Class: Rack::Session::Dalli

Inherits:
Abstract::ID
  • Object
show all
Defined in:
lib/rack/session/dalli.rb

Constant Summary collapse

DEFAULT_OPTIONS = 
Abstract::ID::DEFAULT_OPTIONS.merge \
:namespace => 'rack:session',
:memcache_server => 'localhost:11211'

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(app, options = {}) ⇒ Dalli

Returns a new instance of Dalli.



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# File 'lib/rack/session/dalli.rb', line 13

def initialize(app, options={})
  super
  @mutex = Mutex.new
  mserv = @default_options[:memcache_server]
  mopts = @default_options.reject{|k,v| !DEFAULT_OPTIONS.include? k }
  @pool = options[:cache] || ::Dalli::Client.new(mserv, mopts)
  @pool.alive!
end

Instance Attribute Details

#mutex ⇒ Object (readonly)

Returns the value of attribute mutex.



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# File 'lib/rack/session/dalli.rb', line 7

def mutex
  @mutex
end

#pool ⇒ Object (readonly)

Returns the value of attribute pool.



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# File 'lib/rack/session/dalli.rb', line 7

def pool
  @pool
end

Instance Method Details

#destroy_session(env, session_id, options) ⇒ Object 



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# File 'lib/rack/session/dalli.rb', line 52

def destroy_session(env, session_id, options)
  with_lock(env) do
    @pool.delete(session_id)
    generate_sid unless options[:drop]
  end
end

#generate_sid ⇒ Object 



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# File 'lib/rack/session/dalli.rb', line 22

def generate_sid
  loop do
    sid = super
    break sid unless @pool.get(sid)
  end
end

#get_session(env, sid) ⇒ Object 



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# File 'lib/rack/session/dalli.rb', line 29

def get_session(env, sid)
  with_lock(env, [nil, {}]) do
    unless sid and !sid.empty? 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
end

#set_session(env, session_id, new_session, options) ⇒ Object 



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# File 'lib/rack/session/dalli.rb', line 41

def set_session(env, session_id, new_session, options)
  return false unless session_id
  expiry = options[:expire_after]
  expiry = expiry.nil? ? 0 : expiry + 1

  with_lock(env, false) do
    @pool.set session_id, new_session, expiry
    session_id
  end
end

#with_lock(env, default = nil) ⇒ Object 



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# File 'lib/rack/session/dalli.rb', line 59

def with_lock(env, default=nil)
  @mutex.lock if env['rack.multithread']
  yield
rescue ::Dalli::DalliError, Errno::ECONNREFUSED
  raise if $!.message =~ /undefined class/
  if $VERBOSE
    warn "#{self} is unable to find memcached server."
    warn $!.inspect
  end
  default
ensure
  @mutex.unlock if @mutex.locked?
end