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root/radiance/ray/src/common/lookup.c
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Comparing ray/src/common/lookup.c (file contents):
Revision 2.2 by greg, Tue Apr 11 13:33:37 1995 UTC vs.
Revision 2.8 by greg, Tue May 13 17:58:32 2003 UTC

# Line 1 | Line 1
1 – /* Copyright (c) 1994 Regents of the University of California */
2 –
1   #ifndef lint
2 < static char SCCSid[] = "$SunId$ LBL";
2 > static const char       RCSid[] = "$Id$";
3   #endif
6 –
4   /*
5   * Table lookup routines
6   */
7  
8 + #include "copyright.h"
9 +
10   #include <stdio.h>
11 + #include <stdlib.h>
12   #include "lookup.h"
13  
14 < #define MEM_PTR         char *
14 > #ifdef  NOSTRUCTASS
15 > #define  copystruct(d,s)        bcopy((void *)(s),(void *)(d),sizeof(*(d)))
16 > #else
17 > #define  copystruct(d,s)        (*(d) = *(s))
18 > #endif
19  
16 – extern MEM_PTR  calloc();
20  
18 –
21   int
22   lu_init(tbl, nel)               /* initialize tbl for at least nel elements */
23   register LUTAB  *tbl;
24   int     nel;
25   {
26          static int  hsiztab[] = {
27 <                31, 61, 127, 251, 509, 1021, 2039, 4093, 8191, 16381, 0
27 >                31, 61, 127, 251, 509, 1021, 2039, 4093, 8191, 16381,
28 >                32749, 65521, 131071, 262139, 524287, 1048573, 2097143,
29 >                4194301, 8388593, 0
30          };
31          register int  *hsp;
32  
# Line 40 | Line 44 | int    nel;
44   }
45  
46  
47 < long
47 > unsigned long
48   lu_shash(s)                     /* hash a nul-terminated string */
49 < register char  *s;
49 > char    *s;
50   {
51 +        static unsigned char shuffle[256] = {
52 +                0, 157, 58, 215, 116, 17, 174, 75, 232, 133, 34,
53 +                191, 92, 249, 150, 51, 208, 109, 10, 167, 68, 225,
54 +                126, 27, 184, 85, 242, 143, 44, 201, 102, 3, 160,
55 +                61, 218, 119, 20, 177, 78, 235, 136, 37, 194, 95,
56 +                252, 153, 54, 211, 112, 13, 170, 71, 228, 129, 30,
57 +                187, 88, 245, 146, 47, 204, 105, 6, 163, 64, 221,
58 +                122, 23, 180, 81, 238, 139, 40, 197, 98, 255, 156,
59 +                57, 214, 115, 16, 173, 74, 231, 132, 33, 190, 91,
60 +                248, 149, 50, 207, 108, 9, 166, 67, 224, 125, 26,
61 +                183, 84, 241, 142, 43, 200, 101, 2, 159, 60, 217,
62 +                118, 19, 176, 77, 234, 135, 36, 193, 94, 251, 152,
63 +                53, 210, 111, 12, 169, 70, 227, 128, 29, 186, 87,
64 +                244, 145, 46, 203, 104, 5, 162, 63, 220, 121, 22,
65 +                179, 80, 237, 138, 39, 196, 97, 254, 155, 56, 213,
66 +                114, 15, 172, 73, 230, 131, 32, 189, 90, 247, 148,
67 +                49, 206, 107, 8, 165, 66, 223, 124, 25, 182, 83,
68 +                240, 141, 42, 199, 100, 1, 158, 59, 216, 117, 18,
69 +                175, 76, 233, 134, 35, 192, 93, 250, 151, 52, 209,
70 +                110, 11, 168, 69, 226, 127, 28, 185, 86, 243, 144,
71 +                45, 202, 103, 4, 161, 62, 219, 120, 21, 178, 79,
72 +                236, 137, 38, 195, 96, 253, 154, 55, 212, 113, 14,
73 +                171, 72, 229, 130, 31, 188, 89, 246, 147, 48, 205,
74 +                106, 7, 164, 65, 222, 123, 24, 181, 82, 239, 140,
75 +                41, 198, 99
76 +        };
77          register int    i = 0;
78 <        register long   h = 0;
78 >        register unsigned long  h = 0;
79 >        register unsigned char *t = (unsigned char *)s;
80  
81 <        while (*s)
82 <                h ^= (long)(*s++ & 0xff) << (i++ & 0xf);
81 >        while (*t)
82 >                h ^= (unsigned long)shuffle[*t++] << ((i+=11) & 0xf);
83 >
84          return(h);
85   }
86  
# Line 58 | Line 90 | lu_find(tbl, key)              /* find a table entry */
90   register LUTAB  *tbl;
91   char    *key;
92   {
93 <        long    hval;
94 <        int     i;
93 >        unsigned long   hval;
94 >        int     i, n;
95          register int    ndx;
