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663a0e37 |
1 | /* $Header: hash.c,v 3.0.1.2 89/12/21 20:03:39 lwall Locked $ |
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2 | * |
3 | * Copyright (c) 1989, Larry Wall |
4 | * |
5 | * You may distribute under the terms of the GNU General Public License |
6 | * as specified in the README file that comes with the perl 3.0 kit. |
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7 | * |
8 | * $Log: hash.c,v $ |
663a0e37 |
9 | * Revision 3.0.1.2 89/12/21 20:03:39 lwall |
10 | * patch7: errno may now be a macro with an lvalue |
11 | * |
bf38876a |
12 | * Revision 3.0.1.1 89/11/11 04:34:18 lwall |
13 | * patch2: CX/UX needed to set the key each time in associative iterators |
14 | * |
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15 | * Revision 3.0 89/10/18 15:18:32 lwall |
16 | * 3.0 baseline |
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17 | * |
18 | */ |
19 | |
8d063cd8 |
20 | #include "EXTERN.h" |
8d063cd8 |
21 | #include "perl.h" |
22 | |
23 | STR * |
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24 | hfetch(tb,key,klen,lval) |
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25 | register HASH *tb; |
26 | char *key; |
a687059c |
27 | int klen; |
28 | int lval; |
8d063cd8 |
29 | { |
30 | register char *s; |
31 | register int i; |
32 | register int hash; |
33 | register HENT *entry; |
a687059c |
34 | register int maxi; |
35 | STR *str; |
36 | #ifdef SOME_DBM |
37 | datum dkey,dcontent; |
38 | #endif |
8d063cd8 |
39 | |
40 | if (!tb) |
41 | return Nullstr; |
a687059c |
42 | |
43 | /* The hash function we use on symbols has to be equal to the first |
44 | * character when taken modulo 128, so that str_reset() can be implemented |
45 | * efficiently. We throw in the second character and the last character |
46 | * (times 128) so that long chains of identifiers starting with the |
47 | * same letter don't have to be strEQ'ed within hfetch(), since it |
48 | * compares hash values before trying strEQ(). |
49 | */ |
50 | if (!tb->tbl_coeffsize) |
51 | hash = *key + 128 * key[1] + 128 * key[klen-1]; /* assuming klen > 0 */ |
52 | else { /* use normal coefficients */ |
53 | if (klen < tb->tbl_coeffsize) |
54 | maxi = klen; |
55 | else |
56 | maxi = tb->tbl_coeffsize; |
57 | for (s=key, i=0, hash = 0; |
58 | i < maxi; |
59 | s++, i++, hash *= 5) { |
60 | hash += *s * coeff[i]; |
61 | } |
8d063cd8 |
62 | } |
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63 | |
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64 | entry = tb->tbl_array[hash & tb->tbl_max]; |
65 | for (; entry; entry = entry->hent_next) { |
66 | if (entry->hent_hash != hash) /* strings can't be equal */ |
67 | continue; |
a687059c |
68 | if (entry->hent_klen != klen) |
69 | continue; |
70 | if (bcmp(entry->hent_key,key,klen)) /* is this it? */ |
8d063cd8 |
71 | continue; |
72 | return entry->hent_val; |
73 | } |
a687059c |
74 | #ifdef SOME_DBM |
75 | if (tb->tbl_dbm) { |
76 | dkey.dptr = key; |
77 | dkey.dsize = klen; |
78 | dcontent = dbm_fetch(tb->tbl_dbm,dkey); |
79 | if (dcontent.dptr) { /* found one */ |
80 | str = Str_new(60,dcontent.dsize); |
81 | str_nset(str,dcontent.dptr,dcontent.dsize); |
82 | hstore(tb,key,klen,str,hash); /* cache it */ |
83 | return str; |
84 | } |
85 | } |
86 | #endif |
87 | if (lval) { /* gonna assign to this, so it better be there */ |
88 | str = Str_new(61,0); |
