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352d5a3a | 1 | /* $RCSfile: hash.c,v $$Revision: 4.0.1.1 $$Date: 91/06/07 12:15:55 $ |
a687059c | 2 | * |
352d5a3a | 3 | * Copyright (c) 1991, Larry Wall |
a687059c | 4 | * |
352d5a3a LW |
5 | * You may distribute under the terms of either the GNU General Public |
6 | * License or the Artistic License, as specified in the README file. | |
8d063cd8 LW |
7 | * |
8 | * $Log: hash.c,v $ | |
352d5a3a LW |
9 | * Revision 4.0.1.1 91/06/07 12:15:55 lwall |
10 | * patch4: new copyright notice | |
11 | * | |
fe14fcc3 LW |
12 | * Revision 4.0 91/03/20 01:57:49 lwall |
13 | * 4.0 baseline. | |
8d063cd8 LW |
14 | * |
15 | */ | |
16 | ||
17 | #include <stdio.h> | |
18 | #include "EXTERN.h" | |
19 | #include "handy.h" | |
20 | #include "util.h" | |
21 | #include "a2p.h" | |
22 | ||
23 | STR * | |
24 | hfetch(tb,key) | |
25 | register HASH *tb; | |
26 | char *key; | |
27 | { | |
28 | register char *s; | |
29 | register int i; | |
30 | register int hash; | |
31 | register HENT *entry; | |
32 | ||
33 | if (!tb) | |
34 | return Nullstr; | |
35 | for (s=key, i=0, hash = 0; | |
36 | /* while */ *s; | |
37 | s++, i++, hash *= 5) { | |
38 | hash += *s * coeff[i]; | |
39 | } | |
40 | entry = tb->tbl_array[hash & tb->tbl_max]; | |
41 | for (; entry; entry = entry->hent_next) { | |
42 | if (entry->hent_hash != hash) /* strings can't be equal */ | |
43 | continue; | |
44 | if (strNE(entry->hent_key,key)) /* is this it? */ | |
45 | continue; | |
46 | return entry->hent_val; | |
47 | } | |
48 | return Nullstr; | |
49 | } | |
50 | ||
51 | bool | |
52 | hstore(tb,key,val) | |
53 | register HASH *tb; | |
54 | char *key; | |
55 | STR *val; | |
56 | { | |
57 | register char *s; | |
58 | register int i; | |
59 | register int hash; | |
60 | register HENT *entry; | |
61 | register HENT **oentry; | |
62 | ||
63 | if (!tb) | |
64 | return FALSE; | |
65 | for (s=key, i=0, hash = 0; | |
66 | /* while */ *s; | |
67 | s++, i++, hash *= 5) { | |
68 | hash += *s * coeff[i]; | |
69 | } | |
70 | ||
71 | oentry = &(tb->tbl_array[hash & tb->tbl_max]); | |
72 | i = 1; | |
73 | ||
74 | for (entry = *oentry; entry; i=0, entry = entry->hent_next) { | |
75 | if (entry->hent_hash != hash) /* strings can't be equal */ | |
76 | continue; | |
77 | if (strNE(entry->hent_key,key)) /* is this it? */ | |
78 | continue; | |
fe14fcc3 | 79 | /*NOSTRICT*/ |
8d063cd8 LW |
80 | safefree((char*)entry->hent_val); |
81 | entry->hent_val = val; | |
82 | return TRUE; | |
83 | } | |
fe14fcc3 | 84 | /*NOSTRICT*/ |
8d063cd8 LW |
85 | entry = (HENT*) safemalloc(sizeof(HENT)); |
86 | ||
87 | entry->hent_key = savestr(key); | |
88 | entry->hent_val = val; | |
89 | entry->hent_hash = hash; | |
90 | entry->hent_next = *oentry; | |
91 | *oentry = entry; | |
92 | ||
93 | if (i) { /* initial entry? */ | |
94 | tb->tbl_fill++; | |
95 | if ((tb->tbl_fill * 100 / (tb->tbl_max + 1)) > FILLPCT) | |
96 | hsplit(tb); | |
97 | } | |
98 | ||
99 | return FALSE; | |
100 | } | |
101 | ||
102 | #ifdef NOTUSED | |
103 | bool | |
104 | hdelete(tb,key) | |
105 | register HASH *tb; | |
106 | char *key; | |
107 | { | |
108 | register char *s; | |
109 | register int i; | |
110 | register int hash; | |
111 | register HENT *entry; | |
112 | register HENT **oentry; | |
113 | ||
114 | if (!tb) | |
115 | return FALSE; | |
116 | for (s=key, i=0, hash = 0; | |
117 | /* while */ *s; | |
118 | s++, i++, hash *= 5) { | |
119 | hash += *s * coeff[i]; | |
