ssl/libcrypto/src/crypto/lhash/lhash.c
changeset 0 e4d67989cc36
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     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 /* Code for dynamic hash table routines
       
    60  * Author - Eric Young v 2.0
       
    61  *
       
    62  * 2.2 eay - added #include "crypto.h" so the memory leak checking code is
       
    63  *	     present. eay 18-Jun-98
       
    64  *
       
    65  * 2.1 eay - Added an 'error in last operation' flag. eay 6-May-98
       
    66  *
       
    67  * 2.0 eay - Fixed a bug that occurred when using lh_delete
       
    68  *	     from inside lh_doall().  As entries were deleted,
       
    69  *	     the 'table' was 'contract()ed', making some entries
       
    70  *	     jump from the end of the table to the start, there by
       
    71  *	     skipping the lh_doall() processing. eay - 4/12/95
       
    72  *
       
    73  * 1.9 eay - Fixed a memory leak in lh_free, the LHASH_NODEs
       
    74  *	     were not being free()ed. 21/11/95
       
    75  *
       
    76  * 1.8 eay - Put the stats routines into a separate file, lh_stats.c
       
    77  *	     19/09/95
       
    78  *
       
    79  * 1.7 eay - Removed the fputs() for realloc failures - the code
       
    80  *           should silently tolerate them.  I have also fixed things
       
    81  *           lint complained about 04/05/95
       
    82  *
       
    83  * 1.6 eay - Fixed an invalid pointers in contract/expand 27/07/92
       
    84  *
       
    85  * 1.5 eay - Fixed a misuse of realloc in expand 02/03/1992
       
    86  *
       
    87  * 1.4 eay - Fixed lh_doall so the function can call lh_delete 28/05/91
       
    88  *
       
    89  * 1.3 eay - Fixed a few lint problems 19/3/1991
       
    90  *
       
    91  * 1.2 eay - Fixed lh_doall problem 13/3/1991
       
    92  *
       
    93  * 1.1 eay - Added lh_doall
       
    94  *
       
    95  * 1.0 eay - First version
       
    96  */
       
    97 #include <stdio.h>
       
    98 #include <string.h>
       
    99 #include <stdlib.h>
       
   100 #include <openssl/crypto.h>
       
   101 #include <openssl/lhash.h>
       
   102 
       
   103 const char lh_version[]="lhash" OPENSSL_VERSION_PTEXT;
       
   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 static void expand(LHASH *lh);
       
   111 static void contract(LHASH *lh);
       
   112 static LHASH_NODE **getrn(LHASH *lh, const void *data, unsigned long *rhash);
       
   113 
       
   114 EXPORT_C LHASH *lh_new(LHASH_HASH_FN_TYPE h, LHASH_COMP_FN_TYPE c)
       
   115 	{
       
   116 	LHASH *ret;
       
   117 	int i;
       
   118 
       
   119 	if ((ret=(LHASH *)OPENSSL_malloc(sizeof(LHASH))) == NULL)
       
   120 		goto err0;
       
   121 	if ((ret->b=(LHASH_NODE **)OPENSSL_malloc(sizeof(LHASH_NODE *)*MIN_NODES)) == NULL)
       
   122 		goto err1;
       
   123 	for (i=0; i<MIN_NODES; i++)
       
   124 		ret->b[i]=NULL;
       
   125 	ret->comp=((c == NULL)?(LHASH_COMP_FN_TYPE)strcmp:c);
       
   126 	ret->hash=((h == NULL)?(LHASH_HASH_FN_TYPE)lh_strhash:h);
       
   127 	ret->num_nodes=MIN_NODES/2;
       
   128 	ret->num_alloc_nodes=MIN_NODES;
       
   129 	ret->p=0;
       
   130 	ret->pmax=MIN_NODES/2;
       
   131 	ret->up_load=UP_LOAD;
       
   132 	ret->down_load=DOWN_LOAD;
       
   133 	ret->num_items=0;
       
   134 
       
   135 	ret->num_expands=0;
       
   136 	ret->num_expand_reallocs=0;
       
   137 	ret->num_contracts=0;
       
   138 	ret->num_contract_reallocs=0;
       
   139 	ret->num_hash_calls=0;
       
   140 	ret->num_comp_calls=0;
       
   141 	ret->num_insert=0;
       
   142 	ret->num_replace=0;
       
   143 	ret->num_delete=0;
       
