Closes #516: Experimental memcache support

git-svn-id: https://code.elgg.org/elgg/trunk@2398 36083f99-b078-4883-b0ff-0f9b5a30f544

1 files changed, 62 insertions, 18 deletions

diff --git a/engine/lib/memcache.php b/engine/lib/memcache.php
index 2df93cbaf..b50c3c820 100644
--- a/engine/lib/memcache.php
+++ b/engine/lib/memcache.php
@@ -16,6 +16,12 @@
 	class ElggMemcache extends ElggCache
 	{
 		/**
+		 * Minimum version of memcached needed to run
+		 *
+		 */
+		private static $MINSERVERVERSION = '1.1.12';
+		
+		/**
 		 * Namespace variable used for key
 		 *
 		 * @var string
@@ -66,20 +72,36 @@
 			if (!$CONFIG->memcache_servers)
 				throw new ConfigurationException(elgg_echo('memcache:noservers'));
 				
-			foreach ($CONFIG->memcache_servers as $server)
+			if (is_callable($this->memcache, 'addServer'))
 			{
-				if (is_array($server))
+				foreach ($CONFIG->memcache_servers as $server)
 				{
-					$this->memcache->addServer(
-						$server[0], 
-						isset($server[1]) ? $server[1] : 11211,
-						isset($server[2]) ? $server[2] : true,
-						isset($server[3]) ? $server[3] : null,
-						isset($server[4]) ? $server[4] : 1,
-						isset($server[5]) ? $server[5] : 15,
-						isset($server[6]) ? $server[6] : true
-					);
+					if (is_array($server))
+					{
+						$this->memcache->addServer(
+							$server[0], 
+							isset($server[1]) ? $server[1] : 11211,
+							isset($server[2]) ? $server[2] : true,
+							isset($server[3]) ? $server[3] : null,
+							isset($server[4]) ? $server[4] : 1,
+							isset($server[5]) ? $server[5] : 15,
+							isset($server[6]) ? $server[6] : true
+						);
+						
+					}
+					else
+						$this->memcache->addServer($server, 11211);
+				}
+			}
+			else
+			{
+				if ((isset($CONFIG->debug)) && ($CONFIG->debug == true))
+					error_log(elgg_echo('memcache:noaddserver'));
 					
+				$server = $CONFIG->memcache_servers[0];
+				if (is_array($server))
+				{
+					$this->memcache->connect($server[0], $server[1]);
 				}
 				else
 					$this->memcache->addServer($server, 11211);
@@ -87,13 +109,23 @@
 			
 			// Get version
 			$this->version = $this->memcache->getversion();
-			if (version_compare($this->version, '2.0.0', '<'))
-				throw new ConfigurationException(sprintf(elgg_echo('memcache:versiontoolow'), $this->version));
-			
+			if (version_compare($this->version, ElggMemcache::$MINSERVERVERSION, '<'))
+				throw new ConfigurationException(sprintf(elgg_echo('memcache:versiontoolow'), ElggMemcache::$MINSERVERVERSION, $this->version));
+		
 			// Set some defaults
 			if (isset($CONFIG->memcache_expires))
 				$this->expires = $CONFIG->memcache_expires;
-			
+		
+		}
+		
+		/**
+		 * Set the default expiry.
+		 *
+		 * @param int $expires The lifetime as a unix timestamp or time from now. Defaults forever.
+		 */
+		public function setDefaultExpiry($expires = 0)
+		{
+			$this->expires = $expires;
 		}
 		
 		/**
@@ -117,14 +149,26 @@
 		{
 			$key = $this->make_memcache_key($key);
 			
-			return $this->memcache->add($key, $data, null, $this->expires);	
+			$this->keys_so_far[$key] = time();
+			
+			$result = $this->memcache->set($key, $data, null, $this->expires);	
+			if ((isset($CONFIG->debug)) && ($CONFIG->debug == true) && (!$result))
+				error_log("MEMCACHE: FAILED TO SAVE $key"); 
+			
+			return $result;			
 		}
 		
 		public function load($key, $offset = 0, $limit = null)
 		{
 			$key = $this->make_memcache_key($key);
 			
-			return $this->memcache->get($key);
+			$this->keys_so_far[$key] = time();
+
+			$result = $this->memcache->get($key);
+			if ((isset($CONFIG->debug)) && ($CONFIG->debug == true) && (!$result))
+				error_log("MEMCACHE: FAILED TO LOAD $key");
+			
+			return $result;
 		}
 		
 		public function delete($key) 
@@ -136,7 +180,7 @@
 		
 		public function clear()
 		{
-			foreach ($this->keys_so_far as $key)
+			foreach ($this->keys_so_far as $key => $ts)
 				$this->memcache->delete($key, 0);
 				
 			$this->keys_so_far = array();