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, 1995, 1996
9 * Keith Bostic. All rights reserved.
10 */
11 /*
12 * Copyright (c) 1990, 1993, 1994, 1995
13 * The Regents of the University of California. All rights reserved.
14 *
15 * This code is derived from software contributed to Berkeley by
16 * Mike Olson.
17 *
18 * Redistribution and use in source and binary forms, with or without
19 * modification, are permitted provided that the following conditions
20 * are met:
21 * 1. Redistributions of source code must retain the above copyright
22 * notice, this list of conditions and the following disclaimer.
23 * 2. Redistributions in binary form must reproduce the above copyright
24 * notice, this list of conditions and the following disclaimer in the
25 * documentation and/or other materials provided with the distribution.
26 * 3. All advertising materials mentioning features or use of this software
27 * must display the following acknowledgement:
28 * This product includes software developed by the University of
29 * California, Berkeley and its contributors.
30 * 4. Neither the name of the University nor the names of its contributors
31 * may be used to endorse or promote products derived from this software
32 * without specific prior written permission.
33 *
34 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
35 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
36 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
37 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
38 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
39 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
40 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
41 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
42 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
43 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
44 * SUCH DAMAGE.
45 */
46
47 #include "config.h"
48
49 #ifndef lint
50 static const char sccsid[] = "@(#)bt_put.c 10.54 (Sleepycat) 12/6/98";
51 #endif /* not lint */
52
53 #ifndef NO_SYSTEM_INCLUDES
54 #include <sys/types.h>
55
56 #include <errno.h>
57 #include <string.h>
58 #endif
59
60 #include "db_int.h"
61 #include "db_page.h"
62 #include "btree.h"
63
64 static int __bam_fixed __P((DBC *, DBT *));
65 static int __bam_ndup __P((DBC *, PAGE *, u_int32_t));
66 static int __bam_ovput __P((DBC *, PAGE *, u_int32_t, DBT *));
67 static int __bam_partial __P((DBC *,
68 DBT *, PAGE *, u_int32_t, u_int32_t, u_int32_t));
69 static u_int32_t __bam_partsize __P((DBT *, PAGE *, u_int32_t));
70
71 /*
72 * __bam_iitem --
73 * Insert an item into the tree.
74 *
75 * PUBLIC: int __bam_iitem __P((DBC *,
76 * PUBLIC: PAGE **, db_indx_t *, DBT *, DBT *, u_int32_t, u_int32_t));
77 */
78 int
__bam_iitem(dbc,hp,indxp,key,data,op,flags)79 __bam_iitem(dbc, hp, indxp, key, data, op, flags)
80 DBC *dbc;
81 PAGE **hp;
82 db_indx_t *indxp;
83 DBT *key, *data;
84 u_int32_t op, flags;
85 {
86 BTREE *t;
87 BKEYDATA *bk;
88 DB *dbp;
89 DBT tdbt;
90 PAGE *h;
91 db_indx_t indx, nbytes;
92 u_int32_t data_size, have_bytes, need_bytes, needed;
93 int bigkey, bigdata, dupadjust, replace, ret;
94
95 COMPQUIET(bk, NULL);
96
97 dbp = dbc->dbp;
98 t = dbp->internal;
99 h = *hp;
100 indx = *indxp;
101 dupadjust = replace = 0;
102
103 /*
104 * If it's a page of duplicates, call the common code to do the work.
105 *
106 * !!!
107 * Here's where the hp and indxp are important. The duplicate code
108 * may decide to rework/rearrange the pages and indices we're using,
109 * so the caller must understand that the page stack may change.
