Merged updates from trunk into stable branch

[feedcatcher.git] / vendor / rails / actionpack / lib / action_controller / vendor / rack-1.0 / rack / session / memcache.rb

diff --git a/vendor/rails/actionpack/lib/action_controller/vendor/rack-1.0/rack/session/memcache.rb b/vendor/rails/actionpack/lib/action_controller/vendor/rack-1.0/rack/session/memcache.rb
new file mode 100644 (file)
index 0000000..4a65cbf
--- /dev/null
+++ b/vendor/rails/actionpack/lib/action_controller/vendor/rack-1.0/rack/session/memcache.rb
@@ -0,0 +1,109 @@
+# AUTHOR: blink <blinketje@gmail.com>; blink#ruby-lang@irc.freenode.net
+
+require 'rack/session/abstract/id'
+require 'memcache'
+
+module Rack
+  module Session
+    # Rack::Session::Memcache provides simple cookie based session management.
+    # Session data is stored in memcached. The corresponding session key is
+    # maintained in the cookie.
+    # You may treat Session::Memcache as you would Session::Pool with the
+    # following caveats.
+    #
+    # * Setting :expire_after to 0 would note to the Memcache server to hang
+    #   onto the session data until it would drop it according to it's own
+    #   specifications. However, the cookie sent to the client would expire
+    #   immediately.
+    #
+    # Note that memcache does drop data before it may be listed to expire. For
+    # a full description of behaviour, please see memcache's documentation.
+
+    class Memcache < Abstract::ID
+      attr_reader :mutex, :pool
+      DEFAULT_OPTIONS = Abstract::ID::DEFAULT_OPTIONS.merge \
+        :namespace => 'rack:session',
+        :memcache_server => 'localhost:11211'
+
+      def initialize(app, options={})
+        super
+
+        @mutex = Mutex.new
+        @pool = MemCache.
+          new @default_options[:memcache_server], @default_options
+        raise 'No memcache servers' unless @pool.servers.any?{|s|s.alive?}
+      end
+
+      def generate_sid
+        loop do
+          sid = super
+          break sid unless @pool.get(sid, true)
+        end
+      end
+
+      def get_session(env, sid)
+        session = @pool.get(sid) if sid
+        @mutex.lock if env['rack.multithread']
+        unless sid and session
+          env['rack.errors'].puts("Session '#{sid.inspect}' not found, initializing...") if $VERBOSE and not sid.nil?
+          session = {}
+          sid = generate_sid
+          ret = @pool.add sid, session
+          raise "Session collision on '#{sid.inspect}'" unless /^STORED/ =~ ret
+        end
+        session.instance_variable_set('@old', {}.merge(session))
+        return [sid, session]
+      rescue MemCache::MemCacheError, Errno::ECONNREFUSED # MemCache server cannot be contacted
+        warn "#{self} is unable to find server."
+        warn $!.inspect
+        return [ nil, {} ]
+      ensure
+        @mutex.unlock if env['rack.multithread']
+      end
+
+      def set_session(env, session_id, new_session, options)
+        expiry = options[:expire_after]
+        expiry = expiry.nil? ? 0 : expiry + 1
+
+        @mutex.lock if env['rack.multithread']
+        session = @pool.get(session_id) || {}
+        if options[:renew] or options[:drop]
+          @pool.delete session_id
+          return false if options[:drop]
+          session_id = generate_sid
+          @pool.add session_id, 0 # so we don't worry about cache miss on #set
+        end
+        old_session = new_session.instance_variable_get('@old') || {}
+        session = merge_sessions session_id, old_session, new_session, session
+        @pool.set session_id, session, expiry
+        return session_id
+      rescue MemCache::MemCacheError, Errno::ECONNREFUSED # MemCache server cannot be contacted
+        warn "#{self} is unable to find server."
+        warn $!.inspect
+        return false
+      ensure
+        @mutex.unlock if env['rack.multithread']
+      end
+
+      private
+
+      def merge_sessions sid, old, new, cur=nil
+        cur ||= {}
+        unless Hash === old and Hash === new
+          warn 'Bad old or new sessions provided.'
+          return cur
+        end
+
+        delete = old.keys - new.keys
+        warn "//@#{sid}: delete #{delete*','}" if $VERBOSE and not delete.empty?
+        delete.each{|k| cur.delete k }
+
+        update = new.keys.select{|k| new[k] != old[k] }
+        warn "//@#{sid}: update #{update*','}" if $VERBOSE and not update.empty?
+        update.each{|k| cur[k] = new[k] }
+
+        cur
+      end
+    end
+  end
+end