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/dbwrap.h"
  22 #include "dbwrap/dbwrap_rbt.h"
  23 #include "talloc_dict.h"
  24 #include "util_tdb.h"
  25
  26 struct talloc_dict {
  27         struct db_context *db;
  28 };
  29
  30 struct talloc_dict *talloc_dict_init(TALLOC_CTX *mem_ctx)
  31 {
  32         struct talloc_dict *result;
  33
  34         result = talloc(mem_ctx, struct talloc_dict);
  35         if (result == NULL) {
  36                 return NULL;
  37         }
  38         result->db = db_open_rbt(result);
  39         if (result->db == NULL) {
  40                 TALLOC_FREE(result);
  41                 return NULL;
  42         }
  43         return result;
  44 }
  45
  46 /*
  47  * Add a talloced object to the dict. Nulls out the pointer to indicate that
  48  * the talloc ownership has been taken. If an object for "key" already exists,
  49  * the existing object is talloc_free()ed and overwritten by the new
  50  * object. If "data" is NULL, object for key "key" is deleted. Return false
  51  * for "no memory".
  52  */
  53
  54 bool talloc_dict_set(struct talloc_dict *dict, DATA_BLOB key, void *pdata)
  55 {
  56         struct db_record *rec;
  57         NTSTATUS status = NT_STATUS_OK;
  58         void *data = *(void **)pdata;
  59         TDB_DATA value;
  60
  61         rec = dbwrap_fetch_locked(dict->db, talloc_tos(),
  62                                   make_tdb_data(key.data, key.length));
  63         if (rec == NULL) {
  64                 return false;
  65         }
  66
  67         value = dbwrap_record_get_value(rec);
  68
  69         if (value.dsize != 0) {
  70                 void *old_data;
  71                 if (value.dsize != sizeof(void *)) {
  72                         TALLOC_FREE(rec);
  73                         return false;
  74                 }
  75                 old_data = *(void **)(value.dptr);
  76                 TALLOC_FREE(old_data);
  77                 if (data == NULL) {
  78                         status = dbwrap_record_delete(rec);
  79                 }
  80         }
  81         if (data != NULL) {
  82                 void *mydata = talloc_move(dict->db, &data);
  83                 *(void **)pdata = NULL;
  84                 status = dbwrap_record_store(rec,
  85                                              make_tdb_data((uint8_t *)&mydata,
  86                                              sizeof(mydata)), 0);
  87         }
  88         TALLOC_FREE(rec);
  89         return NT_STATUS_IS_OK(status);
  90 }
  91
  92 /*
  93  * Fetch a talloced object. If "mem_ctx!=NULL", talloc_move the object there
  94  * and delete it from the dict.
  95  */
  96
  97 void *talloc_dict_fetch(struct talloc_dict *dict, DATA_BLOB key,
  98                         TALLOC_CTX *mem_ctx)
  99 {
 100         struct db_record *rec;
 101         void *result;
 102         TDB_DATA value;
 103
 104         rec = dbwrap_fetch_locked(dict->db, talloc_tos(),
 105                                   make_tdb_data(key.data, key.length));
 106         if (rec == NULL) {
 107                 return NULL;
 108         }
 109
 110         value = dbwrap_record_get_value(rec);
 111         if (value.dsize != sizeof(void *)) {
 112                 TALLOC_FREE(rec);
 113                 return NULL;
 114         }
 115         result = *(void **)value.dptr;
 116
 117         if (mem_ctx != NULL) {
 118                 NTSTATUS status;
 119                 status = dbwrap_record_delete(rec);
 120                 if (!NT_STATUS_IS_OK(status)) {
 121                         TALLOC_FREE(rec);
 122                         return NULL;
 123                 }
 124                 result = talloc_move(mem_ctx, &result);
 125         }
 126
 127         return result;
 128 }
 129
 130 struct talloc_dict_traverse_state {
 131         int (*fn)(DATA_BLOB key, void *data, void *private_data);
 132         void *private_data;
 133 };
 134
 135 static int talloc_dict_traverse_fn(struct db_record *rec, void *private_data)
 136 {
 137         TDB_DATA key;
 138         TDB_DATA value;
 139         struct talloc_dict_traverse_state *state =
 140                 (struct talloc_dict_traverse_state *)private_data;
 141
 142         key = dbwrap_record_get_key(rec);
 143         value = dbwrap_record_get_value(rec);
 144
 145         if (value.dsize != sizeof(void *)) {
 146                 return -1;
 147         }
 148         return state->fn(data_blob_const(key.dptr, key.dsize),
 149                          *(void **)value.dptr, state->private_data);
 150 }
 151
 152 /*
 153  * Traverse a talloc_dict. If "fn" returns non-null, quit the traverse
 154  */
 155
 156 int talloc_dict_traverse(struct talloc_dict *dict,
 157                          int (*fn)(DATA_BLOB key, void *data,
 158                                    void *private_data),
 159                          void *private_data)
 160 {
 161         struct talloc_dict_traverse_state state;
 162         NTSTATUS status;
 163         int count = 0;
 164
 165         state.fn = fn;
 166         state.private_data = private_data;
 167         status = dbwrap_traverse(dict->db, talloc_dict_traverse_fn, &state,
 168                                  &count);
 169         if (!NT_STATUS_IS_OK(status)) {
 170                 return -1;
 171         } else {
 172                 return count;
 173         }
 174 }