1 /*-
2 * See the file LICENSE for redistribution information.
3 *
4 * Copyright (c) 1996, 1997, 1998
5 * Sleepycat Software. All rights reserved.
6 */
7 /*
8 * Copyright (c) 1990, 1993, 1994
9 * The Regents of the University of California. All rights reserved.
10 *
11 * This code is derived from software contributed to Berkeley by
12 * Margo Seltzer.
13 *
14 * Redistribution and use in source and binary forms, with or without
15 * modification, are permitted provided that the following conditions
16 * are met:
17 * 1. Redistributions of source code must retain the above copyright
18 * notice, this list of conditions and the following disclaimer.
19 * 2. Redistributions in binary form must reproduce the above copyright
20 * notice, this list of conditions and the following disclaimer in the
21 * documentation and/or other materials provided with the distribution.
22 * 3. All advertising materials mentioning features or use of this software
23 * must display the following acknowledgement:
24 * This product includes software developed by the University of
25 * California, Berkeley and its contributors.
26 * 4. Neither the name of the University nor the names of its contributors
27 * may be used to endorse or promote products derived from this software
28 * without specific prior written permission.
29 *
30 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
31 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
32 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
34 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
35 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
36 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
37 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
38 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
39 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
40 * SUCH DAMAGE.
41 */
42 #include "config.h"
43
44 #ifndef lint
45 static const char sccsid[] = "@(#)hash_dup.c 10.27 (Sleepycat) 12/6/98";
46 #endif /* not lint */
47
48 /*
49 * PACKAGE: hashing
50 *
51 * DESCRIPTION:
52 * Manipulation of duplicates for the hash package.
53 *
54 * ROUTINES:
55 *
56 * External
57 * __add_dup
58 * Internal
59 */
60
61 #ifndef NO_SYSTEM_INCLUDES
62 #include <sys/types.h>
63
64 #include <errno.h>
65 #include <string.h>
66 #endif
67
68 #include "db_int.h"
69 #include "db_page.h"
70 #include "hash.h"
71 #include "btree.h"
72
73 static int __ham_check_move __P((DBC *, int32_t));
74 static int __ham_dup_convert __P((DBC *));
75 static int __ham_make_dup __P((const DBT *, DBT *d, void **, u_int32_t *));
76
77 /*
78 * Called from hash_access to add a duplicate key. nval is the new
79 * value that we want to add. The flags correspond to the flag values
80 * to cursor_put indicating where to add the new element.
81 * There are 4 cases.
82 * Case 1: The existing duplicate set already resides on a separate page.
83 * We can use common code for this.
84 * Case 2: The element is small enough to just be added to the existing set.
85 * Case 3: The element is large enough to be a big item, so we're going to
86 * have to push the set onto a new page.
87 * Case 4: The element is large enough to push the duplicate set onto a
88 * separate page.
89 *
90 * PUBLIC: int __ham_add_dup __P((DBC *, DBT *, u_int32_t));
91 */
92 int
__ham_add_dup(dbc,nval,flags)93 __ham_add_dup(dbc, nval, flags)
94 DBC *dbc;
95 DBT *nval;
96 u_int32_t flags;
97 {
98 DB *dbp;
99 HASH_CURSOR *hcp;
100 DBT dbt, pval, tmp_val;
101 u_int32_t del_len, new_size;
102 int cmp, ret;
103 u_int8_t *hk;
104
105 dbp = dbc->dbp;
106 hcp = (HASH_CURSOR *)dbc->internal;
107 if (flags == DB_CURRENT && hcp->dpgno == PGNO_INVALID)
108 del_len = hcp->dup_len;
109 else
110 del_len = 0;
111
112 if ((ret = __ham_check_move(dbc,
113 (int32_t)DUP_SIZE(nval->size) - (int32_t)del_len)) != 0)
114 return (ret);
115
116 /*
117 * Check if resulting duplicate set is going to need to go
118 * onto a separate duplicate page. If so, convert the
119 * duplicate set and add the new one. After conversion,
120 * hcp->dndx is the first free ndx or the index of the
121 * current pointer into the duplicate set.
122 */
123 hk = H_PAIRDATA(hcp->pagep, hcp->bndx);
124 new_size = DUP_SIZE(nval->size) - del_len + LEN_HKEYDATA(hcp->pagep,
125 hcp->hdr->pagesize, H_DATAINDEX(hcp->bndx));
126
127 /*
128 * We convert to off-page duplicates if the item is a big item,
129 * the addition of the new item will make the set large, or
130 * if there isn't enough room on this page to add the next item.
