From 2c8ae22b87e26eeeffdda19a353ea46594b21672 Mon Sep 17 00:00:00 2001
From: Sam <sam.saffron@gmail.com>
Date: Mon, 17 Mar 2014 11:59:34 +1100
Subject: [PATCH] FEATURE: add a simple queue Scheduler::Defer.later {}

For quick jobs that do not need to be sent to sidekiq,
runs inline in a single thread but does not block
---
 lib/auth/default_current_user_provider.rb |  9 +++--
 lib/scheduler/defer.rb                    | 48 +++++++++++++++++++++++
 lib/scheduler/scheduler.rb                |  1 +
 spec/components/scheduler/defer_spec.rb   | 40 +++++++++++++++++++
 4 files changed, 95 insertions(+), 3 deletions(-)
 create mode 100644 lib/scheduler/defer.rb
 create mode 100644 spec/components/scheduler/defer_spec.rb

diff --git a/lib/auth/default_current_user_provider.rb b/lib/auth/default_current_user_provider.rb
index b48472e91af..835c9586c39 100644
--- a/lib/auth/default_current_user_provider.rb
+++ b/lib/auth/default_current_user_provider.rb
@@ -33,9 +33,12 @@ class Auth::DefaultCurrentUserProvider
 
     if current_user
 
-      Jobs.enqueue(:update_user_info,
-                    user_id: current_user.id,
-                    ip: request.ip)
+      u = current_user
+      Scheduler::Defer.later do
+        u.update_last_seen!
+        u.update_ip_address!(request.ip)
+      end
+
     end
 
     # possible we have an api call, impersonate
diff --git a/lib/scheduler/defer.rb b/lib/scheduler/defer.rb
new file mode 100644
index 00000000000..46b94ee508d
--- /dev/null
+++ b/lib/scheduler/defer.rb
@@ -0,0 +1,48 @@
+module Scheduler
+  module Deferrable
+    def initialize
+      @async = Rails.env != "test"
+      @queue = Queue.new
+      @thread = Thread.new {
+        while true
+          do_work
+        end
+      }
+    end
+
+    # for test
+    def async=(val)
+      @async = val
+    end
+
+    def later(&blk)
+      if @async
+        @queue << [RailsMultisite::ConnectionManagement.current_db, blk]
+      else
+        blk.call
+      end
+    end
+
+    def stop!
+      @thread.kill
+    end
+
+    private
+
+    def do_work
+      db, job = @queue.deq
+      RailsMultisite::ConnectionManagement.establish_connection(db: db)
+      job.call
+    rescue => ex
+      Discourse.handle_exception(ex)
+    ensure
+      ActiveRecord::Base.connection_handler.clear_active_connections!
+    end
+
+  end
+
+  class Defer
+    extend Deferrable
+    initialize
+  end
+end
diff --git a/lib/scheduler/scheduler.rb b/lib/scheduler/scheduler.rb
index a69b1f7a5ce..e9f389194f0 100644
--- a/lib/scheduler/scheduler.rb
+++ b/lib/scheduler/scheduler.rb
@@ -4,3 +4,4 @@ end
 require_dependency 'scheduler/schedule'
 require_dependency 'scheduler/schedule_info'
 require_dependency 'scheduler/manager'
+require_dependency 'scheduler/defer'
diff --git a/spec/components/scheduler/defer_spec.rb b/spec/components/scheduler/defer_spec.rb
new file mode 100644
index 00000000000..b27c36c3a7b
--- /dev/null
+++ b/spec/components/scheduler/defer_spec.rb
@@ -0,0 +1,40 @@
+# encoding: utf-8
+require 'spec_helper'
+require 'scheduler/scheduler'
+
+describe Scheduler::Defer do
+  class DeferInstance
+    include Scheduler::Deferrable
+  end
+
+  def wait_for(timeout, &blk)
+    till = Time.now + (timeout.to_f / 1000)
+    while Time.now < till && !blk.call
+      sleep 0.001
+    end
+  end
+
+  before do
+    @defer = DeferInstance.new
+    @defer.async = true
+  end
+
+  after do
+    @defer.stop!
+  end
+
+  it "can queue jobs properly" do
+    s = nil
+
+    @defer.later do
+      s = "good"
+    end
+
+    wait_for(10) do
+      s == "good"
+    end
+
+    s.should == "good"
+  end
+
+end