Improving the caching mechanism, in preparation for providing a memcache...

Bugzilla.php

@@ -37,6 +37,10 @@
 $wgAutoloadClasses['BugzillaCacheI'] = $cwd . '/cache/BugzillaCacheI.class.php';
 $wgAutoloadClasses['BugzillaCacheMysql'] = $cwd . '/cache/BugzillaCacheMysql.class.php';
 $wgAutoloadClasses['BugzillaCacheDummy'] = $cwd . '/cache/BugzillaCacheDummy.class.php';
+$wgAutoloadClasses['BugzillaCacheApc'] = $cwd . '/cache/BugzillaCacheApc.class.php';
+$wgAutoloadClasses['BugzillaCacheMemcache'] = $cwd . '/cache/BugzillaCacheMemcache.class.php';
+
+
 
 
 /**

BugzillaOutput.class.php

@@ -147,7 +147,7 @@ public function setup_template_data() {
         $key = md5($this->query->id . $this->_get_size() . get_class($this));
         $cache = $this->_getCache();
         if($result = $cache->get($key)) {
-            $image = $result['data'];
+            $image = $result;
             $this->response->image = $wgBugzillaChartUrl . '/' . $image;
         } else {
             $this->response->image = $wgBugzillaChartUrl . '/' . $this->generate_chart($key) . '.png';

BugzillaQuery.class.php

@@ -32,7 +32,7 @@ public function __construct($type, $options, $title) {
         $this->cache            = FALSE;
         $this->_set_options($options);
     }
-
+    
     protected function _getCache()
     {
         global $wgCacheObject;
@@ -119,7 +119,7 @@ public function fetch() {
 
         // If the cache entry is older than this we need to invalidate it
         $expiry = strtotime("-$wgBugzillaCacheMins minutes");
-
+        
         if( !$row ) { 
             // No cache entry
 
@@ -132,10 +132,7 @@ public function fetch() {
             return $this->data;
         }else {
             // Cache is good, use it
-
-            $this->id = $row['id'];
-            $this->fetched_at = wfTimestamp(TS_DB, $row['fetched_at']);
-            $this->data = unserialize($row['data']);
+            $this->data = unserialize($row);
             $this->cached = TRUE;
         }
     }

cache/BugzillaCacheApc.class.php

@@ -0,0 +1,18 @@
+<?php
+
+class BugzillaCacheApc implements BugzillaCacheI
+{
+
+    public function set($key, $value, $ttl = 300) {
+        return apc_store($key, $value, $ttl);
+    }
+
+    public function get($key) {
+        return apc_fetch($key);
+    }
+
+    public function expire($key) {
+        return apc_delete($key);
+    }
+
+}

cache/BugzillaCacheMemcache.class.php

@@ -0,0 +1,35 @@
+<?php
+
+class BugzillaCacheMemcache implements BugzillaCacheI
+{
+
+    protected $_memcache;
+
+    public function __construct() {
+        // As much as I detest using a global here, it is necessary to avoid
+        // needing to inject the $wgMemc object, thus breaking the usefulness
+        // of the interface. Using the $wgMemc object is important for the
+        // consistency of the code.
+        global $wgMemc;
+        $this->_memcache = $wgMemc;
+    }
+
+    public function set($key, $value, $ttl = 300) {
+        // Get the wikimedia key style expected
+        $key = wfMemcKey($key);
+        return $this->_memcache->set($key, $value, $ttl);
+    }
+
+    public function get($key) {
+        // Get the wikimedia key style expected
+        $key = wfMemcKey($key);
+        return $this->_memcache->get($key);
+    }
+
+    public function expire($key) {
+        // Get the wikimedia key style expected
+        $key = wfMemcKey($key);
+        return $this->_memcache->delete($key);
+    }
+
+}

cache/BugzillaCacheMysql.class.php

@@ -2,43 +2,51 @@
 
 class BugzillaCacheMysql implements BugzillaCacheI
 {
-    protected $_slave;
-    protected $_master;
-
-    public function __construct()
-    {
-        // TO-DO: This methodology creates some difficulties to unit testing.
-        $this->_slave = wfGetDB( DB_SLAVE );
-        $this->_master = wfGetDB( DB_MASTER );
-    }
-
+
+
     public function set($key, $value, $ttl = 300)
     {
-        //TO-DO: It's probably a bad thing to write straight SQL against an
-        //       abstraction layer. The abstraction layer doens't offer full
-        //       functionality, though, and this reduces the number of queries
-        //       for something as simple as caching. Also, the doQuery() method
-        //       is marked "private" but that is commented out; that may change
-        //       in a future release.
-        $key_c = $this->_master->strencode($key);
-        $value_c = $this->_master->strencode($value);
-        $date = wfTimestamp(TS_DB);
-        $now = time(); // Using time() because it's a PHP built-in.
-        $expires = $now+$ttl;
-
-        $sql = 'REPLACE INTO bugzilla_cache
-                (`key`, `fetched_at`, `data`, `expires`) 
-                VALUES
-                ("%s", "%s", "%s", %d)';
-
-        $sql = sprintf($sql, $key_c, $date, $value_c, $expires);
-        $res = $this->_master->doQuery($sql);
+        $master = $this->_getDatabase();
+        $key_c   = $key;
+        $value_c = $value;
+
+        $date    = wfTimestamp(TS_DB);
+        $now     = time(); // Using time() because it's a PHP built-in.
+        $expires = $now + $ttl;
+        if (null === $this->get($key)) {
+            $res = $master->insert(
+                'bugzilla_cache',
+                array(
+                    '`key`'        => $key_c,
+                    'fetched_at' => $date,
+                    'data'       => $value_c,
+                    'expires'    => $expires
+                ),
+                __METHOD__
+            );
+        } else {
+            $res = $this->update(
+                'bugzilla_cache',
+                array(
+                    'fetched_at' => $date
+                ),
+                '`key` = "' . $key_c . '"',
+
+                __METHOD__
+            );
+        }
+
         return $res;
     }
 
+    protected function _getDatabase($type = DB_MASTER) {
+        return wfGetDB($type);
+    }
+
     public function get($key)
     {
-         $res = $this->_slave->select(
+         $slave = $this->_getDatabase(DB_SLAVE);
+         $res = $slave->select(
                         'bugzilla_cache',
                         array('id', 'fetched_at', 'data', 'expires'),
                         '`key` = "' . $key . '"',
@@ -54,12 +62,13 @@ public function get($key)
             return;
         }
 
-        return $row;
+        return $row['data'];
     }
 
     public function expire($key)
     {
-        return $this->_master->delete(
+        $master = $this->_getDatabase();
+        return $master->delete(
                 'bugzilla_cache',
                 array('`key`="' . $key .'"')
             );