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79072805 | 1 | /* $RCSfile: hash.c,v $$Revision: 4.1 $$Date: 92/08/07 18:29:20 $ |
a687059c | 2 | * |
4bb101f2 JH |
3 | * Copyright (C) 1991, 1992, 1993, 1994, 1995, 1999, 2000, 2001, 2002, |
4 | * by Larry Wall and others | |
a687059c | 5 | * |
352d5a3a LW |
6 | * You may distribute under the terms of either the GNU General Public |
7 | * License or the Artistic License, as specified in the README file. | |
8d063cd8 LW |
8 | * |
9 | * $Log: hash.c,v $ | |
8d063cd8 LW |
10 | */ |
11 | ||
12 | #include <stdio.h> | |
13 | #include "EXTERN.h" | |
8d063cd8 | 14 | #include "a2p.h" |
9c8d0b29 | 15 | #include "util.h" |
8d063cd8 | 16 | |
011f1a1a JH |
17 | #ifdef NETWARE |
18 | char *savestr(char *str); | |
19 | #endif | |
20 | ||
8d063cd8 | 21 | STR * |
f0f333f4 | 22 | hfetch(register HASH *tb, char *key) |
8d063cd8 LW |
23 | { |
24 | register char *s; | |
25 | register int i; | |
26 | register int hash; | |
27 | register HENT *entry; | |
28 | ||
29 | if (!tb) | |
30 | return Nullstr; | |
31 | for (s=key, i=0, hash = 0; | |
32 | /* while */ *s; | |
33 | s++, i++, hash *= 5) { | |
34 | hash += *s * coeff[i]; | |
35 | } | |
36 | entry = tb->tbl_array[hash & tb->tbl_max]; | |
37 | for (; entry; entry = entry->hent_next) { | |
38 | if (entry->hent_hash != hash) /* strings can't be equal */ | |
39 | continue; | |
40 | if (strNE(entry->hent_key,key)) /* is this it? */ | |
41 | continue; | |
42 | return entry->hent_val; | |
43 | } | |
44 | return Nullstr; | |
45 | } | |
46 | ||
47 | bool | |
f0f333f4 | 48 | hstore(register HASH *tb, char *key, STR *val) |
8d063cd8 LW |
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; | |
fe14fcc3 | 72 | /*NOSTRICT*/ |
8c52afec | 73 | safefree(entry->hent_val); |
8d063cd8 LW |
74 | entry->hent_val = val; |
75 | return TRUE; | |
76 | } | |
fe14fcc3 | 77 | /*NOSTRICT*/ |
8d063cd8 LW |
78 | entry = (HENT*) safemalloc(sizeof(HENT)); |
79 | ||
80 | entry->hent_key = savestr(key); | |
81 | entry->hent_val = val; | |
82 | entry->hent_hash = hash; | |
83 | entry->hent_next = *oentry; | |
84 | *oentry = entry; | |
85 | ||
86 | if (i) { /* initial entry? */ | |
87 | tb->tbl_fill++; | |
88 | if ((tb->tbl_fill * 100 / (tb->tbl_max + 1)) > FILLPCT) | |
89 | hsplit(tb); | |
90 | } | |
91 | ||
92 | return FALSE; | |
93 | } | |
94 | ||
95 | #ifdef NOTUSED | |
96 | bool | |
ba106d47 | 97 | hdelete(register HASH *tb, char *key) |
8d063cd8 LW |
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 | ||
9c8d0b29 | 133 | void |
f0f333f4 | 134 | hsplit(HASH *tb) |
8d063cd8 LW |
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*)); | |
948ed65c | 145 | memset(&a[oldsize], 0, oldsize * sizeof(HENT*)); /* zero second half */ |
8d063cd8 LW |
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 * | |
f0f333f4 | 171 | hnew(void) |
8d063cd8 LW |
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 */ | |
948ed65c | 179 | memset(tb->tbl_array, 0, 8 * sizeof(HENT*)); |
8d063cd8 LW |
180 | return tb; |
181 | } | |
182 | ||
183 | #ifdef NOTUSED | |
ba106d47 | 184 | hshow(register HASH *tb) |
8d063cd8 LW |
185 | { |
186 | fprintf(stderr,"%5d %4d (%2d%%)\n", | |
187 | tb->tbl_max+1, | |
188 | tb->tbl_fill, | |
189 | tb->tbl_fill * 100 / (tb->tbl_max+1)); | |
190 | } | |
191 | #endif | |
192 | ||
9c8d0b29 | 193 | int |
f0f333f4 | 194 | hiterinit(register HASH *tb) |
8d063cd8 LW |
195 | { |
196 | tb->tbl_riter = -1; | |
197 | tb->tbl_eiter = Null(HENT*); | |
198 | return tb->tbl_fill; | |
199 | } | |
200 | ||
201 | HENT * | |
f0f333f4 | 202 | hiternext(register HASH *tb) |
8d063cd8 LW |
203 | { |
204 | register HENT *entry; | |
205 | ||
206 | entry = tb->tbl_eiter; | |
207 | do { | |
208 | if (entry) | |
209 | entry = entry->hent_next; | |
210 | if (!entry) { | |
211 | tb->tbl_riter++; | |
212 | if (tb->tbl_riter > tb->tbl_max) { | |
213 | tb->tbl_riter = -1; | |
214 | break; | |
215 | } | |
216 | entry = tb->tbl_array[tb->tbl_riter]; | |
217 | } | |
218 | } while (!entry); | |
219 | ||
220 | tb->tbl_eiter = entry; | |
221 | return entry; | |
222 | } | |
223 | ||
224 | char * | |
f0f333f4 | 225 | hiterkey(register HENT *entry) |
8d063cd8 LW |
226 | { |
227 | return entry->hent_key; | |
228 | } | |
229 | ||
230 | STR * | |
f0f333f4 | 231 | hiterval(register HENT *entry) |
8d063cd8 LW |
232 | { |
233 | return entry->hent_val; | |
234 | } |