1 #pragma ident "%Z%%M% %I% %E% SMI"
2
3 /*-
4 * Copyright (c) 1990, 1993, 1994
5 * The Regents of the University of California. All rights reserved.
6 *
7 * This code is derived from software contributed to Berkeley by
8 * Mike Olson.
9 *
10 * Redistribution and use in source and binary forms, with or without
11 * modification, are permitted provided that the following conditions
12 * are met:
13 * 1. Redistributions of source code must retain the above copyright
14 * notice, this list of conditions and the following disclaimer.
15 * 2. Redistributions in binary form must reproduce the above copyright
16 * notice, this list of conditions and the following disclaimer in the
17 * documentation and/or other materials provided with the distribution.
18 * 3. All advertising materials mentioning features or use of this software
19 * must display the following acknowledgement:
20 * This product includes software developed by the University of
21 * California, Berkeley and its contributors.
22 * 4. Neither the name of the University nor the names of its contributors
23 * may be used to endorse or promote products derived from this software
24 * without specific prior written permission.
25 *
26 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
27 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
28 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
29 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
30 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
31 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
32 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
33 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
34 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
35 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * SUCH DAMAGE.
37 */
38
39 #if defined(LIBC_SCCS) && !defined(lint)
40 static char sccsid[] = "@(#)bt_put.c 8.8 (Berkeley) 7/26/94";
41 #endif /* LIBC_SCCS and not lint */
42
43 #include <sys/types.h>
44
45 #include <errno.h>
46 #include <stdio.h>
47 #include <stdlib.h>
48 #include <string.h>
49
50 #include "db-int.h"
51 #include "btree.h"
52
53 static EPG *bt_fast __P((BTREE *, const DBT *, const DBT *, int *));
54
55 /*
56 * __BT_PUT -- Add a btree item to the tree.
57 *
58 * Parameters:
59 * dbp: pointer to access method
60 * key: key
61 * data: data
62 * flag: R_NOOVERWRITE
63 *
64 * Returns:
65 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the
66 * tree and R_NOOVERWRITE specified.
67 */
68 int
__bt_put(dbp,key,data,flags)69 __bt_put(dbp, key, data, flags)
70 const DB *dbp;
71 DBT *key;
72 const DBT *data;
73 u_int flags;
74 {
75 BTREE *t;
76 DBT tkey, tdata;
77 EPG *e = 0;
78 PAGE *h;
79 indx_t idx, nxtindex;
80 db_pgno_t pg;
81 u_int32_t nbytes;
82 int dflags, exact, status;
83 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE];
84
85 t = dbp->internal;
86
87 /* Toss any page pinned across calls. */
88 if (t->bt_pinned != NULL) {
89 mpool_put(t->bt_mp, t->bt_pinned, 0);
90 t->bt_pinned = NULL;
91 }
92
93 /* Check for change to a read-only tree. */
94 if (F_ISSET(t, B_RDONLY)) {
95 errno = EPERM;
96 return (RET_ERROR);
97 }
98
99 switch (flags) {
100 case 0:
101 case R_NOOVERWRITE:
102 break;
103 case R_CURSOR:
104 /*
105 * If flags is R_CURSOR, put the cursor. Must already
106 * have started a scan and not have already deleted it.
107 */
108 if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
109 !F_ISSET(&t->bt_cursor,
110 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE))
111 break;
112 /* FALLTHROUGH */
113 default:
114 errno = EINVAL;
115 return (RET_ERROR);
116 }
117
118 /*
119 * If the key/data pair won't fit on a page, store it on overflow
120 * pages. Only put the key on the overflow page if the pair are
121 * still too big after moving the data to an overflow page.
122 *
123 * XXX
124 * If the insert fails later on, the overflow pages aren't recovered.
125 */
126 dflags = 0;
127 if (key->size + data->size > t->bt_ovflsize) {
128 if (key->size > t->bt_ovflsize) {
129 u_int32_t yuck_this_is_gross_code;
130 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR)
131 return (RET_ERROR);
132 tkey.data = kb;
133 tkey.size = NOVFLSIZE;
134 memmove(kb, &pg, sizeof(db_pgno_t));
135 yuck_this_is_gross_code = key->size;
136 if (yuck_this_is_gross_code != key->size)
137 abort ();
138 memmove(kb + sizeof(db_pgno_t),
139 &yuck_this_is_gross_code, sizeof(u_int32_t));
140 dflags |= P_BIGKEY;
141 key = &tkey;
142 }
143 if (key->size + data->size > t->bt_ovflsize) {
144 u_int32_t yuck_this_is_gross_code = data->size;
145 if (__ovfl_put(t, data, &pg) == RET_ERROR)
146 return (RET_ERROR);
147 tdata.data = db;
148 tdata.size = NOVFLSIZE;
149 memmove(db, &pg, sizeof(db_pgno_t));
150 if (yuck_this_is_gross_code != data->size)
151 abort ();
152 memmove(db + sizeof(db_pgno_t),
153 &yuck_this_is_gross_code, sizeof(u_int32_t));
154 dflags |= P_BIGDATA;
155 data = &tdata;
156 }
157 if (key->size + data->size > t->bt_ovflsize)
158 goto storekey;
159 }
160
161 /* Replace the cursor. */
162 if (flags == R_CURSOR) {
163 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL)
164 return (RET_ERROR);
165 idx = t->bt_cursor.pg.index;
166 goto delete;
167 }
168
169 /*
170 * Find the key to delete, or, the location at which to insert.
