lhash.c revision 65c4736d9c0ebc6d9b1d991593b55566909da9cd
/* crypto/lhash/lhash.c */
/* Copyright (C) 1995-1998 Eric Young (eay@cryptsoft.com)
* All rights reserved.
*
* This package is an SSL implementation written
* by Eric Young (eay@cryptsoft.com).
* The implementation was written so as to conform with Netscapes SSL.
*
* This library is free for commercial and non-commercial use as long as
* the following conditions are aheared to. The following conditions
* apply to all code found in this distribution, be it the RC4, RSA,
* lhash, DES, etc., code; not just the SSL code. The SSL documentation
* included with this distribution is covered by the same copyright terms
* except that the holder is Tim Hudson (tjh@cryptsoft.com).
*
* Copyright remains Eric Young's, and as such any Copyright notices in
* the code are not to be removed.
* If this package is used in a product, Eric Young should be given attribution
* as the author of the parts of the library used.
* This can be in the form of a textual message at program startup or
* in documentation (online or textual) provided with the package.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* "This product includes cryptographic software written by
* Eric Young (eay@cryptsoft.com)"
* The word 'cryptographic' can be left out if the rouines from the library
* being used are not cryptographic related :-).
* 4. If you include any Windows specific code (or a derivative thereof) from
* the apps directory (application code) you must include an acknowledgement:
* "This product includes software written by Tim Hudson (tjh@cryptsoft.com)"
*
* THIS SOFTWARE IS PROVIDED BY ERIC YOUNG ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* The licence and distribution terms for any publically available version or
* derivative of this code cannot be changed. i.e. this code cannot simply be
* copied and put under another distribution licence
* [including the GNU Public Licence.]
*/
/* Code for dynamic hash table routines
* Author - Eric Young v 2.0
*
* 2.2 eay - added #include "crypto.h" so the memory leak checking code is
* present. eay 18-Jun-98
*
* 2.1 eay - Added an 'error in last operation' flag. eay 6-May-98
*
* 2.0 eay - Fixed a bug that occured when using lh_delete
* from inside lh_doall(). As entries were deleted,
* the 'table' was 'contract()ed', making some entries
* jump from the end of the table to the start, there by
* skiping the lh_doall() processing. eay - 4/12/95
*
* 1.9 eay - Fixed a memory leak in lh_free, the LHASH_NODEs
* were not being free()ed. 21/11/95
*
* 1.8 eay - Put the stats routines into a separate file, lh_stats.c
* 19/09/95
*
* 1.7 eay - Removed the fputs() for realloc failures - the code
* should silently tolerate them. I have also fixed things
* lint complained about 04/05/95
*
* 1.6 eay - Fixed an invalid pointers in contract/expand 27/07/92
*
* 1.5 eay - Fixed a misuse of realloc in expand 02/03/1992
*
* 1.4 eay - Fixed lh_doall so the function can call lh_delete 28/05/91
*
* 1.3 eay - Fixed a few lint problems 19/3/1991
*
* 1.2 eay - Fixed lh_doall problem 13/3/1991
*
* 1.1 eay - Added lh_doall
