Video listing optimization and caching

lib/Caching/VideosCaching.php

@@ -0,0 +1,137 @@
+<?php
+
+namespace Opencast\Caching;
+
+use Opencast\Models\Videos;
+
+class VideosCaching
+{
+    private $cache_factory;
+    private $cache_name;
+    const OC_CACHE_KEY_DOMAIN_USERS = 'OpencastV3/videos/users/';
+    const OC_CACHE_KEY_DOMAIN_COURSES = 'OpencastV3/videos/courses/';
+    const OC_CACHE_KEY_DOMAIN_PLAYLIST = 'OpencastV3/videos/playlist/';
+
+    public function __construct() {
+        $this->cache_factory = \StudipCacheFactory::getCache();
+    }
+
+    public function userVideos(string $user_id)
+    {
+        $this->cache_name = self::OC_CACHE_KEY_DOMAIN_USERS . $user_id;
+        return $this;
+    }
+
+    public function courseVideos(string $course_id)
+    {
+        $this->cache_name = self::OC_CACHE_KEY_DOMAIN_COURSES . $course_id;
+        return $this;
+    }
+
+    public function playlistVideos(int $playlist_id)
+    {
+        $this->cache_name = self::OC_CACHE_KEY_DOMAIN_PLAYLIST . $playlist_id;
+        return $this;
+    }
+
+    public function readAll()
+    {
+        if (empty($this->cache_name)) {
+            throw new \Error('Unable to read the cache due to missing cache name!');
+        }
+
+        $content = $this->cache_factory->read($this->cache_name);
+        return $content ? unserialize($content) : [];
+    }
+
+    public function read(string $unique_query_id)
+    {
+        if (empty($unique_query_id)) {
+            throw new \Error('Unable to read the cache due to missing cache name!');
+        }
+
+        $all = $this->readAll();
+
+        if (!isset($all[$unique_query_id])) {
+            return false;
+        }
+
+        return $all[$unique_query_id];
+    }
+
+    public function write($unique_query_id, $content)
+    {
+        if (empty($unique_query_id)) {
+            throw new \Error('Unable to write the cache data due to missing cache name!');
+        }
+
+        $all = $this->readAll();
+
+        $all[$unique_query_id] = $content;
+
+        $serialized_records = serialize($all);
+
+        return $this->cache_factory->write($this->cache_name, $serialized_records);
+    }
+
+    public function delete($unique_query_id)
+    {
+        if (empty($unique_query_id)) {
+            throw new \Error('Unable to expire the cache data due to missing cache name!');
+        }
+
+        $all = $this->readAll();
+
+        if (empty($all)) {
+            return true;
+        }
+
+        if (isset($all[$unique_query_id])) {
+            unset($all[$unique_query_id]);
+        }
+
+        if (empty($all)) {
+            $this->expire();
+            return true;
+        }
+
+        return $this->cache_factory->write($this->cache_name, serialize($all));
+    }
+
+    public function expire()
+    {
+        $this->cache_factory->expire($this->cache_name);
+    }
+
+    public static function expireAllVideoCaches(Videos $video)
+    {
+        $cache = \StudipCacheFactory::getCache();
+        if (!empty($video->perms)) {
+            foreach ($video->perms->pluck('user_id') as $user_id) {
+                $cache->expire(self::OC_CACHE_KEY_DOMAIN_USERS . $user_id);
+            }
+        }
+
+        if (!empty($video->playlists)) {
+            foreach ($video->playlists as $playlist) {
+                $cache->expire(self::OC_CACHE_KEY_DOMAIN_PLAYLIST . $playlist->id);
+
+                if (!empty($playlist->courses)) {
+                    foreach ($playlist->courses as $course) {
+                        $cache->expire(self::OC_CACHE_KEY_DOMAIN_COURSES . $course->id);
+                    }
+                }
+            }
+        }
+
+        // We need to also look for root accounts!
+        $stmt = \DBManager::get()->prepare($q = "SELECT `user_id` FROM `auth_user_md5` WHERE `perms` = :perm");
+        $stmt->execute([
+            ':perm'   => 'root',
+        ]);
+        $root_user_ids = $stmt->fetchAll(\PDO::FETCH_COLUMN);
+        foreach ($root_user_ids as $root_user_id) {
+            $cache->expire(self::OC_CACHE_KEY_DOMAIN_USERS . $root_user_id);
+        }
+    }
+}

