[new] Add Telemere handler

Author: ptaoussanis

src/taoensso/tufte/telemere.cljc

@@ -0,0 +1,54 @@
+(ns taoensso.tufte.telemere
+  "Handler for Telemere,
+    Ref. <https://www.taoensso.com/telemere>."
+  (:require
+   [taoensso.encore         :as enc]
+   [taoensso.encore.signals :as sigs]
+   [taoensso.tufte          :as tufte]
+   [taoensso.tufte.impl     :as impl]
+   [taoensso.telemere       :as tel]))
+
+(defn handler:telemere
+  "Beta, subject to change.
+  Returns a handler fn for use with `add-handler!` that creates a Telemere signal with:
+    `:kind`     - `:tufte`
+    `:location` - Location of `profile` call
+    `:id`       - Id       of `profile` call
+    `:level`    - Level    of `profile` call (override with `:signal-level` opt)
+    `:data`     - {:keys [sample-rate ctx data pstats pstats-str_ ...]} `profile` info
+    `:msg_`     - pstats formatted as string table, may be a delay!
+
+  Options:
+    `:telemere-level-fn` -- (fn [profiling-level]) => telemere-level (default to constantly `:info`)
+    `:format-pstats-opts` - Opts map provided to `format-pstats` (default nil)"
+
+  ([] (handler:telemere nil))
+  ([{:keys [telemere-level-fn format-pstats-opts incl-keys]
+     :or   {telemere-level-fn (fn [profiling-level] :info)}}]
+
+   (let []
+     (fn a-handler:telemere [psignal]
+       (when-let [{:keys [inst ns coords, id level, #?@(:clj [host thread]), ctx data,
+                          pstats format-pstats-fn]} psignal]
+
+         (taoensso.telemere/signal!
+           {:inst     inst
+            :ns       ns
+            :coords   coords
+            :kind     :tufte
+            :id       id
+            :level    (telemere-level-fn level)
+            :data     data
+            :psignal  psignal ; Won't be printed by default (good)
+            :msg      (when-let [ff format-pstats-fn] (delay (ff pstats format-pstats-opts)))
+            :ctx+
+            (fn [old]
+              (if (or (nil? old) (map? old))
+                (enc/merge-nx old ctx)
+                (do           old)))
+
+            #?@(:clj
+                [:host   host
+                 :thread thread])}))))))
+
+(comment ((handler:telemere) (#'tufte/dummy-psignal)))