Use a fake to not allocate an AR model for every reference to a person

app/controllers/aspects_controller.rb

@@ -24,8 +24,9 @@ class AspectsController < ApplicationController
       @aspect_ids = @aspects.map{|a| a.id}
 
       @posts = StatusMessage.joins(:aspects).where(:pending => false,
-               :aspects => {:id => @aspect_ids}).includes({:person => :profile}, {:comments => {:person => :profile}}, :photos).select('DISTINCT `posts`.*').paginate(
+               :aspects => {:id => @aspect_ids}).includes(:comments, :photos).select('DISTINCT `posts`.*').paginate(
                :page => params[:page], :per_page => 15, :order => 'created_at DESC')
+      @fakes = PostsFake.new(@posts)
 
       @contacts = current_user.contacts.includes(:person => :profile).where(:pending => false)
 
@@ -34,7 +35,6 @@ class AspectsController < ApplicationController
 
     end
   end
-
   def create
     @aspect = current_user.aspects.create(params[:aspect])
     if @aspect.valid?

app/controllers/people_controller.rb

@@ -62,6 +62,7 @@ class PeopleController < ApplicationController
       end
 
       @posts = current_user.posts_from(@person).where(:type => "StatusMessage").paginate :page => params[:page]
+      @fakes = PostsFake.new(@posts)
 
       respond_with @person, :locals => {:post_type => :all}
 

app/helpers/application_helper.rb

@@ -26,13 +26,13 @@ module ApplicationHelper
 
   def aspects_with_post aspects, post
     aspects.select do |aspect|
-      aspect.posts.include?(post)
+      aspect.post_ids.include?(post.id)
     end
   end
 
   def aspects_without_post aspects, post
     aspects.reject do |aspect|
-      aspect.posts.include?(post)
+      aspect.post_ids.include?(post.id)
     end
   end
 

app/views/aspects/_aspect_stream.haml

@@ -5,5 +5,5 @@
 
 = render 'shared/publisher', :aspect => aspect, :aspect_ids => aspect_ids
 #main_stream.stream{:data => {:guids => aspect_ids.join(',')}}
-  = render 'shared/stream', :posts => posts
+  = render 'shared/stream', :posts => fakes
 = will_paginate posts

app/views/aspects/index.html.haml

@@ -13,7 +13,8 @@
     = render 'aspect_stream',
       :aspect => @aspect,
       :aspect_ids => @aspect_ids,
-      :posts => @posts
+      :posts => @posts,
+      :fakes => @fakes
 
 .span-7.last
   #home_user_badge

app/views/aspects/index.js.erb

@@ -1,4 +1,4 @@
-$('#aspect_stream_container').html("<%= escape_javascript(render('aspects/aspect_stream', :aspect => @aspect, :aspect_ids => @aspect_ids, :posts => @posts)) %>");
+$('#aspect_stream_container').html("<%= escape_javascript(render('aspects/aspect_stream', :aspect => @aspect, :aspect_ids => @aspect_ids, :posts => @posts, :fakes => @fakes)) %>");
 $('#aspect_listings').html("<%= escape_javascript(render('aspects/aspect_listings', :aspects => @aspects, :contacts => @contacts)) %>");
 $('a[rel*=facebox]').facebox();
 

app/views/people/show.html.haml

@@ -55,7 +55,7 @@
       = render 'photos/index', :photos => @posts
     - else
       #main_stream.stream
-        = render 'shared/stream', :posts => @posts
+        = render 'shared/stream', :posts => @fakes
 
     = will_paginate @posts
 

config/application.rb

@@ -10,6 +10,8 @@ require 'rails/all'
 Bundler.require(:default, Rails.env) if defined?(Bundler)
 
 require File.expand_path('../../lib/log_overrider', __FILE__)
+require File.expand_path('../../lib/fake', __FILE__)
+
 module Diaspora
   class Application < Rails::Application
     # Settings in config/environments/* take precedence over those specified here.

