Add experimental logging frequency counter (`utils/frequencies.clj`)

src/taoensso/timbre/frequencies.clj

@@ -0,0 +1,76 @@
+(ns taoensso.timbre.frequencies
+  "Frequency logger for Timbre. ALPHA quality."
+  {:author "Peter Taoussanis"}
+  (:require [clojure.string        :as str]
+            [taoensso.timbre       :as timbre]
+            [taoensso.timbre.utils :as utils]))
+
+(def ^:dynamic *fdata* "{::fname {form-value frequency}}" nil)
+
+(declare fdata-table)
+
+(defmacro with-fdata
+  [level & body]
+  `(if-not (timbre/logging-enabled? ~level)
+     {:result (do ~@body)}
+     (binding [*fdata* (atom {})]
+       {:result (do ~@body) :stats @*fdata*})))
+
+(defmacro log-frequencies
+  "When logging is enabled, executes named body with frequency counting enabled.
+  Body forms wrapped in (fspy) will have their result frequencies logged. Always
+  returns body's result.
+
+  Note that logging appenders will receive both a frequencies table string AND
+  the raw frequency stats under a special :frequency-stats key (useful for
+  queryable db logging)."
+  [level name & body]
+  (let [name (utils/fq-keyword name)]
+    `(let [{result# :result stats# :stats} (with-fdata ~level ~@body)]
+       (when stats#
+         (timbre/log* ~level
+                      {:frequency-stats stats#}
+                      (str "Frequencies " ~name)
+                      (str "\n" (fdata-table stats#))))
+       result#)))
+
+(defmacro fspy
+  "Frequency spy. When in the context of a *fdata* binding, records the frequency
+  of each enumerated result. Always returns the body's result."
+  [name & body]
+  (let [name (utils/fq-keyword name)]
+    `(if-not *fdata*
+       (do ~@body)
+       (let [name#   ~name
+             result# (do ~@body)]
+         (swap! *fdata* #(assoc-in % [name# result#]
+                                  (inc (get-in % [name# result#] 0))))
+         result#))))
+
+(defmacro f [name & body] `(fspy name ~@body)) ; Alias
+
+(defn fdata-table
+  "Returns formatted table string for given fdata stats."
+  [stats]
+  (let [sorted-fnames (sort (keys stats))
+        sorted-fvals  (fn [form-stats] (reverse (sort-by form-stats
+                                                        (keys form-stats))))]
+    (str/join "\n"
+     (for [fname sorted-fnames]
+       (let [form-stats (stats fname)
+             sorted-fvs (sorted-fvals form-stats)]
+         (str fname " "
+              (str/join " "
+                (mapv (fn [v] (vector v (get form-stats v 0)))
+                      sorted-fvs))))))))
+
+(comment (fdata-table {:name1 {:a 10 :b 4 :c 20}
+                       :name2 {33 8 12 2 false 6}}))
+
+(comment
+  (with-fdata :info
+    (vec (repeatedly 20 (fn [] (fspy :rand-nth (rand-nth [:a :b :c]))))))
+
+  (log-frequencies
+   :info :my-frequencies
+   (vec (repeatedly 20 (fn [] (fspy :rand-nth (rand-nth [:a :b :c])))))))