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-rw-r--r--engine/lib/database.php95
1 files changed, 51 insertions, 44 deletions
diff --git a/engine/lib/database.php b/engine/lib/database.php
index 7d90b30b8..a7949788d 100644
--- a/engine/lib/database.php
+++ b/engine/lib/database.php
@@ -12,15 +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.
*
- * @global array $DB_QUERY_CACHE
+ * @warning Elgg used to set this as an empty array to turn off the 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.
@@ -38,6 +42,7 @@ $DB_QUERY_CACHE = array();
* </code>
*
* @global array $DB_DELAYED_QUERIES
+ * @access private
*/
global $DB_DELAYED_QUERIES;
$DB_DELAYED_QUERIES = array();
@@ -48,7 +53,8 @@ $DB_DELAYED_QUERIES = array();
* Each database link created with establish_db_link($name) is stored in
* $dblink as $dblink[$name] => resource. Use get_db_link($name) to retrieve it.
*
- * @global array $dblink
+ * @global resource[] $dblink
+ * @access private
*/
global $dblink;
$dblink = array();
@@ -59,6 +65,7 @@ $dblink = array();
* Each call to the database increments this counter.
*
* @global integer $dbcalls
+ * @access private
*/
global $dbcalls;
$dbcalls = 0;
@@ -72,11 +79,12 @@ $dbcalls = 0;
* resource. eg "read", "write", or "readwrite".
*
* @return void
+ * @throws DatabaseException
* @access private
*/
function establish_db_link($dblinkname = "readwrite") {
// Get configuration, and globalise database link
- global $CONFIG, $dblink, $DB_QUERY_CACHE, $dbcalls;
+ global $CONFIG, $dblink, $DB_QUERY_CACHE;
if ($dblinkname != "readwrite" && isset($CONFIG->db[$dblinkname])) {
if (is_array($CONFIG->db[$dblinkname])) {
@@ -120,7 +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)) {
- $DB_QUERY_CACHE = new ElggStaticVariableCache('db_query_cache');
+ // @todo if we keep this cache in 1.9, expose the size as a config parameter
+ $DB_QUERY_CACHE = new ElggLRUCache(200);
}
}
@@ -134,7 +143,7 @@ function establish_db_link($dblinkname = "readwrite") {
* @access private
*/
function setup_db_connections() {
- global $CONFIG, $dblink;
+ global $CONFIG;
if (!empty($CONFIG->db->split)) {
establish_db_link('read');
@@ -197,7 +206,7 @@ function db_delayedexecution_shutdown_hook() {
*
* @param string $dblinktype The type of link we want: "read", "write" or "readwrite".
*
- * @return object Database link
+ * @return resource Database link
* @access private
*/
function get_db_link($dblinktype) {
@@ -216,7 +225,7 @@ function get_db_link($dblinktype) {
/**
* Execute an EXPLAIN for $query.
*
- * @param str $query The query to explain
+ * @param string $query The query to explain
* @param mixed $link The database link resource to user.
*
* @return mixed An object of the query's result, or FALSE
@@ -240,14 +249,14 @@ function explain_query($query, $link) {
* {@link $dbcalls} is incremented and the query is saved into the {@link $DB_QUERY_CACHE}.
*
* @param string $query The query
- * @param link $dblink The DB link
+ * @param resource $dblink The DB link
*
- * @return The result of mysql_query()
+ * @return resource result of mysql_query()
* @throws DatabaseException
* @access private
*/
function execute_query($query, $dblink) {
- global $CONFIG, $dbcalls;
+ global $dbcalls;
if ($query == NULL) {
throw new DatabaseException(elgg_echo('DatabaseException:InvalidQuery'));
@@ -275,7 +284,7 @@ function execute_query($query, $dblink) {
* the raw result from {@link mysql_query()}.
*
* @param string $query The query to execute
- * @param resource $dblink The database link to use or the link type (read | write)
+ * @param resource|string $dblink The database link to use or the link type (read | write)
* @param string $handler A callback function to pass the results array to
*
* @return true
@@ -386,20 +395,18 @@ function get_data_row($query, $callback = "") {
* @access private
*/
function elgg_query_runner($query, $callback = null, $single = false) {
- global $CONFIG, $DB_QUERY_CACHE;
+ global $DB_QUERY_CACHE;
// Since we want to cache results of running the callback, we need to
// need to namespace the query with the callback and single result request.
- // http://trac.elgg.org/ticket/4049
+ // https://github.com/elgg/elgg/issues/4049
$hash = (string)$callback . (int)$single . $query;
// Is cached?
if ($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];
}
}
@@ -410,7 +417,7 @@ function elgg_query_runner($query, $callback = null, $single = false) {
// test for callback once instead of on each iteration.
// @todo check profiling to see if this needs to be broken out into
- // explicit cases instead of checking in the interation.
+ // explicit cases instead of checking in the iteration.
$is_callable = is_callable($callback);
while ($row = mysql_fetch_object($result)) {
if ($is_callable) {
@@ -451,18 +458,12 @@ function elgg_query_runner($query, $callback = null, $single = false) {
* @access private
*/
function insert_data($query) {
- global $CONFIG, $DB_QUERY_CACHE;
elgg_log("DB query $query", 'NOTICE');
$dblink = get_db_link('write');
- // Invalidate query cache
- if ($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);
@@ -472,7 +473,7 @@ function insert_data($query) {
}
/**
- * Update a row in the database.
+ * Update the database.
*
* @note Altering the DB invalidates all queries in {@link $DB_QUERY_CACHE}.
*
@@ -482,17 +483,12 @@ function insert_data($query) {
* @access private
*/
function update_data($query) {
- global $CONFIG, $DB_QUERY_CACHE;
elgg_log("DB query $query", 'NOTICE');
$dblink = get_db_link('write');
- // Invalidate query cache
- if ($DB_QUERY_CACHE) {
- $DB_QUERY_CACHE->clear();
- elgg_log("Query cache invalidated", 'NOTICE');
- }
+ _elgg_invalidate_query_cache();
if (execute_query("$query", $dblink)) {
return TRUE;
@@ -502,7 +498,7 @@ function update_data($query) {
}
/**
- * Remove a row from the database.
+ * Remove data from the database.
*
* @note Altering the DB invalidates all queries in {@link $DB_QUERY_CACHE}.
*
@@ -512,17 +508,12 @@ function update_data($query) {
* @access private
*/
function delete_data($query) {
- global $CONFIG, $DB_QUERY_CACHE;
elgg_log("DB query $query", 'NOTICE');
$dblink = get_db_link('write');
- // Invalidate query cache
- if ($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);
@@ -531,6 +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 $CONFIG->dbprefix}% in the currently
@@ -638,7 +645,7 @@ function run_sql_script($scriptlocation) {
$statement = str_replace("prefix_", $CONFIG->dbprefix, $statement);
if (!empty($statement)) {
try {
- $result = update_data($statement);
+ update_data($statement);
} catch (DatabaseException $e) {
$errors[] = $e->getMessage();
}
@@ -661,7 +668,7 @@ function run_sql_script($scriptlocation) {
/**
* Format a query string for logging
- *
+ *
* @param string $query Query string
* @return string
* @access private
generated by cgit v1.2.3 (git 2.39.1) at 2024-04-23 12:53:09 +0000