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root/radiance/ray/src/common/lookup.c
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Comparing ray/src/common/lookup.c (file contents):
Revision 2.1 by greg, Wed Jul 6 15:14:15 1994 UTC vs.
Revision 2.9 by schorsch, Mon Jun 30 14:59:11 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 <string.h>
13 +
14   #include "lookup.h"
15  
16 < #define MEM_PTR         char *
16 > #ifdef  NOSTRUCTASS
17 > #define  copystruct(d,s)        memcpy((void *)(d),(void *)(s),sizeof(*(d)))
18 > #else
19 > #define  copystruct(d,s)        (*(d) = *(s))
20 > #endif
21  
16 extern MEM_PTR  calloc();
22  
18
23   int
24   lu_init(tbl, nel)               /* initialize tbl for at least nel elements */
25   register LUTAB  *tbl;
26   int     nel;
27   {
28          static int  hsiztab[] = {
29 <                31, 61, 127, 251, 509, 1021, 2039, 4093, 8191, 16381, 0
29 >                31, 61, 127, 251, 509, 1021, 2039, 4093, 8191, 16381,
30 >                32749, 65521, 131071, 262139, 524287, 1048573, 2097143,
31 >                4194301, 8388593, 0
32          };
33          register int  *hsp;
34  
# Line 40 | Line 46 | int    nel;
46   }
47  
48  
49 < long
49 > unsigned long
50   lu_shash(s)                     /* hash a nul-terminated string */
51 < register char  *s;
51 > char    *s;
52   {
53 +        static unsigned char shuffle[256] = {
54 +                0, 157, 58, 215, 116, 17, 174, 75, 232, 133, 34,
55 +                191, 92, 249, 150, 51, 208, 109, 10, 167, 68, 225,
56 +                126, 27, 184, 85, 242, 143, 44, 201, 102, 3, 160,
57 +                61, 218, 119, 20, 177, 78, 235, 136, 37, 194, 95,
58 +                252, 153, 54, 211, 112, 13, 170, 71, 228, 129, 30,
59 +                187, 88, 245, 146, 47, 204, 105, 6, 163, 64, 221,
60 +                122, 23, 180, 81, 238, 139, 40, 197, 98, 255, 156,
61 +                57, 214, 115, 16, 173, 74, 231, 132, 33, 190, 91,
62 +                248, 149, 50, 207, 108, 9, 166, 67, 224, 125, 26,
63 +                183, 84, 241, 142, 43, 200, 101, 2, 159, 60, 217,
64 +                118, 19, 176, 77, 234, 135, 36, 193, 94, 251, 152,
65 +                53, 210, 111, 12, 169, 70, 227, 128, 29, 186, 87,
66 +                244, 145, 46, 203, 104, 5, 162, 63, 220, 121, 22,
67 +                179, 80, 237, 138, 39, 196, 97, 254, 155, 56, 213,
68 +                114, 15, 172, 73, 230, 131, 32, 189, 90, 247, 148,
69 +                49, 206, 107, 8, 165, 66, 223, 124, 25, 182, 83,
70 +                240, 141, 42, 199, 100, 1, 158, 59, 216, 117, 18,
71 +                175, 76, 233, 134, 35, 192, 93, 250, 151, 52, 209,
72 +                110, 11, 168, 69, 226, 127, 28, 185, 86, 243, 144,
73 +                45, 202, 103, 4, 161, 62, 219, 120, 21, 178, 79,
74 +                236, 137, 38, 195, 96, 253, 154, 55, 212, 113, 14,
75 +                171, 72, 229, 130, 31, 188, 89, 246, 147, 48, 205,
76 +                106, 7, 164, 65, 222, 123, 24, 181, 82, 239, 140,
77 +                41, 198, 99
78 +        };
79          register int    i = 0;
80 <        register long   h = 0;
80 >        register unsigned long  h = 0;
81 >        register unsigned char *t = (unsigned char *)s;
82  
83 <        while (*s)
84 <                h ^= (long)(*s++ & 0xff) << (i++ & 15);
83 >        while (*t)
84 >                h ^= (unsigned long)shuffle[*t++] << ((i+=11) & 0xf);
85 >
86          return(h);
87   }
88  
# Line 58 | Line 92 | lu_find(tbl, key)              /* find a table entry */
92   register LUTAB  *tbl;
93   char    *key;
94   {
95 <        long    hval;
96 <        int     i;
95 >        unsigned long   hval;
96 >        int     i, n;
97          register int    ndx;
98 <        register LUENT  *oldtabl;
98 >        register LUENT  *le;
99                                          /* look up object */
100 +        if (tbl->tsiz == 0 && !lu_init(tbl, 1))