96 <        register LUENT  *oldtabl;
96 >        register LUENT  *le;
97                                          /* look up object */
98 +        if (tbl->tsiz == 0 && !lu_init(tbl, 1))
99 +                return(NULL);
100          hval = (*tbl->hashf)(key);
101   tryagain:
102 <        for (i = 0; i < tbl->tsiz; i++) {
103 <                ndx = (hval + i*i) % tbl->tsiz;
104 <                if (tbl->tabl[ndx].key == NULL) {
105 <                        tbl->tabl[ndx].hval = hval;
106 <                        return(&tbl->tabl[ndx]);
102 >        ndx = hval % tbl->tsiz;
103 >        for (i = 0, n = 1; i < tbl->tsiz; i++, n += 2) {
104 >                le = &tbl->tabl[ndx];
105 >                if (le->key == NULL) {
106 >                        le->hval = hval;
107 >                        return(le);
108                  }
109 <                if ( tbl->tabl[ndx].hval == hval && (tbl->keycmp == NULL ||
110 <                                !(*tbl->keycmp)(tbl->tabl[ndx].key, key)) )
111 <                        return(&tbl->tabl[ndx]);
109 >                if (le->hval == hval &&
110 >                      (tbl->keycmp == NULL || !(*tbl->keycmp)(le->key, key))) {
111 >                        return(le);
112 >                }
113 >                if ((ndx += n) >= tbl->tsiz)    /* this happens rarely */
114 >                        ndx = ndx % tbl->tsiz;
115          }
116                                          /* table is full, reallocate */
117 <        oldtabl = tbl->tabl;
117 >        le = tbl->tabl;
118          ndx = tbl->tsiz;
119          i = tbl->ndel;
120          if (!lu_init(tbl, ndx-i+1)) {   /* no more memory! */
121 <                tbl->tabl = oldtabl;
121 >                tbl->tabl = le;
122                  tbl->tsiz = ndx;
123                  tbl->ndel = i;
124                  return(NULL);
125          }
88 –        if (!ndx)
89 –                goto tryagain;
126          /*
127           * The following code may fail if the user has reclaimed many
128           * deleted entries and the system runs out of memory in a
129           * recursive call to lu_find().
130           */
131          while (ndx--)
132 <                if (oldtabl[ndx].key != NULL)
133 <                        if (oldtabl[ndx].data != NULL)
134 <                                *lu_find(tbl, oldtabl[ndx].key) = oldtabl[ndx];
132 >                if (le[ndx].key != NULL)
133 >                        if (le[ndx].data != NULL)
134 >                                copystruct(lu_find(tbl,le[ndx].key), &le[ndx]);
135                          else if (tbl->freek != NULL)
136 <                                (*tbl->freek)(oldtabl[ndx].key);
137 <        free((MEM_PTR)oldtabl);
136 >                                (*tbl->freek)(le[ndx].key);
137 >        free((void *)le);
138          goto tryagain;                  /* should happen only once! */
139   }
140  
# Line 121 | Line 157 | char   *key;
157   }
158  
159  
160 + int
161 + lu_doall(tbl, f)                /* loop through all valid table entries */
162 + register LUTAB  *tbl;
163 + int     (*f)();
164 + {
165 +        int     rval = 0;
166 +        register LUENT  *tp;
167 +
168 +        for (tp = tbl->tabl + tbl->tsiz; tp-- > tbl->tabl; )
169 +                if (tp->data != NULL)
170 +                        if (f != NULL)
171 +                                rval += (*f)(tp);
172 +                        else
173 +                                rval++;
174 +        return(rval);
175 + }
176 +
177 +
178   void
179   lu_done(tbl)                    /* free table and contents */
180   register LUTAB  *tbl;
# Line 136 | Line 190 | register LUTAB *tbl;
190                          if (tp->data != NULL && tbl->freed != NULL)
191                                  (*tbl->freed)(tp->data);
192                  }
193 <        free((MEM_PTR)tbl->tabl);
193 >        free((void *)tbl->tabl);
194          tbl->tabl = NULL;
195          tbl->tsiz = 0;
196          tbl->ndel = 0;

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