131 */
132 if (HPAGE_PTYPE(hk) != H_OFFDUP &&
133 (HPAGE_PTYPE(hk) == H_OFFPAGE || ISBIG(hcp, new_size) ||
134 DUP_SIZE(nval->size) - del_len > P_FREESPACE(hcp->pagep))) {
135
136 if ((ret = __ham_dup_convert(dbc)) != 0)
137 return (ret);
138 else
139 hk = H_PAIRDATA(hcp->pagep, hcp->bndx);
140 }
141
142 /* There are two separate cases here: on page and off page. */
143 if (HPAGE_PTYPE(hk) != H_OFFDUP) {
144 if (HPAGE_PTYPE(hk) != H_DUPLICATE) {
145 HPAGE_PTYPE(hk) = H_DUPLICATE;
146 pval.flags = 0;
147 pval.data = HKEYDATA_DATA(hk);
148 pval.size = LEN_HDATA(hcp->pagep, dbp->pgsize,
149 hcp->bndx);
150 if ((ret =
151 __ham_make_dup(&pval, &tmp_val, &dbc->rdata.data,
152 &dbc->rdata.size)) != 0 || (ret =
153 __ham_replpair(dbc, &tmp_val, 1)) != 0)
154 return (ret);
155 }
156
157 /* Now make the new entry a duplicate. */
158 if ((ret = __ham_make_dup(nval,
159 &tmp_val, &dbc->rdata.data, &dbc->rdata.size)) != 0)
160 return (ret);
161
162 tmp_val.dlen = 0;
163 switch (flags) { /* On page. */
164 case DB_KEYFIRST:
165 case DB_KEYLAST:
166 if (dbp->dup_compare != NULL)
167 __ham_dsearch(dbc, nval, &tmp_val.doff, &cmp);
168 else if (flags == DB_KEYFIRST)
169 tmp_val.doff = 0;
170 else
171 tmp_val.doff = LEN_HDATA(hcp->pagep,
172 hcp->hdr->pagesize, hcp->bndx);
173 break;
174 case DB_CURRENT:
175 /*
176 * If we have a sort function, we need to verify that
177 * the new item sorts identically to the old item.
178 */
179 if (dbp->dup_compare != NULL) {
180 dbt.data = HKEYDATA_DATA(H_PAIRDATA(hcp->pagep,
181 hcp->bndx)) + hcp->dup_off;
182 dbt.size = DUP_SIZE(hcp->dup_len);
183 if (dbp->dup_compare(nval, &dbt) != 0)
184 return (EINVAL);
185 }
186 tmp_val.doff = hcp->dup_off;
187 tmp_val.dlen = DUP_SIZE(hcp->dup_len);
188 break;
189 case DB_BEFORE:
190 tmp_val.doff = hcp->dup_off;
191 break;
192 case DB_AFTER:
193 tmp_val.doff = hcp->dup_off + DUP_SIZE(hcp->dup_len);
194 break;
195 }
196 /* Add the duplicate. */
197 ret = __ham_replpair(dbc, &tmp_val, 0);
198 if (ret == 0)
199 ret = __ham_dirty_page(dbp, hcp->pagep);
200 __ham_c_update(hcp, hcp->pgno, tmp_val.size, 1, 1);
201 return (ret);
202 }
203
204 /* If we get here, then we're on duplicate pages. */
205 if (hcp->dpgno == PGNO_INVALID) {
206 memcpy(&hcp->dpgno, HOFFDUP_PGNO(hk), sizeof(db_pgno_t));
207 hcp->dndx = 0;
208 }
209
210 switch (flags) {
211 case DB_KEYFIRST:
212 if (dbp->dup_compare != NULL)
213 goto sorted_dups;
214 /*
215 * The only way that we are already on a dup page is
216 * if we just converted the on-page representation.
217 * In that case, we've only got one page of duplicates.
