9 files changed, 68 insertions, 25 deletions
diff --git a/app/controllers/accounts_controller.rb b/app/controllers/accounts_controller.rb
index e91013025..41ee1f5ee 100644
--- a/app/controllers/accounts_controller.rb
+++ b/app/controllers/accounts_controller.rb
@@ -40,9 +40,9 @@ class AccountsController < ApplicationController
       end
 
       format.json do
-        render_cached_json(['activitypub', 'actor', @account], content_type: 'application/activity+json') do
-          ActiveModelSerializers::SerializableResource.new(@account, serializer: ActivityPub::ActorSerializer, adapter: ActivityPub::Adapter)
-        end
+        # TODO: Remember to add authorized_fetch_mode, restrict_fields_to when ported
+        expires_in 3.minutes, public: !(signed_request_account.present?)
+        render_with_cache json: @account, content_type: 'application/activity+json', serializer: ActivityPub::ActorSerializer, adapter: ActivityPub::Adapter
       end
     end
   end
diff --git a/app/controllers/activitypub/collections_controller.rb b/app/controllers/activitypub/collections_controller.rb
index e2274ee1a..cd23506f3 100644
--- a/app/controllers/activitypub/collections_controller.rb
+++ b/app/controllers/activitypub/collections_controller.rb
@@ -9,14 +9,8 @@ class ActivityPub::CollectionsController < Api::BaseController
   before_action :set_cache_headers
 
   def show
-    render_cached_json(['activitypub', 'collection', @account, params[:id]], content_type: 'application/activity+json') do
-      ActiveModelSerializers::SerializableResource.new(
-        collection_presenter,
-        serializer: ActivityPub::CollectionSerializer,
-        adapter: ActivityPub::Adapter,
-        skip_activities: true
-      )
-    end
+    expires_in 3.minutes
+    render_with_cache json: collection_presenter, content_type: 'application/activity+json', serializer: ActivityPub::CollectionSerializer, adapter: ActivityPub::Adapter, skip_activities: true
   end
 
   private
diff --git a/app/controllers/api/v1/custom_emojis_controller.rb b/app/controllers/api/v1/custom_emojis_controller.rb
index 1bb19a09d..6ddb5936c 100644
--- a/app/controllers/api/v1/custom_emojis_controller.rb
+++ b/app/controllers/api/v1/custom_emojis_controller.rb
@@ -6,8 +6,7 @@ class Api::V1::CustomEmojisController < Api::BaseController
   skip_before_action :set_cache_headers
 
   def index
-    render_cached_json('api:v1:custom_emojis', expires_in: 1.minute) do
-      ActiveModelSerializers::SerializableResource.new(CustomEmoji.local.where(disabled: false), each_serializer: REST::CustomEmojiSerializer)
-    end
+    expires_in 3.minutes, public: true
+    render_with_cache(each:serializer: REST:CustomEmojiSerializer) { CustomEmoji.local.where(disabled: false) }
   end
 end
diff --git a/app/controllers/api/v1/instances/activity_controller.rb b/app/controllers/api/v1/instances/activity_controller.rb
index 09edfe365..d0080c5c2 100644
--- a/app/controllers/api/v1/instances/activity_controller.rb
+++ b/app/controllers/api/v1/instances/activity_controller.rb
@@ -7,7 +7,8 @@ class Api::V1::Instances::ActivityController < Api::BaseController
   respond_to :json
 
   def show
-    render_cached_json('api:v1:instances:activity:show', expires_in: 1.day) { activity }
+    expires_in 1.day, public: true
+    render_with_cache json: :activity, expires_in: 1.day
   end
 
   private
diff --git a/app/controllers/api/v1/instances/peers_controller.rb b/app/controllers/api/v1/instances/peers_controller.rb
index 93c4c45af..bb04e604d 100644
--- a/app/controllers/api/v1/instances/peers_controller.rb
+++ b/app/controllers/api/v1/instances/peers_controller.rb
@@ -7,7 +7,8 @@ class Api::V1::Instances::PeersController < Api::BaseController
   respond_to :json
 
   def index
-    render_cached_json('api:v1:instances:peers:index', expires_in: 1.day) { actively_federated_domains }
+    expires_in 1.day, public: true
+    render_with_cache(expires_in: 1.day) { actively_federated_domains }
   end
 
   private
diff --git a/app/controllers/application_controller.rb b/app/controllers/application_controller.rb
index eca3180b9..364e8487f 100644
--- a/app/controllers/application_controller.rb
+++ b/app/controllers/application_controller.rb
@@ -10,6 +10,7 @@ class ApplicationController < ActionController::Base
   include Localized
   include UserTrackingConcern
   include SessionTrackingConcern
+  include CacheConcern
 
