instrumenting functions via graphite and robert-hooke

instrument-anything.clj

(defn graphiteisze-path
  "Graphite uses a dot (.) as a separator. Whisper stores metrics on disk by name, so we cannot have slashes in the metric name"
  [path]
  (clojure.string/replace path #"[/\.]" "_"))

(defn timed-hook-fn 
  [metric-registry group type name]
  (let [timer (timer metric-registry [(graphiteisze-path group) (graphiteisze-path type) (graphiteisze-path name)])]
    (fn [f & args]
      (time-fn! timer #(apply f args)))))

(defn- with-timer [metric-registry ns fname f & args]
  (time!
    (timer metric-registry ["functions" (graphiteisze-path (name (ns-name ns))) (graphiteisze-path fname)]) (apply f args)))

(defn- instrument-with-timer! [metric-registry fn]
  (let [{:keys [ns name]} (meta fn)]
    (rh/add-hook fn (timed-hook-fn metric-registry "functions" ns name))))

(defn instrument-functions! [metric-registry]
  (dorun (map (partial instrument-with-timer! metric-registry)
              [#'my-fn-namespace/my-fn-name])))