2 Unix SMB/CIFS implementation.
3 Database interface wrapper around red-black trees
4 Copyright (C) Volker Lendecke 2007, 2008
6 This program is free software; you can redistribute it and/or modify
7 it under the terms of the GNU General Public License as published by
8 the Free Software Foundation; either version 3 of the License, or
9 (at your option) any later version.
11 This program is distributed in the hope that it will be useful,
12 but WITHOUT ANY WARRANTY; without even the implied warranty of
13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
14 GNU General Public License for more details.
16 You should have received a copy of the GNU General Public License
17 along with this program. If not, see <http://www.gnu.org/licenses/>.
21 #include "dbwrap/dbwrap.h"
22 #include "dbwrap/dbwrap_private.h"
23 #include "dbwrap/dbwrap_rbt.h"
24 #include "../lib/util/rbtree.h"
26 #define DBWRAP_RBT_ALIGN(_size_) (((_size_)+15)&~15)
33 struct db_rbt_node
*node
;
36 /* The structure that ends up in the tree */
39 struct rb_node rb_node
;
40 size_t keysize
, valuesize
;
43 * key and value are appended implicitly, "data" is only here as a
44 * target for offsetof()
51 * Hide the ugly pointer calculations in a function
54 static struct db_rbt_node
*db_rbt2node(struct rb_node
*node
)
56 return (struct db_rbt_node
*)
57 ((char *)node
- offsetof(struct db_rbt_node
, rb_node
));
64 static int db_rbt_compare(TDB_DATA a
, TDB_DATA b
)
68 res
= memcmp(a
.dptr
, b
.dptr
, MIN(a
.dsize
, b
.dsize
));
70 if ((res
< 0) || ((res
== 0) && (a
.dsize
< b
.dsize
))) {
73 if ((res
> 0) || ((res
== 0) && (a
.dsize
> b
.dsize
))) {
80 * dissect a db_rbt_node into its implicit key and value parts
83 static void db_rbt_parse_node(struct db_rbt_node
*node
,
84 TDB_DATA
*key
, TDB_DATA
*value
)
86 key
->dptr
= ((uint8_t *)node
) + offsetof(struct db_rbt_node
, data
);
87 key
->dsize
= node
->keysize
;
88 value
->dptr
= key
->dptr
+ node
->keysize
;
89 value
->dsize
= node
->valuesize
;
92 static NTSTATUS
db_rbt_store(struct db_record
*rec
, TDB_DATA data
, int flag
)
94 struct db_rbt_ctx
*db_ctx
= talloc_get_type_abort(
95 rec
->db
->private_data
, struct db_rbt_ctx
);
96 struct db_rbt_rec
*rec_priv
= (struct db_rbt_rec
*)rec
->private_data
;
97 struct db_rbt_node
*node
;
100 struct rb_node
* parent
;
102 TDB_DATA this_key
, this_val
;
104 if (rec_priv
->node
!= NULL
) {
107 * The record was around previously
110 db_rbt_parse_node(rec_priv
->node
, &this_key
, &this_val
);
112 SMB_ASSERT(this_key
.dsize
== rec
->key
.dsize
);
113 SMB_ASSERT(memcmp(this_key
.dptr
, rec
->key
.dptr
,
114 this_key
.dsize
) == 0);
116 if (this_val
.dsize
>= data
.dsize
) {
118 * The new value fits into the old space
120 memcpy(this_val
.dptr
, data
.dptr
, data
.dsize
);
121 rec_priv
->node
->valuesize
= data
.dsize
;
126 node
= (struct db_rbt_node
*)talloc_size(db_ctx
,
127 offsetof(struct db_rbt_node
, data
) + rec
->key
.dsize
131 return NT_STATUS_NO_MEMORY
;
134 if (rec_priv
->node
!= NULL
) {
136 * We need to delete the key from the tree and start fresh,
137 * there's not enough space in the existing record
140 rb_erase(&rec_priv
->node
->rb_node
, &db_ctx
->tree
);
143 * Keep the existing node around for a while: If the record
144 * existed before, we reference the key data in there.
