Added MemCacheStore for storing session data in Danga's MemCache system [Bob Cottrell]

git-svn-id: http://svn-commit.rubyonrails.org/rails/trunk@330 5ecf4fe2-1ee6-0310-87b1-e25e094e27de

actionpack/CHANGELOG

@@ -1,5 +1,8 @@
 *SVN*
 
+* Added MemCacheStore for storing session data in Danga's MemCache system [Bob Cottrell]
+  Depends on: MemCached server (http://www.danga.com/memcached/), MemCache client (http://raa.ruby-lang.org/project/memcache/)
+
 * Fixed redirects when the controller and action is named the same. Still haven't fixed same controller, module, and action, though #201 [Josh]
 
 * Fixed problems with running multiple functional tests in Rails under 1.8.2 by including hack for test/unit weirdness

actionpack/lib/action_controller/session/mem_cache_store.rb

@@ -0,0 +1,95 @@
+# cgi/session/memcached.rb - persistent storage of marshalled session data
+#
+# == Overview
+#
+# This file provides the CGI::Session::MemCache class, which builds
+# persistence of storage data on top of the MemCache library.  See
+# cgi/session.rb for more details on session storage managers.
+#
+
+begin
+  require 'cgi/session'
+  require 'memcache'
+
+  class CGI
+    class Session
+      # MemCache-based session storage class.
+      #
+      # This builds upon the top-level MemCache class provided by the
+      # library file memcache.rb.  Session data is marshalled and stored
+      # in a memcached cache.
+      class MemCacheStore
+        def check_id(id) #:nodoc:#
+          /[^0-9a-zA-Z]+/ =~ id.to_s ? false : true
+        end
+
+        # Create a new CGI::Session::MemCache instance
+        #
+        # This constructor is used internally by CGI::Session.  The
+        # user does not generally need to call it directly.
+        #
+        # +session+ is the session for which this instance is being
+        # created.  The session id must only contain alphanumeric
+        # characters; automatically generated session ids observe
+        # this requirement.
+        #
+        # +option+ is a hash of options for the initialiser.  The
+        # following options are recognized:
+        #
+        # cache::  an instance of a MemCache client to use as the
+        #      session cache.
+        #
+        # This session's memcache entry will be created if it does
+        # not exist, or retrieved if it does.
+        def initialize(session, options = {})
+          id = session.session_id
+          unless check_id(id)
+            raise ArgumentError, "session_id '%s' is invalid" % id
+  	      end
+          @cache = options['cache']
+  	      @session_key = "session:#{id}"
+  	      @hash = {}
+        end
+
+        # Restore session state from the session's memcache entry.
+        #
+        # Returns the session state as a hash.
+        def restore
+          begin
+            @hash = @cache[@session_key]
+          rescue
+            # Ignore session get failures.
+          end
+          @hash = {} unless @hash
+  	      @hash
+        end
+
+        # Save session state to the session's memcache entry.
+        def update
+          begin
+            @cache[@session_key] = @hash
+          rescue
+            # Ignore session update failures.
+          end
+        end
+      
+        # Update and close the session's memcache entry.
+        def close
+          update
+        end
+
+        # Delete the session's memcache entry.
+        def delete
+          begin
+            @cache.delete(@session_key)
+          rescue
+            # Ignore session delete failures.
+          end
+  	      @hash = {}
+        end
+      end
+    end
+  end
+rescue LoadError
+  # MemCache wasn't available so neither can the store be
+end