89 | hstore(tb,key,klen,str,hash); |
90 | return str; |
91 | } |
8d063cd8 |
92 | return Nullstr; |
93 | } |
94 | |
95 | bool |
a687059c |
96 | hstore(tb,key,klen,val,hash) |
8d063cd8 |
97 | register HASH *tb; |
98 | char *key; |
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99 | int klen; |
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100 | STR *val; |
a687059c |
101 | register int hash; |
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102 | { |
103 | register char *s; |
104 | register int i; |
8d063cd8 |
105 | register HENT *entry; |
106 | register HENT **oentry; |
a687059c |
107 | register int maxi; |
8d063cd8 |
108 | |
109 | if (!tb) |
110 | return FALSE; |
a687059c |
111 | |
112 | if (hash) |
113 | ; |
114 | else if (!tb->tbl_coeffsize) |
115 | hash = *key + 128 * key[1] + 128 * key[klen-1]; |
116 | else { /* use normal coefficients */ |
117 | if (klen < tb->tbl_coeffsize) |
118 | maxi = klen; |
119 | else |
120 | maxi = tb->tbl_coeffsize; |
121 | for (s=key, i=0, hash = 0; |
122 | i < maxi; |
123 | s++, i++, hash *= 5) { |
124 | hash += *s * coeff[i]; |
125 | } |
8d063cd8 |
126 | } |
127 | |
128 | oentry = &(tb->tbl_array[hash & tb->tbl_max]); |
129 | i = 1; |
130 | |
131 | for (entry = *oentry; entry; i=0, entry = entry->hent_next) { |
132 | if (entry->hent_hash != hash) /* strings can't be equal */ |
133 | continue; |
a687059c |
134 | if (entry->hent_klen != klen) |
135 | continue; |
136 | if (bcmp(entry->hent_key,key,klen)) /* is this it? */ |
8d063cd8 |
137 | continue; |
a687059c |
138 | Safefree(entry->hent_val); |
8d063cd8 |
139 | entry->hent_val = val; |
140 | return TRUE; |
141 | } |
a687059c |
142 | New(501,entry, 1, HENT); |
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143 | |
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144 | entry->hent_klen = klen; |
145 | entry->hent_key = nsavestr(key,klen); |
8d063cd8 |
146 | entry->hent_val = val; |
147 | entry->hent_hash = hash; |
148 | entry->hent_next = *oentry; |
149 | *oentry = entry; |
150 | |
a687059c |
151 | /* hdbmstore not necessary here because it's called from stabset() */ |
152 | |
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153 | if (i) { /* initial entry? */ |
154 | tb->tbl_fill++; |
a687059c |
155 | #ifdef SOME_DBM |
156 | if (tb->tbl_dbm && tb->tbl_max >= DBM_CACHE_MAX) |
157 | return FALSE; |
158 | #endif |
159 | if (tb->tbl_fill > tb->tbl_dosplit) |
8d063cd8 |
160 | hsplit(tb); |
161 | } |
a687059c |
162 | #ifdef SOME_DBM |
163 | else if (tb->tbl_dbm) { /* is this just a cache for dbm file? */ |
164 | entry = tb->tbl_array[hash & tb->tbl_max]; |
165 | oentry = &entry->hent_next; |
166 | entry = *oentry; |
167 | while (entry) { /* trim chain down to 1 entry */ |
168 | *oentry = entry->hent_next; |
169 | hentfree(entry); /* no doubt they'll want this next. */ |
170 | entry = *oentry; |
171 | } |
172 | } |
173 | #endif |
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174 | |
175 | return FALSE; |
176 | } |
177 | |
378cc40b |
178 | STR * |
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179 | hdelete(tb,key,klen) |
8d063cd8 |
180 | register HASH *tb; |
181 | char *key; |
a687059c |
182 | int klen; |
8d063cd8 |
183 | { |
184 | register char *s; |
185 | register int i; |
186 | register int hash; |
187 | register HENT *entry; |
188 | register HENT **oentry; |
378cc40b |
189 | STR *str; |
