From b17bc58c76c580911e18f2dd90a17aaae192a2a3 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Jos=C3=A9=20Valim?= <jose.valim@gmail.com>
Date: Thu, 15 Dec 2011 20:46:30 +0100
Subject: [PATCH] Move delegation reponsibilities of Relation to a module. Also
 precompile method missing calls for rofscale.

---
 activerecord/lib/active_record.rb             |  1 +
 activerecord/lib/active_record/relation.rb    | 23 +---------
 .../lib/active_record/relation/delegation.rb  | 42 +++++++++++++++++++
 3 files changed, 44 insertions(+), 22 deletions(-)
 create mode 100644 activerecord/lib/active_record/relation/delegation.rb

diff --git a/activerecord/lib/active_record.rb b/activerecord/lib/active_record.rb
index b1377c24dd..92f3666378 100644
--- a/activerecord/lib/active_record.rb
+++ b/activerecord/lib/active_record.rb
@@ -51,6 +51,7 @@ module ActiveRecord
       autoload :SpawnMethods
       autoload :Batches
       autoload :Explain
+      autoload :Delegation
     end
 
     autoload :Base
diff --git a/activerecord/lib/active_record/relation.rb b/activerecord/lib/active_record/relation.rb
index 8aaab10b1e..0f78fe1ab7 100644
--- a/activerecord/lib/active_record/relation.rb
+++ b/activerecord/lib/active_record/relation.rb
@@ -1,6 +1,5 @@
 # -*- coding: utf-8 -*-
 require 'active_support/core_ext/object/blank'
-require 'active_support/core_ext/module/delegation'
 
 module ActiveRecord
   # = Active Record Relation
@@ -10,13 +9,7 @@ module ActiveRecord
     MULTI_VALUE_METHODS = [:select, :group, :order, :joins, :where, :having, :bind]
     SINGLE_VALUE_METHODS = [:limit, :offset, :lock, :readonly, :from, :reorder, :reverse_order, :uniq]
 
-    include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain
-
-    # These are explicitly delegated to improve performance (avoids method_missing)
-    delegate :to_xml, :to_yaml, :length, :collect, :map, :each, :all?, :include?, :to_ary, :to => :to_a
-    delegate :ast, :engine, :to => :arel
-    delegate :table_name, :quoted_table_name, :primary_key, :quoted_primary_key,
-             :connection, :columns_hash, :auto_explain_threshold_in_seconds, :to => :klass
+    include FinderMethods, Calculations, SpawnMethods, QueryMethods, Batches, Explain, Delegation
 
     attr_reader :table, :klass, :loaded
     attr_accessor :extensions, :default_scoped
@@ -519,20 +512,6 @@ module ActiveRecord
       end
     end
 
-    protected
-
-    def method_missing(method, *args, &block)
-      if Array.method_defined?(method)
-        to_a.send(method, *args, &block)
-      elsif @klass.respond_to?(method)
-        scoping { @klass.send(method, *args, &block) }
-      elsif arel.respond_to?(method)
-        arel.send(method, *args, &block)
-      else
-        super
-      end
-    end
-
     private
 
     def references_eager_loaded_tables?
diff --git a/activerecord/lib/active_record/relation/delegation.rb b/activerecord/lib/active_record/relation/delegation.rb
new file mode 100644
index 0000000000..c1fcd48a8e
--- /dev/null
+++ b/activerecord/lib/active_record/relation/delegation.rb
@@ -0,0 +1,42 @@
+require 'active_support/core_ext/module/delegation'
+
+module ActiveRecord
+  module Delegation
+    # These are explicitly delegated to improve performance (avoids method_missing)
+    delegate :to_xml, :to_yaml, :length, :collect, :map, :each, :all?, :include?, :to_ary, :to => :to_a
+    delegate :ast, :engine, :to => :arel
+    delegate :table_name, :quoted_table_name, :primary_key, :quoted_primary_key,
+             :connection, :columns_hash, :auto_explain_threshold_in_seconds, :to => :klass
+
+    def self.delegate_to_scoped_klass(method)
+      if method.to_s =~ /[a-z]\w*!?/
+        module_eval <<-RUBY, __FILE__, __LINE__ + 1
+          def #{method}(*args, &block)
+            scoping { @klass.#{method}(*args, &block) }
+          end
+        RUBY
+      else
+        module_eval <<-RUBY, __FILE__, __LINE__ + 1
+          def #{method}(*args, &block)
+            scoping { @klass.send(#{method.inspect}, *args, &block) }
+          end
+        RUBY
+      end
+    end
+
+    protected
+
+    def method_missing(method, *args, &block)
+      if Array.method_defined?(method)
+        to_a.send(method, *args, &block)
+      elsif @klass.respond_to?(method)
+        ::ActiveRecord::Delegation.delegate_to_scoped_klass(method)
+        scoping { @klass.send(method, *args, &block) }
+      elsif arel.respond_to?(method)
+        arel.send(method, *args, &block)
+      else
+        super
+      end
+    end
+  end
+end
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