speeding up clone_attributes, changing readonly to be initialized in def initialize

Signed-off-by: wycats <wycats@gmail.com>

activerecord/lib/active_record/base.rb

@@ -1507,6 +1507,7 @@ module ActiveRecord #:nodoc:
         @attributes = attributes_from_column_definition
         @attributes_cache = {}
         @new_record = true
+        @readonly = false
         ensure_proper_type
 
         if scope = self.class.send(:current_scoped_methods)
@@ -1571,7 +1572,7 @@ module ActiveRecord #:nodoc:
       #   user_path(user)  # => "/users/Phusion"
       def to_param
         # We can't use alias_method here, because method 'id' optimizes itself on the fly.
-        (id = self.id) ? id.to_s : nil # Be sure to stringify the id for routes
+        id && id.to_s # Be sure to stringify the id for routes
       end
 
       # Returns a cache key that can be used to identify this record.
@@ -1696,7 +1697,7 @@ module ActiveRecord #:nodoc:
       # This is especially useful for boolean flags on existing records. The regular +update_attribute+ method
       # in Base is replaced with this when the validations module is mixed in, which it is by default.
       def update_attribute(name, value)
-        send(name.to_s + '=', value)
+        send("#{name}=", value)
         save(:validate => false)
       end
 
@@ -1913,14 +1914,14 @@ module ActiveRecord #:nodoc:
       # Returns duplicated record with unfreezed attributes.
       def dup
         obj = super
-        obj.instance_variable_set('@attributes', instance_variable_get('@attributes').dup)
+        obj.instance_variable_set('@attributes', @attributes.dup)
         obj
       end
 
       # Returns +true+ if the record is read only. Records loaded through joins with piggy-back
       # attributes will be marked as read only since they cannot be saved.
       def readonly?
-        defined?(@readonly) && @readonly == true
+        @readonly
       end
 
       # Marks this record as read only.
@@ -1940,10 +1941,10 @@ module ActiveRecord #:nodoc:
 
     protected
       def clone_attributes(reader_method = :read_attribute, attributes = {})
-        self.attribute_names.inject(attributes) do |attrs, name|
-          attrs[name] = clone_attribute_value(reader_method, name)
-          attrs
+        attribute_names.each do |name|
+          attributes[name] = clone_attribute_value(reader_method, name)
         end
+        attributes
       end
 
       def clone_attribute_value(reader_method, attribute_name)
@@ -2246,4 +2247,4 @@ end
 
 # TODO: Remove this and make it work with LAZY flag
 require 'active_record/connection_adapters/abstract_adapter'
-ActiveRecord.run_base_hooks(ActiveRecord::Base)
+ActiveRecord.run_base_hooks(ActiveRecord::Base)