110 */
111 if (TYPE(h) == P_DUPLICATE) {
112 /* Adjust the index for the new item if it's a DB_AFTER op. */
113 if (op == DB_AFTER)
114 ++*indxp;
115
116 /* Remove the current item if it's a DB_CURRENT op. */
117 if (op == DB_CURRENT) {
118 bk = GET_BKEYDATA(*hp, *indxp);
119 switch (B_TYPE(bk->type)) {
120 case B_KEYDATA:
121 nbytes = BKEYDATA_SIZE(bk->len);
122 break;
123 case B_OVERFLOW:
124 nbytes = BOVERFLOW_SIZE;
125 break;
126 default:
127 return (__db_pgfmt(dbp, h->pgno));
128 }
129 if ((ret = __db_ditem(dbc, *hp, *indxp, nbytes)) != 0)
130 return (ret);
131 }
132
133 /* Put the new/replacement item onto the page. */
134 if ((ret = __db_dput(dbc, data, hp, indxp, __bam_new)) != 0)
135 return (ret);
136
137 goto done;
138 }
139
140 /* Handle fixed-length records: build the real record. */
141 if (F_ISSET(dbp, DB_RE_FIXEDLEN) && data->size != t->recno->re_len) {
142 tdbt = *data;
143 if ((ret = __bam_fixed(dbc, &tdbt)) != 0)
144 return (ret);
145 data = &tdbt;
146 }
147
148 /*
149 * Figure out how much space the data will take, including if it's a
150 * partial record. If either of the key or data items won't fit on
151 * a page, we'll have to store them on overflow pages.
152 */
153 bigkey = LF_ISSET(BI_NEWKEY) && key->size > t->bt_ovflsize;
154 data_size = F_ISSET(data, DB_DBT_PARTIAL) ?
155 __bam_partsize(data, h, indx) : data->size;
156 bigdata = data_size > t->bt_ovflsize;
157
158 needed = 0;
159 if (LF_ISSET(BI_NEWKEY)) {
160 /* If BI_NEWKEY is set we're adding a new key and data pair. */
161 if (bigkey)
162 needed += BOVERFLOW_PSIZE;
163 else
164 needed += BKEYDATA_PSIZE(key->size);
165 if (bigdata)
166 needed += BOVERFLOW_PSIZE;
167 else
168 needed += BKEYDATA_PSIZE(data_size);
169 } else {
170 /*
171 * We're either overwriting the data item of a key/data pair
172 * or we're adding the data item only, i.e. a new duplicate.
173 */
174 if (op == DB_CURRENT) {
175 bk = GET_BKEYDATA(h,
176 indx + (TYPE(h) == P_LBTREE ? O_INDX : 0));
177 if (B_TYPE(bk->type) == B_KEYDATA)
178 have_bytes = BKEYDATA_PSIZE(bk->len);
179 else
180 have_bytes = BOVERFLOW_PSIZE;
181 need_bytes = 0;
182 } else {
183 have_bytes = 0;
184 need_bytes = sizeof(db_indx_t);
185 }
186 if (bigdata)
187 need_bytes += BOVERFLOW_PSIZE;
188 else
189 need_bytes += BKEYDATA_PSIZE(data_size);
190
191 if (have_bytes < need_bytes)
192 needed += need_bytes - have_bytes;
193 }
194
195 /*
196 * If there's not enough room, or the user has put a ceiling on the
197 * number of keys permitted in the page, split the page.
198 *
199 * XXX
200 * The t->bt_maxkey test here may be insufficient -- do we have to
201 * check in the btree split code, so we don't undo it there!?!?
202 */
203 if (P_FREESPACE(h) < needed ||
204 (t->bt_maxkey != 0 && NUM_ENT(h) > t->bt_maxkey))
205 return (DB_NEEDSPLIT);
206
207 /* Handle partial puts: build the real record. */
208 if (F_ISSET(data, DB_DBT_PARTIAL)) {
209 tdbt = *data;
210 if ((ret = __bam_partial(dbc,
211 &tdbt, h, indx, data_size, flags)) != 0)
212 return (ret);
213 data = &tdbt;
214 }
215
216 /*
217 * The code breaks it up into six cases:
218 *
219 * 1. Append a new key/data pair.
220 * 2. Insert a new key/data pair.
221 * 3. Append a new data item (a new duplicate).
222 * 4. Insert a new data item (a new duplicate).
223 * 5. Overflow item: delete and re-add the data item.
224 * 6. Replace the data item.
225 */
226 if (LF_ISSET(BI_NEWKEY)) {
227 switch (op) {
228 case DB_AFTER: /* 1. Append a new key/data pair. */
229 indx += 2;
230 *indxp += 2;
231 break;
232 case DB_BEFORE: /* 2. Insert a new key/data pair. */
233 break;
234 default:
235 return (EINVAL);
236 }
237
238 /* Add the key. */
239 if (bigkey) {
240 if ((ret = __bam_ovput(dbc, h, indx, key)) != 0)
241 return (ret);
242 } else
243 if ((ret = __db_pitem(dbc, h, indx,
244 BKEYDATA_SIZE(key->size), NULL, key)) != 0)
245 return (ret);
246 ++indx;
247 } else {
248 switch (op) {
249 case DB_AFTER: /* 3. Append a new data item. */
250 if (TYPE(h) == P_LBTREE) {
251 /*
252 * Adjust the cursor and copy in the key for
253 * the duplicate.