*
* 1.0 eay - First version
*/
#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <openssl/crypto.h>
#include <openssl/lhash.h>
const char *lh_version="lhash" OPENSSL_VERSION_PTEXT;
#undef MIN_NODES
#define MIN_NODES 16
#define UP_LOAD (2*LH_LOAD_MULT) /* load times 256 (default 2) */
#define DOWN_LOAD (LH_LOAD_MULT) /* load times 256 (default 1) */
#define P_CP char *
#define P_CPP char *,char *
static void expand(LHASH *lh);
static void contract(LHASH *lh);
static LHASH_NODE **getrn(LHASH *lh, char *data, unsigned long *rhash);
LHASH *lh_new(unsigned long (*h)(), int (*c)())
{
LHASH *ret;
int i;
if ((ret=(LHASH *)Malloc(sizeof(LHASH))) == NULL)
goto err0;
if ((ret->b=(LHASH_NODE **)Malloc(sizeof(LHASH_NODE *)*MIN_NODES)) == NULL)
goto err1;
for (i=0; i<MIN_NODES; i++)
ret->b[i]=NULL;
ret->comp=((c == NULL)?(int (*)())strcmp:c);
ret->hash=((h == NULL)?(unsigned long (*)())lh_strhash:h);
ret->num_nodes=MIN_NODES/2;
ret->num_alloc_nodes=MIN_NODES;
ret->p=0;
ret->pmax=MIN_NODES/2;
ret->up_load=UP_LOAD;
ret->down_load=DOWN_LOAD;
ret->num_items=0;
ret->num_expands=0;
ret->num_expand_reallocs=0;
ret->num_contracts=0;
ret->num_contract_reallocs=0;
ret->num_hash_calls=0;
ret->num_comp_calls=0;
ret->num_insert=0;
ret->num_replace=0;
ret->num_delete=0;
ret->num_no_delete=0;
ret->num_retrieve=0;
ret->num_retrieve_miss=0;
ret->num_hash_comps=0;
ret->error=0;
return(ret);
err1:
Free((char *)ret);
err0:
return(NULL);
}
void lh_free(LHASH *lh)
{
unsigned int i;
LHASH_NODE *n,*nn;
if(lh == NULL)
return;
for (i=0; i<lh->num_nodes; i++)
{
n=lh->b[i];
while (n != NULL)
{
nn=n->next;
Free(n);
n=nn;
}
}
Free((char *)lh->b);
Free((char *)lh);
}
char *lh_insert(LHASH *lh, char *data)
{
unsigned long hash;
LHASH_NODE *nn,**rn;
char *ret;
lh->error=0;
if (lh->up_load <= (lh->num_items*LH_LOAD_MULT/lh->num_nodes))
expand(lh);
rn=getrn(lh,data,&hash);
if (*rn == NULL)
{
if ((nn=(LHASH_NODE *)Malloc(sizeof(LHASH_NODE))) == NULL)
{
lh->error++;
return(NULL);
}
nn->data=data;
nn->next=NULL;
#ifndef NO_HASH_COMP
nn->hash=hash;
#endif
*rn=nn;
ret=NULL;
lh->num_insert++;
lh->num_items++;
}
else /* replace same key */
{
ret= (*rn)->data;
(*rn)->data=data;
lh->num_replace++;
}
return(ret);
}
char *lh_delete(LHASH *lh, char *data)
{
unsigned long hash;
LHASH_NODE *nn,**rn;
char *ret;
lh->error=0;
rn=getrn(lh,data,&hash);
if (*rn == NULL)
{
lh->num_no_delete++;
return(NULL);
}
else
{
nn= *rn;
*rn=nn->next;
ret=nn->data;
Free((char *)nn);
lh->num_delete++;
}
lh->num_items--;
if ((lh->num_nodes > MIN_NODES) &&
(lh->down_load >= (lh->num_items*LH_LOAD_MULT/lh->num_nodes)))
contract(lh);
return(ret);
}
char *lh_retrieve(LHASH *lh, char *data)
{
unsigned long hash;
LHASH_NODE **rn;
char *ret;
lh->error=0;
rn=getrn(lh,data,&hash);
if (*rn == NULL)
{
lh->num_retrieve_miss++;
return(NULL);
}
else
{
ret= (*rn)->data;
lh->num_retrieve++;
}
return(ret);
}
void lh_doall(LHASH *lh, void (*func)())
{
lh_doall_arg(lh,func,NULL);
}
void lh_doall_arg(LHASH *lh, void (*func)(), char *arg)
{
int i;
LHASH_NODE *a,*n;
/* reverse the order so we search from 'top to bottom'
* We were having memory leaks otherwise */
