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
|
/*
Unix SMB/CIFS implementation.
Cache db contents for parse_record based on seqnum
Copyright (C) Volker Lendecke 2012
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 3 of the License, or
(at your option) any later version.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "includes.h"
#include "lib/dbwrap/dbwrap.h"
#include "lib/dbwrap/dbwrap_private.h"
#include "lib/dbwrap/dbwrap_rbt.h"
#include "lib/dbwrap/dbwrap_cache.h"
struct db_cache_ctx {
int seqnum;
struct db_context *backing;
struct db_context *positive;
struct db_context *negative;
};
static bool dbwrap_cache_validate(struct db_cache_ctx *ctx)
{
if (ctx->seqnum == dbwrap_get_seqnum(ctx->backing)) {
return true;
}
TALLOC_FREE(ctx->positive);
ctx->positive = db_open_rbt(ctx);
TALLOC_FREE(ctx->negative);
ctx->negative = db_open_rbt(ctx);
return ((ctx->positive != NULL) && (ctx->negative != NULL));
}
static NTSTATUS dbwrap_cache_parse_record(
struct db_context *db, TDB_DATA key,
void (*parser)(TDB_DATA key, TDB_DATA data, void *private_data),
void *private_data)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
TDB_DATA value;
NTSTATUS status;
if (!dbwrap_cache_validate(ctx)) {
return NT_STATUS_NO_MEMORY;
}
status = dbwrap_parse_record(ctx->positive, key, parser, private_data);
if (NT_STATUS_IS_OK(status)) {
return status;
}
if (dbwrap_exists(ctx->negative, key)) {
return NT_STATUS_NOT_FOUND;
}
status = dbwrap_fetch(ctx->backing, talloc_tos(), key, &value);
if (NT_STATUS_IS_OK(status)) {
dbwrap_store(ctx->positive, key, value, 0);
parser(key, value, private_data);
TALLOC_FREE(value.dptr);
return NT_STATUS_OK;
}
if (NT_STATUS_EQUAL(status, NT_STATUS_NOT_FOUND)) {
char c = '\0';
value.dptr = (uint8_t *)&c;
value.dsize = sizeof(c);
dbwrap_store(ctx->negative, key, value, 0);
return NT_STATUS_NOT_FOUND;
}
return status;
}
static struct db_record *dbwrap_cache_fetch_locked(
struct db_context *db, TALLOC_CTX *mem_ctx, TDB_DATA key)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
return dbwrap_fetch_locked(ctx->backing, mem_ctx, key);
}
static int dbwrap_cache_traverse(struct db_context *db,
int (*f)(struct db_record *rec,
void *private_data),
void *private_data)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
NTSTATUS status;
int ret;
status = dbwrap_traverse(ctx->backing, f, private_data, &ret);
if (!NT_STATUS_IS_OK(status)) {
return -1;
}
return ret;
}
static int dbwrap_cache_traverse_read(struct db_context *db,
int (*f)(struct db_record *rec,
void *private_data),
void *private_data)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
NTSTATUS status;
int ret;
status = dbwrap_traverse_read(ctx->backing, f, private_data, &ret);
if (!NT_STATUS_IS_OK(status)) {
return -1;
}
return ret;
}
static int dbwrap_cache_get_seqnum(struct db_context *db)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
return dbwrap_get_seqnum(ctx->backing);
}
static int dbwrap_cache_transaction_start(struct db_context *db)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
return dbwrap_transaction_start(ctx->backing);
}
static int dbwrap_cache_transaction_commit(struct db_context *db)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
return dbwrap_transaction_commit(ctx->backing);
}
static int dbwrap_cache_transaction_cancel(struct db_context *db)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
return dbwrap_transaction_cancel(ctx->backing);
}
static int dbwrap_cache_exists(struct db_context *db, TDB_DATA key)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
if (ctx->positive && dbwrap_exists(ctx->positive, key)) {
return true;
}
if (ctx->negative && dbwrap_exists(ctx->negative, key)) {
return false;
}
return dbwrap_exists(ctx->backing, key);
}
static void dbwrap_cache_id(struct db_context *db, const uint8_t **id,
size_t *idlen)
{
struct db_cache_ctx *ctx = talloc_get_type_abort(
db->private_data, struct db_cache_ctx);
dbwrap_db_id(ctx->backing, id, idlen);
}
struct db_context *db_open_cache(TALLOC_CTX *mem_ctx,
struct db_context *backing)
{
struct db_context *db;
struct db_cache_ctx *ctx;
db = talloc_zero(mem_ctx, struct db_context);
if (db == NULL) {
return NULL;
}
ctx = talloc_zero(db, struct db_cache_ctx);
if (ctx == NULL) {
TALLOC_FREE(db);
return NULL;
}
ctx->seqnum = -1;
ctx->backing = talloc_move(ctx, &backing);
db->private_data = ctx;
if (!dbwrap_cache_validate(ctx)) {
TALLOC_FREE(db);
return NULL;
}
db->fetch_locked = dbwrap_cache_fetch_locked;
db->traverse = dbwrap_cache_traverse;
db->traverse_read = dbwrap_cache_traverse_read;
db->get_seqnum = dbwrap_cache_get_seqnum;
db->transaction_start = dbwrap_cache_transaction_start;
db->transaction_commit = dbwrap_cache_transaction_commit;
db->transaction_cancel = dbwrap_cache_transaction_cancel;
db->parse_record = dbwrap_cache_parse_record;
db->exists = dbwrap_cache_exists;
db->id = dbwrap_cache_id;
db->name = dbwrap_name(ctx->backing);
db->hash_size = dbwrap_hash_size(ctx->backing);
return db;
}
|