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190 | int maxi; |
191 | #ifdef SOME_DBM |
192 | datum dkey; |
193 | #endif |
8d063cd8 |
194 | |
195 | if (!tb) |
378cc40b |
196 | return Nullstr; |
a687059c |
197 | if (!tb->tbl_coeffsize) |
198 | hash = *key + 128 * key[1] + 128 * key[klen-1]; |
199 | else { /* use normal coefficients */ |
200 | if (klen < tb->tbl_coeffsize) |
201 | maxi = klen; |
202 | else |
203 | maxi = tb->tbl_coeffsize; |
204 | for (s=key, i=0, hash = 0; |
205 | i < maxi; |
206 | s++, i++, hash *= 5) { |
207 | hash += *s * coeff[i]; |
208 | } |
8d063cd8 |
209 | } |
210 | |
211 | oentry = &(tb->tbl_array[hash & tb->tbl_max]); |
212 | entry = *oentry; |
213 | i = 1; |
378cc40b |
214 | for (; entry; i=0, oentry = &entry->hent_next, entry = *oentry) { |
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215 | if (entry->hent_hash != hash) /* strings can't be equal */ |
216 | continue; |
a687059c |
217 | if (entry->hent_klen != klen) |
218 | continue; |
219 | if (bcmp(entry->hent_key,key,klen)) /* is this it? */ |
8d063cd8 |
220 | continue; |
8d063cd8 |
221 | *oentry = entry->hent_next; |
378cc40b |
222 | str = str_static(entry->hent_val); |
223 | hentfree(entry); |
8d063cd8 |
224 | if (i) |
225 | tb->tbl_fill--; |
a687059c |
226 | #ifdef SOME_DBM |
227 | do_dbm_delete: |
228 | if (tb->tbl_dbm) { |
229 | dkey.dptr = key; |
230 | dkey.dsize = klen; |
231 | dbm_delete(tb->tbl_dbm,dkey); |
232 | } |
233 | #endif |
378cc40b |
234 | return str; |
8d063cd8 |
235 | } |
a687059c |
236 | #ifdef SOME_DBM |
237 | str = Nullstr; |
238 | goto do_dbm_delete; |
239 | #else |
378cc40b |
240 | return Nullstr; |
a687059c |
241 | #endif |
8d063cd8 |
242 | } |
8d063cd8 |
243 | |
244 | hsplit(tb) |
245 | HASH *tb; |
246 | { |
247 | int oldsize = tb->tbl_max + 1; |
248 | register int newsize = oldsize * 2; |
249 | register int i; |
250 | register HENT **a; |
251 | register HENT **b; |
252 | register HENT *entry; |
253 | register HENT **oentry; |
254 | |
a687059c |
255 | a = tb->tbl_array; |
256 | Renew(a, newsize, HENT*); |
257 | Zero(&a[oldsize], oldsize, HENT*); /* zero 2nd half*/ |
8d063cd8 |
258 | tb->tbl_max = --newsize; |
a687059c |
259 | tb->tbl_dosplit = tb->tbl_max * FILLPCT / 100; |
8d063cd8 |
260 | tb->tbl_array = a; |
261 | |
262 | for (i=0; i<oldsize; i++,a++) { |
263 | if (!*a) /* non-existent */ |
264 | continue; |
265 | b = a+oldsize; |
266 | for (oentry = a, entry = *a; entry; entry = *oentry) { |
267 | if ((entry->hent_hash & newsize) != i) { |
268 | *oentry = entry->hent_next; |
269 | entry->hent_next = *b; |
270 | if (!*b) |
271 | tb->tbl_fill++; |
272 | *b = entry; |
273 | continue; |
274 | } |
275 | else |
276 | oentry = &entry->hent_next; |
277 | } |
278 | if (!*a) /* everything moved */ |
279 | tb->tbl_fill--; |
280 | } |
281 | } |
282 | |
283 | HASH * |
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284 | hnew(lookat) |
285 | unsigned int lookat; |
8d063cd8 |
286 | { |
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287 | register HASH *tb; |
8d063cd8 |
288 | |
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289 | Newz(502,tb, 1, HASH); |
290 | if (lookat) { |
291 | tb->tbl_coeffsize = lookat; |
292 | tb->tbl_max = 7; /* it's a normal associative array */ |
293 | tb->tbl_dosplit = tb->tbl_max * FILLPCT / 100; |
294 | } |
295 | else { |
296 | tb->tbl_max = 127; /* it's a symbol table */ |
297 | tb->tbl_dosplit = 128; /* so never split */ |
