actor-id-hive
actor-id-string
- mlambda define-mhandler
simple-dispatcher build-actions make-action-dispatch
define-simple-actor
message-to message-action message-from
message-id message-body message-in-reply-to
message-wants-reply
- message-ref
+
+ message-auto-reply?
<- <-wait <-reply <-reply-wait
+ call-with-message msg-receive =>
+
ez-run-hive
bootstrap-message
(define-record-type <message>
(make-message-intern id to from action
body in-reply-to wants-reply
- replied
- ;; @@: Not used yet.
- ;; Will we ever find a real use case?
- deferred-reply)
+ replied)
message?
(id message-id)
(to message-to)
(body message-body)
(in-reply-to message-in-reply-to)
(wants-reply message-wants-reply)
- (replied message-replied set-message-replied!)
- (deferred-reply message-deferred-reply set-message-deferred-reply!))
+ (replied message-replied set-message-replied!))
(define* (make-message id to from action body
#:key in-reply-to wants-reply
- replied deferred-reply)
+ replied)
(make-message-intern id to from action body
- in-reply-to wants-reply replied
- deferred-reply))
-
-;; Note: the body of messages is currently an alist, but it's created
-;; from a keyword based property list (see the following two functions).
-;; But, that's an extra conversion step, and maybe totally unnecessary:
-;; we already have message-ref, and this could just pull a keyword
-;; from a property list.
-;; The main ways this might be useful are error checking,
-;; serialization across the wire (but even that might require some
-;; change), and using existing tooling (though adding new tooling
-;; would be negligible in implementation effort.)
-
-;; This cons cell is immutable and unique (for eq? tests)
-(define %nothing-provided (cons 'nothing 'provided))
-
-(define* (message-ref message key #:optional (dflt %nothing-provided))
- "Extract KEY from body of MESSAGE.
-
-Optionally set default with [DFLT]
-If key not found and DFLT not provided, throw an error."
- (let ((result (assoc key (message-body message))))
- (if result (cdr result)
- (if (eq? dflt %nothing-provided)
- (throw 'message-missing-key
- "Message body does not contain key and no default provided"
- #:key key
- #:message message)
- dflt))))
-
-
-(define (message-needs-reply message)
+ in-reply-to wants-reply replied))
+
+(define (message-auto-reply? message)
+ (eq? (message-action message) '*auto-reply*))
+
+(define (message-needs-reply? message)
"See if this message needs a reply still"
(and (message-wants-reply message)
- (not (or (message-replied message)
- (message-deferred-reply message)))))
+ (not (message-replied message))))
(define (kwarg-list-to-alist args)
(let* ((hive (actor-hive from-actor))
(message (make-message (hive-gen-message-id hive) to-id
(actor-id from-actor) action
- (kwarg-list-to-alist message-body-args))))
+ message-body-args)))
(8sync (hive-process-message hive message))))
(define (<-wait from-actor to-id action . message-body-args)
(abort-to (hive-prompt (actor-hive from-actor)))
(message (make-message (hive-gen-message-id hive) to-id
(actor-id from-actor) action
- (kwarg-list-to-alist message-body-args)
+ message-body-args
#:wants-reply #t)))
(abort-to-prompt abort-to from-actor message)))
(new-message (make-message (hive-gen-message-id hive)
(message-from original-message)
(actor-id from-actor) '*reply*
- (kwarg-list-to-alist message-body-args)
+ message-body-args
+ #:in-reply-to (message-id original-message))))
+ (8sync (hive-process-message hive new-message))))
+
+(define (<-auto-reply from-actor original-message)
+ "Auto-reply to a message. Internal use only!"
+ (set-message-replied! original-message #t)
+ (let* ((hive (actor-hive from-actor))
+ (new-message (make-message (hive-gen-message-id hive)
+ (message-from original-message)
+ (actor-id from-actor) '*auto-reply*
+ '()
#:in-reply-to (message-id original-message))))
(8sync (hive-process-message hive new-message))))
(new-message (make-message (hive-gen-message-id hive)
(message-from original-message)
(actor-id from-actor) '*reply*
- (kwarg-list-to-alist message-body-args)
+ message-body-args
#:wants-reply #t
#:in-reply-to (message-id original-message))))
(abort-to-prompt abort-to from-actor new-message)))
;;; Actor utilities
;;; ===============
-
-(define-syntax-rule (with-message-args (message message-arg ...)
- body body* ...)
- (let ((message-arg (message-ref message (quote message-arg))) ...)
- body body* ...))
-
-(define-syntax mlambda
- (lambda (x)
- "A lambda for building message handlers.
-
-Use it like:
- (mlambda (actor message foo)
- ...)