lib/Models/Filter.php

@@ -106,4 +106,9 @@ public function getTrashed()
     {
         return $this->trashed;
     }
+
+    public function decodeVars()
+    {
+        return base64_encode(json_encode(get_object_vars($this)));
+    }
 }

lib/Models/Playlists.php

@@ -5,6 +5,7 @@
 use Opencast\Models\REST\ApiPlaylistsClient;
 use Opencast\Helpers\PlaylistMigration;
 use Opencast\Errors\Error;
+use Opencast\Caching\VideosCaching;
 
 class Playlists extends UPMap
 {
@@ -575,6 +576,8 @@ public function delete()
             $playlist_client->deletePlaylist($this->service_playlist_id);
         }
 
+        (new VideosCaching())->playlistVideos($this->id)->expire();
+
         return parent::delete();
     }
 

lib/Models/ScheduledRecordings.php

@@ -3,7 +3,7 @@
 namespace Opencast\Models;
 
 use Opencast\Models\PlaylistSeminars;
-use Opencast\Models\Video;
+use Opencast\Models\Videos;
 
 class ScheduledRecordings extends \SimpleORMap
 {

lib/Models/Videos.php

@@ -10,6 +10,7 @@
 use Opencast\Models\REST\ApiWorkflowsClient;
 use Opencast\Models\Helpers;
 use Opencast\Models\ScheduledRecordings;
+use Opencast\Caching\VideosCaching;
 
 class Videos extends UPMap
 {
@@ -297,9 +298,14 @@ protected static function getFilteredVideos($query, $filters)
         $course_ids   = [];
         $lecturer_ids = [];
 
+        $count_selected_columns = [
+            'id', 'token', 'config_id', 'created'
+        ];
+
         foreach ($filters->getFilters() as $filter) {
             switch ($filter['type']) {
                 case 'text':
+                    $count_selected_columns[] = 'title';
                     $pname = ':text' . sizeof($params);
                     $where .= " AND (title LIKE $pname OR description LIKE $pname)";
                     $params[$pname] = '%' . $filter['value'] .'%';
@@ -450,7 +456,11 @@ protected static function getFilteredVideos($query, $filters)
 
         $sql .= ' GROUP BY oc_video.id';
 
-        $stmt = \DBManager::get()->prepare($s = "SELECT COUNT(*) FROM (SELECT oc_video.* FROM oc_video $sql) t");
+        // Preparing count sql, specifically define columns to select in order to increase performance.
+        $count_selected_columns = array_map(function($clmn) { return 'oc_video.' . $clmn; }, array_unique($count_selected_columns));
+        $count_select_columns_sql = implode(', ', $count_selected_columns);
+        $s = "SELECT COUNT(*) FROM (SELECT $count_select_columns_sql FROM oc_video $sql) t";
+        $stmt = \DBManager::get()->prepare($s);
         $stmt->execute($params);
         $count = $stmt->fetchColumn();
 
@@ -1273,4 +1283,26 @@ public static function addToCoursePlaylist($episode, $video)
             }
         }
     }
+
+    /**
+     * @inheritDoc
+     *
+     * Overriding store method, in order to expire caches.
+     */
+    public function store()
+    {
+        VideosCaching::expireAllVideoCaches($this);
+        return parent::store();
+    }
+
+    /**
+     * @inheritDoc
+     *
+     * Overriding delete method, in order to expire caches.
+     */
+    public function delete()
+    {
+        VideosCaching::expireAllVideoCaches($this);
+        return parent::delete();
+    }
 }

lib/Routes/Course/CourseVideoList.php

@@ -8,6 +8,7 @@
 use Opencast\OpencastController;
 use Opencast\Models\Filter;
 use Opencast\Models\Videos;
+use Opencast\Caching\VideosCaching;
 
 class CourseVideoList extends OpencastController
 {
@@ -29,22 +30,38 @@ public function __invoke(Request $request, Response $response, $args)
             throw new \AccessDeniedException();
         }
 
