Optimization refactoring for add_limit_offset!. In partial fullfilment of #1236.

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@2509 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

3 files changed, 13 insertions, 9 deletions

diff --git a/activerecord/CHANGELOG b/activerecord/CHANGELOG
index 809c567127..a181c89dde 100644
--- a/activerecord/CHANGELOG
+++ b/activerecord/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Optimization refactoring for add_limit_offset!. In partial fullfilment of #1236. [skaes@web.de]
+
 * Add ability to get all siblings, including the current child, with acts_as_tree. Recloses #2140. [Michael Schuerig <michael@schuerig.de>]
 
 * Add geometric type for postgresql adapter. #2233 [akaspick@gmail.com]
diff --git a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
index a3d22ed809..90dc951b6d 100644
--- a/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
+++ b/activerecord/lib/active_record/connection_adapters/abstract/database_statements.rb
@@ -73,8 +73,7 @@ module ActiveRecord
 
       # Alias for #add_limit_offset!.
       def add_limit!(sql, options)
-        return unless options
-        add_limit_offset!(sql, options)
+        add_limit_offset!(sql, options) if options
       end
 
       # Appends +LIMIT+ and +OFFSET+ options to a SQL statement.
@@ -84,9 +83,12 @@ module ActiveRecord
       # generates
       #  SELECT * FROM suppliers LIMIT 10 OFFSET 50
       def add_limit_offset!(sql, options)
-        return if options[:limit].nil?
-        sql << " LIMIT #{options[:limit]}"
-        sql << " OFFSET #{options[:offset]}" if options.has_key?(:offset) and !options[:offset].nil?
+        if limit = options[:limit]
+          sql << " LIMIT #{limit}"
+          if offset = options[:offset]
+            sql << " OFFSET #{offset}"
+          end
+        end
       end
     end
   end
diff --git a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
index d56e1f90da..886363bcbe 100755
--- a/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
+++ b/activerecord/lib/active_record/connection_adapters/mysql_adapter.rb
@@ -195,11 +195,11 @@ module ActiveRecord
 
 
       def add_limit_offset!(sql, options) #:nodoc
-        if options[:limit]
-          if options[:offset].blank?
-            sql << " LIMIT #{options[:limit]}"
+        if limit = options[:limit]
+          unless offset = options[:offset]
+            sql << " LIMIT #{limit}"
           else
-            sql << " LIMIT #{options[:offset]}, #{options[:limit]}"
+            sql << " LIMIT #{offset}, #{limit}"
           end
         end
       end