Gantt perf: fixed that Project#start_date and #due_date run way too much queries.

git-svn-id: svn+ssh://rubyforge.org/var/svn/redmine/trunk@11135 e93f8b46-1217-0410-a6f0-8f06a7374b81

app/models/project.rb

@@ -289,6 +289,8 @@ class Project < ActiveRecord::Base
     @allowed_parents = nil
     @allowed_permissions = nil
     @actions_allowed = nil
+    @start_date = nil
+    @due_date = nil
     super
   end
 
@@ -538,20 +540,20 @@ class Project < ActiveRecord::Base
 
   # The earliest start date of a project, based on it's issues and versions
   def start_date
-    [
+    @start_date ||= [
      issues.minimum('start_date'),
-     shared_versions.collect(&:effective_date),
-     shared_versions.collect(&:start_date)
-    ].flatten.compact.min
+     shared_versions.minimum('effective_date'),
+     Issue.fixed_version(shared_versions).minimum('start_date')
+    ].compact.min
   end
 
   # The latest due date of an issue or version
   def due_date
-    [
+    @due_date ||= [
      issues.maximum('due_date'),
-     shared_versions.collect(&:effective_date),
-     shared_versions.collect {|v| v.fixed_issues.maximum('due_date')}
-    ].flatten.compact.max
+     shared_versions.maximum('effective_date'),
+     Issue.fixed_version(shared_versions).maximum('due_date')
+    ].compact.max
   end
 
   def overdue?