171 * Bt_fast and __bt_search both pin the returned page.
172 */
173 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL)
174 if ((e = __bt_search(t, key, &exact)) == NULL)
175 return (RET_ERROR);
176 h = e->page;
177 idx = e->index;
178
179 /*
180 * Add the key/data pair to the tree. If an identical key is already
181 * in the tree, and R_NOOVERWRITE is set, an error is returned. If
182 * R_NOOVERWRITE is not set, the key is either added (if duplicates are
183 * permitted) or an error is returned.
184 */
185 switch (flags) {
186 case R_NOOVERWRITE:
187 if (!exact)
188 break;
189 mpool_put(t->bt_mp, h, 0);
190 return (RET_SPECIAL);
191 default:
192 if (!exact || !F_ISSET(t, B_NODUPS))
193 break;
194 /*
195 * !!!
196 * Note, the delete may empty the page, so we need to put a
197 * new entry into the page immediately.
198 */
199 delete: if (__bt_dleaf(t, key, h, idx) == RET_ERROR) {
200 mpool_put(t->bt_mp, h, 0);
201 return (RET_ERROR);
202 }
203 break;
204 }
205
206 /*
207 * If not enough room, or the user has put a ceiling on the number of
208 * keys permitted in the page, split the page. The split code will
209 * insert the key and data and unpin the current page. If inserting
210 * into the offset array, shift the pointers up.
211 */
212 nbytes = NBLEAFDBT(key->size, data->size);
213 if (h->upper - h->lower < nbytes + sizeof(indx_t)) {
214 if ((status = __bt_split(t, h, key,
215 data, dflags, nbytes, idx)) != RET_SUCCESS)
216 return (status);
217 goto success;
218 }
219
220 if (idx < (nxtindex = NEXTINDEX(h)))
221 memmove(h->linp + idx + 1, h->linp + idx,
222 (nxtindex - idx) * sizeof(indx_t));
223 h->lower += sizeof(indx_t);
224
225 h->linp[idx] = h->upper -= nbytes;
226 dest = (char *)h + h->upper;
227 WR_BLEAF(dest, key, data, dflags);
228
229 /* If the cursor is on this page, adjust it as necessary. */
230 if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
231 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) &&
232 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx)
233 ++t->bt_cursor.pg.index;
234
235 if (t->bt_order == NOT) {
236 if (h->nextpg == P_INVALID) {
237 if (idx == NEXTINDEX(h) - 1) {
238 t->bt_order = FORWARD;
239 t->bt_last.index = idx;
240 t->bt_last.pgno = h->pgno;
241 }
242 } else if (h->prevpg == P_INVALID) {
243 if (idx == 0) {
244 t->bt_order = BACK;
245 t->bt_last.index = 0;
246 t->bt_last.pgno = h->pgno;
247 }
248 }
249 }
250
251 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
252
253 success:
254 if (flags == R_SETCURSOR)
255 __bt_setcur(t, e->page->pgno, e->index);
256
257 F_SET(t, B_MODIFIED);
258 return (RET_SUCCESS);
259 }
260
261 #ifdef STATISTICS
262 u_long bt_cache_hit, bt_cache_miss;
263 #endif
264
265 /*
266 * BT_FAST -- Do a quick check for sorted data.
267 *
268 * Parameters:
269 * t: tree
270 * key: key to insert
271 *
272 * Returns:
273 * EPG for new record or NULL if not found.
274 */
275 static EPG *
bt_fast(t,key,data,exactp)276 bt_fast(t, key, data, exactp)
277 BTREE *t;
278 const DBT *key, *data;
279 int *exactp;
280 {
281 PAGE *h;
282 u_int32_t nbytes;
283 int cmp;
284
285 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) {
286 t->bt_order = NOT;
287 return (NULL);
288 }
289 t->bt_cur.page = h;
290 t->bt_cur.index = t->bt_last.index;
291
292 /*
293 * If won't fit in this page or have too many keys in this page,
294 * have to search to get split stack.
295 */
296 nbytes = NBLEAFDBT(key->size, data->size);
297 if (h->upper - h->lower < nbytes + sizeof(indx_t))
298 goto miss;
299
300 if (t->bt_order == FORWARD) {
301 if (t->bt_cur.page->nextpg != P_INVALID)
302 goto miss;
303 if (t->bt_cur.index != NEXTINDEX(h) - 1)
304 goto miss;
305 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0)
306 goto miss;
307 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index;
308 } else {
309 if (t->bt_cur.page->prevpg != P_INVALID)
310 goto miss;
311 if (t->bt_cur.index != 0)
312 goto miss;
313 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0)
314 goto miss;
315 t->bt_last.index = 0;
316 }
317 *exactp = cmp == 0;
318 #ifdef STATISTICS
319 ++bt_cache_hit;
320 #endif
321 return (&t->bt_cur);
322
323 miss:
324 #ifdef STATISTICS
325 ++bt_cache_miss;
326 #endif
327 t->bt_order = NOT;
328 mpool_put(t->bt_mp, h, 0);
329 return (NULL);
330 }
331