* Exim - an Internet mail transport agent *
*************************************************/
-/* Copyright (c) University of Cambridge 1995 - 2009 */
+/* Copyright (c) University of Cambridge 1995 - 2015 */
/* See the file NOTICE for conditions of use and distribution. */
/* A set of functions to search databases in various formats. An open
{
tree_node *t = (tree_node *)handle;
search_cache *c = (search_cache *)(t->data.ptr);
+expiring_data *e;
uschar *data = NULL;
int search_type = t->name[0] - '0';
int old_pool = store_pool;
/* Look up the data for the key, unless it is already in the cache for this
file. No need to check c->item_cache for NULL, tree_search will do so. */
-if ((t = tree_search(c->item_cache, keystring)) == NULL)
+if ( (t = tree_search(c->item_cache, keystring))
+ && (!(e = t->data.ptr)->expiry || e->expiry > time(NULL))
+ )
+ { /* Data was in the cache already; set the pointer from the tree node */
+ data = e->ptr;
+ DEBUG(D_lookup) debug_printf("cached data used for lookup of %s%s%s\n",
+ keystring,
+ filename ? US"\n in " : US"", filename ? filename : US"");
+ }
+else
{
- BOOL do_cache = TRUE;
+ uint do_cache = UINT_MAX;
int keylength = Ustrlen(keystring);
DEBUG(D_lookup)
{
- if (filename != NULL)
- debug_printf("file lookup required for %s\n in %s\n",
- keystring, filename);
- else
- debug_printf("database lookup required for %s\n", keystring);
+ if (t) debug_printf("cached data found but past valid time; ");
+ debug_printf("%s lookup required for %s%s%s\n",
+ filename ? US"file" : US"database",
+ keystring,
+ filename ? US"\n in " : US"", filename ? filename : US"");
}
/* Call the code for the different kinds of search. DEFER is handled
if (lookup_list[search_type]->find(c->handle, filename, keystring, keylength,
&data, &search_error_message, &do_cache) == DEFER)
- {
search_find_defer = TRUE;
- }
/* A record that has been found is now in data, which is either NULL
or points to a bit of dynamic store. Cache the result of the lookup if
else if (do_cache)
{
int len = keylength + 1;
- t = store_get(sizeof(tree_node) + len);
- memcpy(t->name, keystring, len);
- t->data.ptr = data;
- tree_insertnode(&c->item_cache, t);
+
+ if (t) /* Previous, out-of-date cache entry. Update with the */
+ { /* new result and forget the old one */
+ e->expiry = do_cache == UINT_MAX ? 0 : time(NULL)+do_cache;
+ e->ptr = data;
+ }
+ else
+ {
+ e = store_get(sizeof(expiring_data) + sizeof(tree_node) + len);
+ e->expiry = do_cache == UINT_MAX ? 0 : time(NULL)+do_cache;
+ e->ptr = data;
+ t = (tree_node *)(e+1);
+ memcpy(t->name, keystring, len);
+ t->data.ptr = e;
+ tree_insertnode(&c->item_cache, t);
+ }
}
/* If caching was disabled, empty the cache tree. We just set the cache
}
}
-/* Data was in the cache already; set the pointer from the tree node */
-
-else
- {
- data = US t->data.ptr;
- DEBUG(D_lookup) debug_printf("cached data used for lookup of %s%s%s\n",
- keystring,
- (filename == NULL)? US"" : US"\n in ",
- (filename == NULL)? US"" : filename);
- }
-
-/* Debug: output the answer */
-
DEBUG(D_lookup)
{
- if (data == NULL)
- {
- if (search_find_defer) debug_printf("lookup deferred: %s\n",
- search_error_message);
- else debug_printf("lookup failed\n");
- }
- else debug_printf("lookup yielded: %s\n", data);
+ if (data)
+ debug_printf("lookup yielded: %s\n", data);
+ else if (search_find_defer)
+ debug_printf("lookup deferred: %s\n", search_error_message);
+ else debug_printf("lookup failed\n");
}
/* Return it in new dynamic store in the regular pool */
store_pool = old_pool;
-return (data == NULL)? NULL : string_copy(data);
+return data ? string_copy(data) : NULL;
}