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
|
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996-2002
* Sleepycat Software. All rights reserved.
*/
#include "db_config.h"
#ifndef lint
static const char revid[] = "$Id: db_dup.c,v 11.32 2002/08/08 03:57:47 bostic Exp $";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#include <string.h>
#endif
#include "db_int.h"
#include "dbinc/db_page.h"
#include "dbinc/db_shash.h"
#include "dbinc/lock.h"
#include "dbinc/db_am.h"
/*
* __db_ditem --
* Remove an item from a page.
*
* PUBLIC: int __db_ditem __P((DBC *, PAGE *, u_int32_t, u_int32_t));
*/
int
__db_ditem(dbc, pagep, indx, nbytes)
DBC *dbc;
PAGE *pagep;
u_int32_t indx, nbytes;
{
DB *dbp;
DBT ldbt;
db_indx_t cnt, *inp, offset;
int ret;
u_int8_t *from;
dbp = dbc->dbp;
if (DBC_LOGGING(dbc)) {
ldbt.data = P_ENTRY(dbp, pagep, indx);
ldbt.size = nbytes;
if ((ret = __db_addrem_log(dbp, dbc->txn,
&LSN(pagep), 0, DB_REM_DUP, PGNO(pagep),
(u_int32_t)indx, nbytes, &ldbt, NULL, &LSN(pagep))) != 0)
return (ret);
} else
LSN_NOT_LOGGED(LSN(pagep));
/*
* If there's only a single item on the page, we don't have to
* work hard.
*/
if (NUM_ENT(pagep) == 1) {
NUM_ENT(pagep) = 0;
HOFFSET(pagep) = dbp->pgsize;
return (0);
}
inp = P_INP(dbp, pagep);
/*
* Pack the remaining key/data items at the end of the page. Use
* memmove(3), the regions may overlap.
*/
from = (u_int8_t *)pagep + HOFFSET(pagep);
DB_ASSERT((int)inp[indx] - HOFFSET(pagep) >= 0);
memmove(from + nbytes, from, inp[indx] - HOFFSET(pagep));
HOFFSET(pagep) += nbytes;
/* Adjust the indices' offsets. */
offset = inp[indx];
for (cnt = 0; cnt < NUM_ENT(pagep); ++cnt)
if (inp[cnt] < offset)
inp[cnt] += nbytes;
/* Shift the indices down. */
--NUM_ENT(pagep);
if (indx != NUM_ENT(pagep))
memmove(&inp[indx], &inp[indx + 1],
sizeof(db_indx_t) * (NUM_ENT(pagep) - indx));
return (0);
}
/*
* __db_pitem --
* Put an item on a page.
*
* PUBLIC: int __db_pitem
* PUBLIC: __P((DBC *, PAGE *, u_int32_t, u_int32_t, DBT *, DBT *));
*/
int
__db_pitem(dbc, pagep, indx, nbytes, hdr, data)
DBC *dbc;
PAGE *pagep;
u_int32_t indx;
u_int32_t nbytes;
DBT *hdr, *data;
{
DB *dbp;
BKEYDATA bk;
DBT thdr;
db_indx_t *inp;
int ret;
u_int8_t *p;
dbp = dbc->dbp;
if (nbytes > P_FREESPACE(dbp, pagep)) {
DB_ASSERT(nbytes <= P_FREESPACE(dbp, pagep));
return (EINVAL);
}
/*
* Put a single item onto a page. The logic figuring out where to
* insert and whether it fits is handled in the caller. All we do
* here is manage the page shuffling. We cheat a little bit in that
* we don't want to copy the dbt on a normal put twice. If hdr is
* NULL, we create a BKEYDATA structure on the page, otherwise, just
* copy the caller's information onto the page.
*
* This routine is also used to put entries onto the page where the
* entry is pre-built, e.g., during recovery. In this case, the hdr
* will point to the entry, and the data argument will be NULL.
*
* !!!
* There's a tremendous potential for off-by-one errors here, since
* the passed in header sizes must be adjusted for the structure's
* placeholder for the trailing variable-length data field.
