Commit | Line | Data |
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8d063cd8 LW |
1 | /* $Header: hash.c,v 1.0 87/12/18 13:05:17 root Exp $ |
2 | * | |
3 | * $Log: hash.c,v $ | |
4 | * Revision 1.0 87/12/18 13:05:17 root | |
5 | * Initial revision | |
6 | * | |
7 | */ | |
8 | ||
9 | #include <stdio.h> | |
10 | #include "EXTERN.h" | |
11 | #include "handy.h" | |
12 | #include "util.h" | |
13 | #include "search.h" | |
14 | #include "perl.h" | |
15 | ||
16 | STR * | |
17 | hfetch(tb,key) | |
18 | register HASH *tb; | |
19 | char *key; | |
20 | { | |
21 | register char *s; | |
22 | register int i; | |
23 | register int hash; | |
24 | register HENT *entry; | |
25 | ||
26 | if (!tb) | |
27 | return Nullstr; | |
28 | for (s=key, i=0, hash = 0; | |
29 | /* while */ *s; | |
30 | s++, i++, hash *= 5) { | |
31 | hash += *s * coeff[i]; | |
32 | } | |
33 | entry = tb->tbl_array[hash & tb->tbl_max]; | |
34 | for (; entry; entry = entry->hent_next) { | |
35 | if (entry->hent_hash != hash) /* strings can't be equal */ | |
36 | continue; | |
37 | if (strNE(entry->hent_key,key)) /* is this it? */ | |
38 | continue; | |
39 | return entry->hent_val; | |
40 | } | |
41 | return Nullstr; | |
42 | } | |
43 | ||
44 | bool | |
45 | hstore(tb,key,val) | |
46 | register HASH *tb; | |
47 | char *key; | |
48 | STR *val; | |
49 | { | |
50 | register char *s; | |
51 | register int i; | |
52 | register int hash; | |
53 | register HENT *entry; | |
54 | register HENT **oentry; | |
55 | ||
56 | if (!tb) | |
57 | return FALSE; | |
58 | for (s=key, i=0, hash = 0; | |
59 | /* while */ *s; | |
60 | s++, i++, hash *= 5) { | |
61 | hash += *s * coeff[i]; | |
62 | } | |
63 | ||
64 | oentry = &(tb->tbl_array[hash & tb->tbl_max]); | |
65 | i = 1; | |
66 | ||
67 | for (entry = *oentry; entry; i=0, entry = entry->hent_next) { | |
68 | if (entry->hent_hash != hash) /* strings can't be equal */ | |
69 | continue; | |
70 | if (strNE(entry->hent_key,key)) /* is this it? */ | |
71 | continue; | |
72 | safefree((char*)entry->hent_val); | |
73 | entry->hent_val = val; | |
74 | return TRUE; | |
75 | } | |
76 | entry = (HENT*) safemalloc(sizeof(HENT)); | |
77 | ||
78 | entry->hent_key = savestr(key); | |
79 | entry->hent_val = val; | |
80 | entry->hent_hash = hash; | |
81 | entry->hent_next = *oentry; | |
82 | *oentry = entry; | |
83 | ||
84 | if (i) { /* initial entry? */ | |
85 | tb->tbl_fill++; | |
86 | if ((tb->tbl_fill * 100 / (tb->tbl_max + 1)) > FILLPCT) | |
87 | hsplit(tb); | |
88 | } | |
89 | ||
90 | return FALSE; | |
91 | } | |
92 | ||
93 | #ifdef NOTUSED | |
94 | bool | |
95 | hdelete(tb,key) | |
96 | register HASH *tb; | |
97 | char *key; | |
98 | { | |
99 | register char *s; | |
100 | register int i; | |
101 | register int hash; | |
102 | register HENT *entry; | |
103 | register HENT **oentry; | |
104 | ||
105 | if (!tb) | |
106 | return FALSE; | |
107 | for (s=key, i=0, hash = 0; | |
108 | /* while */ *s; | |
109 | s++, i++, hash *= 5) { | |
110 | hash += *s * coeff[i]; | |
111 | } | |
112 | ||
113 | oentry = &(tb->tbl_array[hash & tb->tbl_max]); | |
114 | entry = *oentry; | |
115 | i = 1; | |
116 | for (; entry; i=0, oentry = &entry->hent_next, entry = entry->hent_next) { | |
