class Excon::Socket

def connect
  # nonblocking connect
  begin
    @socket.connect_nonblock(@sockaddr)
  rescue Errno::EINPROGRESS
    IO.select(nil, [@socket], nil, @connection_params[:connect_timeout])
    begin
      @socket.connect_nonblock(@sockaddr)
    rescue Errno::EISCONN
    end
  end
end

def initialize(connection_params = {}, proxy = {})
  @connection_params, @proxy = connection_params, proxy
  @read_buffer, @write_buffer = '', ''
  @sockaddr = if @proxy
    ::Socket.sockaddr_in(@proxy[:port], @proxy[:host])
  else
    ::Socket.sockaddr_in(@connection_params[:port], @connection_params[:host])
  end
  @socket = ::Socket.new(::Socket::Constants::AF_INET, ::Socket::Constants::SOCK_STREAM, 0)
  connect
  @socket
end

def read(max_length)
  begin
    until @read_buffer.length >= max_length
      @read_buffer << @socket.read_nonblock([max_length, max_length - @read_buffer.length].min)
    end
  rescue OpenSSL::SSL::SSLError => error
    if error.message == 'read would block'
      if IO.select([@socket], nil, nil, @connection_params[:read_timeout])
        retry
      else
        raise(Excon::Errors::Timeout.new("read timeout reached"))
      end
    end
  rescue Errno::EAGAIN, Errno::EWOULDBLOCK
    if IO.select([@socket], nil, nil, @connection_params[:read_timeout])
      retry
    else
      raise(Excon::Errors::Timeout.new("read timeout reached"))
    end
  end
  @read_buffer.slice!(0, max_length)
end

def write(data)
  @write_buffer << data
  until @write_buffer.empty?
    begin
      max_length = [@write_buffer.length, Excon::CHUNK_SIZE].min
      written = @socket.write_nonblock(@write_buffer.slice(0, max_length))
      @write_buffer.slice!(0, written)
    rescue Errno::EAGAIN, Errno::EWOULDBLOCK
      if IO.select(nil, [@socket], nil, @connection_params[:write_timeout])
        retry
      else
        raise(Excon::Errors::Timeout.new("write timeout reached"))
      end
    end
  end
end