   144 	ret->num_no_delete=0;
       
   145 	ret->num_retrieve=0;
       
   146 	ret->num_retrieve_miss=0;
       
   147 	ret->num_hash_comps=0;
       
   148 
       
   149 	ret->error=0;
       
   150 	return(ret);
       
   151 err1:
       
   152 	OPENSSL_free(ret);
       
   153 err0:
       
   154 	return(NULL);
       
   155 	}
       
   156 
       
   157 EXPORT_C void lh_free(LHASH *lh)
       
   158 	{
       
   159 	unsigned int i;
       
   160 	LHASH_NODE *n,*nn;
       
   161 
       
   162 	if (lh == NULL)
       
   163 	    return;
       
   164 
       
   165 	for (i=0; i<lh->num_nodes; i++)
       
   166 		{
       
   167 		n=lh->b[i];
       
   168 		while (n != NULL)
       
   169 			{
       
   170 			nn=n->next;
       
   171 			OPENSSL_free(n);
       
   172 			n=nn;
       
   173 			}
       
   174 		}
       
   175 	OPENSSL_free(lh->b);
       
   176 	OPENSSL_free(lh);
       
   177 	}
       
   178 
       
   179 EXPORT_C void *lh_insert(LHASH *lh, void *data)
       
   180 	{
       
   181 	unsigned long hash;
       
   182 	LHASH_NODE *nn,**rn;
       
   183 	void *ret;
       
   184 
       
   185 	lh->error=0;
       
   186 	if (lh->up_load <= (lh->num_items*LH_LOAD_MULT/lh->num_nodes))
       
   187 		expand(lh);
       
   188 
       
   189 	rn=getrn(lh,data,&hash);
       
   190 
       
   191 	if (*rn == NULL)
       
   192 		{
       
   193 		if ((nn=(LHASH_NODE *)OPENSSL_malloc(sizeof(LHASH_NODE))) == NULL)
       
   194 			{
       
   195 			lh->error++;
       
   196 			return(NULL);
       
   197 			}
       
   198 		nn->data=data;
       
   199 		nn->next=NULL;
       
   200 #ifndef OPENSSL_NO_HASH_COMP
       
   201 		nn->hash=hash;
       
   202 #endif
       
   203 		*rn=nn;
       
   204 		ret=NULL;
       
   205 		lh->num_insert++;
       
   206 		lh->num_items++;
       
   207 		}
       
   208 	else /* replace same key */
       
   209 		{
       
   210 		ret= (*rn)->data;
       
   211 		(*rn)->data=data;
       
   212 		lh->num_replace++;
       
   213 		}
       
   214 	return(ret);
       
   215 	}
       
   216 
       
   217 EXPORT_C void *lh_delete(LHASH *lh, const void *data)
       
   218 	{
       
   219 	unsigned long hash;
       
   220 	LHASH_NODE *nn,**rn;
       
   221 	void *ret;
       
   222 
       
   223 	lh->error=0;
       
   224 	rn=getrn(lh,data,&hash);
       
   225 
       
   226 	if (*rn == NULL)
       
   227 		{
       
   228 		lh->num_no_delete++;
       
   229 		return(NULL);
       
   230 		}
       
   231 	else
       
   232 		{
       
   233 		nn= *rn;
       
   234 		*rn=nn->next;
       
   235 		ret=nn->data;
       
   236 		OPENSSL_free(nn);
       
   237 		lh->num_delete++;
       
   238 		}
       
   239 
       
   240 	lh->num_items--;
       
   241 	if ((lh->num_nodes > MIN_NODES) &&
       
   242 		(lh->down_load >= (lh->num_items*LH_LOAD_MULT/lh->num_nodes)))
       
   243 		contract(lh);
       
   244 
       
   245 	return(ret);
       
   246 	}
       
   247 
       
   248 EXPORT_C void *lh_retrieve(LHASH *lh, const void *data)
       
   249 	{
       
   250 	unsigned long hash;
       
   251 	LHASH_NODE **rn;
       
   252 	void *ret;
       
   253 
       
   254 	lh->error=0;
       
   255 	rn=getrn(lh,data,&hash);
       
   256 
       
   257 	if (*rn == NULL)
       
   258 		{
       
   259 		lh->num_retrieve_miss++;
       
   260 		return(NULL);
       
   261 		}
       
   262 	else
       
   263 		{
       
   264 		ret= (*rn)->data;
       
