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