style tweaks.

src/metabase/driver/generic_sql.clj

@@ -109,7 +109,7 @@
   (when-let [pool (get @connection-pools id)]
     (log/debug (u/format-color 'red "Closing connection pool for database %d ..." id))
     ;; remove the cached reference to the pool so we don't try to use it anymore
-    (reset! connection-pools (dissoc @connection-pools id))
+    (swap! connection-pools dissoc id)
     ;; now actively shut down the pool so that any open connections are closed
     (.close ^ComboPooledDataSource (:datasource pool))))
 
@@ -120,12 +120,9 @@
   (if (contains? @connection-pools id)
     ;; we have an existing pool for this database, so use it
     (get @connection-pools id)
-    ;; need to create a new pool
-    (let [new-pool (create-connection-pool database)]
-      ;; add the newly created pool to the cache so we maintain a reference to it
-      (reset! connection-pools (assoc @connection-pools id new-pool))
-      ;; just return the newly created pool
-      new-pool)))
+    ;; create a new pool and add it to our cache, then return it
+    (u/prog1 (create-connection-pool database)
+      (swap! connection-pools assoc id <>))))
 
 (defn db->jdbc-connection-spec
   "Return a JDBC connection spec for DATABASE. Normally this will have a C3P0 pool as its datasource, unless the database is `short-lived`."

src/metabase/events/driver_notifications.clj

@@ -7,7 +7,7 @@
             [metabase.models.database :refer [Database]]))
 
 
-(def ^:const driver-notifications-topics
+(def ^:const ^:private driver-notifications-topics
   "The `Set` of event topics which are subscribed to for use in driver notifications."
   #{:database-update})
 
@@ -23,12 +23,12 @@
   "Handle processing for a single event notification received on the driver-notifications-channel"
   [driver-notifications-event]
   ;; try/catch here to prevent individual topic processing exceptions from bubbling up.  better to handle them here.
-  (try
-    (when-let [{topic :topic database :item} driver-notifications-event]
+  (when-let [{topic :topic database :item} driver-notifications-event]
+    (try
       ;; notify the appropriate driver about the updated database
-      (driver/notify-database-updated (driver/engine->driver (:engine database)) database))
-    (catch Throwable e
-      (log/warn (format "Failed to process driver notifications event. %s" (:topic driver-notifications-event)) e))))
+      (driver/notify-database-updated (driver/engine->driver (:engine database)) database)
+      (catch Throwable e
+        (log/warn (format "Failed to process driver notifications event. %s" (:topic driver-notifications-event)) e)))))