+/* Read string-string key-values from a map. Returns the value associated with
+ * 'key', if found, or NULL */
+static const char *
+read_map_string_column(const struct ovsdb_row *row, const char *column_name,
+ const char *key)
+{
+ const struct ovsdb_datum *datum;
+ union ovsdb_atom *atom_key = NULL, *atom_value = NULL;
+ size_t i;
+
+ datum = get_datum((struct ovsdb_row *) row, column_name, OVSDB_TYPE_STRING,
+ OVSDB_TYPE_STRING, UINT_MAX);
+
+ if (!datum) {
+ return NULL;
+ }
+
+ for (i = 0; i < datum->n; i++) {
+ atom_key = &datum->keys[i];
+ if (!strcmp(atom_key->string, key)){
+ atom_value = &datum->values[i];
+ break;
+ }
+ }
+
+ return atom_value ? atom_value->string : NULL;
+}
+