Add the STORE callback method

So activity-servist can ask the server to cache
objects.

docs/examples/simple-server.lisp

@@ -76,6 +76,12 @@ inbox, and decide what to do with it!"
   (setq *inbox* (append *inbox* (list obj))))
 
 
+(defmethod as:store ((obj json-ld:object))
+  "activity-servist callback: Store a foreign JSON-LD OBJECT (fetched during
+operation of the server) in our object-store."
+  (setf (gethash (json-ld:@id obj) *store*) obj))
+
+
 
 ;;; ID-management
 ;;; ————————————————————————————————————————
@@ -115,14 +121,6 @@ Otherwise, assume “https”."
         (format nil "https://~A" hostname))))
 
 
-
-;;; Data-management
-;;; ————————————————————————————————————————
-(defun save (obj)
-  "Save an object to our object-store, *STORE*."
-  (setf (gethash (json-ld:@id obj) *store*) obj))
-
-
 
 ;;; Users
 ;;; ————————————————————————————————————————

src/activity-servist.lisp

@@ -22,11 +22,12 @@
    ;; Functions
    :server :start-server
    ;; Methods
-   :receive
+   :receive :store
    ;; Globals
    *config*))
 
 (in-package #:activity-servist)
+(defvar *last* nil)
 
 
 ;;; Globals
@@ -98,9 +99,18 @@ Actors, and then calls RECEIVE on them in turn."))
   (let* ((actor-uri (ignore-errors (activity-vocabulary:actor obj))))
     (when actor-uri
       (or (retrieve actor-uri)
-          (fetch-and-receive actor-uri)))))
+          (fetch-and-store actor-uri)))))
 
 
+(defgeneric store (obj)
+  (:documentation
+   "Stores an object in a object-store accessible with the callback function
+RETRIEVE, likely for caching purposes.
+
+You should overload this generic with a method accepting JSON-LD:OBJECTs, as it
+is necessary for activity-servist to function. When called by activity-servist,
+this is solely used to store fetched foreign objects."))
+
 
 
 ;;; Fetching foreign objects