298 | } |
299 | Newz(503,tb->tbl_array, tb->tbl_max + 1, HENT*); |
8d063cd8 |
300 | tb->tbl_fill = 0; |
a687059c |
301 | #ifdef SOME_DBM |
302 | tb->tbl_dbm = 0; |
303 | #endif |
304 | (void)hiterinit(tb); /* so each() will start off right */ |
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305 | return tb; |
306 | } |
307 | |
378cc40b |
308 | void |
309 | hentfree(hent) |
310 | register HENT *hent; |
311 | { |
312 | if (!hent) |
313 | return; |
314 | str_free(hent->hent_val); |
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315 | Safefree(hent->hent_key); |
316 | Safefree(hent); |
378cc40b |
317 | } |
318 | |
319 | void |
320 | hclear(tb) |
321 | register HASH *tb; |
322 | { |
323 | register HENT *hent; |
324 | register HENT *ohent = Null(HENT*); |
325 | |
326 | if (!tb) |
327 | return; |
a687059c |
328 | (void)hiterinit(tb); |
378cc40b |
329 | while (hent = hiternext(tb)) { /* concise but not very efficient */ |
330 | hentfree(ohent); |
331 | ohent = hent; |
332 | } |
333 | hentfree(ohent); |
334 | tb->tbl_fill = 0; |
a687059c |
335 | #ifndef lint |
336 | (void)bzero((char*)tb->tbl_array, (tb->tbl_max + 1) * sizeof(HENT*)); |
337 | #endif |
378cc40b |
338 | } |
339 | |
378cc40b |
340 | void |
341 | hfree(tb) |
a687059c |
342 | register HASH *tb; |
378cc40b |
343 | { |
a687059c |
344 | register HENT *hent; |
345 | register HENT *ohent = Null(HENT*); |
346 | |
378cc40b |
347 | if (!tb) |
a687059c |
348 | return; |
349 | (void)hiterinit(tb); |
378cc40b |
350 | while (hent = hiternext(tb)) { |
351 | hentfree(ohent); |
352 | ohent = hent; |
353 | } |
354 | hentfree(ohent); |
a687059c |
355 | Safefree(tb->tbl_array); |
356 | Safefree(tb); |
378cc40b |
357 | } |
8d063cd8 |
358 | |
a687059c |
359 | int |
8d063cd8 |
360 | hiterinit(tb) |
361 | register HASH *tb; |
362 | { |
363 | tb->tbl_riter = -1; |
364 | tb->tbl_eiter = Null(HENT*); |
365 | return tb->tbl_fill; |
366 | } |
367 | |
368 | HENT * |
369 | hiternext(tb) |
370 | register HASH *tb; |
371 | { |
372 | register HENT *entry; |
a687059c |
373 | #ifdef SOME_DBM |
374 | datum key; |
375 | #endif |
8d063cd8 |
376 | |
377 | entry = tb->tbl_eiter; |
a687059c |
378 | #ifdef SOME_DBM |
379 | if (tb->tbl_dbm) { |
380 | if (entry) { |
381 | #ifdef NDBM |
382 | #ifdef _CX_UX |
bf38876a |
383 | key.dptr = entry->hent_key; |
384 | key.dsize = entry->hent_klen; |
a687059c |
385 | key = dbm_nextkey(tb->tbl_dbm, key); |
386 | #else |
387 | key = dbm_nextkey(tb->tbl_dbm); |
388 | #endif /* _CX_UX */ |
389 | #else |
390 | key.dptr = entry->hent_key; |
391 | key.dsize = entry->hent_klen; |
392 | key = nextkey(key); |
393 | #endif |
394 | } |
395 | else { |
396 | Newz(504,entry, 1, HENT); |
397 | tb->tbl_eiter = entry; |
398 | key = dbm_firstkey(tb->tbl_dbm); |
399 | } |
400 | entry->hent_key = key.dptr; |
401 | entry->hent_klen = key.dsize; |
402 | if (!key.dptr) { |
403 | if (entry->hent_val) |
404 | str_free(entry->hent_val); |
405 | Safefree(entry); |
406 | tb->tbl_eiter = Null(HENT*); |
407 | return Null(HENT*); |
408 | } |
409 | return entry; |
410 | } |
411 | #endif |
8d063cd8 |
412 | do { |
413 | if (entry) |
414 | entry = entry->hent_next; |
415 | if (!entry) { |
416 | tb->tbl_riter++; |
417 | if (tb->tbl_riter > tb->tbl_max) { |
418 | tb->tbl_riter = -1; |
419 | break; |
420 | } |
421 | entry = tb->tbl_array[tb->tbl_riter]; |
422 | } |
423 | } while (!entry); |
424 | |
425 | tb->tbl_eiter = entry; |
