From d0d261bec97595492a4d1da44121c6fb919ea2ed Mon Sep 17 00:00:00 2001
From: "godzilla80@gmx.net" <>
Date: Sat, 9 May 2009 12:56:23 +0000
Subject: Fixed Issue #141 - TDbCache performance: modify structure of indices,
new property 'FlushInterval' to control how often expired items will be
removed
---
framework/Caching/TDbCache.php | 165 +++++++++++++++++++++++++++++++++++++----
1 file changed, 149 insertions(+), 16 deletions(-)
(limited to 'framework/Caching/TDbCache.php')
diff --git a/framework/Caching/TDbCache.php b/framework/Caching/TDbCache.php
index 2c2c863d..376ff249 100644
--- a/framework/Caching/TDbCache.php
+++ b/framework/Caching/TDbCache.php
@@ -31,14 +31,23 @@ Prado::using('System.Data.TDbConnection');
* The cached data is stored in a table in the specified database.
* By default, the name of the table is called 'pradocache'. If the table does not
* exist in the database, it will be automatically created with the following structure:
- * (itemkey CHAR(128) PRIMARY KEY, value BLOB, expire INT)
+ *
+ * CREATE TABLE pradocache (itemkey CHAR(128), value BLOB, expire INT)
+ * CREATE INDEX IX_itemkey ON pradocache (itemkey)
+ * CREATE INDEX IX_expire ON pradocache (expire)
+ *
*
* Note, some DBMS might not support BLOB type. In this case, replace 'BLOB' with a suitable
* binary data type (e.g. LONGBLOB in MySQL, BYTEA in PostgreSQL.)
*
+ * Important: Make sure that the indices are non-unique!
+ *
* If you want to change the cache table name, or if you want to create the table by yourself,
* you may set {@link setCacheTableName CacheTableName} and {@link setAutoCreateCacheTable AutoCreateCacheTableName} properties.
*
+ * {@link setFlushInterval FlushInterval} control how often expired items will be removed from cache.
+ * If you prefer to remove expired items manualy e.g. via cronjob you can disable automatic deletion by setting FlushInterval to '0'.
+ *
* The following basic cache operations are implemented:
* - {@link get} : retrieve the value with a key (if any) from cache
* - {@link set} : store the value with a key into cache
@@ -91,6 +100,18 @@ class TDbCache extends TCache
* @var string name of the DB cache table
*/
private $_cacheTable='pradocache';
+ /**
+ * @var integer Interval expired items will be removed from cache
+ */
+ private $_flushInterval=60;
+ /**
+ * @var boolean
+ */
+ private $_cacheInitialized = false;
+ /**
+ * @var boolean
+ */
+ private $_createCheck= false;
/**
* @var boolean whether the cache DB table should be created automatically
*/
@@ -111,23 +132,70 @@ class TDbCache extends TCache
/**
* Initializes this module.
- * This method is required by the IModule interface. It checks if the DbFile
- * property is set, and creates a SQLiteDatabase instance for it.
- * The database or the cache table does not exist, they will be created.
- * Expired values are also deleted.
+ * This method is required by the IModule interface.
+ * attach {@link doInitializeCache} to TApplication.OnLoadStateComplete event
+ * attach {@link doFlushCacheExpired} to TApplication.OnSaveState event
+ *
* @param TXmlElement configuration for this module, can be null
- * @throws TConfigurationException if sqlite extension is not installed,
- * DbFile is set invalid, or any error happens during creating database or cache table.
*/
public function init($config)
{
+ $this -> getApplication() -> attachEventHandler('OnLoadStateComplete', array($this, 'doInitializeCache'));
+ $this -> getApplication() -> attachEventHandler('OnSaveState', array($this, 'doFlushCacheExpired'));
+ parent::init($config);
+ }
+
+ /**
+ * Event listener for TApplication.OnSaveState
+ * @return void
+ * @since 3.1.5
+ * @see flushCacheExpired
+ */
+ public function doFlushCacheExpired()
+ {
+ $this->flushCacheExpired(false);
+ }
+
+ /**
+ * Event listener for TApplication.OnLoadStateComplete
+ *
+ * @return void
+ * @since 3.1.5
+ * @see initializeCache
+ */
+ public function doInitializeCache()
+ {
+ $this->initializeCache();
+ }
+
+ /**
+ * Initialize TDbCache
+ *
+ * If {@link setAutoCreateCacheTable AutoCreateCacheTableName} is 'true' check existence of cache table
+ * and create table if does not exist.
+ *
+ * @return void
+ * @throws TConfigurationException if any error happens during creating database or cache table.