117 | if (entry->hent_hash != hash) /* strings can't be equal */ | |
118 | continue; | |
119 | if (strNE(entry->hent_key,key)) /* is this it? */ | |
120 | continue; | |
121 | safefree((char*)entry->hent_val); | |
122 | safefree(entry->hent_key); | |
123 | *oentry = entry->hent_next; | |
124 | safefree((char*)entry); | |
125 | if (i) | |
126 | tb->tbl_fill--; | |
127 | return TRUE; | |
128 | } | |
129 | return FALSE; | |
130 | } | |
131 | #endif | |
132 | ||
133 | hsplit(tb) | |
134 | HASH *tb; | |
135 | { | |
136 | int oldsize = tb->tbl_max + 1; | |
137 | register int newsize = oldsize * 2; | |
138 | register int i; | |
139 | register HENT **a; | |
140 | register HENT **b; | |
141 | register HENT *entry; | |
142 | register HENT **oentry; | |
143 | ||
144 | a = (HENT**) saferealloc((char*)tb->tbl_array, newsize * sizeof(HENT*)); | |
145 | bzero((char*)&a[oldsize], oldsize * sizeof(HENT*)); /* zero second half */ | |
146 | tb->tbl_max = --newsize; | |
147 | tb->tbl_array = a; | |
148 | ||
149 | for (i=0; i<oldsize; i++,a++) { | |
150 | if (!*a) /* non-existent */ | |
151 | continue; | |
152 | b = a+oldsize; | |
153 | for (oentry = a, entry = *a; entry; entry = *oentry) { | |
154 | if ((entry->hent_hash & newsize) != i) { | |
155 | *oentry = entry->hent_next; | |
156 | entry->hent_next = *b; | |
157 | if (!*b) | |
158 | tb->tbl_fill++; | |
159 | *b = entry; | |
160 | continue; | |
161 | } | |
162 | else | |
163 | oentry = &entry->hent_next; | |
164 | } | |
165 | if (!*a) /* everything moved */ | |
166 | tb->tbl_fill--; | |
167 | } | |
168 | } | |
169 | ||
170 | HASH * | |
171 | hnew() | |
172 | { | |
173 | register HASH *tb = (HASH*)safemalloc(sizeof(HASH)); | |
174 | ||
175 | tb->tbl_array = (HENT**) safemalloc(8 * sizeof(HENT*)); | |
176 | tb->tbl_fill = 0; | |
177 | tb->tbl_max = 7; | |
178 | hiterinit(tb); /* so each() will start off right */ | |
179 | bzero((char*)tb->tbl_array, 8 * sizeof(HENT*)); | |
180 | return tb; | |
181 | } | |
182 | ||
183 | #ifdef NOTUSED | |
184 | hshow(tb) | |
185 | register HASH *tb; | |
186 | { | |
187 | fprintf(stderr,"%5d %4d (%2d%%)\n", | |
188 | tb->tbl_max+1, | |
189 | tb->tbl_fill, | |
190 | tb->tbl_fill * 100 / (tb->tbl_max+1)); | |
191 | } | |
192 | #endif | |
193 | ||
194 | hiterinit(tb) | |
195 | register HASH *tb; | |
196 | { | |
197 | tb->tbl_riter = -1; | |
198 | tb->tbl_eiter = Null(HENT*); | |
199 | return tb->tbl_fill; | |
200 | } | |
201 | ||
202 | HENT * | |
203 | hiternext(tb) | |
204 | register HASH *tb; | |
205 | { | |
206 | register HENT *entry; | |
207 | ||
208 | entry = tb->tbl_eiter; | |
209 | do { | |
210 | if (entry) | |
211 | entry = entry->hent_next; | |
212 | if (!entry) { | |
213 | tb->tbl_riter++; | |
214 | if (tb->tbl_riter > tb->tbl_max) { | |
215 | tb->tbl_riter = -1; | |
216 | break; | |
217 | } | |
218 | entry = tb->tbl_array[tb->tbl_riter]; | |
219 | } | |
220 | } while (!entry); | |
221 | ||
222 | tb->tbl_eiter = entry; | |
223 | return entry; | |
224 | } | |
225 | ||
226 | char * | |
227 | hiterkey(entry) | |
228 | register HENT *entry; | |
229 | { | |
230 | return entry->hent_key; | |
231 | } | |
232 | ||
233 | STR * | |
234 | hiterval(entry) | |
235 | register HENT *entry; | |
236 | { | |
237 | return entry->hent_val; | |
238 | } |