101 +                return(NULL);
102          hval = (*tbl->hashf)(key);
103   tryagain:
104 <        for (i = 0; i < tbl->tsiz; i++) {
105 <                ndx = (hval + i*i) % tbl->tsiz;
106 <                if (tbl->tabl[ndx].key == NULL) {
107 <                        tbl->tabl[ndx].hval = hval;
108 <                        return(&tbl->tabl[ndx]);
104 >        ndx = hval % tbl->tsiz;
105 >        for (i = 0, n = 1; i < tbl->tsiz; i++, n += 2) {
106 >                le = &tbl->tabl[ndx];
107 >                if (le->key == NULL) {
108 >                        le->hval = hval;
109 >                        return(le);
110                  }
111 <                if ( tbl->tabl[ndx].hval == hval && (tbl->keycmp == NULL ||
112 <                                !(*tbl->keycmp)(tbl->tabl[ndx].key, key)) )
113 <                        return(&tbl->tabl[ndx]);
111 >                if (le->hval == hval &&
112 >                      (tbl->keycmp == NULL || !(*tbl->keycmp)(le->key, key))) {
113 >                        return(le);
114 >                }
115 >                if ((ndx += n) >= tbl->tsiz)    /* this happens rarely */
116 >                        ndx = ndx % tbl->tsiz;
117          }
118                                          /* table is full, reallocate */
119 <        oldtabl = tbl->tabl;
119 >        le = tbl->tabl;
120          ndx = tbl->tsiz;
121          i = tbl->ndel;
122 <        if (!lu_init(tbl, ndx-i)) {     /* no more memory! */
123 <                tbl->tabl = oldtabl;
122 >        if (!lu_init(tbl, ndx-i+1)) {   /* no more memory! */
123 >                tbl->tabl = le;
124                  tbl->tsiz = ndx;
125                  tbl->ndel = i;
126                  return(NULL);
127          }
88        if (!ndx)
89                goto tryagain;
128          /*
129           * The following code may fail if the user has reclaimed many
130           * deleted entries and the system runs out of memory in a
131           * recursive call to lu_find().
132           */
133          while (ndx--)
134 <                if (oldtabl[ndx].key != NULL)
135 <                        if (oldtabl[ndx].data != NULL)
136 <                                *lu_find(tbl, oldtabl[ndx].key) = oldtabl[ndx];
134 >                if (le[ndx].key != NULL)
135 >                        if (le[ndx].data != NULL)
136 >                                copystruct(lu_find(tbl,le[ndx].key), &le[ndx]);
137                          else if (tbl->freek != NULL)
138 <                                (*tbl->freek)(oldtabl[ndx].key);
139 <        free((MEM_PTR)oldtabl);
138 >                                (*tbl->freek)(le[ndx].key);
139 >        free((void *)le);
140          goto tryagain;                  /* should happen only once! */
141   }
142  
# Line 121 | Line 159 | char   *key;
159   }
160  
161  
162 + int
163 + lu_doall(tbl, f)                /* loop through all valid table entries */
164 + register LUTAB  *tbl;
165 + int     (*f)();
166 + {
167 +        int     rval = 0;
168 +        register LUENT  *tp;
169 +
170 +        for (tp = tbl->tabl + tbl->tsiz; tp-- > tbl->tabl; )
171 +                if (tp->data != NULL)
172 +                        if (f != NULL)
173 +                                rval += (*f)(tp);
174 +                        else
175 +                                rval++;
176 +        return(rval);
177 + }
178 +
179 +
180   void
181   lu_done(tbl)                    /* free table and contents */
182   register LUTAB  *tbl;
# Line 136 | Line 192 | register LUTAB *tbl;
192                          if (tp->data != NULL && tbl->freed != NULL)
193                                  (*tbl->freed)(tp->data);
194                  }
195 <        free((MEM_PTR)tbl->tabl);
195 >        free((void *)tbl->tabl);
196          tbl->tabl = NULL;
197          tbl->tsiz = 0;
198          tbl->ndel = 0;

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