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