Improve search performance

src/Api/Controller/ListDiscussionsController.php

@@ -31,9 +31,7 @@ class ListDiscussionsController extends AbstractListController
     public $include = [
         'startUser',
         'lastUser',
-        'relevantPosts',
-        'relevantPosts.discussion',
-        'relevantPosts.user'
+        'mostRelevantPost'
     ];
 
     /**
@@ -84,7 +82,7 @@ protected function data(ServerRequestInterface $request, Document $document)
         $offset = $this->extractOffset($request);
         $load = array_merge($this->extractInclude($request), ['state']);
 
-        $results = $this->searcher->search($criteria, $limit, $offset, $load);
+        $results = $this->searcher->search($criteria, $limit, $offset);
 
         $document->addPaginationLinks(
             $this->url->to('api')->route('discussions.index'),
@@ -94,7 +92,7 @@ protected function data(ServerRequestInterface $request, Document $document)
             $results->areMoreResults() ? null : 0
         );
 
-        $results = $results->getResults();
+        $results = $results->getResults()->load($load);
 
         if ($relations = array_intersect($load, ['startPost', 'lastPost'])) {
             foreach ($results as $discussion) {

src/Api/Serializer/BasicDiscussionSerializer.php

@@ -84,9 +84,9 @@ protected function posts($discussion)
     /**
      * @return \Tobscure\JsonApi\Relationship
      */
-    protected function relevantPosts($discussion)
+    protected function mostRelevantPost($discussion)
     {
-        return $this->hasMany($discussion, BasicPostSerializer::class);
+        return $this->hasOne($discussion, PostSerializer::class);
     }
 
     /**

src/Discussion/Discussion.php

@@ -389,6 +389,16 @@ public function lastUser()
         return $this->belongsTo('Flarum\User\User', 'last_user_id');
     }
 
+    /**
+     * Define the relationship with the discussion's most relevant post.
+     *
+     * @return \Illuminate\Database\Eloquent\Relations\BelongsTo
+     */
+    public function mostRelevantPost()
+    {
+        return $this->belongsTo('Flarum\Post\Post', 'most_relevant_post_id');
+    }
+
     /**
      * Define the relationship with the discussion's readers.
      *

src/Discussion/Search/DiscussionSearcher.php

@@ -11,26 +11,20 @@
 
 namespace Flarum\Discussion\Search;
 
-use Flarum\Discussion\Discussion;
 use Flarum\Discussion\DiscussionRepository;
 use Flarum\Discussion\Event\Searching;
-use Flarum\Post\PostRepository;
 use Flarum\Search\ApplySearchParametersTrait;
 use Flarum\Search\GambitManager;
 use Flarum\Search\SearchCriteria;
 use Flarum\Search\SearchResults;
-use Illuminate\Database\Eloquent\Collection;
+use Illuminate\Contracts\Events\Dispatcher;
 
-/**
- * Takes a DiscussionSearchCriteria object, performs a search using gambits,
- * and spits out a DiscussionSearchResults object.
- */
 class DiscussionSearcher
 {
     use ApplySearchParametersTrait;
 
     /**
-     * @var \Flarum\Search\GambitManager
+     * @var GambitManager
      */
     protected $gambits;
 
@@ -40,37 +34,33 @@ class DiscussionSearcher
     protected $discussions;
 
     /**
-     * @var PostRepository
+     * @var Dispatcher
      */
-    protected $posts;
+    protected $events;
 
     /**
-     * @param \Flarum\Search\GambitManager $gambits
+     * @param GambitManager $gambits
      * @param DiscussionRepository $discussions
-     * @param PostRepository $posts
+     * @param Dispatcher $events
      */
-    public function __construct(
-        GambitManager $gambits,
-        DiscussionRepository $discussions,
-        PostRepository $posts
-    ) {
+    public function __construct(GambitManager $gambits, DiscussionRepository $discussions, Dispatcher $events) {
         $this->gambits = $gambits;
         $this->discussions = $discussions;
-        $this->posts = $posts;
+        $this->events = $events;
     }
 
     /**
      * @param SearchCriteria $criteria
      * @param int|null $limit
      * @param int $offset
-     * @param array $load An array of relationships to load on the results.
+     *
      * @return SearchResults
      */
-    public function search(SearchCriteria $criteria, $limit = null, $offset = 0, array $load = [])
+    public function search(SearchCriteria $criteria, $limit = null, $offset = 0)
     {
         $actor = $criteria->actor;
 
-        $query = $this->discussions->query()->whereVisibleTo($actor);
+        $query = $this->discussions->query()->select('discussions.*')->whereVisibleTo($actor);
 
         // Construct an object which represents this search for discussions.
         // Apply gambits to it, sort, and paging criteria. Also give extensions
@@ -82,8 +72,7 @@ public function search(SearchCriteria $criteria, $limit = null, $offset = 0, arr
         $this->applyOffset($search, $offset);
         $this->applyLimit($search, $limit + 1);
 
-        // TODO: inject dispatcher
-        event(new Searching($search, $criteria));
+        $this->events->dispatch(new Searching($search, $criteria));
 
         // Execute the search query and retrieve the results. We get one more
         // results than the user asked for, so that we can say if there are more
@@ -96,42 +85,6 @@ public function search(SearchCriteria $criteria, $limit = null, $offset = 0, arr
             $discussions->pop();
         }
 
