Rack::Session::Memcache

    # File lib/rack/session/memcache.rb, line 28
28:       def initialize(app, options={})
29:         super
30: 
31:         @mutex = Mutex.new
32:         @pool = MemCache.
33:           new @default_options[:memcache_server], @default_options
34:         raise 'No memcache servers' unless @pool.servers.any?{|s|s.alive?}
35:       end

    # File lib/rack/session/memcache.rb, line 37
37:       def generate_sid
38:         loop do
39:           sid = super
40:           break sid unless @pool.get(sid, true)
41:         end
42:       end

    # File lib/rack/session/memcache.rb, line 44
44:       def get_session(env, sid)
45:         session = @pool.get(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:           ret = @pool.add sid, session
52:           raise "Session collision on '#{sid.inspect}'" unless /^STORED/ =~ ret
53:         end
54:         session.instance_variable_set('@old', {}.merge(session))
55:         return [sid, session]
56:       rescue MemCache::MemCacheError, Errno::ECONNREFUSED # MemCache server cannot be contacted
57:         warn "#{self} is unable to find server."
58:         warn $!.inspect
59:         return [ nil, {} ]
60:       ensure
61:         @mutex.unlock if env['rack.multithread']
62:       end

    # File lib/rack/session/memcache.rb, line 64
64:       def set_session(env, session_id, new_session, options)
65:         expiry = options[:expire_after]
66:         expiry = expiry.nil? ? 0 : expiry + 1
67: 
68:         @mutex.lock if env['rack.multithread']
69:         session = @pool.get(session_id) || {}
70:         if options[:renew] or options[:drop]
71:           @pool.delete session_id
72:           return false if options[:drop]
73:           session_id = generate_sid
74:           @pool.add session_id, 0 # so we don't worry about cache miss on #set
75:         end
76:         old_session = new_session.instance_variable_get('@old') || {}
77:         session = merge_sessions session_id, old_session, new_session, session
78:         @pool.set session_id, session, expiry
79:         return session_id
80:       rescue MemCache::MemCacheError, Errno::ECONNREFUSED # MemCache server cannot be contacted
81:         warn "#{self} is unable to find server."
82:         warn $!.inspect
83:         return false
84:       ensure
85:         @mutex.unlock if env['rack.multithread']
86:       end

     # File lib/rack/session/memcache.rb, line 90
 90:       def merge_sessions sid, old, new, cur=nil
 91:         cur ||= {}
 92:         unless Hash === old and Hash === new
 93:           warn 'Bad old or new sessions provided.'
 94:           return cur
 95:         end
 96: 
 97:         delete = old.keys - new.keys
 98:         warn "//@#{sid}: delete #{delete*','}" if $VERBOSE and not delete.empty?
 99:         delete.each{|k| cur.delete k }
100: 
101:         update = new.keys.select{|k| new[k] != old[k] }
102:         warn "//@#{sid}: update #{update*','}" if $VERBOSE and not update.empty?
103:         update.each{|k| cur[k] = new[k] }
104: 
105:         cur
106:       end