#ifndef lint
static const char RCSid[] = "$Id: lookup.c,v 2.6 2003/02/22 02:07:22 greg Exp $";
#endif
/*
* Table lookup routines
*/
/* ====================================================================
* The Radiance Software License, Version 1.0
*
* Copyright (c) 1990 - 2002 The Regents of the University of California,
* through Lawrence Berkeley National Laboratory. All rights reserved.
*
* 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 above 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. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes Radiance software
* (http://radsite.lbl.gov/)
* developed by the Lawrence Berkeley National Laboratory
* (http://www.lbl.gov/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Radiance," "Lawrence Berkeley National Laboratory"
* and "The Regents of the University of California" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact radiance@radsite.lbl.gov.
*
* 5. Products derived from this software may not be called "Radiance",
* nor may "Radiance" appear in their name, without prior written
* permission of Lawrence Berkeley National Laboratory.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED 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 Lawrence Berkeley National Laboratory OR
* ITS 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.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of Lawrence Berkeley National Laboratory. For more
* information on Lawrence Berkeley National Laboratory, please see
* .
*/
#include
#include
#include "lookup.h"
#ifdef NOSTRUCTASS
#define copystruct(d,s) bcopy((char *)(s),(char *)(d),sizeof(*(d)))
#else
#define copystruct(d,s) (*(d) = *(s))
#endif
int
lu_init(tbl, nel) /* initialize tbl for at least nel elements */
register LUTAB *tbl;
int nel;
{
static int hsiztab[] = {
31, 61, 127, 251, 509, 1021, 2039, 4093, 8191, 16381,
32749, 65521, 131071, 262139, 524287, 1048573, 2097143,
4194301, 8388593, 0
};
register int *hsp;
nel += nel>>1; /* 66% occupancy */
for (hsp = hsiztab; *hsp; hsp++)
if (*hsp > nel)
break;
if (!(tbl->tsiz = *hsp))
tbl->tsiz = nel*2 + 1; /* not always prime */
tbl->tabl = (LUENT *)calloc(tbl->tsiz, sizeof(LUENT));
if (tbl->tabl == NULL)
tbl->tsiz = 0;
tbl->ndel = 0;
return(tbl->tsiz);
}
unsigned long
lu_shash(s) /* hash a nul-terminated string */
char *s;
{
static unsigned char shuffle[256] = {
0, 157, 58, 215, 116, 17, 174, 75, 232, 133, 34,
191, 92, 249, 150, 51, 208, 109, 10, 167, 68, 225,
126, 27, 184, 85, 242, 143, 44, 201, 102, 3, 160,
61, 218, 119, 20, 177, 78, 235, 136, 37, 194, 95,
252, 153, 54, 211, 112, 13, 170, 71, 228, 129, 30,
187, 88, 245, 146, 47, 204, 105, 6, 163, 64, 221,
122, 23, 180, 81, 238, 139, 40, 197, 98, 255, 156,
57, 214, 115, 16, 173, 74, 231, 132, 33, 190, 91,
248, 149, 50, 207, 108, 9, 166, 67, 224, 125, 26,
183, 84, 241, 142, 43, 200, 101, 2, 159, 60, 217,
118, 19, 176, 77, 234, 135, 36, 193, 94, 251, 152,
53, 210, 111, 12, 169, 70, 227, 128, 29, 186, 87,
244, 145, 46, 203, 104, 5, 162, 63, 220, 121, 22,
179, 80, 237, 138, 39, 196, 97, 254, 155, 56, 213,
114, 15, 172, 73, 230, 131, 32, 189, 90, 247, 148,
49, 206, 107, 8, 165, 66, 223, 124, 25, 182, 83,
240, 141, 42, 199, 100, 1, 158, 59, 216, 117, 18,
175, 76, 233, 134, 35, 192, 93, 250, 151, 52, 209,
110, 11, 168, 69, 226, 127, 28, 185, 86, 243, 144,
45, 202, 103, 4, 161, 62, 219, 120, 21, 178, 79,
236, 137, 38, 195, 96, 253, 154, 55, 212, 113, 14,
171, 72, 229, 130, 31, 188, 89, 246, 147, 48, 205,
106, 7, 164, 65, 222, 123, 24, 181, 82, 239, 140,
41, 198, 99
};
register int i = 0;
register unsigned long h = 0;
register unsigned char *t = (unsigned char *)s;
while (*t)
h ^= (unsigned long)shuffle[*t++] << ((i+=11) & 0xf);
return(h);
}
LUENT *
lu_find(tbl, key) /* find a table entry */
register LUTAB *tbl;
char *key;
{
unsigned long hval;
int i, n;
register int ndx;
register LUENT *le;
/* look up object */
if (tbl->tsiz == 0 && !lu_init(tbl, 1))
return(NULL);
hval = (*tbl->hashf)(key);
tryagain:
ndx = hval % tbl->tsiz;
for (i = 0, n = 1; i < tbl->tsiz; i++, n += 2) {
le = &tbl->tabl[ndx];
if (le->key == NULL) {
le->hval = hval;
return(le);
}
if (le->hval == hval &&
(tbl->keycmp == NULL || !(*tbl->keycmp)(le->key, key))) {
return(le);
}
if ((ndx += n) >= tbl->tsiz) /* this happens rarely */
ndx = ndx % tbl->tsiz;
}
/* table is full, reallocate */
le = tbl->tabl;
ndx = tbl->tsiz;
i = tbl->ndel;
if (!lu_init(tbl, ndx-i+1)) { /* no more memory! */
tbl->tabl = le;
tbl->tsiz = ndx;
tbl->ndel = i;
return(NULL);
}
/*
* The following code may fail if the user has reclaimed many
* deleted entries and the system runs out of memory in a
* recursive call to lu_find().
*/
while (ndx--)
if (le[ndx].key != NULL)
if (le[ndx].data != NULL)
copystruct(lu_find(tbl,le[ndx].key), &le[ndx]);
else if (tbl->freek != NULL)
(*tbl->freek)(le[ndx].key);
free((void *)le);
goto tryagain; /* should happen only once! */
}
void
lu_delete(tbl, key) /* delete a table entry */
register LUTAB *tbl;
char *key;
{
register LUENT *le;
if ((le = lu_find(tbl, key)) == NULL)
return;
if (le->key == NULL || le->data == NULL)
return;
if (tbl->freed != NULL)
(*tbl->freed)(le->data);
le->data = NULL;
tbl->ndel++;
}
int
lu_doall(tbl, f) /* loop through all valid table entries */
register LUTAB *tbl;
int (*f)();
{
int rval = 0;
register LUENT *tp;
for (tp = tbl->tabl + tbl->tsiz; tp-- > tbl->tabl; )
if (tp->data != NULL)
if (f != NULL)
rval += (*f)(tp);
else
rval++;
return(rval);
}
void
lu_done(tbl) /* free table and contents */
register LUTAB *tbl;
{
register LUENT *tp;
if (!tbl->tsiz)
return;
for (tp = tbl->tabl + tbl->tsiz; tp-- > tbl->tabl; )
if (tp->key != NULL) {
if (tbl->freek != NULL)
(*tbl->freek)(tp->key);
if (tp->data != NULL && tbl->freed != NULL)
(*tbl->freed)(tp->data);
}
free((void *)tbl->tabl);
tbl->tabl = NULL;
tbl->tsiz = 0;
tbl->ndel = 0;
}