218 */
219 if (hcp->dpagep == NULL && (ret =
220 __db_dend(dbc, hcp->dpgno, &hcp->dpagep)) != 0)
221 return (ret);
222 hcp->dndx = 0;
223 break;
224 case DB_KEYLAST:
225 if (dbp->dup_compare != NULL) {
226 sorted_dups: if ((ret = __db_dsearch(dbc, 1, nval,
227 hcp->dpgno, &hcp->dndx, &hcp->dpagep, &cmp)) != 0)
228 return (ret);
229 if (cmp == 0)
230 hcp->dpgno = PGNO(hcp->dpagep);
231 } else {
232 if (hcp->dpagep == NULL && (ret =
233 __db_dend(dbc, hcp->dpgno, &hcp->dpagep)) != 0)
234 return (ret);
235 hcp->dpgno = PGNO(hcp->dpagep);
236 hcp->dndx = NUM_ENT(hcp->dpagep);
237 }
238 break;
239 case DB_CURRENT:
240 if (dbp->dup_compare != NULL && __bam_cmp(dbp,
241 nval, hcp->dpagep, hcp->dndx, dbp->dup_compare) != 0)
242 return (EINVAL);
243 switch (GET_BKEYDATA(hcp->dpagep, hcp->dndx)->type) {
244 case B_KEYDATA:
245 del_len = BKEYDATA_SIZE(GET_BKEYDATA(hcp->dpagep,
246 hcp->dndx)->len);
247 break;
248 case B_OVERFLOW:
249 del_len = BOVERFLOW_SIZE;
250 break;
251 }
252 if ((ret =
253 __db_ditem(dbc, hcp->dpagep, hcp->dndx, del_len)) != 0)
254 return (ret);
255 break;
256 case DB_BEFORE: /* The default behavior is correct. */
257 break;
258 case DB_AFTER:
259 hcp->dndx++;
260 break;
261 }
262
263 ret = __db_dput(dbc,
264 nval, &hcp->dpagep, &hcp->dndx, __ham_overflow_page);
265 hcp->pgno = PGNO(hcp->pagep);
266 __ham_c_update(hcp, hcp->pgno, nval->size, 1, 1);
267 return (ret);
268 }
269
270 /*
271 * Convert an on-page set of duplicates to an offpage set of duplicates.
272 */
273 static int
__ham_dup_convert(dbc)274 __ham_dup_convert(dbc)
275 DBC *dbc;
276 {
277 DB *dbp;
278 HASH_CURSOR *hcp;
279 BOVERFLOW bo;
280 DBT dbt;
281 HOFFPAGE ho;
282 db_indx_t dndx, i, len, off;
283 int ret;
284 u_int8_t *p, *pend;
285
286 /*
287 * Create a new page for the duplicates.
288 */
289 dbp = dbc->dbp;
290 hcp = (HASH_CURSOR *)dbc->internal;
291 if ((ret =
292 __ham_overflow_page(dbc, P_DUPLICATE, &hcp->dpagep)) != 0)
293 return (ret);
294 hcp->dpagep->type = P_DUPLICATE;
295 hcp->dpgno = PGNO(hcp->dpagep);
296
297 /*
298 * Now put the duplicates onto the new page.
299 */
300 dndx = 0;
301 dbt.flags = 0;
302 switch (HPAGE_PTYPE(H_PAIRDATA(hcp->pagep, hcp->bndx))) {
303 case H_KEYDATA:
304 /* Simple case, one key on page; move it to dup page. */
305 dbt.size =
306 LEN_HDATA(hcp->pagep, hcp->hdr->pagesize, hcp->bndx);
307 dbt.data = HKEYDATA_DATA(H_PAIRDATA(hcp->pagep, hcp->bndx));
308 ret = __db_pitem(dbc, hcp->dpagep,
309 (u_int32_t)dndx, BKEYDATA_SIZE(dbt.size), NULL, &dbt);
310 if (ret == 0)
311 __ham_dirty_page(dbp, hcp->dpagep);
312 break;
313 case H_OFFPAGE:
314 /* Simple case, one key on page; move it to dup page. */
315 memcpy(&ho,
316 P_ENTRY(hcp->pagep, H_DATAINDEX(hcp->bndx)), HOFFPAGE_SIZE);
317 UMRW(bo.unused1);
318 B_TSET(bo.type, ho.type, 0);
319 UMRW(bo.unused2);
320 bo.pgno = ho.pgno;
321 bo.tlen = ho.tlen;
322 dbt.size = BOVERFLOW_SIZE;
323 dbt.data = &bo;
324
325 ret = __db_pitem(dbc, hcp->dpagep,
326 (u_int32_t)dndx, dbt.size, &dbt, NULL);
327 if (ret == 0)
328 __ham_dirty_page(dbp, hcp->dpagep);
329 break;
330 case H_DUPLICATE:
331 p = HKEYDATA_DATA(H_PAIRDATA(hcp->pagep, hcp->bndx));
332 pend = p +
333 LEN_HDATA(hcp->pagep, hcp->hdr->pagesize, hcp->bndx);
334
335 /*
336 * We need to maintain the duplicate cursor position.