426 | return entry; |
427 | } |
428 | |
429 | char * |
a687059c |
430 | hiterkey(entry,retlen) |
8d063cd8 |
431 | register HENT *entry; |
a687059c |
432 | int *retlen; |
8d063cd8 |
433 | { |
a687059c |
434 | *retlen = entry->hent_klen; |
8d063cd8 |
435 | return entry->hent_key; |
436 | } |
437 | |
438 | STR * |
a687059c |
439 | hiterval(tb,entry) |
440 | register HASH *tb; |
8d063cd8 |
441 | register HENT *entry; |
442 | { |
a687059c |
443 | #ifdef SOME_DBM |
444 | datum key, content; |
445 | |
446 | if (tb->tbl_dbm) { |
447 | key.dptr = entry->hent_key; |
448 | key.dsize = entry->hent_klen; |
449 | content = dbm_fetch(tb->tbl_dbm,key); |
450 | if (!entry->hent_val) |
451 | entry->hent_val = Str_new(62,0); |
452 | str_nset(entry->hent_val,content.dptr,content.dsize); |
453 | } |
454 | #endif |
8d063cd8 |
455 | return entry->hent_val; |
456 | } |
a687059c |
457 | |
458 | #ifdef SOME_DBM |
459 | #if defined(FCNTL) && ! defined(O_CREAT) |
460 | #include <fcntl.h> |
461 | #endif |
462 | |
463 | #ifndef O_RDONLY |
464 | #define O_RDONLY 0 |
465 | #endif |
466 | #ifndef O_RDWR |
467 | #define O_RDWR 2 |
468 | #endif |
469 | #ifndef O_CREAT |
470 | #define O_CREAT 01000 |
471 | #endif |
472 | |
473 | #ifndef NDBM |
474 | static int dbmrefcnt = 0; |
475 | #endif |
476 | |
477 | bool |
478 | hdbmopen(tb,fname,mode) |
479 | register HASH *tb; |
480 | char *fname; |
481 | int mode; |
482 | { |
483 | if (!tb) |
484 | return FALSE; |
485 | #ifndef NDBM |
486 | if (tb->tbl_dbm) /* never really closed it */ |
487 | return TRUE; |
488 | #endif |
489 | if (tb->tbl_dbm) |
490 | hdbmclose(tb); |
491 | hclear(tb); |
492 | #ifdef NDBM |
493 | tb->tbl_dbm = dbm_open(fname, O_RDWR|O_CREAT, mode); |
494 | if (!tb->tbl_dbm) /* oops, just try reading it */ |
495 | tb->tbl_dbm = dbm_open(fname, O_RDONLY, mode); |
496 | #else |
497 | if (dbmrefcnt++) |
498 | fatal("Old dbm can only open one database"); |
499 | sprintf(buf,"%s.dir",fname); |
500 | if (stat(buf, &statbuf) < 0) { |
501 | if (close(creat(buf,mode)) < 0) |
502 | return FALSE; |
503 | sprintf(buf,"%s.pag",fname); |
504 | if (close(creat(buf,mode)) < 0) |
505 | return FALSE; |
506 | } |
507 | tb->tbl_dbm = dbminit(fname) >= 0; |
508 | #endif |
509 | return tb->tbl_dbm != 0; |
510 | } |
511 | |
512 | void |
513 | hdbmclose(tb) |
514 | register HASH *tb; |
515 | { |
516 | if (tb && tb->tbl_dbm) { |
517 | #ifdef NDBM |
518 | dbm_close(tb->tbl_dbm); |
519 | tb->tbl_dbm = 0; |
520 | #else |
521 | /* dbmrefcnt--; */ /* doesn't work, rats */ |
522 | #endif |
523 | } |
524 | else if (dowarn) |
525 | warn("Close on unopened dbm file"); |
526 | } |
527 | |
528 | bool |
529 | hdbmstore(tb,key,klen,str) |
530 | register HASH *tb; |
531 | char *key; |
532 | int klen; |
533 | register STR *str; |
534 | { |
535 | datum dkey, dcontent; |
536 | int error; |
537 | |
538 | if (!tb || !tb->tbl_dbm) |
539 | return FALSE; |
540 | dkey.dptr = key; |
541 | dkey.dsize = klen; |
542 | dcontent.dptr = str_get(str); |
543 | dcontent.dsize = str->str_cur; |
544 | error = dbm_store(tb->tbl_dbm, dkey, dcontent, DBM_REPLACE); |
545 | if (error) { |
546 | if (errno == EPERM) |
547 | fatal("No write permission to dbm file"); |
548 | warn("dbm store returned %d, errno %d, key \"%s\"",error,errno,key); |
549 | #ifdef NDBM |
550 | dbm_clearerr(tb->tbl_dbm); |
551 | #endif |
552 | } |
553 | return !error; |
554 | } |
555 | #endif /* SOME_DBM */ |