   265 		lh->num_retrieve++;
       
   266 		}
       
   267 	return(ret);
       
   268 	}
       
   269 
       
   270 static void doall_util_fn(LHASH *lh, int use_arg, LHASH_DOALL_FN_TYPE func,
       
   271 			  LHASH_DOALL_ARG_FN_TYPE func_arg, void *arg)
       
   272 	{
       
   273 	int i;
       
   274 	LHASH_NODE *a,*n;
       
   275 
       
   276 	/* reverse the order so we search from 'top to bottom'
       
   277 	 * We were having memory leaks otherwise */
       
   278 	for (i=lh->num_nodes-1; i>=0; i--)
       
   279 		{
       
   280 		a=lh->b[i];
       
   281 		while (a != NULL)
       
   282 			{
       
   283 			/* 28/05/91 - eay - n added so items can be deleted
       
   284 			 * via lh_doall */
       
   285 			n=a->next;
       
   286 			if(use_arg)
       
   287 				func_arg(a->data,arg);
       
   288 			else
       
   289 				func(a->data);
       
   290 			a=n;
       
   291 			}
       
   292 		}
       
   293 	}
       
   294 
       
   295 EXPORT_C void lh_doall(LHASH *lh, LHASH_DOALL_FN_TYPE func)
       
   296 	{
       
   297 	doall_util_fn(lh, 0, func, (LHASH_DOALL_ARG_FN_TYPE)0, NULL);
       
   298 	}
       
   299 
       
   300 EXPORT_C void lh_doall_arg(LHASH *lh, LHASH_DOALL_ARG_FN_TYPE func, void *arg)
       
   301 	{
       
   302 	doall_util_fn(lh, 1, (LHASH_DOALL_FN_TYPE)0, func, arg);
       
   303 	}
       
   304 
       
   305 static void expand(LHASH *lh)
       
   306 	{
       
   307 	LHASH_NODE **n,**n1,**n2,*np;
       
   308 	unsigned int p,i,j;
       
   309 	unsigned long hash,nni;
       
   310 
       
   311 	lh->num_nodes++;
       
   312 	lh->num_expands++;
       
   313 	p=(int)lh->p++;
       
   314 	n1= &(lh->b[p]);
       
   315 	n2= &(lh->b[p+(int)lh->pmax]);
       
   316 	*n2=NULL;        /* 27/07/92 - eay - undefined pointer bug */
       
   317 	nni=lh->num_alloc_nodes;
       
   318 	
       
   319 	for (np= *n1; np != NULL; )
       
   320 		{
       
   321 #ifndef OPENSSL_NO_HASH_COMP
       
   322 		hash=np->hash;
       
   323 #else
       
   324 		hash=lh->hash(np->data);
       
   325 		lh->num_hash_calls++;
       
   326 #endif
       
   327 		if ((hash%nni) != p)
       
   328 			{ /* move it */
       
   329 			*n1= (*n1)->next;
       
   330 			np->next= *n2;
       
   331 			*n2=np;
       
   332 			}
       
   333 		else
       
   334 			n1= &((*n1)->next);
       
   335 		np= *n1;
       
   336 		}
       
   337 
       
   338 	if ((lh->p) >= lh->pmax)
       
   339 		{
       
   340 		j=(int)lh->num_alloc_nodes*2;
       
   341 		n=(LHASH_NODE **)OPENSSL_realloc(lh->b,
       
   342 			(int)(sizeof(LHASH_NODE *)*j));
       
   343 		if (n == NULL)
       
   344 			{
       
   345 /*			fputs("realloc error in lhash",stderr); */
       
   346 			lh->error++;
       
   347 			lh->p=0;
       
   348 			return;
       
   349 			}
       
   350 		/* else */
       
   351 		for (i=(int)lh->num_alloc_nodes; i<j; i++)/* 26/02/92 eay */
       
   352 			n[i]=NULL;			  /* 02/03/92 eay */
       
   353 		lh->pmax=lh->num_alloc_nodes;
       
   354 		lh->num_alloc_nodes=j;
       
   355 		lh->num_expand_reallocs++;
       
   356 		lh->p=0;
       
   357 		lh->b=n;
       
   358 		}
       
   359 	}
       
   360 
       
   361 static void contract(LHASH *lh)
       