254 */
255 if ((ret = __bam_adjindx(dbc,
256 h, indx + P_INDX, indx, 1)) != 0)
257 return (ret);
258
259 indx += 3;
260 dupadjust = 1;
261
262 *indxp += 2;
263 } else {
264 ++indx;
265 __bam_ca_di(dbp, h->pgno, indx, 1);
266
267 *indxp += 1;
268 }
269 break;
270 case DB_BEFORE: /* 4. Insert a new data item. */
271 if (TYPE(h) == P_LBTREE) {
272 /*
273 * Adjust the cursor and copy in the key for
274 * the duplicate.
275 */
276 if ((ret =
277 __bam_adjindx(dbc, h, indx, indx, 1)) != 0)
278 return (ret);
279
280 ++indx;
281 dupadjust = 1;
282 } else
283 __bam_ca_di(dbp, h->pgno, indx, 1);
284 break;
285 case DB_CURRENT:
286 if (TYPE(h) == P_LBTREE)
287 ++indx;
288
289 /*
290 * 5. Delete/re-add the data item.
291 *
292 * If we're dealing with offpage items, we have to
293 * delete and then re-add the item.
294 */
295 if (bigdata || B_TYPE(bk->type) != B_KEYDATA) {
296 if ((ret = __bam_ditem(dbc, h, indx)) != 0)
297 return (ret);
298 break;
299 }
300
301 /* 6. Replace the data item. */
302 replace = 1;
303 break;
304 default:
305 return (EINVAL);
306 }
307 }
308
309 /* Add the data. */
310 if (bigdata) {
311 if ((ret = __bam_ovput(dbc, h, indx, data)) != 0)
312 return (ret);
313 } else {
314 BKEYDATA __bk;
315 DBT __hdr;
316
317 if (LF_ISSET(BI_DELETED)) {
318 B_TSET(__bk.type, B_KEYDATA, 1);
319 __bk.len = data->size;
320 __hdr.data = &__bk;
321 __hdr.size = SSZA(BKEYDATA, data);
322 ret = __db_pitem(dbc, h, indx,
323 BKEYDATA_SIZE(data->size), &__hdr, data);
324 } else if (replace)
325 ret = __bam_ritem(dbc, h, indx, data);
326 else
327 ret = __db_pitem(dbc, h, indx,
328 BKEYDATA_SIZE(data->size), NULL, data);
329 if (ret != 0)
330 return (ret);
331 }
332
333 if ((ret = memp_fset(dbp->mpf, h, DB_MPOOL_DIRTY)) != 0)
334 return (ret);
335
336 /*
337 * If the page is at least 50% full, and we added a duplicate, see if
338 * that set of duplicates takes up at least 25% of the space. If it
339 * does, move it off onto its own page.
340 */
341 if (dupadjust && P_FREESPACE(h) <= dbp->pgsize / 2) {
342 --indx;
343 if ((ret = __bam_ndup(dbc, h, indx)) != 0)
344 return (ret);
345 }
346
347 /*
348 * If we've changed the record count, update the tree. Record counts
349 * need to be updated in recno databases and in btree databases where
350 * we are supporting records. In both cases, adjust the count if the
351 * operation wasn't performed on the current record or when the caller
352 * overrides and wants the adjustment made regardless.
353 */
354 done: if (LF_ISSET(BI_DOINCR) ||
355 (op != DB_CURRENT &&
356 (F_ISSET(dbp, DB_BT_RECNUM) || dbp->type == DB_RECNO)))
357 if ((ret = __bam_adjust(dbc, 1)) != 0)
358 return (ret);
359
360 /* If we've modified a recno file, set the flag */
361 if (t->recno != NULL)
362 F_SET(t->recno, RECNO_MODIFIED);
363
364 return (ret);
365 }
366
367 /*
368 * __bam_partsize --
369 * Figure out how much space a partial data item is in total.