337 * Keep track of where we are in the duplicate set via
338 * the offset, and when it matches the one in the cursor,
339 * set the off-page duplicate cursor index to the current
340 * index.
341 */
342 for (off = 0, i = 0; p < pend; i++) {
343 if (off == hcp->dup_off)
344 dndx = i;
345 memcpy(&len, p, sizeof(db_indx_t));
346 dbt.size = len;
347 p += sizeof(db_indx_t);
348 dbt.data = p;
349 p += len + sizeof(db_indx_t);
350 off += len + 2 * sizeof(db_indx_t);
351 ret = __db_dput(dbc, &dbt,
352 &hcp->dpagep, &i, __ham_overflow_page);
353 if (ret != 0)
354 break;
355 }
356 break;
357 default:
358 ret = __db_pgfmt(dbp, (u_long)hcp->pgno);
359 break;
360 }
361 if (ret == 0) {
362 /*
363 * Now attach this to the source page in place of
364 * the old duplicate item.
365 */
366 __ham_move_offpage(dbc, hcp->pagep,
367 (u_int32_t)H_DATAINDEX(hcp->bndx), hcp->dpgno);
368
369 /* Can probably just do a "put" here. */
370 ret = __ham_dirty_page(dbp, hcp->pagep);
371 hcp->dndx = dndx;
372 } else {
373 (void)__ham_del_page(dbc, hcp->dpagep);
374 hcp->dpagep = NULL;
375 }
376 return (ret);
377 }
378
379 static int
__ham_make_dup(notdup,duplicate,bufp,sizep)380 __ham_make_dup(notdup, duplicate, bufp, sizep)
381 const DBT *notdup;
382 DBT *duplicate;
383 void **bufp;
384 u_int32_t *sizep;
385 {
386 db_indx_t tsize, item_size;
387 int ret;
388 u_int8_t *p;
389
390 item_size = (db_indx_t)notdup->size;
391 tsize = DUP_SIZE(item_size);
392 if ((ret = __ham_init_dbt(duplicate, tsize, bufp, sizep)) != 0)
393 return (ret);
394
395 duplicate->dlen = 0;
396 duplicate->flags = notdup->flags;
397 F_SET(duplicate, DB_DBT_PARTIAL);
398
399 p = duplicate->data;
400 memcpy(p, &item_size, sizeof(db_indx_t));
401 p += sizeof(db_indx_t);
402 memcpy(p, notdup->data, notdup->size);
403 p += notdup->size;
404 memcpy(p, &item_size, sizeof(db_indx_t));
405
406 duplicate->doff = 0;
407 duplicate->dlen = notdup->size;
408
409 return (0);
410 }
411
412 static int
__ham_check_move(dbc,add_len)413 __ham_check_move(dbc, add_len)
414 DBC *dbc;
415 int32_t add_len;
416 {
417 DB *dbp;
418 HASH_CURSOR *hcp;
419 DBT k, d;
420 DB_LSN new_lsn;
421 PAGE *next_pagep;
422 db_pgno_t next_pgno;
423 u_int32_t new_datalen, old_len, rectype;
424 u_int8_t *hk;
425 int ret;
426
427 dbp = dbc->dbp;
428 hcp = (HASH_CURSOR *)dbc->internal;
429 /*
430 * Check if we can do whatever we need to on this page. If not,
431 * then we'll have to move the current element to a new page.
432 */
433 hk = H_PAIRDATA(hcp->pagep, hcp->bndx);
434
435 /*
436 * If the item is already off page duplicates or an offpage item,
437 * then we know we can do whatever we need to do in-place
438 */
439 if (HPAGE_PTYPE(hk) == H_OFFDUP || HPAGE_PTYPE(hk) == H_OFFPAGE)
440 return (0);
441
442 old_len =
443 LEN_HITEM(hcp->pagep, hcp->hdr->pagesize, H_DATAINDEX(hcp->bndx));
444 new_datalen = old_len - HKEYDATA_SIZE(0) + add_len;
445
446 /*
447 * We need to add a new page under two conditions:
448 * 1. The addition makes the total data length cross the BIG
449 * threshold and the OFFDUP structure won't fit on this page.