+ * @since 3.1.5
+ */
+ protected function initializeCache()
+ {
+ if($this->_cacheInitialized) return;
+
$db=$this->getDbConnection();
$db->setActive(true);
-
- $sql='DELETE FROM '.$this->_cacheTable.' WHERE expire<>0 AND expire<'.time();
try
{
- $db->createCommand($sql)->execute();
+ $key = 'TDbCache:' . $this->_cacheTable . ':created';
+ $this -> _createCheck = $this -> getApplication() -> getGlobalState($key, 0);
+
+ if($this->_autoCreate && !$this -> _createCheck) {
+ $sql='SELECT 1 FROM '.$this->_cacheTable.' WHERE 0';
+ $db->createCommand($sql)->queryScalar();
+
+ $this -> _createCheck = true;
+ $this -> getApplication() -> setGlobalState($key, time());
+ }
}
catch(Exception $e)
{
@@ -142,14 +210,69 @@ class TDbCache extends TCache
else
$blob='BLOB';
- $sql='CREATE TABLE '.$this->_cacheTable." (itemkey CHAR(128) PRIMARY KEY, value $blob, expire INT)";
+ $sql='CREATE TABLE '.$this->_cacheTable." (itemkey CHAR(128), value $blob, expire INT)";
+ $db->createCommand($sql)->execute();
+
+ $sql='CREATE INDEX IX_itemkey ON ' . $this->_cacheTable . ' (itemkey)';
$db->createCommand($sql)->execute();
+
+ $sql='CREATE INDEX IX_expire ON ' . $this->_cacheTable . ' (expire)';
+ $db->createCommand($sql)->execute();
+
+ $this -> _createCheck = true;
+ $this -> getApplication() -> setGlobalState($key, time());
}
else
throw new TConfigurationException('db_cachetable_inexistent',$this->_cacheTable);
}
+ $this->_cacheInitialized = true;
+ }
- parent::init($config);
+ /**
+ * Flush expired values from cache depending on {@link setFlushInterval FlushInterval}
+ * @param boolean override {@link setFlushInterval FlushInterval} and force deletion of expired items
+ * @return void
+ * @since 3.1.5
+ */
+ public function flushCacheExpired($force=false)
+ {
+ $interval = $this -> getFlushInterval();
+ if(!$force && $interval === 0) return;
+
+ $key = 'TDbCache:' . $this->_cacheTable . ':flushed';
+ $now = time();
+ $next = $interval + (integer)$this -> getApplication() -> getGlobalState($key, 0);
+
+ if($force || $next <= $now)
+ {
+ if(!$this->_cacheInitialized) $this->initializeCache();
+ $sql='DELETE FROM '.$this->_cacheTable.' WHERE expire<>0 AND expire<'.$now;
+ $this->getDbConnection()->createCommand($sql)->execute();
+ $this -> getApplication() -> setGlobalState($key, $now);
+ }
+ }
+
+ /**
+ * @return integer Interval in sec expired items will be removed from cache. Default to 60
+ * @since 3.1.5
+ */
+ public function getFlushInterval()
+ {
+ return $this->_flushInterval;
+ }
+
+ /**
+ * Sets interval expired items will be removed from cache
+ *
+ * To disable automatic deletion of expired items,
+ * e.g. for external flushing via cron you can set value to '0'
+ *
+ * @param integer Interval in sec
+ * @since 3.1.5
+ */
+ public function setFlushInterval($value)
+ {
+ $this->_flushInterval = (integer) $value;
}
/**
@@ -284,9 +407,17 @@ class TDbCache extends TCache
* Note, if {@link setAutoCreateCacheTable AutoCreateCacheTable} is false
* and you want to create the DB table manually by yourself,
* you need to make sure the DB table is of the following structure:
- * (itemkey CHAR(128) PRIMARY KEY, value BLOB, expire INT)
+ *
+ * CREATE TABLE pradocache (itemkey CHAR(128), value BLOB, expire INT)
+ * CREATE INDEX IX_itemkey ON pradocache (itemkey)
+ * CREATE INDEX IX_expire ON pradocache (expire)
+ *
+ *
* Note, some DBMS might not support BLOB type. In this case, replace 'BLOB' with a suitable
* binary data type (e.g. LONGBLOB in MySQL, BYTEA in PostgreSQL.)
+ *
+ * Important: Make sure that the indices are non-unique!
+ *
* @param string the name of the DB table to store cache content
* @see setAutoCreateCacheTable
*/
@@ -321,7 +452,8 @@ class TDbCache extends TCache
*/
protected function getValue($key)
{
- $sql='SELECT value FROM '.$this->_cacheTable.' WHERE itemkey=\''.$key.'\' AND (expire=0 OR expire>'.time().')';
+ if(!$this->_cacheInitialized) $this->initializeCache();
+ $sql='SELECT value FROM '.$this->_cacheTable.' WHERE itemkey=\''.$key.'\' AND (expire=0 OR expire>'.time().') ORDER BY expire DESC';
return $this->_db->createCommand($sql)->queryScalar();
}
@@ -351,6 +483,7 @@ class TDbCache extends TCache
*/
protected function addValue($key,$value,$expire)
{
+ if(!$this->_cacheInitialized) $this->initializeCache();
$expire=($expire<=0)?0:time()+$expire;
$sql="INSERT INTO {$this->_cacheTable} (itemkey,value,expire) VALUES(:key,:value,$expire)";
try
@@ -375,6 +508,7 @@ class TDbCache extends TCache
*/
protected function deleteValue($key)
{
+ if(!$this->_cacheInitialized) $this->initializeCache();
$command=$this->_db->createCommand("DELETE FROM {$this->_cacheTable} WHERE itemkey=:key");
$command->bindValue(':key',$key,PDO::PARAM_STR);
$command->execute();
@@ -387,9 +521,8 @@ class TDbCache extends TCache
*/
public function flush()
{
+ if(!$this->_cacheInitialized) $this->initializeCache();
$this->_db->createCommand("DELETE FROM {$this->_cacheTable}")->execute();
return true;
}
}
-
-?>
--
cgit v1.2.3