370 */
371 static u_int32_t
__bam_partsize(data,h,indx)372 __bam_partsize(data, h, indx)
373 DBT *data;
374 PAGE *h;
375 u_int32_t indx;
376 {
377 BKEYDATA *bk;
378 u_int32_t nbytes;
379
380 /*
381 * Figure out how much total space we'll need. If the record doesn't
382 * already exist, it's simply the data we're provided.
383 */
384 if (indx >= NUM_ENT(h))
385 return (data->doff + data->size);
386
387 /*
388 * Otherwise, it's the data provided plus any already existing data
389 * that we're not replacing.
390 */
391 bk = GET_BKEYDATA(h, indx + (TYPE(h) == P_LBTREE ? O_INDX : 0));
392 nbytes =
393 B_TYPE(bk->type) == B_OVERFLOW ? ((BOVERFLOW *)bk)->tlen : bk->len;
394
395 /*
396 * There are really two cases here:
397 *
398 * Case 1: We are replacing some bytes that do not exist (i.e., they
399 * are past the end of the record). In this case the number of bytes
400 * we are replacing is irrelevant and all we care about is how many
401 * bytes we are going to add from offset. So, the new record length
402 * is going to be the size of the new bytes (size) plus wherever those
403 * new bytes begin (doff).
404 *
405 * Case 2: All the bytes we are replacing exist. Therefore, the new
406 * size is the oldsize (nbytes) minus the bytes we are replacing (dlen)
407 * plus the bytes we are adding (size).
408 */
409 if (nbytes < data->doff + data->dlen) /* Case 1 */
410 return (data->doff + data->size);
411
412 return (nbytes + data->size - data->dlen); /* Case 2 */
413 }
414
415 /*
416 * OVPUT --
417 * Copy an overflow item onto a page.
418 */
419 #undef OVPUT
420 #define OVPUT(h, indx, bo) do { \
421 DBT __hdr; \
422 memset(&__hdr, 0, sizeof(__hdr)); \
423 __hdr.data = &bo; \
424 __hdr.size = BOVERFLOW_SIZE; \
425 if ((ret = __db_pitem(dbc, \
426 h, indx, BOVERFLOW_SIZE, &__hdr, NULL)) != 0) \
427 return (ret); \
428 } while (0)
429
430 /*
431 * __bam_ovput --
432 * Build an overflow item and put it on the page.
433 */
434 static int
__bam_ovput(dbc,h,indx,item)435 __bam_ovput(dbc, h, indx, item)
436 DBC *dbc;
437 PAGE *h;
438 u_int32_t indx;
439 DBT *item;
440 {
441 BOVERFLOW bo;
442 int ret;
443
444 UMRW(bo.unused1);
445 B_TSET(bo.type, B_OVERFLOW, 0);
446 UMRW(bo.unused2);
447 if ((ret = __db_poff(dbc, item, &bo.pgno, __bam_new)) != 0)
448 return (ret);
449 bo.tlen = item->size;
450
451 OVPUT(h, indx, bo);
452
453 return (0);
454 }
455
456 /*
457 * __bam_ritem --
458 * Replace an item on a page.
459 *
460 * PUBLIC: int __bam_ritem __P((DBC *, PAGE *, u_int32_t, DBT *));
461 */
462 int
__bam_ritem(dbc,h,indx,data)463 __bam_ritem(dbc, h, indx, data)
464 DBC *dbc;
465 PAGE *h;
466 u_int32_t indx;
467 DBT *data;
468 {
469 BKEYDATA *bk;
470 DB *dbp;
471 DBT orig, repl;
472 db_indx_t cnt, lo, ln, min, off, prefix, suffix;
473 int32_t nbytes;
474 int ret;
475 u_int8_t *p, *t;
476
477 dbp = dbc->dbp;
478
479 /*
480 * Replace a single item onto a page. The logic figuring out where
481 * to insert and whether it fits is handled in the caller. All we do
482 * here is manage the page shuffling.
483 */
484 bk = GET_BKEYDATA(h, indx);
485
486 /* Log the change. */
487 if (DB_LOGGING(dbc)) {
488 /*
489 * We might as well check to see if the two data items share
490 * a common prefix and suffix -- it can save us a lot of log
491 * message if they're large.
