1 /* $NetBSD: bt_put.c,v 1.22 2016/09/24 21:31:25 christos Exp $ */
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. Neither the name of the University nor the names of its contributors
19 * may be used to endorse or promote products derived from this software
20 * without specific prior written permission.
21 *
22 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32 * SUCH DAMAGE.
33 */
34
35 #if HAVE_NBTOOL_CONFIG_H
36 #include "nbtool_config.h"
37 #endif
38
39 #include <sys/cdefs.h>
40 __RCSID("$NetBSD: bt_put.c,v 1.22 2016/09/24 21:31:25 christos Exp $");
41
42 #include "namespace.h"
43 #include <sys/types.h>
44
45 #include <assert.h>
46 #include <errno.h>
47 #include <stdio.h>
48 #include <stdlib.h>
49 #include <string.h>
50
51 #include <db.h>
52 #include "btree.h"
53
54 static EPG *bt_fast(BTREE *, const DBT *, const DBT *, int *);
55
56 /*
57 * __BT_PUT -- Add a btree item to the tree.
58 *
59 * Parameters:
60 * dbp: pointer to access method
61 * key: key
62 * data: data
63 * flag: R_NOOVERWRITE
64 *
65 * Returns:
66 * RET_ERROR, RET_SUCCESS and RET_SPECIAL if the key is already in the
67 * tree and R_NOOVERWRITE specified.
68 */
69 int
__bt_put(const DB * dbp,DBT * key,const DBT * data,u_int flags)70 __bt_put(const DB *dbp, DBT *key, const DBT *data, u_int flags)
71 {
72 BTREE *t;
73 DBT tkey, tdata;
74 EPG *e = NULL; /* pacify gcc */
75 PAGE *h;
76 indx_t idx, nxtindex;
77 pgno_t pg;
78 uint32_t nbytes, temp;
79 int dflags, exact, status;
80 char *dest, db[NOVFLSIZE], kb[NOVFLSIZE];
81
82 t = dbp->internal;
83
84 /* Toss any page pinned across calls. */
85 if (t->bt_pinned != NULL) {
86 mpool_put(t->bt_mp, t->bt_pinned, 0);
87 t->bt_pinned = NULL;
88 }
89
90 /* Check for change to a read-only tree. */
91 if (F_ISSET(t, B_RDONLY)) {
92 errno = EPERM;
93 return (RET_ERROR);
94 }
95
96 switch (flags) {
97 case 0:
98 case R_NOOVERWRITE:
99 break;
100 case R_CURSOR:
101 /*
102 * If flags is R_CURSOR, put the cursor. Must already
103 * have started a scan and not have already deleted it.
104 */
105 if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
106 !F_ISSET(&t->bt_cursor,
107 CURS_ACQUIRE | CURS_AFTER | CURS_BEFORE))
108 break;
109 /* FALLTHROUGH */
110 default:
111 errno = EINVAL;
112 return (RET_ERROR);
113 }
114
115 /*
116 * If the key/data pair won't fit on a page, store it on overflow
117 * pages. Only put the key on the overflow page if the pair are
118 * still too big after moving the data to an overflow page.
119 *
120 * XXX
121 * If the insert fails later on, the overflow pages aren't recovered.
122 */
123 dflags = 0;
124 if (key->size + data->size > t->bt_ovflsize) {
125 if (key->size > t->bt_ovflsize) {
126 storekey: if (__ovfl_put(t, key, &pg) == RET_ERROR)
127 return (RET_ERROR);
128 tkey.data = kb;
129 tkey.size = NOVFLSIZE;
130 memmove(kb, &pg, sizeof(pg));
131 memmove(kb + sizeof(pgno_t),
132 &key->size, sizeof(uint32_t));
133 dflags |= P_BIGKEY;
134 key = &tkey;
135 }
136 if (key->size + data->size > t->bt_ovflsize) {
137 if (__ovfl_put(t, data, &pg) == RET_ERROR)
138 return (RET_ERROR);
139 tdata.data = db;
140 tdata.size = NOVFLSIZE;
141 memmove(db, &pg, sizeof(pg));
142 _DBFIT(data->size, uint32_t);
143 temp = (uint32_t)data->size;
144 (void)memmove(db + sizeof(pgno_t),
145 &temp, sizeof(uint32_t));
146 dflags |= P_BIGDATA;
147 data = &tdata;
148 }
149 if (key->size + data->size > t->bt_ovflsize)
150 goto storekey;
151 }
152
153 /* Replace the cursor. */
154 if (flags == R_CURSOR) {
155 if ((h = mpool_get(t->bt_mp, t->bt_cursor.pg.pgno, 0)) == NULL)
156 return (RET_ERROR);
157 idx = t->bt_cursor.pg.index;
158 goto delete;
159 }
160
161 /*
162 * Find the key to delete, or, the location at which to insert.
163 * Bt_fast and __bt_search both pin the returned page.
164 */
165 if (t->bt_order == NOT || (e = bt_fast(t, key, data, &exact)) == NULL)
166 if ((e = __bt_search(t, key, &exact)) == NULL)
167 return (RET_ERROR);
168 h = e->page;
169 idx = e->index;
170
171 /*
172 * Add the key/data pair to the tree. If an identical key is already
173 * in the tree, and R_NOOVERWRITE is set, an error is returned. If
174 * R_NOOVERWRITE is not set, the key is either added (if duplicates are
175 * permitted) or an error is returned.
