Moved caching to function so it can be easily replaced

git-svn-id: https://code.elgg.org/elgg/trunk@2390 36083f99-b078-4883-b0ff-0f9b5a30f544

3 files changed, 40 insertions, 22 deletions

diff --git a/engine/lib/cache.php b/engine/lib/cache.php
index 399552785..7523a0a68 100644
--- a/engine/lib/cache.php
+++ b/engine/lib/cache.php
@@ -167,7 +167,7 @@
 		 *
 		 * @var unknown_type
 		 */
-		private static $__cache;
+		public static $__cache;
 		
 		/**
 		 * ID of a cache to use.
@@ -385,4 +385,26 @@
 			}
 		}
 	}
+	
+	
+	/**
+	 * A simple function that selects the default caching engine. 
+	 * 
+	 * This function provides a central way to get a cache for storing local variables.
+	 * 
+	 * TODO: Do this better & allow plugin overrides.
+	 *
+	 * @param string $namespace Define which memory space to use.
+	 */
+	function select_default_memcache($namespace = "default")
+	{
+		// hook out to the world ? (can't if using as object cache)
+		
+		// if nothing then use shared memory cache.
+		
+		// TODO: Use memcache if available?
+		
+		return new ElggStaticVariableCache($namespace);
+		
+	}
 ?>
\ No newline at end of file
diff --git a/engine/lib/database.php b/engine/lib/database.php
index e9f3667f7..0e5b43106 100644
--- a/engine/lib/database.php
+++ b/engine/lib/database.php
@@ -23,7 +23,7 @@
 		function establish_db_link($dblinkname = "readwrite") {

 			

 			// Get configuration, and globalise database link

-		        global $CONFIG, $dblink;

+		        global $CONFIG, $dblink, $DB_QUERY_CACHE;

 		        

 		        if (!isset($dblink)) {

 		        	$dblink = array();

@@ -54,7 +54,10 @@
 		        	throw new DatabaseException(sprintf(elgg_echo('DatabaseException:WrongCredentials'), $CONFIG->dbuser, $CONFIG->dbhost, $CONFIG->debug ? $CONFIG->dbpass : "****"));

 		        if (!mysql_select_db($CONFIG->dbname, $dblink[$dblinkname]))

 		        	throw new DatabaseException(sprintf(elgg_echo('DatabaseException:NoConnect'), $CONFIG->dbname));

-			

+			
+		    // Set up cache
+		    	if (!$DB_QUERY_CACHE) 
+		    		$DB_QUERY_CACHE = select_default_memcache('db_query_cache'); //array();

 		}

 		

 	/**

@@ -158,7 +161,6 @@
             

             $resultarray = array();

             
-            if (!$DB_QUERY_CACHE) $DB_QUERY_CACHE = new ElggStaticVariableCache('db_query_cache'); //array();
        		if (isset($DB_QUERY_CACHE[$query])) {
        			if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
             		error_log ("$query results returned from cache");
@@ -209,7 +211,6 @@
             

             $dblink = get_db_link('read');

             
-            if (!$DB_QUERY_CACHE) $DB_QUERY_CACHE = new ElggStaticVariableCache('db_query_cache'); //array();
         	if (isset($DB_QUERY_CACHE[$query])) {
         		if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
             		error_log ("$query results returned from cache");
@@ -265,10 +266,7 @@
             }
             
             // Invalidate query cache
-            if ($DB_QUERY_CACHE)
-            	$DB_QUERY_CACHE->clear();
-            else
-            	$DB_QUERY_CACHE = new ElggStaticVariableCache('db_query_cache'); //array();
+            if ($DB_QUERY_CACHE) $DB_QUERY_CACHE->clear();
             if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
             	error_log("Query cache invalidated");

             

@@ -304,10 +302,7 @@
             }
             
             // Invalidate query cache
-            if ($DB_QUERY_CACHE)
-            	$DB_QUERY_CACHE->clear();
-            else
-            	$DB_QUERY_CACHE = new ElggStaticVariableCache('db_query_cache'); //array();
+            if ($DB_QUERY_CACHE) $DB_QUERY_CACHE->clear();
             if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
             	error_log("Query cache invalidated");

             

@@ -344,10 +339,7 @@
             }

             
             // Invalidate query cache
-            if ($DB_QUERY_CACHE)
-            	$DB_QUERY_CACHE->clear();
-            else
-            	$DB_QUERY_CACHE = new ElggStaticVariableCache('db_query_cache'); //array();
+            if ($DB_QUERY_CACHE) $DB_QUERY_CACHE->clear();
             if ((isset($CONFIG->debug)) && ($CONFIG->debug==true))
             	error_log("Query cache invalidated");
             

diff --git a/engine/lib/entities.php b/engine/lib/entities.php
index 1daa46a00..d1c4ba3eb 100644
--- a/engine/lib/entities.php
+++ b/engine/lib/entities.php
@@ -921,7 +921,7 @@
 		global $ENTITY_CACHE;
 		
 		if (!$ENTITY_CACHE)
-			$ENTITY_CACHE = new ElggStaticVariableCache('entity_cache'); // TODO: Replace with memcache?
+			$ENTITY_CACHE = select_default_memcache('entity_cache'); // TODO: Replace with memcache?
 	}
 	
 	/**
@@ -1013,7 +1013,8 @@
 
 		if ($result) {
 			
-			if (!$SUBTYPE_CACHE) $SUBTYPE_CACHE = new ElggStaticVariableCache('subtype_cache');
+			if (!$SUBTYPE_CACHE) 
+				$SUBTYPE_CACHE = select_default_memcache('subtype_cache');
 			
 			$SUBTYPE_CACHE[$result->id] = $result;
 			return $result->id;
@@ -1043,7 +1044,8 @@
 		$result = get_data_row("SELECT * from {$CONFIG->dbprefix}entity_subtypes where id=$subtype_id");
 		if ($result) {
 			
-			if (!$SUBTYPE_CACHE) $SUBTYPE_CACHE = new ElggStaticVariableCache('subtype_cache');
+			if (!$SUBTYPE_CACHE) 
+				$SUBTYPE_CACHE = select_default_memcache('subtype_cache');
 			
 			$SUBTYPE_CACHE[$subtype_id] = $result;
 			return $result->subtype;
@@ -1071,7 +1073,8 @@
 		$result = get_data_row("SELECT * from {$CONFIG->dbprefix}entity_subtypes where type='$type' and subtype='$subtype'");
 		if ($result) {
 			
-			if (!$SUBTYPE_CACHE) $SUBTYPE_CACHE = new ElggStaticVariableCache('subtype_cache');
+			if (!$SUBTYPE_CACHE) 
+				$SUBTYPE_CACHE = select_default_memcache('subtype_cache');
 			
 			$SUBTYPE_CACHE[$result->id] = $result;
 			return $result->class;
@@ -1100,7 +1103,8 @@
 		$result = get_data_row("SELECT * from {$CONFIG->dbprefix}entity_subtypes where id=$subtype_id");
 		if ($result) {
 			
-			if (!$SUBTYPE_CACHE) $SUBTYPE_CACHE = new ElggStaticVariableCache('subtype_cache');
+			if (!$SUBTYPE_CACHE) 
+				$SUBTYPE_CACHE = select_default_memcache('subtype_cache');
 			
 			$SUBTYPE_CACHE[$subtype_id] = $result;
 			return $result->class;