492 */
493 min = data->size < bk->len ? data->size : bk->len;
494 for (prefix = 0,
495 p = bk->data, t = data->data;
496 prefix < min && *p == *t; ++prefix, ++p, ++t)
497 ;
498
499 min -= prefix;
500 for (suffix = 0,
501 p = (u_int8_t *)bk->data + bk->len - 1,
502 t = (u_int8_t *)data->data + data->size - 1;
503 suffix < min && *p == *t; ++suffix, --p, --t)
504 ;
505
506 /* We only log the parts of the keys that have changed. */
507 orig.data = (u_int8_t *)bk->data + prefix;
508 orig.size = bk->len - (prefix + suffix);
509 repl.data = (u_int8_t *)data->data + prefix;
510 repl.size = data->size - (prefix + suffix);
511 if ((ret = __bam_repl_log(dbp->dbenv->lg_info, dbc->txn,
512 &LSN(h), 0, dbp->log_fileid, PGNO(h), &LSN(h),
513 (u_int32_t)indx, (u_int32_t)B_DISSET(bk->type),
514 &orig, &repl, (u_int32_t)prefix, (u_int32_t)suffix)) != 0)
515 return (ret);
516 }
517
518 /*
519 * Set references to the first in-use byte on the page and the
520 * first byte of the item being replaced.
521 */
522 p = (u_int8_t *)h + HOFFSET(h);
523 t = (u_int8_t *)bk;
524
525 /*
526 * If the entry is growing in size, shift the beginning of the data
527 * part of the page down. If the entry is shrinking in size, shift
528 * the beginning of the data part of the page up. Use memmove(3),
529 * the regions overlap.
530 */
531 lo = BKEYDATA_SIZE(bk->len);
532 ln = BKEYDATA_SIZE(data->size);
533 if (lo != ln) {
534 nbytes = lo - ln; /* Signed difference. */
535 if (p == t) /* First index is fast. */
536 h->inp[indx] += nbytes;
537 else { /* Else, shift the page. */
538 memmove(p + nbytes, p, t - p);
539
540 /* Adjust the indices' offsets. */
541 off = h->inp[indx];
542 for (cnt = 0; cnt < NUM_ENT(h); ++cnt)
543 if (h->inp[cnt] <= off)
544 h->inp[cnt] += nbytes;
545 }
546
547 /* Clean up the page and adjust the item's reference. */
548 HOFFSET(h) += nbytes;
549 t += nbytes;
550 }
551
552 /* Copy the new item onto the page. */
553 bk = (BKEYDATA *)t;
554 B_TSET(bk->type, B_KEYDATA, 0);
555 bk->len = data->size;
556 memcpy(bk->data, data->data, data->size);
557
558 return (0);
559 }
560
561 /*
562 * __bam_ndup --
563 * Check to see if the duplicate set at indx should have its own page.
564 * If it should, create it.
565 */
566 static int
__bam_ndup(dbc,h,indx)567 __bam_ndup(dbc, h, indx)
568 DBC *dbc;
569 PAGE *h;
570 u_int32_t indx;
571 {
572 BKEYDATA *bk;
573 BOVERFLOW bo;
574 DB *dbp;
575 DBT hdr;
576 PAGE *cp;
577 db_indx_t cnt, cpindx, first, sz;
578 int ret;
579
580 dbp = dbc->dbp;
581
582 while (indx > 0 && h->inp[indx] == h->inp[indx - P_INDX])
583 indx -= P_INDX;
584 for (cnt = 0, sz = 0, first = indx;; ++cnt, indx += P_INDX) {
585 if (indx >= NUM_ENT(h) || h->inp[first] != h->inp[indx])
586 break;
587 bk = GET_BKEYDATA(h, indx);
588 sz += B_TYPE(bk->type) == B_KEYDATA ?
589 BKEYDATA_PSIZE(bk->len) : BOVERFLOW_PSIZE;
590 bk = GET_BKEYDATA(h, indx + O_INDX);
591 sz += B_TYPE(bk->type) == B_KEYDATA ?
592 BKEYDATA_PSIZE(bk->len) : BOVERFLOW_PSIZE;
593 }
594
595 /*
596 * If this set of duplicates is using more than 25% of the page, move
597 * them off. The choice of 25% is a WAG, but it has to be small enough
598 * that we can always split regardless of the presence of duplicates.
