CLJS-892: Improve performance of compare-symbols/compare-keywords

Author: tonsky

benchmark/cljs/benchmark_runner.cljs

@@ -111,6 +111,18 @@
   (= a b) 1)
 (println)
 
+(println ";;; keyword compare")
+(let [seed ["amelia" "olivia" "jessica" "emily" "lily" "ava" "isla" "sophie" "mia" "isabella" "evie" "poppy" "ruby" "grace" "sophia" "chloe" "freya" "isabelle" "ella" "charlotte" "scarlett" "daisy" "lola" "holly" "eva" "lucy" "millie" "phoebe" "layla" "maisie" "sienna" "alice" "florence" "lilly" "ellie" "erin" "elizabeth" "imogen" "summer" "molly" "hannah" "sofia" "abigail" "jasmine" "matilda" "megan" "rosie" "lexi" "lacey" "emma" "amelie" "maya" "gracie" "emilia" "georgia" "hollie" "evelyn" "eliza" "amber" "eleanor" "bella" "amy" "brooke" "leah" "esme" "harriet" "anna" "katie" "zara" "willow" "elsie" "annabelle" "bethany" "faith" "madison" "isabel" "rose" "julia" "martha" "maryam" "paige" "heidi" "maddison" "niamh" "skye" "aisha" "mollie" "ivy" "francesca" "darcey" "maria" "zoe" "keira" "sarah" "tilly" "isobel" "violet" "lydia" "sara" "caitlin"]]
+  (simple-benchmark
+    [arr (into-array (repeatedly 10000 #(keyword (rand-nth seed))))]
+    (.sort arr compare)
+    100)
+  (simple-benchmark
+    [arr (into-array (repeatedly 10000 #(keyword (rand-nth seed) (rand-nth seed))))]
+    (.sort arr compare)
+    100))
+(println)
+
 (println ";;; reduce lazy-seqs, vectors, ranges")
 (simple-benchmark [coll (take 100000 (iterate inc 0))] (reduce + 0 coll) 1)
 (simple-benchmark [coll (range 1000000)] (reduce + 0 coll) 1)

src/cljs/cljs/core.cljs

@@ -566,15 +566,15 @@
 
 (defn- compare-symbols [a b]
   (cond
-   (= a b) 0
+   (identical? (.-str a) (.-str b)) 0
    (and (not (.-ns a)) (.-ns b)) -1
    (.-ns a) (if-not (.-ns b)
               1
-              (let [nsc (compare (.-ns a) (.-ns b))]
-                (if (zero? nsc)
-                  (compare (.-name a) (.-name b))
+              (let [nsc (garray/defaultCompare (.-ns a) (.-ns b))]
+                (if (== 0 nsc)
+                  (garray/defaultCompare (.-name a) (.-name b))
                   nsc)))
-   :default (compare (.-name a) (.-name b))))
+   :default (garray/defaultCompare (.-name a) (.-name b))))
 
 (deftype Symbol [ns name str ^:mutable _hash _meta]
   Object
@@ -2419,6 +2419,18 @@ reduces them without incurring seq initialization"
 (defn hash-keyword [k]
   (int (+ (hash-symbol k) 0x9e3779b9)))
 
+(defn- compare-keywords [a b]
+  (cond
+   (identical? (.-fqn a) (.-fqn b)) 0
+   (and (not (.-ns a)) (.-ns b)) -1
+   (.-ns a) (if-not (.-ns b)
+              1
+              (let [nsc (garray/defaultCompare (.-ns a) (.-ns b))]
+                (if (== 0 nsc)
+                  (garray/defaultCompare (.-name a) (.-name b))
+                  nsc)))
+   :default (garray/defaultCompare (.-name a) (.-name b))))
+
 (deftype Keyword [ns name fqn ^:mutable _hash]
   Object
   (toString [_] (str ":" fqn))
@@ -8307,8 +8319,7 @@ reduces them without incurring seq initialization"
   (-compare [x y] (compare-symbols x y))
 
   Keyword
-  ; keyword happens to have the same fields as Symbol, so this just works
-  (-compare [x y] (compare-symbols x y))
+  (-compare [x y] (compare-keywords x y))
 
   Subvec
   (-compare [x y] (compare-indexed x y))