450 * 2. The addition does not make the total data cross the
451 * threshold, but the new data won't fit on the page.
452 * If neither of these is true, then we can return.
453 */
454 if (ISBIG(hcp, new_datalen) && (old_len > HOFFDUP_SIZE ||
455 HOFFDUP_SIZE - old_len <= P_FREESPACE(hcp->pagep)))
456 return (0);
457
458 if (!ISBIG(hcp, new_datalen) &&
459 add_len <= (int32_t)P_FREESPACE(hcp->pagep))
460 return (0);
461
462 /*
463 * If we get here, then we need to move the item to a new page.
464 * Check if there are more pages in the chain.
465 */
466
467 new_datalen = ISBIG(hcp, new_datalen) ?
468 HOFFDUP_SIZE : HKEYDATA_SIZE(new_datalen);
469
470 next_pagep = NULL;
471 for (next_pgno = NEXT_PGNO(hcp->pagep); next_pgno != PGNO_INVALID;
472 next_pgno = NEXT_PGNO(next_pagep)) {
473 if (next_pagep != NULL &&
474 (ret = __ham_put_page(dbp, next_pagep, 0)) != 0)
475 return (ret);
476
477 if ((ret =
478 __ham_get_page(dbp, next_pgno, &next_pagep)) != 0)
479 return (ret);
480
481 if (P_FREESPACE(next_pagep) >= new_datalen)
482 break;
483 }
484
485 /* No more pages, add one. */
486 if (next_pagep == NULL && (ret = __ham_add_ovflpage(dbc,
487 hcp->pagep, 0, &next_pagep)) != 0)
488 return (ret);
489
490 /* Add new page at the end of the chain. */
491 if (P_FREESPACE(next_pagep) < new_datalen && (ret =
492 __ham_add_ovflpage(dbc, next_pagep, 1, &next_pagep)) != 0)
493 return (ret);
494
495 /* Copy the item to the new page. */
496 if (DB_LOGGING(hcp->dbc)) {
497 rectype = PUTPAIR;
498 k.flags = 0;
499 d.flags = 0;
500 if (HPAGE_PTYPE(
501 H_PAIRKEY(hcp->pagep, hcp->bndx)) == H_OFFPAGE) {
502 rectype |= PAIR_KEYMASK;
503 k.data = H_PAIRKEY(hcp->pagep, hcp->bndx);
504 k.size = HOFFPAGE_SIZE;
505 } else {
506 k.data =
507 HKEYDATA_DATA(H_PAIRKEY(hcp->pagep, hcp->bndx));
508 k.size = LEN_HKEY(hcp->pagep,
509 hcp->hdr->pagesize, hcp->bndx);
510 }
511
512 if (HPAGE_PTYPE(hk) == H_OFFPAGE) {
513 rectype |= PAIR_DATAMASK;
514 d.data = H_PAIRDATA(hcp->pagep, hcp->bndx);
515 d.size = HOFFPAGE_SIZE;
516 } else {
517 d.data =
518 HKEYDATA_DATA(H_PAIRDATA(hcp->pagep, hcp->bndx));
519 d.size = LEN_HDATA(hcp->pagep,
520 hcp->hdr->pagesize, hcp->bndx);
521 }
522
523
524 if ((ret = __ham_insdel_log(dbp->dbenv->lg_info,
525 dbc->txn, &new_lsn, 0, rectype,
526 dbp->log_fileid, PGNO(next_pagep),
527 (u_int32_t)H_NUMPAIRS(next_pagep), &LSN(next_pagep),
528 &k, &d)) != 0)
529 return (ret);
530
531 /* Move lsn onto page. */
532 LSN(next_pagep) = new_lsn; /* Structure assignment. */
533 }
534
535 __ham_copy_item(dbp->pgsize,
536 hcp->pagep, H_KEYINDEX(hcp->bndx), next_pagep);
537 __ham_copy_item(dbp->pgsize,
538 hcp->pagep, H_DATAINDEX(hcp->bndx), next_pagep);
539
540 /* Now delete the pair from the current page. */
541 ret = __ham_del_pair(dbc, 0);
542
543 (void)__ham_put_page(dbp, hcp->pagep, 1);
544 hcp->pagep = next_pagep;
545 hcp->pgno = PGNO(hcp->pagep);
546 hcp->bndx = H_NUMPAIRS(hcp->pagep) - 1;
547 F_SET(hcp, H_EXPAND);
548 return (ret);
549 }
550
551 /*
552 * __ham_move_offpage --
553 * Replace an onpage set of duplicates with the OFFDUP structure
554 * that references the duplicate page.