599 */
600 if (sz < dbp->pgsize / 4)
601 return (0);
602
603 /* Get a new page. */
604 if ((ret = __bam_new(dbc, P_DUPLICATE, &cp)) != 0)
605 return (ret);
606
607 /*
608 * Move this set of duplicates off the page. First points to the first
609 * key of the first duplicate key/data pair, cnt is the number of pairs
610 * we're dealing with.
611 */
612 memset(&hdr, 0, sizeof(hdr));
613 for (indx = first + O_INDX, cpindx = 0;; ++cpindx) {
614 /* Copy the entry to the new page. */
615 bk = GET_BKEYDATA(h, indx);
616 hdr.data = bk;
617 hdr.size = B_TYPE(bk->type) == B_KEYDATA ?
618 BKEYDATA_SIZE(bk->len) : BOVERFLOW_SIZE;
619 if ((ret =
620 __db_pitem(dbc, cp, cpindx, hdr.size, &hdr, NULL)) != 0)
621 goto err;
622
623 /*
624 * Move cursors referencing the old entry to the new entry.
625 * Done after the page put because __db_pitem() adjusts
626 * cursors on the new page, and before the delete because
627 * __db_ditem adjusts cursors on the old page.
628 */
629 __bam_ca_dup(dbp,
630 PGNO(h), first, indx - O_INDX, PGNO(cp), cpindx);
631
632 /* Delete the data item. */
633 if ((ret = __db_ditem(dbc, h, indx, hdr.size)) != 0)
634 goto err;
635
636 /* Delete all but the first reference to the key. */
637 if (--cnt == 0)
638 break;
639 if ((ret = __bam_adjindx(dbc, h, indx, first, 0)) != 0)
640 goto err;
641 }
642
643 /* Put in a new data item that points to the duplicates page. */
644 UMRW(bo.unused1);
645 B_TSET(bo.type, B_DUPLICATE, 0);
646 UMRW(bo.unused2);
647 bo.pgno = cp->pgno;
648 bo.tlen = 0;
649
650 OVPUT(h, indx, bo);
651
652 return (memp_fput(dbp->mpf, cp, DB_MPOOL_DIRTY));
653
654 err: (void)__bam_free(dbc, cp);
655 return (ret);
656 }
657
658 /*
659 * __bam_fixed --
660 * Build the real record for a fixed length put.
661 */
662 static int
__bam_fixed(dbc,dbt)663 __bam_fixed(dbc, dbt)
664 DBC *dbc;
665 DBT *dbt;
666 {
667 DB *dbp;
668 RECNO *rp;
669 int ret;
670
671 dbp = dbc->dbp;
672 rp = ((BTREE *)dbp->internal)->recno;
673
674 /*
675 * If database contains fixed-length records, and the record is long,
676 * return EINVAL.
677 */
678 if (dbt->size > rp->re_len)
679 return (EINVAL);
680
681 /*
682 * The caller checked to see if it was just right, so we know it's
683 * short. Pad it out. We use the record data return memory, it's
684 * only a short-term use.
685 */
686 if (dbc->rdata.ulen < rp->re_len) {
687 if ((ret = __os_realloc(&dbc->rdata.data, rp->re_len)) != 0) {
688 dbc->rdata.ulen = 0;
689 dbc->rdata.data = NULL;
690 return (ret);
691 }
692 dbc->rdata.ulen = rp->re_len;
693 }
694 memcpy(dbc->rdata.data, dbt->data, dbt->size);
695 memset((u_int8_t *)dbc->rdata.data + dbt->size,
696 rp->re_pad, rp->re_len - dbt->size);
697
698 /*
699 * Clean up our flags and other information just in case, and
700 * change the caller's DBT to reference our created record.
701 */
702 dbc->rdata.size = rp->re_len;
703 dbc->rdata.dlen = 0;
704 dbc->rdata.doff = 0;
705 dbc->rdata.flags = 0;
706 *dbt = dbc->rdata;
707
708 return (0);
709 }
710
711 /*
712 * __bam_partial --
713 * Build the real record for a partial put.
