Clear changesets and changes with raw sql when deleting a repository (#1627).

git-svn-id: http://redmine.rubyforge.org/svn/trunk@1666 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/repository.rb

@@ -17,9 +17,13 @@
 
 class Repository < ActiveRecord::Base
   belongs_to :project
-  has_many :changesets, :dependent => :destroy, :order => "#{Changeset.table_name}.committed_on DESC, #{Changeset.table_name}.id DESC"
+  has_many :changesets, :order => "#{Changeset.table_name}.committed_on DESC, #{Changeset.table_name}.id DESC"
   has_many :changes, :through => :changesets
   
+  # Raw SQL to delete changesets and changes in the database
+  # has_many :changesets, :dependent => :destroy is too slow for big repositories
+  before_destroy :clear_changesets
+  
   # Checks if the SCM is enabled when creating a repository
   validate_on_create { |r| r.errors.add(:type, :activerecord_error_invalid) unless Setting.enabled_scm.include?(r.class.name.demodulize) }
   
@@ -127,4 +131,9 @@ class Repository < ActiveRecord::Base
     root_url.strip!
     true
   end
+  
+  def clear_changesets
+    connection.delete("DELETE FROM changes WHERE changes.changeset_id IN (SELECT changesets.id FROM changesets WHERE changesets.repository_id = #{id})")
+    connection.delete("DELETE FROM changesets WHERE changesets.repository_id = #{id}")
+  end
 end