176 */
177 switch (flags) {
178 case R_NOOVERWRITE:
179 if (!exact)
180 break;
181 mpool_put(t->bt_mp, h, 0);
182 return (RET_SPECIAL);
183 default:
184 if (!exact || !F_ISSET(t, B_NODUPS))
185 break;
186 /*
187 * !!!
188 * Note, the delete may empty the page, so we need to put a
189 * new entry into the page immediately.
190 */
191 delete: if (__bt_dleaf(t, key, h, (u_int)idx) == RET_ERROR) {
192 mpool_put(t->bt_mp, h, 0);
193 return (RET_ERROR);
194 }
195 break;
196 }
197
198 /*
199 * If not enough room, or the user has put a ceiling on the number of
200 * keys permitted in the page, split the page. The split code will
201 * insert the key and data and unpin the current page. If inserting
202 * into the offset array, shift the pointers up.
203 */
204 nbytes = NBLEAFDBT(key->size, data->size);
205 if ((uint32_t)h->upper - (uint32_t)h->lower < nbytes + sizeof(indx_t)) {
206 if ((status = __bt_split(t, h, key,
207 data, dflags, nbytes, (u_int)idx)) != RET_SUCCESS)
208 return (status);
209 goto success;
210 }
211
212 if (idx < (nxtindex = NEXTINDEX(h)))
213 memmove(h->linp + idx + 1, h->linp + idx,
214 (nxtindex - idx) * sizeof(indx_t));
215 h->lower += sizeof(indx_t);
216
217 h->linp[idx] = h->upper -= nbytes;
218 dest = (char *)(void *)h + h->upper;
219 WR_BLEAF(dest, key, data, dflags);
220
221 /* If the cursor is on this page, adjust it as necessary. */
222 if (F_ISSET(&t->bt_cursor, CURS_INIT) &&
223 !F_ISSET(&t->bt_cursor, CURS_ACQUIRE) &&
224 t->bt_cursor.pg.pgno == h->pgno && t->bt_cursor.pg.index >= idx)
225 ++t->bt_cursor.pg.index;
226
227 if (t->bt_order == NOT) {
228 if (h->nextpg == P_INVALID) {
229 if (idx == NEXTINDEX(h) - 1) {
230 t->bt_order = FORWARD;
231 t->bt_last.index = idx;
232 t->bt_last.pgno = h->pgno;
233 }
234 } else if (h->prevpg == P_INVALID) {
235 if (idx == 0) {
236 t->bt_order = BACK;
237 t->bt_last.index = 0;
238 t->bt_last.pgno = h->pgno;
239 }
240 }
241 }
242
243 mpool_put(t->bt_mp, h, MPOOL_DIRTY);
244
245 success:
246 if (flags == R_SETCURSOR)
247 __bt_setcur(t, e->page->pgno, (u_int)e->index);
248
249 F_SET(t, B_MODIFIED);
250 return (RET_SUCCESS);
251 }
252
253 #ifdef STATISTICS
254 unsigned long bt_cache_hit, bt_cache_miss;
255 #endif
256
257 /*
258 * BT_FAST -- Do a quick check for sorted data.
259 *
260 * Parameters:
261 * t: tree
262 * key: key to insert
263 *
264 * Returns:
265 * EPG for new record or NULL if not found.
266 */
267 static EPG *
bt_fast(BTREE * t,const DBT * key,const DBT * data,int * exactp)268 bt_fast(BTREE *t, const DBT *key, const DBT *data, int *exactp)
269 {
270 PAGE *h;
271 uint32_t nbytes;
272 int cmp;
273
274 if ((h = mpool_get(t->bt_mp, t->bt_last.pgno, 0)) == NULL) {
275 t->bt_order = NOT;
276 return (NULL);
277 }
278 t->bt_cur.page = h;
279 t->bt_cur.index = t->bt_last.index;
280
281 /*
282 * If won't fit in this page or have too many keys in this page,
283 * have to search to get split stack.
284 */
285 nbytes = NBLEAFDBT(key->size, data->size);
286 if ((uint32_t)h->upper - (uint32_t)h->lower < nbytes + sizeof(indx_t))
287 goto miss;
288
289 if (t->bt_order == FORWARD) {
290 if (t->bt_cur.page->nextpg != P_INVALID)
291 goto miss;
292 if (t->bt_cur.index != NEXTINDEX(h) - 1)
293 goto miss;
294 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) < 0)
295 goto miss;
296 t->bt_last.index = cmp ? ++t->bt_cur.index : t->bt_cur.index;
297 } else {
298 if (t->bt_cur.page->prevpg != P_INVALID)
299 goto miss;
300 if (t->bt_cur.index != 0)
301 goto miss;
302 if ((cmp = __bt_cmp(t, key, &t->bt_cur)) > 0)
303 goto miss;
304 t->bt_last.index = 0;
305 }
306 *exactp = cmp == 0;
307 #ifdef STATISTICS
308 ++bt_cache_hit;
309 #endif
310 return (&t->bt_cur);
311
312 miss:
313 #ifdef STATISTICS
314 ++bt_cache_miss;
315 #endif
316 t->bt_order = NOT;
317 mpool_put(t->bt_mp, h, 0);
318 return (NULL);
319 }
320