1 files changed, 30 insertions, 0 deletions
diff --git a/actionpack/lib/action_controller/cgi_ext/session_performance_fix.rb b/actionpack/lib/action_controller/cgi_ext/session_performance_fix.rb
new file mode 100644
index 0000000000..7305167860
--- /dev/null
+++ b/actionpack/lib/action_controller/cgi_ext/session_performance_fix.rb
@@ -0,0 +1,30 @@
+# CGI::Session#create_new_id requires 'digest/md5' on every call.  This makes
+# sense when spawning processes per request, but is unnecessarily expensive
+# when serving requests from a long-lived process.
+#
+# http://railsexpress.de/blog/articles/2005/11/22/speeding-up-the-creation-of-new-sessions
+require 'cgi/session'
+require 'digest/md5'
+
+class CGI
+  class Session #:nodoc:
+    private
+      # Create a new session id.
+      #
+      # The session id is an MD5 hash based upon the time,
+      # a random number, and a constant string.  This routine
+      # is used internally for automatically generated
+      # session ids.
+      def create_new_id
+        md5 = Digest::MD5::new
+        now = Time::now
+        md5.update(now.to_s)
+        md5.update(String(now.usec))
+        md5.update(String(rand(0)))
+        md5.update(String($$))
+        md5.update('foobar')
+        @new_session = true
+        md5.hexdigest
+      end
+  end
+end