for (i=lh->num_nodes-1; i>=0; i--)
{
a=lh->b[i];
while (a != NULL)
{
/* 28/05/91 - eay - n added so items can be deleted
* via lh_doall */
n=a->next;
func(a->data,arg);
a=n;
}
}
}
static void expand(LHASH *lh)
{
LHASH_NODE **n,**n1,**n2,*np;
unsigned int p,i,j;
unsigned long hash,nni;
lh->num_nodes++;
lh->num_expands++;
p=(int)lh->p++;
n1= &(lh->b[p]);
n2= &(lh->b[p+(int)lh->pmax]);
*n2=NULL; /* 27/07/92 - eay - undefined pointer bug */
nni=lh->num_alloc_nodes;
for (np= *n1; np != NULL; )
{
#ifndef NO_HASH_COMP
hash=np->hash;
#else
hash=(*(lh->hash))(np->data);
lh->num_hash_calls++;
#endif
if ((hash%nni) != p)
{ /* move it */
*n1= (*n1)->next;
np->next= *n2;
*n2=np;
}
else
n1= &((*n1)->next);
np= *n1;
}
if ((lh->p) >= lh->pmax)
{
j=(int)lh->num_alloc_nodes*2;
n=(LHASH_NODE **)Realloc((char *)lh->b,
(unsigned int)sizeof(LHASH_NODE *)*j);
if (n == NULL)
{
/* fputs("realloc error in lhash",stderr); */
lh->error++;
lh->p=0;
return;
}
/* else */
for (i=(int)lh->num_alloc_nodes; i<j; i++)/* 26/02/92 eay */
n[i]=NULL; /* 02/03/92 eay */
lh->pmax=lh->num_alloc_nodes;
lh->num_alloc_nodes=j;
lh->num_expand_reallocs++;
lh->p=0;
lh->b=n;
}
}
static void contract(LHASH *lh)
{
LHASH_NODE **n,*n1,*np;
np=lh->b[lh->p+lh->pmax-1];
lh->b[lh->p+lh->pmax-1]=NULL; /* 24/07-92 - eay - weird but :-( */
if (lh->p == 0)
{
n=(LHASH_NODE **)Realloc((char *)lh->b,
(unsigned int)(sizeof(LHASH_NODE *)*lh->pmax));
if (n == NULL)
{
/* fputs("realloc error in lhash",stderr); */
lh->error++;
return;
}
lh->num_contract_reallocs++;
lh->num_alloc_nodes/=2;
lh->pmax/=2;
lh->p=lh->pmax-1;
lh->b=n;
}
else
lh->p--;
lh->num_nodes--;
lh->num_contracts++;
n1=lh->b[(int)lh->p];
if (n1 == NULL)
lh->b[(int)lh->p]=np;
else
{
while (n1->next != NULL)
n1=n1->next;
n1->next=np;
}
}
static LHASH_NODE **getrn(LHASH *lh, char *data, unsigned long *rhash)
{
LHASH_NODE **ret,*n1;
unsigned long hash,nn;
int (*cf)();
hash=(*(lh->hash))(data);
lh->num_hash_calls++;
*rhash=hash;
nn=hash%lh->pmax;
if (nn < lh->p)
nn=hash%lh->num_alloc_nodes;
cf=lh->comp;
ret= &(lh->b[(int)nn]);
for (n1= *ret; n1 != NULL; n1=n1->next)
{
#ifndef NO_HASH_COMP
lh->num_hash_comps++;
if (n1->hash != hash)
{
ret= &(n1->next);
continue;
}
#endif
lh->num_comp_calls++;
if ((*cf)(n1->data,data) == 0)
break;
ret= &(n1->next);
}
return(ret);
}
/*
static unsigned long lh_strhash(str)
char *str;
{
int i,l;
unsigned long ret=0;
unsigned short *s;
if (str == NULL) return(0);
l=(strlen(str)+1)/2;
s=(unsigned short *)str;
for (i=0; i<l; i++)
ret^=(s[i]<<(i&0x0f));
return(ret);
} */
/* The following hash seems to work very well on normal text strings
* no collisions on /usr/dict/words and it distributes on %2^n quite
* well, not as good as MD5, but still good.
*/
unsigned long lh_strhash(const char *c)
{
unsigned long ret=0;
long n;
unsigned long v;
int r;
if ((c == NULL) || (*c == '\0'))
return(ret);
/*
unsigned char b[16];
MD5(c,strlen(c),b);
return(b[0]|(b[1]<<8)|(b[2]<<16)|(b[3]<<24));
*/
n=0x100;
while (*c)
{
v=n|(*c);
n+=0x100;
r= (int)((v>>2)^v)&0x0f;
ret=(ret<<r)|(ret>>(32-r));
ret&=0xFFFFFFFFL;
ret^=v*v;
c++;
}
return((ret>>16)^ret);
}