay - Fixed a memory leak in lh_free, the LHASH_NODEs
  76  *           were not being free()ed. 21/11/95
  77  *
  78  * 1.8 eay - Put the stats routines into a separate file, lh_stats.c
  79  *           19/09/95
  80  *
  81  * 1.7 eay - Removed the fputs() for realloc failures - the code
  82  *           should silently tolerate them.  I have also fixed things
  83  *           lint complained about 04/05/95
  84  *
  85  * 1.6 eay - Fixed an invalid pointers in contract/expand 27/07/92
  86  *
  87  * 1.5 eay - Fixed a misuse of realloc in expand 02/03/1992
  88  *
  89  * 1.4 eay - Fixed lh_doall so the function can call lh_delete 28/05/91
  90  *
  91  * 1.3 eay - Fixed a few lint problems 19/3/1991
  92  *
  93  * 1.2 eay - Fixed lh_doall problem 13/3/1991
  94  *
  95  * 1.1 eay - Added lh_doall
  96  *
  97  * 1.0 eay - First version
  98  */
  99 #include <stdio.h>
 100 #include <string.h>
 101 #include <stdlib.h>
 102 #include "crypto.h"
 103 #include "lhash.h"
 104
 105 #undef MIN_NODES
 106 #define MIN_NODES       16
 107 #define UP_LOAD         (2*LH_LOAD_MULT) /* load times 256  (default 2) */
 108 #define DOWN_LOAD       (LH_LOAD_MULT)   /* load times 256  (default 1) */
 109
 110 #ifndef NOPROTO
 111
 112 #define P_CP    char *
 113 #define P_CPP   char *,char *
 114 static void expand(LHASH *lh);
 115 static void contract(LHASH *lh);
 116 static LHASH_NODE **getrn(LHASH *lh, char *data, unsigned long *rhash);
 117
 118 #else
 119
 120 #define P_CP
 121 #define P_CPP
 122 static void expand();
 123 static void contract();
 124 static LHASH_NODE **getrn();
 125
 126 #endif
 127
 128 LHASH *lh_new(h, c)
 129 unsigned long (*h)();
 130 int (*c)();
 131         {
 132         LHASH *ret;
 133         int i;
 134
 135         if ((ret=(LHASH *)Malloc(sizeof(LHASH))) == NULL)
 136                 goto err0;
 137         if ((ret->b=(LHASH_NODE **)Malloc(sizeof(LHASH_NODE *)*MIN_NODES)) == NULL)
 138                 goto err1;
 139         for (i=0; i<MIN_NODES; i++)
 140                 ret->b[i]=NULL;
 141         ret->comp=((c == NULL)?(int (*)())strcmp:c);
 142         ret->hash=((h == NULL)?(unsigned long (*)())lh_strhash:h);
 143         ret->num_nodes=MIN_NODES/2;
 144         ret->num_alloc_nodes=MIN_NODES;
 145         ret->p=0;
 146         ret->pmax=MIN_NODES/2;
 147         ret->up_load=UP_LOAD;
 148         ret->down_load=DOWN_LOAD;
 149         ret->num_items=0;
 150
 151         ret->num_expands=0;
 152         ret->num_expand_reallocs=0;
 153         ret->num_contracts=0;
 154         ret->num_contract_reallocs=0;
 155         ret->num_hash_calls=0;
 156         ret->num_comp_calls=0;
 157         ret->num_insert=0;
 158         ret->num_replace=0;
 159         ret->num_delete=0;
 160         ret->num_no_delete=0;
 161         ret->num_retrieve=0;
 162         ret->num_retrieve_miss=0;
 163         ret->num_hash_comps=0;
 164
 165         ret->error=0;
 166         return(ret);
 167 err1:
 168         Free((char *)ret);
 169 err0:
 170         return(NULL);
 171         }
 172
 173 void lh_free(lh)
 174 LHASH *lh;
 175         {
 176         unsigned int i;
 177         LHASH_NODE *n,*nn;
 178
 179         for (i=0; i<lh->num_nodes; i++)
 180                 {
 181                 n=lh->b[i];
 182                 while (n != NULL)
 183                         {
 184                         nn=n->next;
 185                         Free(n);
 186                         n=nn;
 187                         }
 188                 }
 189         Free((char *)lh->b);
 190         Free((char *)lh);
 191         }
 192
 193 char *lh_insert(lh, data)
 194 LHASH *lh;
 195 char *data;
 196         {
 197         unsigned long hash;
 198         LHASH_NODE *nn,**rn;
 199         char *ret;
 200
 201         lh->error=0;
 202         if (lh->up_load <= (lh->num_items*LH_LOAD_MULT/lh->num_nodes))
 203                 expand(lh);
 204
 205         rn=getrn(lh,data,&hash);
 206
 207         if (*rn == NULL)
 208                 {
 209                 if ((nn=(LHASH_NODE *)Malloc(sizeof(LHASH_NODE))) == NULL)
 210                         {
 211                         lh->error++;
 212                         return(NULL);
 213                         }
 214                 nn->data=data;
 215                 nn->next=NULL;
 216 #ifndef NO_HASH_COMP
 217                 nn->hash=hash;
