source3/lib/talloc_dict.c

   1 /*
   2    Unix SMB/CIFS implementation.
   3    Little dictionary style data structure based on dbwrap_rbt
   4    Copyright (C) Volker Lendecke 2009
   5
   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.
  10
  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.
  15
  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/>.
  18 */
  19
  20 #include "includes.h"
  21 #include "dbwrap.h"
  22 #include "talloc_dict.h"
  23
  24 struct talloc_dict {
  25         struct db_context *db;
  26 };
  27
  28 struct talloc_dict *talloc_dict_init(TALLOC_CTX *mem_ctx)
  29 {
  30         struct talloc_dict *result;
  31
  32         result = talloc(mem_ctx, struct talloc_dict);
  33         if (result == NULL) {
  34                 return NULL;
  35         }
  36         result->db = db_open_rbt(result);
  37         if (result->db == NULL) {
  38                 TALLOC_FREE(result);
  39                 return NULL;
  40         }
  41         return result;
  42 }
  43
  44 /*
  45  * Add a talloced object to the dict. Nulls out the pointer to indicate that
  46  * the talloc ownership has been taken. If an object for "key" already exists,
  47  * the existing object is talloc_free()ed and overwritten by the new
  48  * object. If "data" is NULL, object for key "key" is deleted. Return false
  49  * for "no memory".
  50  */
  51
  52 bool talloc_dict_set(struct talloc_dict *dict, DATA_BLOB key, void *pdata)
  53 {
  54         struct db_record *rec;
  55         NTSTATUS status = NT_STATUS_OK;
  56         void *data = *(void **)pdata;
  57
  58         rec = dict->db->fetch_locked(dict->db, talloc_tos(),
  59                                      make_tdb_data(key.data, key.length));
  60         if (rec == NULL) {
  61                 return false;
  62         }
  63         if (rec->value.dsize != 0) {
  64                 void *old_data;
  65                 if (rec->value.dsize != sizeof(void *)) {
  66                         TALLOC_FREE(rec);
  67                         return false;
  68                 }
  69                 old_data = *(void **)(rec->value.dptr);
  70                 TALLOC_FREE(old_data);
  71                 if (data == NULL) {
  72                         status = rec->delete_rec(rec);
  73                 }
  74         }
  75         if (data != NULL) {
  76                 void *mydata = talloc_move(dict->db, &data);
  77                 *(void **)pdata = NULL;
  78                 status = rec->store(rec, make_tdb_data((uint8_t *)&mydata,
  79                                                        sizeof(mydata)), 0);
  80         }
  81         TALLOC_FREE(rec);
  82         return NT_STATUS_IS_OK(status);
  83 }
  84
  85 /*
  86  * Fetch a talloced object. If "mem_ctx!=NULL", talloc_move the object there
  87  * and delete it from the dict.
  88  */
  89
  90 void *talloc_dict_fetch(struct talloc_dict *dict, DATA_BLOB key,
  91                         TALLOC_CTX *mem_ctx)
  92 {
  93         struct db_record *rec;
  94         void *result;
  95
  96         rec = dict->db->fetch_locked(dict->db, talloc_tos(),
  97                                      make_tdb_data(key.data, key.length));
  98         if (rec == NULL) {
  99                 return NULL;
 100         }
 101         if (rec->value.dsize != sizeof(void *)) {
 102                 TALLOC_FREE(rec);
 103                 return NULL;
 104         }
 105         result = *(void **)rec->value.dptr;
 106
 107         if (mem_ctx != NULL) {
 108                 NTSTATUS status;
 109                 status = rec->delete_rec(rec);
 110                 if (!NT_STATUS_IS_OK(status)) {
 111                         TALLOC_FREE(rec);
 112                         return NULL;
 113                 }
 114                 result = talloc_move(mem_ctx, &result);
 115         }
 116
 117         return result;
 118 }
 119
 120 struct talloc_dict_traverse_state {
 121         int (*fn)(DATA_BLOB key, void *data, void *private_data);
 122         void *private_data;
 123 };
 124
 125 static int talloc_dict_traverse_fn(struct db_record *rec, void *private_data)
 126 {
 127         struct talloc_dict_traverse_state *state =
 128                 (struct talloc_dict_traverse_state *)private_data;
 129
 130         if (rec->value.dsize != sizeof(void *)) {
 131                 return -1;
 132         }
 133         return state->fn(data_blob_const(rec->key.dptr, rec->key.dsize),
 134                          *(void **)rec->value.dptr, state->private_data);
 135 }
 136
 137 /*
 138  * Traverse a talloc_dict. If "fn" returns non-null, quit the traverse
 139  */
 140
 141 int talloc_dict_traverse(struct talloc_dict *dict,
 142                          int (*fn)(DATA_BLOB key, void *data,
 143                                    void *private_data),
 144                          void *private_data)
 145 {
 146         struct talloc_dict_traverse_state state;
 147         state.fn = fn;
 148         state.private_data = private_data;
 149         return dict->db->traverse(dict->db, talloc_dict_traverse_fn, &state);
 150 }