[hunchentoot-devel] Is there a better way?

[Kevin Raison]

I am trying to determine the best way to accomplish the following task 
and could use some help.  I am writing a web-based (using hunchentoot, 
of course) application for managing voicemail that is stored in Cisco's 
Unity system.  I can access the voicemail box of a given use via IMAP. 
The mel project has helped make that part easy.  However, I am not sure 
the best way to send the audio stream to the user's browser.  The method 
below illustrates (inefficiently) what I need to do.  Can anyone suggest 
a more efficient method that does not use (send-headers)?  The 
hunchentoot docs say, "If your handlers return the full body as a string 
or as an array of octets, you should not call this function."  However, 
I cannot find an alternative way to do what I need to do.  I must fetch 
the voicemail as an email via IMAP and then decode the base64-encoded 
body, which contains the voicemail as a wav file.  Writing out a wav 
file and pointing the user's browser to it would introduce security 
issues, so I must do this entire process in memory.  Any help is 
appreciated.

(defmethod send-audio-stream ((user user) msg-id)
   "Convert the message body and send the wav content to the user."
   (handler-case
       (let ((msg (mel:find-message (mbox user) msg-id)))
         (setf (content-type) "audio/x-wav")
         (setf (header-out "Content-Disposition")
               (format t "inline; filename=~a.wav" msg-id))
         (setf (content-length) ;; FIXME!  Why do this twice?
               (length (base64-decode-msg-body-to-array msg)))
         (let ((stream (send-headers)))
           (base64-decode-msg-body-to-stream msg :stream stream)))
     (error (condition)
       (format nil "Unable to play message: ~a" condition))))

Cheers.
Kevin Raison