714 */
715 static int
__bam_partial(dbc,dbt,h,indx,nbytes,flags)716 __bam_partial(dbc, dbt, h, indx, nbytes, flags)
717 DBC *dbc;
718 DBT *dbt;
719 PAGE *h;
720 u_int32_t indx, nbytes, flags;
721 {
722 BKEYDATA *bk, tbk;
723 BOVERFLOW *bo;
724 DB *dbp;
725 DBT copy;
726 u_int32_t len, tlen;
727 u_int8_t *p;
728 int ret;
729
730 COMPQUIET(bo, NULL);
731
732 dbp = dbc->dbp;
733
734 /* We use the record data return memory, it's only a short-term use. */
735 if (dbc->rdata.ulen < nbytes) {
736 if ((ret = __os_realloc(&dbc->rdata.data, nbytes)) != 0) {
737 dbc->rdata.ulen = 0;
738 dbc->rdata.data = NULL;
739 return (ret);
740 }
741 dbc->rdata.ulen = nbytes;
742 }
743
744 /*
745 * We use nul bytes for any part of the record that isn't specified;
746 * get it over with.
747 */
748 memset(dbc->rdata.data, 0, nbytes);
749
750 /*
751 * In the next clauses, we need to do three things: a) set p to point
752 * to the place at which to copy the user's data, b) set tlen to the
753 * total length of the record, not including the bytes contributed by
754 * the user, and c) copy any valid data from an existing record.
755 */
756 if (LF_ISSET(BI_NEWKEY)) {
757 tlen = dbt->doff;
758 p = (u_int8_t *)dbc->rdata.data + dbt->doff;
759 goto ucopy;
760 }
761
762 /* Find the current record. */
763 if (indx < NUM_ENT(h)) {
764 bk = GET_BKEYDATA(h, indx + (TYPE(h) == P_LBTREE ? O_INDX : 0));
765 bo = (BOVERFLOW *)bk;
766 } else {
767 bk = &tbk;
768 B_TSET(bk->type, B_KEYDATA, 0);
769 bk->len = 0;
770 }
771 if (B_TYPE(bk->type) == B_OVERFLOW) {
772 /*
773 * In the case of an overflow record, we shift things around
774 * in the current record rather than allocate a separate copy.
775 */
776 memset(©, 0, sizeof(copy));
777 if ((ret = __db_goff(dbp, ©, bo->tlen,
778 bo->pgno, &dbc->rdata.data, &dbc->rdata.ulen)) != 0)
779 return (ret);
780
781 /* Skip any leading data from the original record. */
782 tlen = dbt->doff;
783 p = (u_int8_t *)dbc->rdata.data + dbt->doff;
784
785 /*
786 * Copy in any trailing data from the original record.
787 *
788 * If the original record was larger than the original offset
789 * plus the bytes being deleted, there is trailing data in the
790 * original record we need to preserve. If we aren't deleting
791 * the same number of bytes as we're inserting, copy it up or
792 * down, into place.
793 *
794 * Use memmove(), the regions may overlap.
795 */
796 if (bo->tlen > dbt->doff + dbt->dlen) {
797 len = bo->tlen - (dbt->doff + dbt->dlen);
798 if (dbt->dlen != dbt->size)
799 memmove(p + dbt->size, p + dbt->dlen, len);
800 tlen += len;
801 }
802 } else {
803 /* Copy in any leading data from the original record. */
804 memcpy(dbc->rdata.data,
805 bk->data, dbt->doff > bk->len ? bk->len : dbt->doff);
806 tlen = dbt->doff;
807 p = (u_int8_t *)dbc->rdata.data + dbt->doff;
808
809 /* Copy in any trailing data from the original record. */
810 len = dbt->doff + dbt->dlen;
811 if (bk->len > len) {
812 memcpy(p + dbt->size, bk->data + len, bk->len - len);
813 tlen += bk->len - len;
814 }
815 }
816
817 ucopy: /*
818 * Copy in the application provided data -- p and tlen must have been
819 * initialized above.
820 */
821 memcpy(p, dbt->data, dbt->size);
822 tlen += dbt->size;
823
824 /* Set the DBT to reference our new record. */
825 dbc->rdata.size = tlen;
826 dbc->rdata.dlen = 0;
827 dbc->rdata.doff = 0;
828 dbc->rdata.flags = 0;
829 *dbt = dbc->rdata;
830 return (0);
831 }
832