lib/diaspora/user/querying.rb

@@ -78,7 +78,7 @@ module Diaspora
       def posts_from(person)
         asp = Aspect.arel_table
         p = Post.arel_table
-        person.posts.includes(:aspects, :comments => {:person => :profile}).where( p[:public].eq(true).or(asp[:user_id].eq(self.id))).select('DISTINCT `posts`.*').order("posts.updated_at DESC")
+        person.posts.includes(:aspects, :comments).where( p[:public].eq(true).or(asp[:user_id].eq(self.id))).select('DISTINCT `posts`.*').order("posts.updated_at DESC")
       end
     end
   end

lib/fake.rb

@@ -0,0 +1,48 @@
+class PostsFake
+  attr_reader :people_hash, :post_fakes
+
+  def method_missing(method, *args, &block)
+    @post_fakes.send(method, *args, &block)
+  end
+
+  def initialize(posts)
+    person_ids = []
+    posts.each do |p| 
+      person_ids << p.person_id
+      p.comments.each do |c|
+        person_ids << c.person_id
+      end
+    end
+
+    people = Person.where(:id => person_ids).includes(:profile)
+    @people_hash = {}
+    people.each{|person| @people_hash[person.id] = person}
+
+    @post_fakes = posts.map do |post|
+      f = Fake.new(post, self) 
+      f.comments = post.comments.map do |comment|
+        Fake.new(comment, self) 
+      end
+      f
+    end
+  end
+
+  class Fake
+    attr_accessor :comments
+    def initialize(model, fakes_collection)
+      @fakes_collection = fakes_collection
+      @model = model
+    end
+
+    def id
+      @model.id
+    end
+    def person
+      @fakes_collection.people_hash[@model.person_id]
+    end
+
+    def method_missing(method, *args)
+      @model.send(method, *args)
+    end
+  end
+end

spec/controllers/aspects_controller_spec.rb

@@ -303,4 +303,9 @@ describe AspectsController do
       @aspect0.contacts.include?(@contact).should be false
     end
   end
+
+  describe "#hashes_for_posts" do
+    it 'returns only distinct people' do
+    end
+  end
 end

spec/factories.rb

@@ -78,5 +78,6 @@ end
 
 Factory.define(:comment) do |comment|
   comment.sequence(:text) {|n| "#{n} cats"}
+  comment.association(:person)
 end
 

spec/lib/fake_spec.rb

@@ -0,0 +1,53 @@
+require 'spec_helper'
+describe PostsFake do
+  before do
+    @posts = []
+    @people = []
+    4.times do
+      post = Factory(:status_message)
+      @people << post.person
+      4.times do
+        comment = Factory(:comment, :post => post)
+        @people << comment.person
+      end
+      @posts << post
+    end
+  end
+
+  describe '#initialize' do
+    before do
+      @posts_fake = PostsFake.new(@posts)
+    end
+    it 'sets @people_hash' do
+      @people.each do |person|
+        @posts_fake.people_hash[person.reload.id].should == person
+      end
+      @posts_fake.people_hash.length.should == @people.length
+    end
+
+    it 'sets @post_fakes to an array of fakes' do
+      @posts_fake.post_fakes.each{|x| x.class.should be PostsFake::Fake}
+    end
+  end
+  describe PostsFake::Fake do
+    before do
+      @post = mock()
+      @fakes = mock()
+      @fake = PostsFake::Fake.new(@post, @fakes)
+    end
+    it 'refers to the parent collection for a person' do
+      @post.should_receive(:person_id)
+      @fakes.should_receive(:people_hash).and_return({})
+      @fake.person
+    end
+    it 'refers to its comments array for comments' do
+      @fake.comments = [mock()]
+      @fake.comments
+    end
+    it 'refers to its post for any other field' do
+      @post.should_receive(:text)
+      @fake.text
+    end
+  end
+end
+