Add native Rack session handler, fixes GH-143

History.md

@@ -1,6 +1,16 @@
 Dalli Changelog
 =====================
 
+HEAD
+=======
+
+- Added support for native Rack session store.  Until now, Dalli's
+  session store has required Rails.  Now you can use Dalli to store
+  sessions for any Rack application.
+
+    require 'rack/session/dalli'
+    use Rack::Session::Dalli, :memcache_server => 'localhost:11211', :compression => true
+
 1.1.3
 =======
 

lib/rack/session/dalli.rb

@@ -0,0 +1,52 @@
+require 'rack/session/abstract/id'
+require 'dalli'
+
+module Rack
+  module Session
+    class Dalli < Abstract::ID
+      attr_reader :pool
+
+      DEFAULT_OPTIONS = Abstract::ID::DEFAULT_OPTIONS.merge \
+        :namespace => 'rack:session',
+        :memcache_server => 'localhost:11211'
+
+      def initialize(app, options={})
+        super
+        mserv = @default_options[:memcache_server]
+        mopts = @default_options.reject{|k,v| !MemCache::DEFAULT_OPTIONS.include? k }
+        @pool = options[:cache] || Dalli::Client.new(mserv, mopts)
+      end
+
+      def generate_sid
+        loop do
+          sid = super
+          break sid unless @pool.get(sid)
+        end
+      end
+
+      def get_session(env, sid)
+        unless sid and session = @pool.get(sid)
+          sid, session = generate_sid, {}
+          unless @pool.add(sid, session)
+            raise "Session collision on '#{sid.inspect}'"
+          end
+        end
+        [sid, session]
+      end
+
+      def set_session(env, session_id, new_session, options)
+        expiry = options[:expire_after]
+        expiry = expiry.nil? ? 0 : expiry + 1
+
+        @pool.set session_id, new_session, expiry
+        session_id
+      end
+
+      def destroy_session(env, session_id, options)
+        @pool.delete(session_id)
+        generate_sid unless options[:drop]
+      end
+
+    end
+  end
+end