120 | } | |
121 | ||
122 | oentry = &(tb->tbl_array[hash & tb->tbl_max]); | |
123 | entry = *oentry; | |
124 | i = 1; | |
125 | for (; entry; i=0, oentry = &entry->hent_next, entry = entry->hent_next) { | |
126 | if (entry->hent_hash != hash) /* strings can't be equal */ | |
127 | continue; | |
128 | if (strNE(entry->hent_key,key)) /* is this it? */ | |
129 | continue; | |
130 | safefree((char*)entry->hent_val); | |
131 | safefree(entry->hent_key); | |
132 | *oentry = entry->hent_next; | |
133 | safefree((char*)entry); | |
134 | if (i) | |
135 | tb->tbl_fill--; | |
136 | return TRUE; | |
137 | } | |
138 | return FALSE; | |
139 | } | |
140 | #endif | |
141 | ||
142 | hsplit(tb) | |
143 | HASH *tb; | |
144 | { | |
145 | int oldsize = tb->tbl_max + 1; | |
146 | register int newsize = oldsize * 2; | |
147 | register int i; | |
148 | register HENT **a; | |
149 | register HENT **b; | |
150 | register HENT *entry; | |
151 | register HENT **oentry; | |
152 | ||
153 | a = (HENT**) saferealloc((char*)tb->tbl_array, newsize * sizeof(HENT*)); | |
154 | bzero((char*)&a[oldsize], oldsize * sizeof(HENT*)); /* zero second half */ | |
155 | tb->tbl_max = --newsize; | |
156 | tb->tbl_array = a; | |
157 | ||
158 | for (i=0; i<oldsize; i++,a++) { | |
159 | if (!*a) /* non-existent */ | |
160 | continue; | |
161 | b = a+oldsize; | |
162 | for (oentry = a, entry = *a; entry; entry = *oentry) { | |
163 | if ((entry->hent_hash & newsize) != i) { | |
164 | *oentry = entry->hent_next; | |
165 | entry->hent_next = *b; | |
166 | if (!*b) | |
167 | tb->tbl_fill++; | |
168 | *b = entry; | |
169 | continue; | |
170 | } | |
171 | else | |
172 | oentry = &entry->hent_next; | |
173 | } | |
174 | if (!*a) /* everything moved */ | |
175 | tb->tbl_fill--; | |
176 | } | |
177 | } | |
178 | ||
179 | HASH * | |
180 | hnew() | |
181 | { | |
182 | register HASH *tb = (HASH*)safemalloc(sizeof(HASH)); | |
183 | ||
184 | tb->tbl_array = (HENT**) safemalloc(8 * sizeof(HENT*)); | |
185 | tb->tbl_fill = 0; | |
186 | tb->tbl_max = 7; | |
187 | hiterinit(tb); /* so each() will start off right */ | |
188 | bzero((char*)tb->tbl_array, 8 * sizeof(HENT*)); | |
189 | return tb; | |
190 | } | |
191 | ||
192 | #ifdef NOTUSED | |
193 | hshow(tb) | |
194 | register HASH *tb; | |
195 | { | |
196 | fprintf(stderr,"%5d %4d (%2d%%)\n", | |
197 | tb->tbl_max+1, | |
198 | tb->tbl_fill, | |
199 | tb->tbl_fill * 100 / (tb->tbl_max+1)); | |
200 | } | |
201 | #endif | |
202 | ||
203 | hiterinit(tb) | |
204 | register HASH *tb; | |
205 | { | |
206 | tb->tbl_riter = -1; | |
207 | tb->tbl_eiter = Null(HENT*); | |
208 | return tb->tbl_fill; | |
209 | } | |
210 | ||
211 | HENT * | |
212 | hiternext(tb) | |
213 | register HASH *tb; | |
214 | { | |
215 | register HENT *entry; | |
216 | ||
217 | entry = tb->tbl_eiter; | |
218 | do { | |
219 | if (entry) | |
220 | entry = entry->hent_next; | |
221 | if (!entry) { | |
222 | tb->tbl_riter++; | |
223 | if (tb->tbl_riter > tb->tbl_max) { | |
224 | tb->tbl_riter = -1; | |
225 | break; | |
226 | } | |
227 | entry = tb->tbl_array[tb->tbl_riter]; | |
228 | } | |
229 | } while (!entry); | |
230 | ||
231 | tb->tbl_eiter = entry; | |
232 | return entry; | |
233 | } | |
234 | ||
235 | char * | |
236 | hiterkey(entry) | |
237 | register HENT *entry; | |
238 | { | |
239 | return entry->hent_key; | |
240 | } | |
241 | ||
242 | STR * | |
243 | hiterval(entry) | |
244 | register HENT *entry; | |
245 | { | |
246 | return entry->hent_val; | |
247 | } |