diff options
Diffstat (limited to 'engine/lib/database.php')
| -rw-r--r-- | engine/lib/database.php | 67 |
1 files changed, 33 insertions, 34 deletions
diff --git a/engine/lib/database.php b/engine/lib/database.php index 2b348366d..3553d787d 100644 --- a/engine/lib/database.php +++ b/engine/lib/database.php @@ -12,17 +12,19 @@ /** * Query cache for all queries. * - * Each query and its results are stored in this array as: + * Each query and its results are stored in this cache as: * <code> - * $DB_QUERY_CACHE[$query] => array(result1, result2, ... resultN) + * $DB_QUERY_CACHE[query hash] => array(result1, result2, ... resultN) * </code> + * @see elgg_query_runner() for details on the hash. * - * @warning be array this var may be an array or ElggStaticVariableCache depending on when called :( + * @warning Elgg used to set this as an empty array to turn off the cache * - * @global ElggStaticVariableCache|array $DB_QUERY_CACHE + * @global ElggLRUCache|null $DB_QUERY_CACHE + * @access private */ global $DB_QUERY_CACHE; -$DB_QUERY_CACHE = array(); +$DB_QUERY_CACHE = null; /** * Queries to be executed upon shutdown. @@ -40,6 +42,7 @@ $DB_QUERY_CACHE = array(); * </code> * * @global array $DB_DELAYED_QUERIES + * @access private */ global $DB_DELAYED_QUERIES; $DB_DELAYED_QUERIES = array(); @@ -51,6 +54,7 @@ $DB_DELAYED_QUERIES = array(); * $dblink as $dblink[$name] => resource. Use get_db_link($name) to retrieve it. * * @global resource[] $dblink + * @access private */ global $dblink; $dblink = array(); @@ -61,6 +65,7 @@ $dblink = array(); * Each call to the database increments this counter. * * @global integer $dbcalls + * @access private */ global $dbcalls; $dbcalls = 0; @@ -123,9 +128,8 @@ function establish_db_link($dblinkname = "readwrite") { // Set up cache if global not initialized and query cache not turned off if ((!$DB_QUERY_CACHE) && (!$db_cache_off)) { - // @todo everywhere else this is assigned to array(), making it dangerous to call - // object methods on this. We should consider making this an plain array - $DB_QUERY_CACHE = new ElggStaticVariableCache('db_query_cache'); + // @todo if we keep this cache in 1.9, expose the size as a config parameter + $DB_QUERY_CACHE = new ElggLRUCache(200); } } @@ -400,11 +404,9 @@ function elgg_query_runner($query, $callback = null, $single = false) { // Is cached? if ($DB_QUERY_CACHE) { - $cached_query = $DB_QUERY_CACHE[$hash]; - - if ($cached_query !== FALSE) { + if (isset($DB_QUERY_CACHE[$hash])) { elgg_log("DB query $query results returned from cache (hash: $hash)", 'NOTICE'); - return $cached_query; + return $DB_QUERY_CACHE[$hash]; } } @@ -456,19 +458,12 @@ function elgg_query_runner($query, $callback = null, $single = false) { * @access private */ function insert_data($query) { - global $DB_QUERY_CACHE; elgg_log("DB query $query", 'NOTICE'); $dblink = get_db_link('write'); - // Invalidate query cache - if ($DB_QUERY_CACHE) { - /* @var ElggStaticVariableCache $DB_QUERY_CACHE */ - $DB_QUERY_CACHE->clear(); - } - - elgg_log("Query cache invalidated", 'NOTICE'); + _elgg_invalidate_query_cache(); if (execute_query("$query", $dblink)) { return mysql_insert_id($dblink); @@ -488,18 +483,12 @@ function insert_data($query) { * @access private */ function update_data($query) { - global $DB_QUERY_CACHE; elgg_log("DB query $query", 'NOTICE'); $dblink = get_db_link('write'); - // Invalidate query cache - if ($DB_QUERY_CACHE) { - /* @var ElggStaticVariableCache $DB_QUERY_CACHE */ - $DB_QUERY_CACHE->clear(); - elgg_log("Query cache invalidated", 'NOTICE'); - } + _elgg_invalidate_query_cache(); if (execute_query("$query", $dblink)) { return TRUE; @@ -519,18 +508,12 @@ function update_data($query) { * @access private */ function delete_data($query) { - global $DB_QUERY_CACHE; elgg_log("DB query $query", 'NOTICE'); $dblink = get_db_link('write'); - // Invalidate query cache - if ($DB_QUERY_CACHE) { - /* @var ElggStaticVariableCache $DB_QUERY_CACHE */ - $DB_QUERY_CACHE->clear(); - elgg_log("Query cache invalidated", 'NOTICE'); - } + _elgg_invalidate_query_cache(); if (execute_query("$query", $dblink)) { return mysql_affected_rows($dblink); @@ -539,6 +522,22 @@ function delete_data($query) { return FALSE; } +/** + * Invalidate the query cache + * + * @access private + */ +function _elgg_invalidate_query_cache() { + global $DB_QUERY_CACHE; + if ($DB_QUERY_CACHE instanceof ElggLRUCache) { + $DB_QUERY_CACHE->clear(); + elgg_log("Query cache invalidated", 'NOTICE'); + } elseif ($DB_QUERY_CACHE) { + // In case someone sets the cache to an array and primes it with data + $DB_QUERY_CACHE = array(); + elgg_log("Query cache invalidated", 'NOTICE'); + } +} /** * Return tables matching the database prefix {@link $CONFIG->dbprefix}% in the currently |