xref: /illumos-gate/usr/src/lib/krb5/plugins/kdb/db2/libdb2/btree/bt_put.c (revision 54925bf60766fbb4f1f2d7c843721406a7b7a3fb)
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
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 *
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