   helper_method :current_account
   helper_method :current_session
diff --git a/app/controllers/concerns/cache_concern.rb b/app/controllers/concerns/cache_concern.rb
new file mode 100644
index 000000000..c7d25ae00
--- /dev/null
+++ b/app/controllers/concerns/cache_concern.rb
@@ -0,0 +1,50 @@
+# frozen_string_literal: true
+
+module CacheConcern
+  extend ActiveSupport::Concern
+
+  def render_with_cache(**options)
+    raise ArgumentError, 'only JSON render calls are supported' unless options.key?(:json) || block_given?
+
+    key        = options.delete(:key) || [[params[:controller], params[:action]].join('/'), options[:json].respond_to?(:cache_key) ? options[:json].cache_key : nil, options[:fields].nil? ? nil : options[:fields].join(',')].compact.join(':')
+    expires_in = options.delete(:expires_in) || 3.minutes
+    body       = Rails.cache.read(key, raw: true)
+
+    if body
+      render(options.except(:json, :serializer, :each_serializer, :adapter, :fields).merge(json: body))
+    else
+      if block_given?
+        options[:json] = yield
+      elsif options[:json].is_a?(Symbol)
+        options[:json] = send(options[:json])
+      end
+
+      render(options)
+      Rails.cache.write(key, response.body, expires_in: expires_in, raw: true)
+    end
+  end
+
+  def set_cache_headers
+    response.headers['Vary'] = public_fetch_mode? ? 'Accept' : 'Accept, Signature'
+  end
+
+  def cache_collection(raw, klass)
+    return raw unless klass.respond_to?(:with_includes)
+
+    raw                    = raw.cache_ids.to_a if raw.is_a?(ActiveRecord::Relation)
+    cached_keys_with_value = Rails.cache.read_multi(*raw).transform_keys(&:id)
+    uncached_ids           = raw.map(&:id) - cached_keys_with_value.keys
+
+    klass.reload_stale_associations!(cached_keys_with_value.values) if klass.respond_to?(:reload_stale_associations!)
+
+    unless uncached_ids.empty?
+      uncached = klass.where(id: uncached_ids).with_includes.each_with_object({}) { |item, h| h[item.id] = item }
+
+      uncached.each_value do |item|
+        Rails.cache.write(item, item)
+      end
+    end
+
+    raw.map { |item| cached_keys_with_value[item.id] || uncached[item.id] }.compact
+  end
+end
diff --git a/app/controllers/emojis_controller.rb b/app/controllers/emojis_controller.rb
index 3feb08132..41f1e1c5c 100644
--- a/app/controllers/emojis_controller.rb
+++ b/app/controllers/emojis_controller.rb
@@ -7,9 +7,8 @@ class EmojisController < ApplicationController
   def show
     respond_to do |format|
       format.json do
-        render_cached_json(['activitypub', 'emoji', @emoji], content_type: 'application/activity+json') do
-          ActiveModelSerializers::SerializableResource.new(@emoji, serializer: ActivityPub::EmojiSerializer, adapter: ActivityPub::Adapter)
-        end
+        expires_in 3.minutes, public: true
+        render_with_cache json: @emoji, content_type: 'application/activity+json', serializer: ActivityPub::EmojiSerializer, adapter: ActivityPub::Adapter
       end
     end
   end
diff --git a/app/controllers/statuses_controller.rb b/app/controllers/statuses_controller.rb
index 2edd19064..a000f4dcf 100644
--- a/app/controllers/statuses_controller.rb
+++ b/app/controllers/statuses_controller.rb
@@ -42,17 +42,15 @@ class StatusesController < ApplicationController
       end
 
       format.json do
-        render_cached_json(['activitypub', 'note', @status], content_type: 'application/activity+json', public: !@stream_entry.hidden?) do
-          ActiveModelSerializers::SerializableResource.new(@status, serializer: ActivityPub::NoteSerializer, adapter: ActivityPub::Adapter)
-        end
+        expires_in 3.minutes, public: @status.distributable?
+        render_with_cache json: @status, content_type: 'application/activity+json', serializer: ActivityPub::NoteSerializer, adapter: ActivityPub::Adapter
       end
     end
   end
 
   def activity
-    render_cached_json(['activitypub', 'activity', @status], content_type: 'application/activity+json', public: !@stream_entry.hidden?) do
-      ActiveModelSerializers::SerializableResource.new(@status, serializer: ActivityPub::ActivitySerializer, adapter: ActivityPub::Adapter)
-    end
+    expires_in 3.minutes, public: @status.distributable? 
+    render_with_cache json: @status, content_type: 'application/activity+json', serializer: ActivityPub::NoteSerializer, adapter: ActivityPub::Adapter
   end
 
   def embed