Add docstrings to functions

Author: weavejester

src/ring/middleware/websocket_keepalive.clj

@@ -4,44 +4,57 @@
   (:import [java.util.concurrent
             Executors Future ScheduledExecutorService TimeUnit]))
 
-(def default-schedule-executor
+(def ^:private default-schedule-executor
   (delay (Executors/newSingleThreadScheduledExecutor)))
 
-(defn websocket-keepalive-response [response options]
-  (if (ws/websocket-response? response)
-    (let [listener (::ws/listener response)
-          executor (:executor options @default-schedule-executor)
-          period   (:period options 30000)
-          task     (promise)]
-      (assoc response ::ws/listener
-             (reify wsp/Listener
-               (on-open [_ socket]
-                 (deliver task (.scheduleAtFixedRate
-                                ^ScheduledExecutorService executor
-                                #(ws/ping socket)
-                                period period TimeUnit/MILLISECONDS))
-                 (wsp/on-open listener socket))
-               (on-message [_ socket message]
-                 (wsp/on-message listener socket message))
-               (on-pong [_ socket data]
-                 (wsp/on-pong listener socket data))
-               (on-error [_ socket throwable]
-                 (wsp/on-error listener socket throwable))
-               (on-close [_ socket code reason]
-                 (.cancel ^Future @task false)
-                 (wsp/on-close listener socket code reason))
-               wsp/PingListener
-               (on-ping [_ socket data]
-                 (if (satisfies? wsp/PingListener listener)
-                   (wsp/on-ping listener socket data)
-                   (wsp/-ping socket data))))))
-    response))
+(defn websocket-keepalive-response
+  "Adds a periodic ping to a WebSocket response; returns the response unaltered
+  otherwise. See wrap-websocket-keepalive for the available options."
+  ([response]
+   (websocket-keepalive-response response {}))
+  ([response options]
+   (if (ws/websocket-response? response)
+     (let [listener (::ws/listener response)
+           executor (:executor options @default-schedule-executor)
+           period   (:period options 30000)
+           task     (promise)]
+       (assoc response ::ws/listener
+              (reify wsp/Listener
+                (on-open [_ socket]
+                  (deliver task (.scheduleAtFixedRate
+                                 ^ScheduledExecutorService executor
+                                 #(ws/ping socket)
+                                 period period TimeUnit/MILLISECONDS))
+                  (wsp/on-open listener socket))
+                (on-message [_ socket message]
+                  (wsp/on-message listener socket message))
+                (on-pong [_ socket data]
+                  (wsp/on-pong listener socket data))
+                (on-error [_ socket throwable]
+                  (wsp/on-error listener socket throwable))
+                (on-close [_ socket code reason]
+                  (.cancel ^Future @task false)
+                  (wsp/on-close listener socket code reason))
+                wsp/PingListener
+                (on-ping [_ socket data]
+                  (if (satisfies? wsp/PingListener listener)
+                    (wsp/on-ping listener socket data)
+                    (wsp/-ping socket data))))))
+     response)))
 
-(defn wrap-websocket-keepalive [handler options]
-  (fn
-    ([request]
-     (websocket-keepalive-response (handler request) options))
-    ([request respond raise]
-     (handler request
-              #(respond (websocket-keepalive-response % options))
-              raise))))
+(defn wrap-websocket-keepalive
+  "Middleware that adds a periodic ping to WebSocket responses, in order to
+  stop them from timing out. Takes the following options:
+
+    :period   - the time in milliseconds between pings (default 30000)
+    :executor - a custom ScheduledExecutorService to handle scheduling"
+  ([handler]
+   (wrap-websocket-keepalive handler {}))
+  ([handler options]
+   (fn
+     ([request]
+      (websocket-keepalive-response (handler request) options))
+     ([request respond raise]
+      (handler request
+               #(respond (websocket-keepalive-response % options))
+               raise)))))