apns_connection.rb

require 'socket'
require 'openssl'

module Apns
  class ApnsConnection
    def initialize(host, port, cert, key)
      @host, @port, @cert, @key = host, port, cert, key
    end
    
    def connect
      ctx = OpenSSL::SSL::SSLContext.new()
      ctx.cert = OpenSSL::X509::Certificate.new(File::read(@cert))
      ctx.key  = OpenSSL::PKey::RSA.new(File::read(@key))

      begin
        s = TCPSocket.new(@host, @port)
        ssl = OpenSSL::SSL::SSLSocket.new(s, ctx)
        ssl.connect # start SSL session
        ssl.sync_close = true # close underlying socket on SSLSocket#close
        @ssl = ssl
        true
      rescue Errno::ETIMEDOUT
        nil
      end
    end
    
    def push(notification)
      delay = 2
      begin
        @ssl.write(notification.to_s)
      rescue OpenSSL::SSL::SSLError, Errno::EPIPE
        sleep(delay)
        raise Timeout::Error unless connect
        delay *= 2 and retry if delay < 60
        raise Timeout::Error
      end
    end

    def close_connection
      @ssl.close
      @ssl = nil
    end
  end
end

notification.rb

require 'json'

class Hash
  MAX_PAYLOAD_LEN = 256

  # Converts hash into JSON String.
  # When payload is too long but can be chopped, tries to cut self.[:aps][:alert].
  # If payload still don't fit Apple's restrictions, returns nil
  #
  # @return [String, nil] the object converted into JSON or nil.
  def to_payload
    # Payload too long
    if (to_json.length > MAX_PAYLOAD_LEN)
      alert = self[:aps][:alert]
      self[:aps][:alert] = ''
      # can be chopped?
      if (to_json.length > MAX_PAYLOAD_LEN)
        return nil
      else # inefficient way, but payload may be full of unicode-escaped chars, so...
        self[:aps][:alert] = alert
        while (self.to_json.length > MAX_PAYLOAD_LEN)
          self[:aps][:alert].chop!
        end
      end
    end
    to_json
  end

  # Invokes {Hash#to_payload} and returns it's length
  # @return [Fixnum, nil] length of object converted into JSON or nil.
  def payload_length
    p = to_payload
    p ? p.length : nil
  end
end


module Apns
  class Notification
    def Notification.create(token, payload)
      Notification.new token.kind_of?(String) ? token.delete(' ') : token.to_s(16) , payload.kind_of?(Hash) ? payload.to_payload : payload
    end

    def Notification.parse(bitstring)
      command, tokenlen, token, payloadlen, payload = bitstring.unpack("CnH64na*")
      Notification.new(token, payload)
    end    

    def initialize(token, payload)
      @token, @payload = token, payload
    end

    def to_s
      [0, 32, @token, @payload.length, @payload ].pack("CnH*na*")
    end
  end
end