(define-method (files:get root path #!key rev) "https://api-content.dropbox.com/1/files"
	       #f
	       (lambda (in-port) ; Based on copy-port from spiffy-cgi-handlers.
		 (let ((bufsize 65536)
		       (total 0))
		   (let loop ((data (read-string bufsize in-port)))
		     (unless (string-null? data)
		       (display data)
		       (if (callback)
			 (begin
			   (set! total (+ total (string-length data)))
			   (if (port? (old-output-port))
			     (with-output-to-port
			       (old-output-port)
			       (lambda () ((callback) total)))
			     ((callback) total))))
		       (loop (read-string bufsize in-port))))))
	       (lambda (headers) ; read-headers
		 (let ((metadata (header-value 'x-dropbox-metadata headers)))
		   (if metadata
		     (read-json metadata)
		     #f))))