-
-Which is like doing manually:
- (lambda (actor message)
- (let ((foo (message-ref message foo)))
- ...))"
- (syntax-case x ()
- ((_ (actor message message-arg ...)
- docstring
- body ...)
- (string? (syntax->datum #'docstring))
- #'(lambda (actor message)
- docstring
- (with-message-args (message message-arg ...) body ...)))
- ((_ (actor message message-arg ...)
- body body* ...)
- #'(lambda (actor message)
- (with-message-args (message message-arg ...) body body* ...))))))
-
-(define-syntax-rule (define-mhandler (name actor message message-arg ...)
- body ...)
- (define name
- (mlambda (actor message message-arg ...)
- body ...)))
-
(define (simple-dispatcher action-map)
(lambda (actor message)
(let* ((action (message-action message))
#:actor actor
#:message message
#:available-actions (map car action-map)))
- (method actor message))))
+ (apply method actor message (message-body message)))))
(define-syntax %expand-action-item
(syntax-rules ()
- ((_ ((action-name action-args ...) body ...))
- (cons (quote action-name)
- (mlambda (action-args ...)
- body ...)))
((_ (action-name handler))
(cons (quote action-name) handler))))
(set-message-replied! original-message #t)
(let* ((new-message-body
(if (orig-actor-on-same-hive?)
- `((original-message . ,original-message)
- (error-key . ,error-key)
- (error-args . ,error-args))
- `((original-message . ,original-message)
- (error-key . ,error-key))))
+ `(#:original-message ,original-message
+ #:error-key ,error-key
+ #:error-args ,error-args)
+ `(#:original-message ,original-message
+ #:error-key ,error-key)))
(new-message (make-message (hive-gen-message-id hive)
(message-from original-message)
(actor-id hive) '*error*
"Handle one message, or forward it via an ambassador"
(define (maybe-autoreply actor)
;; Possibly autoreply
- (if (message-needs-reply message)
- ;; @@: Should we give *autoreply* as the action instead of *reply*?
- (<-reply actor message #:*auto-reply* #t)))
+ (if (message-needs-reply? message)
+ (<-auto-reply actor message)))
(define (resolve-actor-to)
"Get the actor the message was aimed at"
(lambda _ #f)
;; If an error happens, we raise it
(lambda (key . args)
- (if (message-needs-reply message)
+ (if (message-needs-reply? message)
;; If the message is waiting on a reply, let them know
;; something went wrong.
(hive-reply-with-error hive message key args))
(define (resume-waiting-coroutine)
(cond
- ((eq? (message-action message) '*reply*)
+ ((or (eq? (message-action message) '*reply*)
+ (eq? (message-action message) '*auto-reply*))
(call-catching-coroutine
(lambda ()
(match (hash-remove! (hive-waiting-coroutines hive)
(%hive-create-actor hive actor-class
init id-cookie))
+(define (call-with-message message proc)
+ "Applies message body arguments into procedure, with message as first
+argument. Similar to call-with-values in concept."
+ (apply proc message (message-body message)))
+
+;; (msg-receive (<- bar baz)
+;; (baz)
+;; basil)
+
+;; Emacs: (put 'msg-receive 'scheme-indent-function 2)
+
+;; @@: Or receive-msg or receieve-message or??
+(define-syntax-rule (msg-receive arglist the-message body ...)
+ (call-with-message the-message
+ (lambda* arglist
+ body ...)))
+
+;; Emacs: (put '=> 'scheme-indent-function 2)
+;;; An experimental alias.
+(define-syntax-rule (=> rest ...)
+ (msg-receive rest ...))
+
\f
;;; Various API methods for actors to interact with the system
(message-body message)
(message-in-reply-to message)
(message-wants-reply message)
- (message-replied message)
- (message-deferred-reply message)))
+ (message-replied message)))
(define* (write-message message #:optional (port (current-output-port)))
"Write out a message to a port for easy reading later.
(body ,(message-body message))
(in-reply-to ,(message-in-reply-to message))
(wants-reply ,(message-wants-reply message))
- (replied ,(message-replied message))
- (deferred-reply ,(message-deferred-reply message))))
+ (replied ,(message-replied message))))
(define (pprint-message message)
"Pretty print a message."
(define* (read-message #:optional (port (current-input-port)))
"Read a message serialized via serialize-message from PORT"
(match (read port)
- ((id to from action body in-reply-to wants-reply replied deferred-reply)
+ ((id to from action body in-reply-to wants-reply replied)
(make-message-intern
id to from action body
- in-reply-to wants-reply replied deferred-reply))
+ in-reply-to wants-reply replied))
(anything-else
(throw 'message-read-bad-structure
"Could not read message from structure"