PERF: reduce storage requirements for incoming links

Only store incoming links for topics.

app/models/incoming_link.rb

@@ -2,38 +2,50 @@ class IncomingLink < ActiveRecord::Base
   belongs_to :topic
   belongs_to :user
 
-  validates :url, presence: true
   validate :referer_valid
+  validate :post_id, presence: true
 
   before_validation :extract_domain
-  before_validation :extract_topic_and_post
   after_create :update_link_counts
 
-  def self.add(request,current_user=nil)
-    user_id, host, referer = nil
+  attr_accessor :url
 
-    if request['u']
-      u = User.select(:id).find_by(username_lower: request["u"].downcase)
+  def self.add(opts)
+    user_id, host, referer = nil
+    current_user = opts[:current_user]
+
+    if username = opts[:username]
+      u = User.select(:id).find_by(username_lower: username.downcase)
       user_id = u.id if u
     end
 
-    if request.referer.present?
+    if opts[:referer].present?
       begin
-        host = URI.parse(request.referer).host
-        referer = request.referer[0..999]
+        host = URI.parse(opts[:referer]).host
+        referer = opts[:referer][0..999]
       rescue URI::InvalidURIError
         # bad uri, skip
       end
     end
 
-    if host != request.host && (user_id || referer)
+    if host != opts[:host] && (user_id || referer)
+
+      post_id = opts[:post_id]
+      post_id ||= Post.where(topic_id: opts[:topic_id],
+                             post_number: opts[:post_number] || 1)
+                            .pluck(:id).first
+
       cid = current_user ? (current_user.id) : (nil)
+
+
       unless cid && cid == user_id
-        IncomingLink.create(url: request.url,
-                            referer: referer,
+
+        IncomingLink.create(referer: referer,
                             user_id: user_id,
+                            post_id: post_id,
                             current_user_id: cid,
-                            ip_address: request.remote_ip)
+                            ip_address: opts[:ip_address]) if post_id
+
       end
     end
 
@@ -49,35 +61,14 @@ class IncomingLink < ActiveRecord::Base
     end
   end
 
-  # Internal: If link is internal and points to topic/post, extract their IDs.
-  def extract_topic_and_post
-    if url.present?
-      parsed = URI.parse(url)
-
-      begin
-        # TODO achieve same thing with no exception
-        params = Rails.application.routes.recognize_path(parsed.path)
-        if self.topic_id = params[:topic_id]
-          self.post_number = params[:post_number] || 1
-        end
-      rescue ActionController::RoutingError
-        # If we can't route to the url, that's OK. Don't save those two fields.
-      end
-    end
-  end
-
   # Internal: Update appropriate link counts.
   def update_link_counts
-    if topic_id.present?
-      exec_sql("UPDATE topics
-                SET incoming_link_count = incoming_link_count + 1
-                WHERE id = ?", topic_id)
-      if post_number.present?
-        exec_sql("UPDATE posts
-                  SET incoming_link_count = incoming_link_count + 1
-                  WHERE topic_id = ? and post_number = ?", topic_id, post_number)
-      end
-    end
+    exec_sql("UPDATE topics
+              SET incoming_link_count = incoming_link_count + 1
+              WHERE id = (SELECT topic_id FROM posts where id = ?)", post_id)
+    exec_sql("UPDATE posts
+              SET incoming_link_count = incoming_link_count + 1
+              WHERE id = ?", post_id)
   end
 
   protected