#:use-module (8sync systems web)
#:use-module (8sync systems websocket frame)
#:use-module (8sync systems websocket utils)
+ #:use-module (fibers)
+ #:use-module (fibers conditions)
+ #:use-module (fibers operations)
+ #:use-module (fibers timers)
#:export (<websocket-server>
.websocket-handler))
;; @@: We probably could just increment a counter...
(define client-id (web-server-gen-client-id websocket-server))
+ (define client-dead? (make-condition))
+
(define (close-down)
(close-port client)
(hash-remove! (.ws-clients websocket-server) client-id)
+ (signal-condition! client-dead?)
((.on-ws-client-disconnect websocket-server)
websocket-server client-id))
((.on-ws-client-connect websocket-server)
websocket-server client-id)
- (with-actor-nonblocking-ports
- (lambda ()
- ;; Perform the HTTP handshake and upgrade to WebSocket protocol.
- (let* ((client-key (assoc-ref (request-headers request) 'sec-websocket-key))
- (response (make-handshake-response client-key)))
- (write-response response client)
- (let loop ((fragments '())
- (type #f))
- (let ((frame (read-frame-maybe)))
- (cond
- ;; EOF - port is closed.
- ;; @@: Sometimes the eof object appears here as opposed to
- ;; at lookahead, but I'm not sure why
- ((or (not frame) (eof-object? frame))
- (close-down))
- ;; Per section 5.4, control frames may appear interspersed
- ;; along with a fragmented message.
- ((close-frame? frame)
- ;; Per section 5.5.1, echo the close frame back to the
- ;; client before closing the socket. The client may no
- ;; longer be listening.
- (false-if-exception
- (write-frame (make-close-frame (frame-data frame)) client))
- (close-down))
- ((ping-frame? frame)
- ;; Per section 5.5.3, a pong frame must include the exact
- ;; same data as the ping frame.
- (write-frame (make-pong-frame (frame-data frame)) client)
- (loop fragments type))
- ((pong-frame? frame) ; silently ignore pongs
- (loop fragments type))
- ((first-fragment-frame? frame) ; begin accumulating fragments
- (loop (list frame) (frame-type frame)))
- ((final-fragment-frame? frame) ; concatenate all fragments
- (handle-data-frame type (frame-concatenate (reverse fragments)))
- (loop '() #f))
- ((fragment-frame? frame) ; add a fragment
- (loop (cons frame fragments) type))
- ((data-frame? frame) ; unfragmented data frame
- (handle-data-frame (frame-type frame) (frame-data frame))
- (loop '() #f)))))))))
+ ;; Perform the HTTP handshake and upgrade to WebSocket protocol.
+ (let* ((client-key (assoc-ref (request-headers request) 'sec-websocket-key))
+ (response (make-handshake-response client-key)))
+ (write-response response client)
+ ;; TODO: we shoud split clients into their own objects or fibers
+ ;; structure... what happens if we try to write at the same time
+ ;; that we're writing another frame?
+ ;; Probably it's good to have different fibers or methods for:
+ ;; - reader method/fiber
+ ;; - checks for client-dead? condition
+ ;; - may kick off some logic, which may send a message to writer
+ ;; - "nonblocking" reads
+ ;; - writer method/thread
+ ;; - checks for client-dead? condition
+ ;; - accepts one message at a time to write
+ ;; - "blocking" writes
+ ;; - ping timer method
+ ;; - checks for client-dead? condition
+ ;; - occasionally sends a message to the writer to do a ping
+ (let* ((ws (actor-id websocket-server))
+ (send-ping
+ (lambda ()
+ (<- ws 'ws-send client-id 'ping))))
+ (spawn-fiber
+ (lambda ()
+ (let lp ()
+ (and (perform-operation
+ (choice-operation
+ ;; sleep and send a ping
+ (wrap-operation (sleep-operation 5)
+ (lambda ()
+ (send-ping)
+ #t)) ; loop again
+ ;; If the client is dead, don't loop
+ (wrap-operation (wait-operation client-dead?)
+ (const #f))))
+ (lp))))))
+
+ (with-actor-nonblocking-ports
+ (let loop ((fragments '())
+ (type #f))
+ (let ((frame (read-frame-maybe)))
+ (cond
+ ;; EOF - port is closed.
+ ;; @@: Sometimes the eof object appears here as opposed to
+ ;; at lookahead, but I'm not sure why
+ ((or (not frame) (eof-object? frame))
+ (close-down))
+ ;; Per section 5.4, control frames may appear interspersed
+ ;; along with a fragmented message.
+ ((close-frame? frame)
+ ;; Per section 5.5.1, echo the close frame back to the
+ ;; client before closing the socket. The client may no
+ ;; longer be listening.
+ (false-if-exception
+ (write-frame (make-close-frame (frame-data frame)) client))
+ (close-down))
+ ((ping-frame? frame)
+ ;; Per section 5.5.3, a pong frame must include the exact
+ ;; same data as the ping frame.
+ (write-frame (make-pong-frame (frame-data frame)) client)
+ (loop fragments type))
+ ((pong-frame? frame) ; silently ignore pongs
+ (loop fragments type))
+ ((first-fragment-frame? frame) ; begin accumulating fragments
+ (loop (list frame) (frame-type frame)))
+ ((final-fragment-frame? frame) ; concatenate all fragments
+ (handle-data-frame type (frame-concatenate (reverse fragments)))
+ (loop '() #f))
+ ((fragment-frame? frame) ; add a fragment
+ (loop (cons frame fragments) type))
+ ((data-frame? frame) ; unfragmented data frame
+ (handle-data-frame (frame-type frame) (frame-data frame))
+ (loop '() #f))))))))
(define (websocket-server-send websocket-server message client-id data)
(with-actor-nonblocking-ports
(cond ((string? data)
(make-text-frame data))
((bytevector? data)
- (make-binary-frame data)))
+ (make-binary-frame data))
+ ('ping
+ (make-ping-frame (string->utf8 "hi"))))
client)
;; ok is like success, amirite
'ok))
projects / 8sync.git / blobdiff