[mod] SLF4J->Telemere backend: move noisy stuff out of signal data

This is a BREAKING change for the small minority of users that:

  1. Are using the `taoensso.telemere.slf4j` backend, AND
  2. Are using the low-level `:slf4j/args` or `:slf4j/marker-names`
     values in signal `:data`

BEFORE this commit:

  SLF4J signals contain:
  {:data {:slf4j/kvs {...},
          :slf4j/args [...],
          :slf4j/marker-names #{...}},
   ...}.

AFTER this commit:

  SLF4J signals contain:
  {:data {:slf4j/kvs {...}},
   :kvs  {:slf4j/args <Object[]>,
          :slf4j/markers #{...}},
   ...}

  So:
    - [:data :slf4j/marker-names] has moved to [:kvs :slf4j/markers].
    - [:data :slf4j/args]         has moved to [:kvs :slf4j/args],
      and is now an Object[] rather than vector.

Motivation for the change:

  The new behaviour is a more sensible default.

  Basically: anything in `:data` is included by default in output.
  But :slf4j/args are generally anyway already in the signal's formatted
  message, so this ends up just creating duplicate output.

  Likewise markers are generally used more for filtering/xfns than for
  output labelling, so excluding them from default output is sensible.

main/test/taoensso/telemere_tests.cljc

@@ -727,7 +727,7 @@
                (is (sm? (with-sig (-> (.atWarn sl) (.log "Hello"))) {:level :warn, :ns "my.class", :kind :slf4j, :msg_ "Hello", :inst enc/inst?}) "Fluent API: warn basics")])
 
             (testing "Message formatting"
-             (let [msgp "x={},y={}", expected {:msg_ "x=1,y=2", :data {:slf4j/args ["1" "2"]}}]
+             (let [msgp "x={},y={}", expected {:msg_ "x=1,y=2", :slf4j/args (fn [objs] (= (vec objs) ["1" "2"]))}]
                [(is (sm? (with-sig (.info sl msgp "1" "2"))                                                           expected) "Legacy API: formatted message, raw args")
                 (is (sm? (with-sig (-> (.atInfo sl) (.setMessage msgp) (.addArgument "1") (.addArgument "2") (.log))) expected) "Fluent API: formatted message, raw args")]))
 
@@ -738,8 +738,8 @@
                     m2 (#'slf4j/est-marker! "M2")
                     cm (#'slf4j/est-marker! "Compound" "M1" "M2")]
 
-                [(is (sm? (with-sig (.info sl cm "Hello"))                                    {:data {:slf4j/marker-names #{"Compound" "M1" "M2"}}}) "Legacy API: markers")
+                [(is (sm? (with-sig (.info sl cm "Hello"))                                    {:slf4j/markers #{"Compound" "M1" "M2"}}) "Legacy API: markers")
-                 (is (sm? (with-sig (-> (.atInfo sl) (.addMarker m1) (.addMarker cm) (.log))) {:data {:slf4j/marker-names #{"Compound" "M1" "M2"}}}) "Fluent API: markers")]))
+                 (is (sm? (with-sig (-> (.atInfo sl) (.addMarker m1) (.addMarker cm) (.log))) {:slf4j/markers #{"Compound" "M1" "M2"}}) "Fluent API: markers")]))
 
             (testing "Errors"
               [(is (sm? (with-sig (.warn sl "An error" ^Throwable ex1))     {:level :warn, :error ex1}) "Legacy API: errors")

slf4j/src/taoensso/telemere/slf4j.clj

@@ -63,13 +63,13 @@
 
 (comment [(est-marker! "a1" "a2") (get-marker  "a1") (= (get-marker "a1") (get-marker "a1"))])
 
-(def ^:private marker-names
+(def ^:private get-marker-names
   "Returns #{<MarkerName>}. Cached => assumes markers NOT modified after creation."
   ;; We use `BasicMarkerFactory` so:
   ;;   1. Our markers are just labels (no other content besides their name).
   ;;   2. Markers with the same name are identical (enabling caching).
   (enc/fmemoize
-    (fn marker-names [marker-or-markers]
+    (fn get-marker-names             [marker-or-markers]
       (if (instance? org.slf4j.Marker marker-or-markers)
 
         ;; Single marker
@@ -82,12 +82,12 @@
               (fn [acc      ^org.slf4j.Marker in]
                 (if-not   (.hasReferences     in)
                   (conj acc (.getName         in))
-                  (into acc (marker-names in))))
+                  (into acc (get-marker-names in))))
               acc (.iterator m))))
 
         ;; Vector of markers
         (reduce
-          (fn [acc in] (into acc (marker-names in)))
+          (fn [acc in] (into acc (get-marker-names in)))
           #{} (truss/have vector? marker-or-markers))))))
 
 (comment
@@ -97,9 +97,9 @@
         ms [m1 m2]]
 
     (enc/qb 1e6 ; [45.52 47.48 44.85]
-      (marker-names m1)
+      (get-marker-names m1)
-      (marker-names cm)
+      (get-marker-names cm)
-      (marker-names ms))))
+      (get-marker-names ms))))
 
 ;;;; Interop fns (called by `TelemereLogger`)
 
@@ -132,11 +132,10 @@
        (org.slf4j.helpers.MessageFormatter/basicArrayFormat
          msg-pattern args))
 
-     :data
+     :slf4j/args    args ; Object[]
-     (enc/assoc-some nil
+     :slf4j/markers marker-names ; Usu. used for routing, filtering, xfns, etc.
-       :slf4j/marker-names marker-names
+     :data (when kvs {:slf4j/kvs kvs})})
-       :slf4j/args (when args (vec args))
+
-       :slf4j/kvs  kvs)})
   nil)
 
 (defn- log!
@@ -149,7 +148,7 @@
          error        (.getThrowable event)
          msg-pattern  (.getMessage   event)
          args         (when-let [args    (.getArgumentArray event)] args)
-         markers     (when-let [markers (.getMarkers       event)] (marker-names (vec markers)))
+         marker-names (when-let [markers (.getMarkers       event)] (get-marker-names (vec markers)))
          kvs          (when-let [kvps    (.getKeyValuePairs event)]
                         (reduce
                           (fn [acc ^org.slf4j.event.KeyValuePair kvp]
@@ -157,11 +156,11 @@
                           nil kvps))]
 
      (when-debug (println [:slf4j/fluent-log-call (sig-level level) logger-name]))
-     (normalized-log! logger-name level inst error msg-pattern args markers kvs)))
+     (normalized-log! logger-name level inst error msg-pattern args marker-names kvs)))
 
   ;; Legacy API calls
   ([logger-name ^org.slf4j.event.Level level error msg-pattern args marker]
-   (let [marker-names (when marker (marker-names marker))]
+   (let [marker-names (when marker (get-marker-names marker))]
      (when-debug (println [:slf4j/legacy-log-call (sig-level level) logger-name]))
      (normalized-log! logger-name level (enc/now-inst*) error msg-pattern args marker-names nil))))