148 ZERO_STRUCT(node
->rb_node
);
150 node
->keysize
= rec
->key
.dsize
;
151 node
->valuesize
= data
.dsize
;
153 db_rbt_parse_node(node
, &this_key
, &this_val
);
155 memcpy(this_key
.dptr
, rec
->key
.dptr
, node
->keysize
);
156 TALLOC_FREE(rec_priv
->node
);
157 rec_priv
->node
= node
;
159 memcpy(this_val
.dptr
, data
.dptr
, node
->valuesize
);
162 p
= &db_ctx
->tree
.rb_node
;
165 struct db_rbt_node
*r
;
166 TDB_DATA search_key
, search_val
;
173 db_rbt_parse_node(r
, &search_key
, &search_val
);
175 res
= db_rbt_compare(this_key
, search_key
);
184 smb_panic("someone messed with the tree");
188 rb_link_node(&node
->rb_node
, parent
, p
);
189 rb_insert_color(&node
->rb_node
, &db_ctx
->tree
);
194 static NTSTATUS
db_rbt_delete(struct db_record
*rec
)
196 struct db_rbt_ctx
*db_ctx
= talloc_get_type_abort(
197 rec
->db
->private_data
, struct db_rbt_ctx
);
198 struct db_rbt_rec
*rec_priv
= (struct db_rbt_rec
*)rec
->private_data
;
200 if (rec_priv
->node
== NULL
) {
204 rb_erase(&rec_priv
->node
->rb_node
, &db_ctx
->tree
);
205 TALLOC_FREE(rec_priv
->node
);
209 struct db_rbt_search_result
{
212 struct db_rbt_node
* node
;
215 static bool db_rbt_search_internal(struct db_context
*db
, TDB_DATA key
,
216 struct db_rbt_search_result
*result
)
218 struct db_rbt_ctx
*ctx
= talloc_get_type_abort(
219 db
->private_data
, struct db_rbt_ctx
);
223 struct db_rbt_node
*r
= NULL
;
224 TDB_DATA search_key
, search_val
;
226 n
= ctx
->tree
.rb_node
;
233 db_rbt_parse_node(r
, &search_key
, &search_val
);
235 res
= db_rbt_compare(key
, search_key
);
248 if (result
!= NULL
) {
250 result
->key
= search_key
;
251 result
->val
= search_val
;
254 ZERO_STRUCT(*result
);
260 static struct db_record
*db_rbt_fetch_locked(struct db_context
*db_ctx
,
264 struct db_rbt_rec
*rec_priv
;
265 struct db_record
*result
;
268 struct db_rbt_search_result res
;
270 found
= db_rbt_search_internal(db_ctx
, key
, &res
);
273 * In this low-level routine, play tricks to reduce the number of
274 * tallocs to one. Not recommened for general use, but here it pays
278 size
= DBWRAP_RBT_ALIGN(sizeof(struct db_record
))
279 + sizeof(struct db_rbt_rec
);
283 * We need to keep the key around for later store
288 result
= (struct db_record
*)talloc_size(mem_ctx
, size
);
289 if (result
== NULL
) {
293 rec_priv
= (struct db_rbt_rec
*)
294 ((char *)result
+ DBWRAP_RBT_ALIGN(sizeof(struct db_record
)));
296 result
->store
= db_rbt_store
;
297 result
->delete_rec
= db_rbt_delete
;
298 result
->private_data
= rec_priv
;
300 rec_priv
->node
= res
.node
;
301 result
->value
= res
.val
;
304 result
->key
= res
.key
;
307 result
->key
.dptr
= (uint8_t *)
308 ((char *)rec_priv
+ sizeof(*rec_priv
));
309 result
->key
.dsize
= key
.dsize
;
310 memcpy(result
->key
.dptr
, key
.dptr
, key
.dsize
);
316 static int db_rbt_exists(struct db_context
*db
, TDB_DATA key
)
318 return db_rbt_search_internal(db
, key
, NULL
);
321 static int db_rbt_wipe(struct db_context
*db
)
323 struct db_rbt_ctx
*old_ctx
= talloc_get_type_abort(
324 db
->private_data
, struct db_rbt_ctx
);
325 struct db_rbt_ctx
*new_ctx
= talloc_zero(db
, struct db_rbt_ctx
);
326 if (new_ctx
== NULL
) {
329 db
->private_data
= new_ctx
;
330 talloc_free(old_ctx
);
334 static NTSTATUS
db_rbt_parse_record(struct db_context
*db
, TDB_DATA key
,
335 void (*parser
)(TDB_DATA key
, TDB_DATA data
,
339 struct db_rbt_search_result res
;
340 bool found
= db_rbt_search_internal(db
, key
, &res
);
343 return NT_STATUS_NOT_FOUND
;
345 parser(res
.key
, res
.val
, private_data
);
349 static int db_rbt_traverse_internal(struct rb_node
*n
,
350 int (*f
)(struct db_record
*db
,
352 void *private_data
, uint32_t* count
)
354 struct db_rbt_node
*r
;
355 struct db_record rec
;
362 ret
= db_rbt_traverse_internal(n
->rb_left
, f
, private_data
, count
);
369 db_rbt_parse_node(r
, &rec
.key
, &rec
.value
);
371 ret
= f(&rec
, private_data
);
377 return db_rbt_traverse_internal(n
->rb_right
, f
, private_data
, count
);
380 static int db_rbt_traverse(struct db_context
*db
,
381 int (*f
)(struct db_record
*db
,
385 struct db_rbt_ctx
*ctx
= talloc_get_type_abort(
386 db
->private_data
, struct db_rbt_ctx
);
389 int ret
= db_rbt_traverse_internal(ctx
->tree
.rb_node
, f
, private_data
, &count
);
393 if (count
> INT_MAX
) {
399 static int db_rbt_get_seqnum(struct db_context
*db
)
404 static int db_rbt_trans_dummy(struct db_context
*db
)
407 * Transactions are pretty pointless in-memory, just return success.
412 static void db_rbt_id(struct db_context
*db
, const uint8_t **id
, size_t *idlen
)
415 *idlen
= sizeof(struct db_context
*);
418 struct db_context
*db_open_rbt(TALLOC_CTX
*mem_ctx
)
420 struct db_context
*result
;
422 result
= talloc(mem_ctx
, struct db_context
);
424 if (result
== NULL
) {
428 result
->private_data
= talloc_zero(result
, struct db_rbt_ctx
);
430 if (result
->private_data
== NULL
) {
435 result
->fetch_locked
= db_rbt_fetch_locked
;
436 result
->try_fetch_locked
= NULL
;
437 result
->traverse
= db_rbt_traverse
;
438 result
->traverse_read
= db_rbt_traverse
;
439 result
->get_seqnum
= db_rbt_get_seqnum
;
440 result
->transaction_start
= db_rbt_trans_dummy
;
441 result
->transaction_commit
= db_rbt_trans_dummy
;
442 result
->transaction_cancel
= db_rbt_trans_dummy
;
443 result
->exists
= db_rbt_exists
;
444 result
->wipe
= db_rbt_wipe
;
445 result
->parse_record
= db_rbt_parse_record
;
446 result
->lock_order
= 0;
447 result
->id
= db_rbt_id
;
448 result
->stored_callback
= NULL
;