-        // show videos for this course and filter them with optional additional filters
-        $videos = Videos::getCourseVideos($course_id, new Filter($params));
+        $response_result = [
+            'videos' => [],
+            'count'  => 0,
+        ];
 
-        $ret = [];
-        foreach ($videos['videos'] as $video) {
-            $video_array = $video->toSanitizedArray($params['cid']);
-            if (!empty($video_array['perm']) && ($video_array['perm'] == 'owner' || $video_array['perm'] == 'write'))
-            {
-                $video_array['perms'] = $video->perms->toSanitizedArray();
+        $filter = new Filter($params);
+        $video_caching = new VideosCaching();
+        $course_videos_cache = $video_caching->courseVideos($course_id);
+        $unique_query_id = $filter->decodeVars();
+        $response_result = $course_videos_cache->read($unique_query_id);
+        if (empty($response_result)) {
+            // show videos for this course and filter them with optional additional filters
+            $videos = Videos::getCourseVideos($course_id, $filter);
+
+            $ret = [];
+            foreach ($videos['videos'] as $video) {
+                $video_array = $video->toSanitizedArray($params['cid']);
+                if (!empty($video_array['perm']) && ($video_array['perm'] == 'owner' || $video_array['perm'] == 'write'))
+                {
+                    $video_array['perms'] = $video->perms->toSanitizedArray();
+                }
+                $ret[] = $video_array;
             }
-            $ret[] = $video_array;
+
+            $response_result = [
+                'videos' => $ret,
+                'count'  => $videos['count'],
+            ];
+
+            $course_videos_cache->write($unique_query_id, $response_result);
         }
 
-        return $this->createResponse([
-            'videos' => $ret,
-            'count'  => $videos['count'],
-        ], $response);
+        return $this->createResponse($response_result, $response);
     }
 }

lib/Routes/Playlist/PlaylistVideoList.php

@@ -12,6 +12,7 @@
 use Opencast\Models\Playlists;
 use Opencast\Models\Videos;
 use Opencast\Models\PlaylistSeminarVideos;
+use Opencast\Caching\VideosCaching;
 
 class PlaylistVideoList extends OpencastController
 {
@@ -49,22 +50,38 @@ public function __invoke(Request $request, Response $response, $args)
             }
         }
 
-        // show videos for this playlist and filter them with optional additional filters
-        $videos = Videos::getPlaylistVideos($playlist->id, new Filter($params));
+        $response_result = [
+            'videos' => [],
+            'count'  => 0,
+        ];
 
-        $ret = [];
-        foreach ($videos['videos'] as $video) {
-            $video_array = $video->toSanitizedArray($course_id, $playlist->id);
-            if (!empty($video_array['perm']) && ($video_array['perm'] == 'owner' || $video_array['perm'] == 'write'))
-            {
-                $video_array['perms'] = $video->perms->toSanitizedArray();
+        $filter = new Filter($params);
+        $video_caching = new VideosCaching();
+        $playlist_videos_cache = $video_caching->playlistVideos($playlist->id);
+        $unique_query_id = $filter->decodeVars();
+        $response_result = $playlist_videos_cache->read($unique_query_id);
+        if (empty($response_result)) {
+            // show videos for this playlist and filter them with optional additional filters
+            $videos = Videos::getPlaylistVideos($playlist->id, $filter);
+
+            $ret = [];
+            foreach ($videos['videos'] as $video) {
+                $video_array = $video->toSanitizedArray($course_id, $playlist->id);
+                if (!empty($video_array['perm']) && ($video_array['perm'] == 'owner' || $video_array['perm'] == 'write'))
+                {
+                    $video_array['perms'] = $video->perms->toSanitizedArray();
+                }
+                $ret[] = $video_array;
             }
-            $ret[] = $video_array;
+
+            $response_result = [
+                'videos' => $ret,
+                'count'  => $videos['count'],
+            ];
+
+            $playlist_videos_cache->write($unique_query_id, $response_result);
         }
 
-        return $this->createResponse([
-            'videos' => $ret,
-            'count'  => $videos['count']
-        ], $response);
+        return $this->createResponse($response_result, $response);
     }
 }