-        // The relevant posts relationship isn't a typical Eloquent
-        // relationship; rather, we need to extract that information from our
-        // search object. We will delegate that task and prevent Eloquent
-        // from trying to load it.
-        if (in_array('relevantPosts', $load)) {
-            $this->loadRelevantPosts($discussions, $search);
-
-            $load = array_diff($load, ['relevantPosts', 'relevantPosts.discussion', 'relevantPosts.user']);
-        }
-
-        Discussion::setStateUser($actor);
-        $discussions->load($load);
-
         return new SearchResults($discussions, $areMoreResults);
     }
-
-    /**
-     * Load relevant posts onto each discussion using information from the
-     * search.
-     *
-     * @param Collection $discussions
-     * @param DiscussionSearch $search
-     */
-    protected function loadRelevantPosts(Collection $discussions, DiscussionSearch $search)
-    {
-        $postIds = [];
-        foreach ($search->getRelevantPostIds() as $relevantPostIds) {
-            $postIds = array_merge($postIds, array_slice($relevantPostIds, 0, 2));
-        }
-
-        $posts = $postIds ? $this->posts->findByIds($postIds, $search->getActor())->load('user')->all() : [];
-
-        foreach ($discussions as $discussion) {
-            $discussion->relevantPosts = array_filter($posts, function ($post) use ($discussion) {
-                return $post->discussion_id == $discussion->id;
-            });
-        }
-    }
 }

src/Discussion/Search/Gambit/FulltextGambit.php

@@ -12,26 +12,12 @@
 namespace Flarum\Discussion\Search\Gambit;
 
 use Flarum\Discussion\Search\DiscussionSearch;
-use Flarum\Discussion\Search\Fulltext\DriverInterface;
 use Flarum\Search\AbstractSearch;
 use Flarum\Search\GambitInterface;
 use LogicException;
 
 class FulltextGambit implements GambitInterface
 {
-    /**
-     * @var \Flarum\Discussion\Search\Fulltext\DriverInterface
-     */
-    protected $fulltext;
-
-    /**
-     * @param \Flarum\Discussion\Search\Fulltext\DriverInterface $fulltext
-     */
-    public function __construct(DriverInterface $fulltext)
-    {
-        $this->fulltext = $fulltext;
-    }
-
     /**
      * {@inheritdoc}
      */
@@ -41,14 +27,22 @@ public function apply(AbstractSearch $search, $bit)
             throw new LogicException('This gambit can only be applied on a DiscussionSearch');
         }
 
-        $relevantPostIds = $this->fulltext->match($bit);
-
-        $discussionIds = array_keys($relevantPostIds);
-
-        $search->setRelevantPostIds($relevantPostIds);
-
-        $search->getQuery()->whereIn('id', $discussionIds);
-
-        $search->setDefaultSort(['id' => $discussionIds]);
+        // TODO: add a migration for fulltext index on discussions.title
+        $search->getQuery()
+            ->selectRaw('SUBSTRING_INDEX(GROUP_CONCAT(posts.id ORDER BY MATCH(posts.content) AGAINST (?) DESC), \',\', 1) as most_relevant_post_id', [$bit])
+            ->join('posts', function ($join) use ($bit) {
+                $join->on('posts.discussion_id', '=', 'discussions.id')
+                    ->whereRaw('MATCH(posts.content) AGAINST (? IN BOOLEAN MODE)', [$bit]);
+
+                // TODO: need to scope post visibility
+            })
+            ->whereRaw('MATCH(discussions.title) AGAINST (? IN BOOLEAN MODE)', [$bit])
+            ->orWhereNotNull('posts.id')
+            ->groupBy('discussions.id');
+
+        $search->setDefaultSort(function ($query) use ($bit) {
+            $query->orderByRaw('MATCH(discussions.title) AGAINST (?) desc', [$bit]);
+            $query->orderByRaw('SUM(MATCH(posts.content) AGAINST (?)) desc', [$bit]);
+        });
     }
 }

src/Search/AbstractSearch.php

@@ -85,12 +85,12 @@ public function getDefaultSort()
      * Set the default sort order for the search. This will only be applied if
      * a sort order has not been specified in the search criteria.
      *
-     * @param array $defaultSort An array of sort-order pairs, where the column
+     * @param mixed $defaultSort An array of sort-order pairs, where the column
      *     is the key, and the order is the value. The order may be 'asc',
      *     'desc', or an array of IDs to order by.
      * @return mixed
      */
-    public function setDefaultSort(array $defaultSort)
+    public function setDefaultSort($defaultSort)
     {
         $this->defaultSort = $defaultSort;
     }

src/Search/ApplySearchParametersTrait.php

@@ -23,13 +23,17 @@ protected function applySort(AbstractSearch $search, array $sort = null)
     {
         $sort = $sort ?: $search->getDefaultSort();
 
-        foreach ($sort as $field => $order) {
-            if (is_array($order)) {
-                foreach ($order as $value) {
-                    $search->getQuery()->orderByRaw(snake_case($field).' != ?', [$value]);
+        if (is_callable($sort)) {
+            $sort($search->getQuery());
+        } else {
+            foreach ($sort as $field => $order) {
+                if (is_array($order)) {
+                    foreach ($order as $value) {
+                        $search->getQuery()->orderByRaw(snake_case($field).' != ?', [$value]);
+                    }
+                } else {
+                    $search->getQuery()->orderBy(snake_case($field), $order);
                 }
-            } else {
-                $search->getQuery()->orderBy(snake_case($field), $order);
             }
         }
     }