(defun download-encrypted-packet (connection cipher)
  (declare (optimize (speed 3)(safety 1)))
  (handler-case
      (tlet* ((stream stream (c-stream connection))
              (len u-byte (timed-non-block-read-byte stream))
              (encrypted-packet byte-array (read-n-bytes len stream)))
        (flexi-streams:make-in-memory-input-stream (decrypt-byte-array cipher encrypted-packet)))
    (stream-error (c)
      (write-error c)
      :EOF)
    (SB-INT:SIMPLE-STREAM-ERROR ()
      :EOF)
    (broken-packet ()
      (sb-ext:atomic-incf (car oofs))
      :EOF)))

;;;my three functions that read bytes from a stream
;;;these functions seem to get 'bound up' or freeze when used on the flexi-stream:memory-input-stream

(defun non-block-read-byte (stream)
  "read byte that is non blocking, if there is nothing to read it simply returns nil"
  ;; (declare (optimize (speed 3)(safety 0))
  ;;  (type stream stream))
  (the (or u-byte boolean)
       (and (listen stream)
            (tlet ((byte u-byte (read-byte stream t)))
              (the u-byte byte)))))

(defun timed-non-block-read-byte (stream)
  "This is a non blocking version of read byte which is timed. loops *increment* amount of times and checks if there is anything on the stream to be read, if not it'll sleep for *sleep-time*
if it eventually finds something to read it'll read and then return that byte. if it reaches the 
timeout it'll signal an error"
  ;; (declare (optimize (speed 3)(safety 1))
  ;;  (type stream stream))
  (tlet ((byte (or u-byte boolean) (non-block-read-byte stream)))
    (or byte
        (the u-byte
             (loop :for x fixnum :from 1 :to *increment*
                   :for byte? := (the (or boolean u-byte) (non-block-read-byte stream))
                     :then (the (or u-byte boolean) (non-block-read-byte stream))
                   :if byte?
                     :do (return byte?)                    
                   :else
                     :do (sleep *sleep-time*)
                   :finally (error 'stream-error :stream stream))))))

(defun read-n-bytes (n stream)
  "Reads n bytes from stream and puts them into an array of length n and type unsigned-byte 8"
  ;; (declare (optimize (speed 3)(safety 0))
  ;;  (type u-byte n)
  ;; (type stream  stream))
  (tlet ((data byte-array (make-array n :element-type 'u-byte)))
    (declare (type byte-array data))
    (dotimes (i n (the byte-array data))
      (declare (type fixnum i)
               (type fixnum n))
      (the u-byte 
           (setf (aref data i) (the u-byte (timed-non-block-read-byte stream)))))))