Merge pull request #2 from rll/dave/tuning

Performance tuning

api/search.rb

@@ -70,15 +70,12 @@ get "#{APIPREFIX}/search/threads/recent_active" do
   query_params["commentable_id"] = params["commentable_id"] if params["commentable_id"]
 
   comment_threads = if follower_id 
-    User.find(follower_id).subscribed_threads.select do |thread|
-      thread.last_activity_at >= from_time and \
-      query_params.to_a.map {|query| thread[query.first] == query.last}.all?
-    end
+    User.find(follower_id).subscribed_threads
   else
-    CommentThread.all.where(query_params.merge(:last_activity_at => {:$gte => from_time}))
+    CommentThread.all
   end
 
-  comment_threads.to_a.sort {|x, y| y.last_activity_at <=> x.last_activity_at}[0..4].map(&:to_hash).to_json
+  comment_threads.where(query_params.merge(:last_activity_at => {:$gte => from_time})).order_by(:last_activity_at.desc).limit(5).to_a.map(&:to_hash).to_json
 end
 
 
@@ -86,7 +83,7 @@ get "#{APIPREFIX}/search/tags/trending" do
   query_params = {}
   query_params["course_id"] = params["course_id"] if params["course_id"]
   query_params["commentable_id"] = params["commentable_id"] if params["commentable_id"]
-  CommentThread.all.where(query_params).to_a
+  CommentThread.where(query_params).only(:tags_array).to_a
                .map(&:tags_array).flatten.group_by{|x| x}
                .map{|k, v| [k, v.count]}
                .sort_by {|x| - x.last}[0..4]

models/comment.rb

@@ -15,6 +15,8 @@ class Comment < Content
   field :anonymous, type: Boolean, default: false
   field :at_position_list, type: Array, default: []
 
+  index({author_id: 1, course_id: 1})
+
   belongs_to :comment_thread, index: true
   belongs_to :author, class_name: "User", index: true
 

models/comment_thread.rb

@@ -21,6 +21,8 @@ class CommentThread < Content
   field :at_position_list, type: Array, default: []
   field :last_activity_at, type: Time
 
+  index({author_id: 1, course_id: 1})
+
   include Tire::Model::Search
   include Tire::Model::Callbacks
 

models/subscription.rb

@@ -7,6 +7,8 @@ class Subscription
   field :source_type, type: String
   
   index({subscriber_id: 1, source_id: 1, source_type: 1})
+  index({subscriber_id: 1, source_type: 1})
+  index({subscriber_id: 1})
 
   def to_hash
     as_document.slice(*%w[subscriber_id source_id source_type])

models/user.rb

@@ -31,23 +31,23 @@ class User
   end
 
   def subscribed_thread_ids
-    subscriptions_as_subscriber.where(source_type: "CommentThread").map(&:source_id)
+    Subscription.where(subscriber_id: id.to_s, source_type: "CommentThread").only(:source_id).map(&:source_id)
   end
 
   def subscribed_commentable_ids
-    subscriptions_as_subscriber.where(source_type: "Commentable").map(&:source_id)
+    subscriptions_as_subscriber.where(source_type: "Commentable").only(:source_id).map(&:source_id)
   end
 
   def subscribed_user_ids
-    subscriptions_as_subscriber.where(source_type: "User").map(&:source_id)
+    subscriptions_as_subscriber.where(source_type: "User").only(:source_id).map(&:source_id)
   end
 
   def subscribed_threads
-    subscribed_thread_ids.map {|id| CommentThread.find(id)}
+    CommentThread.where(:id.in => subscribed_thread_ids)
   end
 
   def subscribed_commentables
-    subscribed_commentable_ids.map {|id| Commentable.find(id)}
+    Commentable.find(*subscribed_commentable_ids).only(:id).map(&:id)
   end
 
   def subscribed_users
@@ -60,15 +60,16 @@ class User
       hash = hash.merge("subscribed_thread_ids" => subscribed_thread_ids,
                         "subscribed_commentable_ids" => subscribed_commentable_ids,
                         "subscribed_user_ids" => subscribed_user_ids,
-                        "follower_ids" => subscriptions_as_source.map(&:subscriber_id),
+                        "follower_ids" => subscriptions_as_source.only(:subscriber_id).map(&:subscriber_id),
                         "id" => id,
                         "upvoted_ids" => upvoted_ids,
                         "downvoted_ids" => downvoted_ids,
-                        "default_sort_key" => default_sort_key)
+                        "default_sort_key" => default_sort_key
+                       )
     end
     if params[:course_id]
-      hash = hash.merge("threads_count" => comment_threads.where(course_id: params[:course_id]).count,
-                        "comments_count" => comments.where(course_id: params[:course_id]).count,
+      hash = hash.merge("threads_count" => CommentThread.where(user_id: id, course_id: params[:course_id]).count,
+                        "comments_count" => Comment.where(user_id: id, course_id: params[:course_id]).count
                        )
     end
     hash