remove hidden posts from the cache; add unhidden posts to the cache

app/controllers/post_visibilities_controller.rb

@@ -9,17 +9,36 @@ class PostVisibilitiesController < ApplicationController
   def update
     #note :id references a postvisibility
 
-    @post = Post.where(:id => params[:post_id]).select("id, guid, author_id").first
+    @post = accessible_post
     @contact = current_user.contact_for(@post.author)
 
     if @contact && @vis = PostVisibility.where(:contact_id => @contact.id,
                                                :post_id => params[:post_id]).first
       @vis.hidden = !@vis.hidden 
       if @vis.save
+        update_cache(@vis)
         render 'update'
         return
       end
     end
     render :nothing => true, :status => 403
   end
+
+  protected
+
+  def update_cache(visibility)
+    return unless RedisCache.configured?
+
+    cache = RedisCache.new(current_user, 'created_at')
+
+    if visibility.hidden?
+      cache.remove(accessible_post.id)
+    else
+      cache.add(accessible_post.created_at.to_i, accessible_post.id)
+    end
+  end
+
+  def accessible_post
+    @post ||= Post.where(:id => params[:post_id]).select("id, guid, author_id, created_at").first
+  end
 end

lib/diaspora/redis_cache.rb

@@ -81,6 +81,11 @@ class RedisCache
     self.trim!
   end
 
+  def remove(id)
+    return unless self.cache_exists?
+    self.redis.zrem(set_key, id)
+  end
+
   # exposing the need to tie cache to a stream
   # @return [Array<String>] Acceptable Post types for the given cache
   def self.acceptable_types

spec/controllers/post_visibilities_controller_spec.rb

@@ -8,11 +8,12 @@ describe PostVisibilitiesController do
   before do
     @status = alice.post(:status_message, :text => "hello", :to => alice.aspects.first)
     @vis = @status.post_visibilities.first
+    sign_in :user, bob
   end
 
   describe '#update' do
     before do
-      sign_in :user, bob
+      @controller.stub(:update_cache)
     end
 
     context "on a post you can see" do
@@ -21,6 +22,11 @@ describe PostVisibilitiesController do
         response.should be_success
       end
 
+      it 'calls #update_cache' do
+        @controller.should_receive(:update_cache).with(an_instance_of(PostVisibility))
+        put :update, :format => :js, :id => 42, :post_id => @status.id
+      end
+
       it 'marks hidden if visible' do
         put :update, :format => :js, :id => 42, :post_id => @status.id
         @vis.reload.hidden.should be_true
@@ -51,4 +57,42 @@ describe PostVisibilitiesController do
       end
     end
   end
+  
+  describe '#update_cache' do
+    before do
+      @controller.params[:post_id] = @status.id
+      @cache = RedisCache.new(bob, 'created_at')
+      RedisCache.stub(:new).and_return(@cache)
+      RedisCache.stub(:configured?).and_return(true)
+    end
+
+    it 'does nothing if cache is not configured' do
+      RedisCache.stub(:configured?).and_return(false)
+      RedisCache.should_not_receive(:new)
+      @controller.send(:update_cache, @vis)
+    end
+
+    it 'removes the post from the cache if visibility is marked as hidden' do
+      @vis.hidden = true
+      @cache.should_receive(:remove).with(@vis.post_id)
+      @controller.send(:update_cache, @vis)
+    end
+
+    it 'adds the post from the cache if visibility is marked as hidden' do
+      @vis.hidden = false
+      @cache.should_receive(:add).with(@status.created_at.to_i, @vis.post_id)
+      @controller.send(:update_cache, @vis)
+    end
+  end
+
+  describe "#accessible_post" do
+    it "memoizes a query for a post given a post_id param" do
+      id = 1
+      @controller.params[:post_id] = id
+      Post.should_receive(:where).with(hash_including(:id => id)).once.and_return(stub.as_null_object)
+      2.times do |n|
+        @controller.send(:accessible_post)
+      end
+    end
+  end
 end

spec/lib/diaspora/redis_cache_spec.rb

@@ -160,7 +160,27 @@ describe RedisCache do
       @cache.stub(:cache_exists?).and_return(false)
 
       @redis.should_not_receive(:zadd)
-      @cache.add(@score, @id).should be_false
+      @cache.add(@score, @id)
+    end
+  end
+
+  describe "#remove" do
+    before do
+      @id = 1
+    end
+
+    it "doesn't add if the cache does not exist" do
+      @cache.stub(:cache_exists?).and_return(false)
+
+      @redis.should_not_receive(:zrem)
+      @cache.remove(@id).should be_false
+    end
+
+    it "removes a given id" do
+      @cache.stub(:cache_exists?).and_return(true)
+
+      @redis.should_receive(:zrem).with(@cache.send(:set_key), @id)
+      @cache.remove(@id)
     end
   end
 
@@ -190,6 +210,4 @@ describe RedisCache do
       RedisCache.acceptable_types.should =~ AspectStream::TYPES_OF_POST_IN_STREAM
     end
   end
-
-  describe "#remove"
 end