MDL-55628 Completion: Use simpledata for completion cache
authorsam marshall <s.marshall@open.ac.uk>
Fri, 19 Aug 2016 11:56:42 +0000 (12:56 +0100)
committersam marshall <s.marshall@open.ac.uk>
Mon, 22 Aug 2016 16:13:36 +0000 (17:13 +0100)
The completion cache is currently not marked as simpledata. On the
course page it is frequently retrieved hundreds of times which results
in many calls to the slow unserialize function. By making a slight
change to the data format (using arrays instead of objects) we can
mark it as simpledata, which will avoid using unserialize.

lib/completionlib.php
lib/db/caches.php
lib/tests/completionlib_test.php

index de9b8a4..cba3ed9 100644 (file)
@@ -894,15 +894,16 @@ class completion_info {
         $usecache = $userid == $USER->id;
         $cacheddata = array();
         if ($usecache) {
+            $key = $userid . '_' . $this->course->id;
             if (!isset($this->course->cacherev)) {
                 $this->course = get_course($this->course_id);
             }
-            if ($cacheddata = $completioncache->get($userid . '_' . $this->course->id)) {
+            if ($cacheddata = $completioncache->get($key)) {
                 if ($cacheddata['cacherev'] != $this->course->cacherev) {
                     // Course structure has been changed since the last caching, forget the cache.
                     $cacheddata = array();
-                } else if (array_key_exists($cm->id, $cacheddata)) {
-                    return $cacheddata[$cm->id];
+                } else if (isset($cacheddata[$cm->id])) {
+                    return (object)$cacheddata[$cm->id];
                 }
             }
         }
@@ -921,10 +922,8 @@ class completion_info {
 
             // Reindex by cm id
             $alldata = array();
-            if ($alldatabycmc) {
-                foreach ($alldatabycmc as $data) {
-                    $alldata[$data->coursemoduleid] = $data;
-                }
+            foreach ($alldatabycmc as $data) {
+                $alldata[$data->coursemoduleid] = (array)$data;
             }
 
             // Get the module info and build up condition info for each one
@@ -932,17 +931,17 @@ class completion_info {
                 $modinfo = get_fast_modinfo($this->course, $userid);
             }
             foreach ($modinfo->cms as $othercm) {
-                if (array_key_exists($othercm->id, $alldata)) {
+                if (isset($alldata[$othercm->id])) {
                     $data = $alldata[$othercm->id];
                 } else {
                     // Row not present counts as 'not complete'
-                    $data = new StdClass;
-                    $data->id              = 0;
-                    $data->coursemoduleid  = $othercm->id;
-                    $data->userid          = $userid;
-                    $data->completionstate = 0;
-                    $data->viewed          = 0;
-                    $data->timemodified    = 0;
+                    $data = array();
+                    $data['id'] = 0;
+                    $data['coursemoduleid'] = $othercm->id;
+                    $data['userid'] = $userid;
+                    $data['completionstate'] = 0;
+                    $data['viewed'] = 0;
+                    $data['timemodified'] = 0;
                 }
                 $cacheddata[$othercm->id] = $data;
             }
@@ -954,15 +953,17 @@ class completion_info {
         } else {
             // Get single record
             $data = $DB->get_record('course_modules_completion', array('coursemoduleid'=>$cm->id, 'userid'=>$userid));
-            if ($data == false) {
+            if ($data) {
+                $data = (array)$data;
+            } else {
                 // Row not present counts as 'not complete'
-                $data = new StdClass;
-                $data->id              = 0;
-                $data->coursemoduleid  = $cm->id;
-                $data->userid          = $userid;
-                $data->completionstate = 0;
-                $data->viewed          = 0;
-                $data->timemodified    = 0;
+                $data = array();
+                $data['id'] = 0;
+                $data['coursemoduleid'] = $cm->id;
+                $data['userid'] = $userid;
+                $data['completionstate'] = 0;
+                $data['viewed'] = 0;
+                $data['timemodified'] = 0;
             }
 
             // Put in cache
@@ -971,9 +972,9 @@ class completion_info {
 
         if ($usecache) {
             $cacheddata['cacherev'] = $this->course->cacherev;
-            $completioncache->set($userid . '_' . $this->course->id, $cacheddata);
+            $completioncache->set($key, $cacheddata);
         }
-        return $cacheddata[$cm->id];
+        return (object)$cacheddata[$cm->id];
     }
 
     /**
index 912fe5a..da6b531 100644 (file)
@@ -223,6 +223,7 @@ $definitions = array(
     'completion' => array(
         'mode' => cache_store::MODE_APPLICATION,
         'simplekeys' => true,
+        'simpledata' => true,
         'ttl' => 3600,
         'staticacceleration' => true,
         'staticaccelerationsize' => 2, // Should be current course and site course.
index ee008ef..da9265f 100644 (file)
@@ -428,7 +428,7 @@ class core_completionlib_testcase extends advanced_testcase {
         $result = $c->get_data($cm);
         $this->assertEquals($sillyrecord, $result);
         $cachevalue = $cache->get('314159_42');
-        $this->assertEquals($sillyrecord, $cachevalue[13]);
+        $this->assertEquals((array)$sillyrecord, $cachevalue[13]);
 
         // 4. Current user, 'whole course', but from cache.
         $result = $c->get_data($cm, true);
@@ -453,8 +453,8 @@ class core_completionlib_testcase extends advanced_testcase {
 
         // Check the cache contents.
         $cachevalue = $cache->get('314159_42');
-        $this->assertEquals($basicrecord, $cachevalue[13]);
-        $this->assertEquals((object)array('id'=>'0', 'coursemoduleid'=>14,
+        $this->assertEquals($basicrecord, (object)$cachevalue[13]);
+        $this->assertEquals(array('id' => '0', 'coursemoduleid' => 14,
             'userid'=>314159, 'completionstate'=>0, 'viewed'=>0, 'timemodified'=>0),
             $cachevalue[14]);
     }