*/
if (DBC_LOGGING(dbc)) {
if ((ret = __db_addrem_log(dbp, dbc->txn,
&LSN(pagep), 0, DB_ADD_DUP, PGNO(pagep),
(u_int32_t)indx, nbytes, hdr, data, &LSN(pagep))) != 0)
return (ret);
} else
LSN_NOT_LOGGED(LSN(pagep));
if (hdr == NULL) {
B_TSET(bk.type, B_KEYDATA, 0);
bk.len = data == NULL ? 0 : data->size;
thdr.data = &bk;
thdr.size = SSZA(BKEYDATA, data);
hdr = &thdr;
}
inp = P_INP(dbp, pagep);
/* Adjust the index table, then put the item on the page. */
if (indx != NUM_ENT(pagep))
memmove(&inp[indx + 1], &inp[indx],
sizeof(db_indx_t) * (NUM_ENT(pagep) - indx));
HOFFSET(pagep) -= nbytes;
inp[indx] = HOFFSET(pagep);
++NUM_ENT(pagep);
p = P_ENTRY(dbp, pagep, indx);
memcpy(p, hdr->data, hdr->size);
if (data != NULL)
memcpy(p + hdr->size, data->data, data->size);
return (0);
}
/*
* __db_relink --
* Relink around a deleted page.
*
* PUBLIC: int __db_relink __P((DBC *, u_int32_t, PAGE *, PAGE **, int));
*/
int
__db_relink(dbc, add_rem, pagep, new_next, needlock)
DBC *dbc;
u_int32_t add_rem;
PAGE *pagep, **new_next;
int needlock;
{
DB *dbp;
PAGE *np, *pp;
DB_LOCK npl, ppl;
DB_LSN *nlsnp, *plsnp, ret_lsn;
DB_MPOOLFILE *mpf;
int ret;
dbp = dbc->dbp;
np = pp = NULL;
LOCK_INIT(npl);
LOCK_INIT(ppl);
nlsnp = plsnp = NULL;
mpf = dbp->mpf;
ret = 0;
/*
* Retrieve and lock the one/two pages. For a remove, we may need
* two pages (the before and after). For an add, we only need one
* because, the split took care of the prev.
*/
if (pagep->next_pgno != PGNO_INVALID) {
if (needlock && (ret = __db_lget(dbc,
0, pagep->next_pgno, DB_LOCK_WRITE, 0, &npl)) != 0)
goto err;
if ((ret = mpf->get(mpf, &pagep->next_pgno, 0, &np)) != 0) {
__db_pgerr(dbp, pagep->next_pgno, ret);
goto err;
}
nlsnp = &np->lsn;
}
if (add_rem == DB_REM_PAGE && pagep->prev_pgno != PGNO_INVALID) {
if (needlock && (ret = __db_lget(dbc,
0, pagep->prev_pgno, DB_LOCK_WRITE, 0, &ppl)) != 0)
goto err;
if ((ret = mpf->get(mpf, &pagep->prev_pgno, 0, &pp)) != 0) {
__db_pgerr(dbp, pagep->next_pgno, ret);
goto err;
}
plsnp = &pp->lsn;
}
/* Log the change. */
if (DBC_LOGGING(dbc)) {
if ((ret = __db_relink_log(dbp, dbc->txn, &ret_lsn, 0, add_rem,
pagep->pgno, &pagep->lsn, pagep->prev_pgno, plsnp,
pagep->next_pgno, nlsnp)) != 0)
goto err;
} else
LSN_NOT_LOGGED(ret_lsn);
if (np != NULL)
np->lsn = ret_lsn;
if (pp != NULL)
pp->lsn = ret_lsn;
if (add_rem == DB_REM_PAGE)
pagep->lsn = ret_lsn;
/*
* Modify and release the two pages.
*
* !!!
* The parameter new_next gets set to the page following the page we
* are removing. If there is no following page, then new_next gets
* set to NULL.
*/
if (np != NULL) {
if (add_rem == DB_ADD_PAGE)
np->prev_pgno = pagep->pgno;
else
np->prev_pgno = pagep->prev_pgno;
if (new_next == NULL)
ret = mpf->put(mpf, np, DB_MPOOL_DIRTY);
else {
*new_next = np;
ret = mpf->set(mpf, np, DB_MPOOL_DIRTY);
}
if (ret != 0)
goto err;
if (needlock)
(void)__TLPUT(dbc, npl);
} else if (new_next != NULL)
*new_next = NULL;
if (pp != NULL) {
pp->next_pgno = pagep->next_pgno;
if ((ret = mpf->put(mpf, pp, DB_MPOOL_DIRTY)) != 0)
goto err;
if (needlock)
(void)__TLPUT(dbc, ppl);
}
return (0);
err: if (np != NULL)
(void)mpf->put(mpf, np, 0);
if (needlock)
(void)__TLPUT(dbc, npl);
if (pp != NULL)
(void)mpf->put(mpf, pp, 0);
if (needlock)
(void)__TLPUT(dbc, ppl);
return (ret);
}
|