   362 	{
       
   363 	LHASH_NODE **n,*n1,*np;
       
   364 
       
   365 	np=lh->b[lh->p+lh->pmax-1];
       
   366 	lh->b[lh->p+lh->pmax-1]=NULL; /* 24/07-92 - eay - weird but :-( */
       
   367 	if (lh->p == 0)
       
   368 		{
       
   369 		n=(LHASH_NODE **)OPENSSL_realloc(lh->b,
       
   370 			(unsigned int)(sizeof(LHASH_NODE *)*lh->pmax));
       
   371 		if (n == NULL)
       
   372 			{
       
   373 /*			fputs("realloc error in lhash",stderr); */
       
   374 			lh->error++;
       
   375 			return;
       
   376 			}
       
   377 		lh->num_contract_reallocs++;
       
   378 		lh->num_alloc_nodes/=2;
       
   379 		lh->pmax/=2;
       
   380 		lh->p=lh->pmax-1;
       
   381 		lh->b=n;
       
   382 		}
       
   383 	else
       
   384 		lh->p--;
       
   385 
       
   386 	lh->num_nodes--;
       
   387 	lh->num_contracts++;
       
   388 
       
   389 	n1=lh->b[(int)lh->p];
       
   390 	if (n1 == NULL)
       
   391 		lh->b[(int)lh->p]=np;
       
   392 	else
       
   393 		{
       
   394 		while (n1->next != NULL)
       
   395 			n1=n1->next;
       
   396 		n1->next=np;
       
   397 		}
       
   398 	}
       
   399 
       
   400 static LHASH_NODE **getrn(LHASH *lh, const void *data, unsigned long *rhash)
       
   401 	{
       
   402 	LHASH_NODE **ret,*n1;
       
   403 	unsigned long hash,nn;
       
   404 	LHASH_COMP_FN_TYPE cf;
       
   405 
       
   406 	hash=(*(lh->hash))(data);
       
   407 	lh->num_hash_calls++;
       
   408 	*rhash=hash;
       
   409 
       
   410 	nn=hash%lh->pmax;
       
   411 	if (nn < lh->p)
       
   412 		nn=hash%lh->num_alloc_nodes;
       
   413 
       
   414 	cf=lh->comp;
       
   415 	ret= &(lh->b[(int)nn]);
       
   416 	for (n1= *ret; n1 != NULL; n1=n1->next)
       
   417 		{
       
   418 #ifndef OPENSSL_NO_HASH_COMP
       
   419 		lh->num_hash_comps++;
       
   420 		if (n1->hash != hash)
       
   421 			{
       
   422 			ret= &(n1->next);
       
   423 			continue;
       
   424 			}
       
   425 #endif
       
   426 		lh->num_comp_calls++;
       
   427 		if(cf(n1->data,data) == 0)
       
   428 			break;
       
   429 		ret= &(n1->next);
       
   430 		}
       
   431 	return(ret);
       
   432 	}
       
   433 
       
   434 /* The following hash seems to work very well on normal text strings
       
   435  * no collisions on /usr/dict/words and it distributes on %2^n quite
       
   436  * well, not as good as MD5, but still good.
       
   437  */
       
   438 EXPORT_C unsigned long lh_strhash(const char *c)
       
   439 	{
       
   440 	unsigned long ret=0;
       
   441 	long n;
       
   442 	unsigned long v;
       
   443 	int r;
       
   444 
       
   445 	if ((c == NULL) || (*c == '\0'))
       
   446 		return(ret);
       
   447 /*
       
   448 	unsigned char b[16];
       
   449 	MD5(c,strlen(c),b);
       
   450 	return(b[0]|(b[1]<<8)|(b[2]<<16)|(b[3]<<24)); 
       
   451 */
       
   452 
       
   453 	n=0x100;
       
   454 	while (*c)
       
   455 		{
       
   456 		v=n|(*c);
       
   457 		n+=0x100;
       
   458 		r= (int)((v>>2)^v)&0x0f;
       
   459 		ret=(ret<<r)|(ret>>(32-r));
       
   460 		ret&=0xFFFFFFFFL;
       
   461 		ret^=v*v;
       
   462 		c++;
       
   463 		}
       
   464 	return((ret>>16)^ret);
       
   465 	}
       
   466 
       
   467 EXPORT_C unsigned long lh_num_items(const LHASH *lh)
       
   468 	{
       
   469 	return lh ? lh->num_items : 0;
       
   470 	}