Merge pull request #37 from okbreathe/dm-compat

Add DM compatibility

lib/hirefire/backend.rb

@@ -27,6 +27,10 @@ def self.included(base)
           end
         end
 
+        if defined?(::Delayed::Backend::DataMapper::Job)
+          base.send(:include, HireFire::Backend::DelayedJob::DataMapper)
+        end
+
         if defined?(::Delayed::Backend::Mongoid::Job)
           base.send(:include, HireFire::Backend::DelayedJob::Mongoid)
         end

lib/hirefire/backend/delayed_job.rb

@@ -6,6 +6,7 @@ module DelayedJob
       autoload :ActiveRecord,  'hirefire/backend/delayed_job/active_record'
       autoload :ActiveRecord2, 'hirefire/backend/delayed_job/active_record_2'
       autoload :Mongoid,       'hirefire/backend/delayed_job/mongoid'
+      autoload :DataMapper,    'hirefire/backend/delayed_job/data_mapper'
     end
   end
 end

lib/hirefire/backend/delayed_job/data_mapper.rb

@@ -0,0 +1,30 @@
+# encoding: utf-8
+
+module HireFire
+  module Backend
+    module DelayedJob
+      module DataMapper
+
+        ##
+        # Counts the amount of queued jobs in the database,
+        # failed jobs are excluded from the sum
+        #
+        # @return [Fixnum] the amount of pending jobs
+        def jobs
+          ::Delayed::Job.count(:failed_at => nil, :run_at.lte => Time.now.utc)
+        end
+
+        ##
+        # Counts the amount of jobs that are locked by a worker
+        # There is no other performant way to determine the amount
+        # of workers there currently are
+        #
+        # @return [Fixnum] the amount of (assumably working) workers
+        def working
+          ::Delayed::Job.count(:locked_by.not => nil)
+        end
+
+      end
+    end
+  end
+end

lib/hirefire/environment.rb

@@ -42,6 +42,20 @@ def self.included(base)
           after_update  'self.class.environment.fire',
             :unless => Proc.new { |job| job.failed_at.nil? }
         end
+      elsif base.name == "Delayed::Backend::DataMapper::Job"
+        base.send :extend, HireFire::Environment::DelayedJob::ClassMethods
+
+        base.class_eval do
+          after :create do
+            self.class.hirefire_hire
+          end
+          after :destroy do
+            self.class.environment.fire
+          end
+          after :update do
+            self.class.environment.fire unless self.failed_at.nil?
+          end
+        end
       end
 
       Logger.message("#{ base.name } detected!")

lib/hirefire/initializer.rb

@@ -43,6 +43,15 @@ def self.initialize!
           send(:include, HireFire::Backend)
         end
 
+        ##
+        # If DelayedJob is using DataMapper, then include
+        # HireFire::Environment in to the DataMapper Delayed Job Backend
+        if defined?(::Delayed::Backend::DataMapper::Job)
+          ::Delayed::Backend::DataMapper::Job.
+          send(:include, HireFire::Environment).
+          send(:include, HireFire::Backend)
+        end
+
         ##
         # Load Delayed Job extensions, this will patch Delayed::Worker
         # to implement the necessary hooks to invoke HireFire from