PERF: move message bus to the front of the middleware stack

Organise all initializers so they are properly ordered and use the same naming scheme

Gemfile.lock

@@ -193,7 +193,7 @@ GEM
     mail (2.6.3)
       mime-types (>= 1.16, < 3)
     memory_profiler (0.9.4)
-    message_bus (1.0.16)
+    message_bus (1.1.0)
       rack (>= 1.1.3)
       redis
     metaclass (0.0.4)
@@ -315,7 +315,7 @@ GEM
       ffi (>= 1.0.6)
       msgpack (>= 0.4.3)
       trollop (>= 1.16.2)
-    redis (3.2.1)
+    redis (3.2.2)
     redis-namespace (1.5.2)
       redis (~> 3.0, >= 3.0.4)
     ref (2.0.0)

config/initializers/004-message_bus.rb

@@ -0,0 +1,79 @@
+MessageBus.site_id_lookup do
+  RailsMultisite::ConnectionManagement.current_db
+end
+
+def setup_message_bus_env(env)
+  return if env["__mb"]
+
+  host = RailsMultisite::ConnectionManagement.host(env)
+  RailsMultisite::ConnectionManagement.with_hostname(host) do
+    user = CurrentUser.lookup_from_env(env)
+    user_id = user && user.id
+    is_admin = !!(user && user.admin?)
+    group_ids = if is_admin
+      # special rule, admin is allowed access to all groups
+      Group.pluck(:id)
+    elsif user
+      user.groups.pluck('groups.id')
+    end
+
+    hash = {
+      extra_headers:
+        {
+          "Access-Control-Allow-Origin" => Discourse.base_url_no_prefix,
+          "Access-Control-Allow-Methods" => "GET, POST",
+          "Access-Control-Allow-Headers" => "X-SILENCE-LOGGER, X-Shared-Session-Key"
+        },
+      user_id: user_id,
+      group_ids: group_ids,
+      is_admin: is_admin
+
+    }
+    env["__mb"] = hash
+  end
+
+  nil
+end
+
+MessageBus.extra_response_headers_lookup do |env|
+  setup_message_bus_env(env)
+  env["__mb"][:extra_headers]
+end
+
+MessageBus.user_id_lookup do |env|
+  setup_message_bus_env(env)
+  env["__mb"][:user_id]
+end
+
+MessageBus.group_ids_lookup do |env|
+  setup_message_bus_env(env)
+  env["__mb"][:group_ids]
+end
+
+MessageBus.is_admin_lookup do |env|
+  setup_message_bus_env(env)
+  env["__mb"][:is_admin]
+end
+
+MessageBus.on_connect do |site_id|
+  RailsMultisite::ConnectionManagement.establish_connection(db: site_id)
+end
+
+MessageBus.on_disconnect do |site_id|
+  ActiveRecord::Base.connection_handler.clear_active_connections!
+end
+
+# Point at our redis
+MessageBus.redis_config = GlobalSetting.redis_config
+
+MessageBus.long_polling_enabled = SiteSetting.enable_long_polling
+MessageBus.long_polling_interval = SiteSetting.long_polling_interval
+
+
+MessageBus.cache_assets = !Rails.env.development?
+MessageBus.enable_diagnostics
+
+if Rails.env == "test" || $0 =~ /rake$/
+  # disable keepalive in testing
+  MessageBus.keepalive_interval = -1
+end

config/initializers/04-message_bus.rb

@@ -1,57 +0,0 @@
-MessageBus.site_id_lookup do
-  RailsMultisite::ConnectionManagement.current_db
-end
-
-MessageBus.extra_response_headers_lookup do |env|
-  {
-    "Access-Control-Allow-Origin" => Discourse.base_url_no_prefix,
-    "Access-Control-Allow-Methods" => "GET, POST",
-    "Access-Control-Allow-Headers" => "X-SILENCE-LOGGER, X-Shared-Session-Key"
-  }
-end
-
-MessageBus.user_id_lookup do |env|
-  user = CurrentUser.lookup_from_env(env)
-  user.id if user
-end
-
-MessageBus.group_ids_lookup do |env|
-  user = CurrentUser.lookup_from_env(env)
-  if user && user.admin?
-    # special rule, admin is allowed access to all groups
-    Group.pluck(:id)
-  elsif user
-    user.groups.pluck('groups.id')
-  end
-end
-
-MessageBus.on_connect do |site_id|
-  RailsMultisite::ConnectionManagement.establish_connection(db: site_id)
-end
-
-MessageBus.on_disconnect do |site_id|
-  ActiveRecord::Base.connection_handler.clear_active_connections!
-end
-
-# Point at our redis
-MessageBus.redis_config = GlobalSetting.redis_config
-
-MessageBus.long_polling_enabled = SiteSetting.enable_long_polling
-MessageBus.long_polling_interval = SiteSetting.long_polling_interval
-
-MessageBus.is_admin_lookup do |env|
-  user = CurrentUser.lookup_from_env(env)
-  if user && user.admin
-    true
-  else
-    false
-  end
-end
-
-MessageBus.cache_assets = !Rails.env.development?
-MessageBus.enable_diagnostics
-
-if Rails.env == "test" || $0 =~ /rake$/
-  # disable keepalive in testing
-  MessageBus.keepalive_interval = -1
-end

config/initializers/050-force_https.rb

@@ -12,6 +12,3 @@ class Discourse::ForceHttpsMiddleware
 
 end
 
-# this code plays up, skip for now
-#Rails.configuration.middleware.insert_before MessageBus::Rack::Middleware, Discourse::ForceHttpsMiddleware
-

config/initializers/200-message_bus_request_tracker.rb

@@ -0,0 +1,13 @@
+# we want MesageBus in the absolute front
+# this is important cause the vast majority of web requests go to it
+# this allows us to avoid full middleware crawls each time
+Rails.configuration.middleware.delete MessageBus::Rack::Middleware
+Rails.configuration.middleware.unshift MessageBus::Rack::Middleware
+
+# no reason to track this in development, that is 300+ redis calls saved per
+# page view (we serve all assets out of thin in development)
+if Rails.env != 'development' || ENV['TRACK_REQUESTS']
+  require 'middleware/request_tracker'
+  Rails.configuration.middleware.unshift Middleware::RequestTracker
+end
+

config/initializers/99-request_tracker.rb

@@ -1,6 +0,0 @@
-# no reason to track this in development, that is 300+ redis calls saved per
-# page view (we serve all assets out of thin in development)
-if Rails.env != 'development' || ENV['TRACK_REQUESTS']
-  require 'middleware/request_tracker'
-  Rails.configuration.middleware.unshift Middleware::RequestTracker
-end

config/initializers/inflections.rb

@@ -1,10 +0,0 @@
-# Be sure to restart your server when you modify this file.
-
-# Add new inflection rules using the following format
-# (all these examples are active by default):
-# ActiveSupport::Inflector.inflections do |inflect|
-#   inflect.plural /^(ox)$/i, '\1en'
-#   inflect.singular /^(ox)en/i, '\1'
-#   inflect.irregular 'person', 'people'
-#   inflect.uncountable %w( fish sheep )
-# end

config/initializers/mime_types.rb

@@ -1,5 +0,0 @@
-# Be sure to restart your server when you modify this file.
-
-# Add new mime types for use in respond_to blocks:
-# Mime::Type.register "text/richtext", :rtf
-# Mime::Type.register_alias "text/html", :iphone