1 #include "mk.h"
2
3 #define NHASH 4099
4 #define HASHMUL 79L /* this is a good value */
5 static Symtab *hash[NHASH];
6
7 void
syminit(void)8 syminit(void)
9 {
10 Symtab **s, *ss;
11
12 for(s = hash; s < &hash[NHASH]; s++){
13 for(ss = *s; ss; ss = ss->next)
14 free((char *)ss);
15 *s = 0;
16 }
17 }
18
19 Symtab *
symlook(char * sym,int space,void * install)20 symlook(char *sym, int space, void *install)
21 {
22 long h;
23 char *p;
24 Symtab *s;
25
26 for(p = sym, h = space; *p; h += *p++)
27 h *= HASHMUL;
28 if(h < 0)
29 h = ~h;
30 h %= NHASH;
31 for(s = hash[h]; s; s = s->next)
32 if((s->space == space) && (strcmp(s->name, sym) == 0))
33 return(s);
34 if(install == 0)
35 return(0);
36 s = (Symtab *)Malloc(sizeof(Symtab));
37 s->space = space;
38 s->name = sym;
39 s->u.ptr = install;
40 s->next = hash[h];
41 hash[h] = s;
42 return(s);
43 }
44
45 void
symdel(char * sym,int space)46 symdel(char *sym, int space)
47 {
48 long h;
49 char *p;
50 Symtab *s, *ls;
51
52 /* multiple memory leaks */
53
54 for(p = sym, h = space; *p; h += *p++)
55 h *= HASHMUL;
56 if(h < 0)
57 h = ~h;
58 h %= NHASH;
59 for(s = hash[h], ls = 0; s; ls = s, s = s->next)
60 if((s->space == space) && (strcmp(s->name, sym) == 0)){
61 if(ls)
62 ls->next = s->next;
63 else
64 hash[h] = s->next;
65 free((char *)s);
66 }
67 }
68
69 void
symtraverse(int space,void (* fn)(Symtab *))70 symtraverse(int space, void (*fn)(Symtab*))
71 {
72 Symtab **s, *ss;
73
74 for(s = hash; s < &hash[NHASH]; s++)
75 for(ss = *s; ss; ss = ss->next)
76 if(ss->space == space)
77 (*fn)(ss);
78 }
79
80 void
symstat(void)81 symstat(void)
82 {
83 Symtab **s, *ss;
84 int n;
85 int l[1000];
86
87 memset((char *)l, 0, sizeof(l));
88 for(s = hash; s < &hash[NHASH]; s++){
89 for(ss = *s, n = 0; ss; ss = ss->next)
90 n++;
91 l[n]++;
92 }
93 for(n = 0; n < 1000; n++)
94 if(l[n]) Bprint(&bout, "%d of length %d\n", l[n], n);
95 }
96