 218 #endif
 219                 *rn=nn;
 220                 ret=NULL;
 221                 lh->num_insert++;
 222                 lh->num_items++;
 223                 }
 224         else /* replace same key */
 225                 {
 226                 ret= (*rn)->data;
 227                 (*rn)->data=data;
 228                 lh->num_replace++;
 229                 }
 230         return(ret);
 231         }
 232
 233 char *lh_delete(lh, data)
 234 LHASH *lh;
 235 char *data;
 236         {
 237         unsigned long hash;
 238         LHASH_NODE *nn,**rn;
 239         char *ret;
 240
 241         lh->error=0;
 242         rn=getrn(lh,data,&hash);
 243
 244         if (*rn == NULL)
 245                 {
 246                 lh->num_no_delete++;
 247                 return(NULL);
 248                 }
 249         else
 250                 {
 251                 nn= *rn;
 252                 *rn=nn->next;
 253                 ret=nn->data;
 254                 Free((char *)nn);
 255                 lh->num_delete++;
 256                 }
 257
 258         lh->num_items--;
 259         if ((lh->num_nodes > MIN_NODES) &&
 260                 (lh->down_load >= (lh->num_items*LH_LOAD_MULT/lh->num_nodes)))
 261                 contract(lh);
 262
 263         return(ret);
 264         }
 265
 266 char *lh_retrieve(lh, data)
 267 LHASH *lh;
 268 char *data;
 269         {
 270         unsigned long hash;
 271         LHASH_NODE **rn;
 272         char *ret;
 273
 274         lh->error=0;
 275         rn=getrn(lh,data,&hash);
 276
 277         if (*rn == NULL)
 278                 {
 279                 lh->num_retrieve_miss++;
 280                 return(NULL);
 281                 }
 282         else
 283                 {
 284                 ret= (*rn)->data;
 285                 lh->num_retrieve++;
 286                 }
 287         return(ret);
 288         }
 289
 290 void lh_doall(lh, func)
 291 LHASH *lh;
 292 void (*func)();
 293         {
 294         lh_doall_arg(lh,func,NULL);
 295         }
 296
 297 void lh_doall_arg(lh, func, arg)
 298 LHASH *lh;
 299 void (*func)();
 300 char *arg;
 301         {
 302         int i;
 303         LHASH_NODE *a,*n;
 304
 305         /* reverse the order so we search from 'top to bottom'
 306          * We were having memory leaks otherwise */
 307         for (i=lh->num_nodes-1; i>=0; i--)
 308                 {
 309                 a=lh->b[i];
 310                 while (a != NULL)
 311                         {
 312                         /* 28/05/91 - eay - n added so items can be deleted
 313                          * via lh_doall */
 314                         n=a->next;
 315                         func(a->data,arg);
 316                         a=n;
 317                         }
 318                 }
 319         }
 320
 321 static void expand(lh)
 322 LHASH *lh;
 323         {
 324         LHASH_NODE **n,**n1,**n2,*np;
 325         unsigned int p,i,j;
 326         unsigned long hash,nni;
 327
 328         lh->num_nodes++;
 329         lh->num_expands++;
 330         p=(int)lh->p++;
 331         n1= &(lh->b[p]);
 332         n2= &(lh->b[p+(int)lh->pmax]);
 333         *n2=NULL;        /* 27/07/92 - eay - undefined pointer bug */
 334         nni=lh->num_alloc_nodes;
 335
 336         for (np= *n1; np != NULL; )
 337                 {
 338 #ifndef NO_HASH_COMP
 339                 hash=np->hash;
 340 #else
 341                 hash=(*(lh->hash))(np->data);
 342                 lh->num_hash_calls++;
 343 #endif
 344                 if ((hash%nni) != p)
 345                         { /* move it */
 346                         *n1= (*n1)->next;
 347                         np->next= *n2;
 348                         *n2=np;
 349                         }
 350                 else
 351                         n1= &((*n1)->next);
 352                 np= *n1;
 353                 }
 354
 355         if ((lh->p) >= lh->pmax)
 356                 {
 357                 j=(int)lh->num_alloc_nodes*2;
 358                 n=(LHASH_NODE **)Realloc((char *)lh->b,
 359                         (unsigned int)sizeof(LHASH_NODE *)*j);
 360                 if (n == NULL)
 361                         {
 362 /*                      fputs("realloc error in lhash",stderr); */
 363                         lh->error++;
