vendor/rails/actionpack/lib/action_controller/vendor/rack-1.0/rack/session/pool.rb

   1 # AUTHOR: blink <blinketje@gmail.com>; blink#ruby-lang@irc.freenode.net
   2 # THANKS:
   3 #   apeiros, for session id generation, expiry setup, and threadiness
   4 #   sergio, threadiness and bugreps
   5
   6 require 'rack/session/abstract/id'
   7 require 'thread'
   8
   9 module Rack
  10   module Session
  11     # Rack::Session::Pool provides simple cookie based session management.
  12     # Session data is stored in a hash held by @pool.
  13     # In the context of a multithreaded environment, sessions being
  14     # committed to the pool is done in a merging manner.
  15     #
  16     # The :drop option is available in rack.session.options if you with to
  17     # explicitly remove the session from the session cache.
  18     #
  19     # Example:
  20     #   myapp = MyRackApp.new
  21     #   sessioned = Rack::Session::Pool.new(myapp,
  22     #     :domain => 'foo.com',
  23     #     :expire_after => 2592000
  24     #   )
  25     #   Rack::Handler::WEBrick.run sessioned
  26
  27     class Pool < Abstract::ID
  28       attr_reader :mutex, :pool
  29       DEFAULT_OPTIONS = Abstract::ID::DEFAULT_OPTIONS.merge :drop => false
  30
  31       def initialize(app, options={})
  32         super
  33         @pool = Hash.new
  34         @mutex = Mutex.new
  35       end
  36
  37       def generate_sid
  38         loop do
  39           sid = super
  40           break sid unless @pool.key? sid
  41         end
  42       end
  43
  44       def get_session(env, sid)
  45         session = @pool[sid] if sid
  46         @mutex.lock if env['rack.multithread']
  47         unless sid and session
  48           env['rack.errors'].puts("Session '#{sid.inspect}' not found, initializing...") if $VERBOSE and not sid.nil?
  49           session = {}
  50           sid = generate_sid
  51           @pool.store sid, session
  52         end
  53         session.instance_variable_set('@old', {}.merge(session))
  54         return [sid, session]
  55       ensure
  56         @mutex.unlock if env['rack.multithread']
  57       end
  58
  59       def set_session(env, session_id, new_session, options)
  60         @mutex.lock if env['rack.multithread']
  61         session = @pool[session_id]
  62         if options[:renew] or options[:drop]
  63           @pool.delete session_id
  64           return false if options[:drop]
  65           session_id = generate_sid
  66           @pool.store session_id, 0
  67         end
  68         old_session = new_session.instance_variable_get('@old') || {}
  69         session = merge_sessions session_id, old_session, new_session, session
  70         @pool.store session_id, session
  71         return session_id
  72       rescue
  73         warn "#{new_session.inspect} has been lost."
  74         warn $!.inspect
  75       ensure
  76         @mutex.unlock if env['rack.multithread']
  77       end
  78
  79       private
  80
  81       def merge_sessions sid, old, new, cur=nil
  82         cur ||= {}
  83         unless Hash === old and Hash === new
  84           warn 'Bad old or new sessions provided.'
  85           return cur
  86         end
  87
  88         delete = old.keys - new.keys
  89         warn "//@#{sid}: dropping #{delete*','}" if $DEBUG and not delete.empty?
  90         delete.each{|k| cur.delete k }
  91
  92         update = new.keys.select{|k| new[k] != old[k] }
  93         warn "//@#{sid}: updating #{update*','}" if $DEBUG and not update.empty?
  94         update.each{|k| cur[k] = new[k] }
  95
  96         cur
  97       end
  98     end
  99   end
 100 end