2 Unix SMB/CIFS implementation.
3 Database interface wrapper around red-black trees
4 Copyright (C) Volker Lendecke 2007
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/>.
28 struct db_rbt_ctx *db_ctx;
29 struct db_rbt_node *node;
32 /* The structure that ends up in the tree */
35 struct rb_node rb_node;
36 size_t keysize, valuesize;
39 * key and value are appended implicitly, "data" is only here as a
40 * target for offsetof()
47 * dissect a db_rbt_node into its implicit key and value parts
50 static void db_rbt_parse_node(struct db_rbt_node *node,
51 TDB_DATA *key, TDB_DATA *value)
53 key->dptr = ((uint8 *)node) + offsetof(struct db_rbt_node, data);
54 key->dsize = node->keysize;
55 value->dptr = key->dptr + node->keysize;
56 value->dsize = node->valuesize;
59 static NTSTATUS db_rbt_store(struct db_record *rec, TDB_DATA data, int flag)
61 struct db_rbt_rec *rec_priv = talloc_get_type_abort(
62 rec->private_data, struct db_rbt_rec);
64 struct db_rbt_node *node;
67 struct rb_node * parent;
69 TDB_DATA this_key, this_val;
71 bool del_old_keyval = false;
73 if (rec_priv->node != NULL) {
76 * The record was around previously
79 db_rbt_parse_node(rec_priv->node, &this_key, &this_val);
81 SMB_ASSERT(this_key.dsize == rec->key.dsize);
82 SMB_ASSERT(memcmp(this_key.dptr, rec->key.dptr,
83 this_key.dsize) == 0);
85 if (this_val.dsize >= data.dsize) {
87 * The new value fits into the old space
89 memcpy(this_val.dptr, data.dptr, data.dsize);
90 rec_priv->node->valuesize = data.dsize;
95 * We need to delete the key from the tree and start fresh,
96 * there's not enough space in the existing record
99 rb_erase(&rec_priv->node->rb_node, &rec_priv->db_ctx->tree);
100 del_old_keyval = true;
103 node = (struct db_rbt_node *)SMB_MALLOC(
104 offsetof(struct db_rbt_node, data) + rec->key.dsize
108 if (del_old_keyval) {
109 SAFE_FREE(rec_priv->node);
111 return NT_STATUS_NO_MEMORY;
114 ZERO_STRUCT(node->rb_node);
116 node->keysize = rec->key.dsize;
117 node->valuesize = data.dsize;
119 db_rbt_parse_node(node, &this_key, &this_val);
121 memcpy(this_key.dptr, rec->key.dptr, node->keysize);
122 memcpy(this_val.dptr, data.dptr, node->valuesize);
125 p = &rec_priv->db_ctx->tree.rb_node;
128 struct db_rbt_node *r;
129 TDB_DATA search_key, search_val;
134 r = (struct db_rbt_node *)
135 ((char *)(*p) - offsetof(struct db_rbt_node, rb_node));
137 db_rbt_parse_node(r, &search_key, &search_val);
139 res = memcmp(this_key.dptr, search_key.dptr,
140 MIN(this_key.dsize, search_key.dsize));
144 && (this_key.dsize < search_key.dsize))) {
149 && (this_key.dsize > search_key.dsize))) {
153 smb_panic("someone messed with the tree");
157 rb_link_node(&node->rb_node, parent, p);
158 rb_insert_color(&node->rb_node, &rec_priv->db_ctx->tree);
160 if (del_old_keyval) {
161 SAFE_FREE(rec_priv->node);
167 static NTSTATUS db_rbt_delete(struct db_record *rec)
169 struct db_rbt_rec *rec_priv = talloc_get_type_abort(
170 rec->private_data, struct db_rbt_rec);
172 if (rec_priv->node == NULL) {
176 rb_erase(&rec_priv->node->rb_node, &rec_priv->db_ctx->tree);
177 SAFE_FREE(rec_priv->node);
182 static struct db_record *db_rbt_fetch_locked(struct db_context *db_ctx,
186 struct db_rbt_ctx *ctx = talloc_get_type_abort(
187 db_ctx->private_data, struct db_rbt_ctx);
189 struct db_rbt_rec *rec_priv;
190 struct db_record *result;
193 result = talloc(mem_ctx, struct db_record);
195 if (result == NULL) {
199 rec_priv = talloc(result, struct db_rbt_rec);
201 if (rec_priv == NULL) {
206 rec_priv->db_ctx = ctx;
208 result->store = db_rbt_store;
209 result->delete_rec = db_rbt_delete;
210 result->private_data = rec_priv;
212 n = ctx->tree.rb_node;
215 struct db_rbt_node *r;
216 TDB_DATA search_key, search_val;
219 r = (struct db_rbt_node *)
220 ((char *)n - offsetof(struct db_rbt_node, rb_node));
222 db_rbt_parse_node(r, &search_key, &search_val);
224 res = memcmp(key.dptr, search_key.dptr,
225 MIN(key.dsize, search_key.dsize));
228 || ((res == 0) && (key.dsize < search_key.dsize))) {
232 || ((res == 0) && (key.dsize > search_key.dsize))) {
237 result->key = search_key;
238 result->value = search_val;
243 result->key.dsize = key.dsize;
244 result->key.dptr = (uint8_t *)talloc_memdup(
245 result, key.dptr, key.dsize);
247 if (result->key.dptr == NULL) {
252 rec_priv->node = NULL;
253 result->value.dsize = 0;
254 result->value.dptr = NULL;
258 static int db_rbt_fetch(struct db_context *db, TALLOC_CTX *mem_ctx,
259 TDB_DATA key, TDB_DATA *data)
261 struct db_record *rec;
263 if (!(rec = db->fetch_locked(db, mem_ctx, key))) {
267 data->dsize = rec->value.dsize;
268 data->dptr = (uint8 *)talloc_memdup(mem_ctx, rec->value.dptr,
275 static int db_rbt_traverse(struct db_context *db,
276 int (*f)(struct db_record *db,
283 static int db_rbt_get_seqnum(struct db_context *db)
288 struct db_context *db_open_rbt(TALLOC_CTX *mem_ctx)
290 struct db_context *result;
292 result = talloc(mem_ctx, struct db_context);
294 if (result == NULL) {
298 result->private_data = TALLOC_ZERO_P(result, struct db_rbt_ctx);
300 if (result->private_data == NULL) {
305 result->fetch_locked = db_rbt_fetch_locked;
306 result->fetch = db_rbt_fetch;
307 result->traverse = db_rbt_traverse;
308 result->traverse_read = db_rbt_traverse;
309 result->get_seqnum = db_rbt_get_seqnum;