 364                         lh->p=0;
 365                         return;
 366                         }
 367                 /* else */
 368                 for (i=(int)lh->num_alloc_nodes; i<j; i++)/* 26/02/92 eay */
 369                         n[i]=NULL;                        /* 02/03/92 eay */
 370                 lh->pmax=lh->num_alloc_nodes;
 371                 lh->num_alloc_nodes=j;
 372                 lh->num_expand_reallocs++;
 373                 lh->p=0;
 374                 lh->b=n;
 375                 }
 376         }
 377
 378 static void contract(lh)
 379 LHASH *lh;
 380         {
 381         LHASH_NODE **n,*n1,*np;
 382
 383         np=lh->b[lh->p+lh->pmax-1];
 384         lh->b[lh->p+lh->pmax-1]=NULL; /* 24/07-92 - eay - weird but :-( */
 385         if (lh->p == 0)
 386                 {
 387                 n=(LHASH_NODE **)Realloc((char *)lh->b,
 388                         (unsigned int)(sizeof(LHASH_NODE *)*lh->pmax));
 389                 if (n == NULL)
 390                         {
 391 /*                      fputs("realloc error in lhash",stderr); */
 392                         lh->error++;
 393                         return;
 394                         }
 395                 lh->num_contract_reallocs++;
 396                 lh->num_alloc_nodes/=2;
 397                 lh->pmax/=2;
 398                 lh->p=lh->pmax-1;
 399                 lh->b=n;
 400                 }
 401         else
 402                 lh->p--;
 403
 404         lh->num_nodes--;
 405         lh->num_contracts++;
 406
 407         n1=lh->b[(int)lh->p];
 408         if (n1 == NULL)
 409                 lh->b[(int)lh->p]=np;
 410         else
 411                 {
 412                 while (n1->next != NULL)
 413                         n1=n1->next;
 414                 n1->next=np;
 415                 }
 416         }
 417
 418 static LHASH_NODE **getrn(lh, data, rhash)
 419 LHASH *lh;
 420 char *data;
 421 unsigned long *rhash;
 422         {
 423         LHASH_NODE **ret,*n1;
 424         unsigned long hash,nn;
 425         int (*cf)();
 426
 427         hash=(*(lh->hash))(data);
 428         lh->num_hash_calls++;
 429         *rhash=hash;
 430
 431         nn=hash%lh->pmax;
 432         if (nn < lh->p)
 433                 nn=hash%lh->num_alloc_nodes;
 434
 435         cf=lh->comp;
 436         ret= &(lh->b[(int)nn]);
 437         for (n1= *ret; n1 != NULL; n1=n1->next)
 438                 {
 439 #ifndef NO_HASH_COMP
 440                 lh->num_hash_comps++;
 441                 if (n1->hash != hash)
 442                         {
 443                         ret= &(n1->next);
 444                         continue;
 445                         }
 446 #endif
 447                 lh->num_comp_calls++;
 448                 if ((*cf)(n1->data,data) == 0)
 449                         break;
 450                 ret= &(n1->next);
 451                 }
 452         return(ret);
 453         }
 454
 455 /*
 456 static unsigned long lh_strhash(str)
 457 char *str;
 458         {
 459         int i,l;
 460         unsigned long ret=0;
 461         unsigned short *s;
 462
 463         if (str == NULL) return(0);
 464         l=(strlen(str)+1)/2;
 465         s=(unsigned short *)str;
 466         for (i=0; i<l; i++)
 467                 ret^=(s[i]<<(i&0x0f));
 468         return(ret);
 469         } */
 470
 471 /* The following hash seems to work very well on normal text strings
 472  * no collisions on /usr/dict/words and it distributes on %2^n quite
 473  * well, not as good as MD5, but still good.
 474  */
 475 unsigned long lh_strhash(c)
 476 char *c;
 477         {
 478         unsigned long ret=0;
 479         long n;
 480         unsigned long v;
 481         int r;
 482
 483         if ((c == NULL) || (*c == '\0'))
 484                 return(ret);
 485 /*
 486         unsigned char b[16];
 487         MD5(c,strlen(c),b);
 488         return(b[0]|(b[1]<<8)|(b[2]<<16)|(b[3]<<24));
 489 */
 490
 491         n=0x100;
 492         while (*c)
 493                 {
 494                 v=n|(*c);
 495                 n+=0x100;
 496                 r= (int)((v>>2)^v)&0x0f;
 497                 ret=(ret<<r)|(ret>>(32-r));
 498                 ret&=0xFFFFFFFFL;
 499                 ret^=v*v;
 500                 c++;
 501                 }
 502         return((ret>>16)^ret);
 503         }
 504