555 *
556 * XXX
557 * This is really just a special case of __onpage_replace; we should
558 * probably combine them.
559 *
560 * PUBLIC: void __ham_move_offpage __P((DBC *, PAGE *, u_int32_t, db_pgno_t));
561 */
562 void
__ham_move_offpage(dbc,pagep,ndx,pgno)563 __ham_move_offpage(dbc, pagep, ndx, pgno)
564 DBC *dbc;
565 PAGE *pagep;
566 u_int32_t ndx;
567 db_pgno_t pgno;
568 {
569 DB *dbp;
570 HASH_CURSOR *hcp;
571 DBT new_dbt;
572 DBT old_dbt;
573 HOFFDUP od;
574 db_indx_t i;
575 int32_t shrink;
576 u_int8_t *src;
577
578 dbp = dbc->dbp;
579 hcp = (HASH_CURSOR *)dbc->internal;
580 od.type = H_OFFDUP;
581 UMRW(od.unused[0]);
582 UMRW(od.unused[1]);
583 UMRW(od.unused[2]);
584 od.pgno = pgno;
585
586 if (DB_LOGGING(dbc)) {
587 new_dbt.data = &od;
588 new_dbt.size = HOFFDUP_SIZE;
589 old_dbt.data = P_ENTRY(pagep, ndx);
590 old_dbt.size = LEN_HITEM(pagep, hcp->hdr->pagesize, ndx);
591 (void)__ham_replace_log(dbp->dbenv->lg_info,
592 dbc->txn, &LSN(pagep), 0, dbp->log_fileid,
593 PGNO(pagep), (u_int32_t)ndx, &LSN(pagep), -1,
594 &old_dbt, &new_dbt, 0);
595 }
596
597 shrink =
598 LEN_HITEM(pagep, hcp->hdr->pagesize, ndx) - HOFFDUP_SIZE;
599
600 if (shrink != 0) {
601 /* Copy data. */
602 src = (u_int8_t *)(pagep) + HOFFSET(pagep);
603 memmove(src + shrink, src, pagep->inp[ndx] - HOFFSET(pagep));
604 HOFFSET(pagep) += shrink;
605
606 /* Update index table. */
607 for (i = ndx; i < NUM_ENT(pagep); i++)
608 pagep->inp[i] += shrink;
609 }
610
611 /* Now copy the offdup entry onto the page. */
612 memcpy(P_ENTRY(pagep, ndx), &od, HOFFDUP_SIZE);
613 }
614
615 /*
616 * __ham_dsearch:
617 * Locate a particular duplicate in a duplicate set.
618 *
619 * PUBLIC: void __ham_dsearch __P((DBC *, DBT *, u_int32_t *, int *));
620 */
621 void
__ham_dsearch(dbc,dbt,offp,cmpp)622 __ham_dsearch(dbc, dbt, offp, cmpp)
623 DBC *dbc;
624 DBT *dbt;
625 u_int32_t *offp;
626 int *cmpp;
627 {
628 DB *dbp;
629 HASH_CURSOR *hcp;
630 DBT cur;
631 db_indx_t i, len;
632 int (*func) __P((const DBT *, const DBT *));
633 u_int8_t *data;
634
635 dbp = dbc->dbp;
636 hcp = (HASH_CURSOR *)dbc->internal;
637 if (dbp->dup_compare == NULL)
638 func = __bam_defcmp;
639 else
640 func = dbp->dup_compare;
641
642 i = F_ISSET(dbc, DBC_CONTINUE) ? hcp->dup_off: 0;
643 data = HKEYDATA_DATA(H_PAIRDATA(hcp->pagep, hcp->bndx)) + i;
644 while (i < LEN_HDATA(hcp->pagep, hcp->hdr->pagesize, hcp->bndx)) {
645 memcpy(&len, data, sizeof(db_indx_t));
646 data += sizeof(db_indx_t);
647 cur.data = data;
648 cur.size = (u_int32_t)len;
649 *cmpp = func(dbt, &cur);
650 if (*cmpp == 0 || (*cmpp < 0 && dbp->dup_compare != NULL))
651 break;
652 i += len + 2 * sizeof(db_indx_t);
653 data += len + sizeof(db_indx_t);
654 }
655 *offp = i;
656 }
657