CLJS-2238: Perf regression with node module indexing

Author: anmonteiro

src/main/clojure/cljs/closure.clj

@@ -2206,47 +2206,53 @@
          (node-inputs [{:file (.getAbsolutePath deps-file)}] opts))
        []))))
 
+(defn- node-file-seq->libs-spec*
+  [module-fseq]
+  (letfn [(package-json? [path]
+            (boolean (re-find #"node_modules[/\\](@[^/\\]+?[/\\])?[^/\\]+?[/\\]package\.json$" path)))]
+    (let [pkg-jsons (into {}
+                      (comp
+                        (map #(.getAbsolutePath %))
+                        (filter package-json?)
+                        (map (fn [path]
+                               [path (json/read-str (slurp path))])))
+                      module-fseq)]
+      (into []
+        (comp
+          (map #(.getAbsolutePath %))
+          (map (fn [path]
+                 (merge
+                   {:file path
+                    :module-type :commonjs}
+                   (when-not (package-json? path)
+                     (let [pkg-json-main (some
+                                           (fn [[pkg-json-path {:strs [main name]}]]
+                                             (when-not (nil? main)
+                                               (let [main-path (str (string/replace pkg-json-path #"package\.json$" "")
+                                                                 main)]
+                                                 (when (= main-path path)
+                                                   name))))
+                                           pkg-jsons)]
+                       {:provides (if (some? pkg-json-main)
+                                    [pkg-json-main]
+                                    (let [module-rel-name (string/replace
+                                                            (subs path (.lastIndexOf path "node_modules"))
+                                                            #"node_modules[\\\/]" "")]
+                                      (cond-> [module-rel-name (string/replace module-rel-name #"\.js(on)?$" "")]
+                                        (boolean (re-find #"[\\\/]index\.js(on)?$" module-rel-name))
+                                        (conj (string/replace module-rel-name #"[\\\/]index\.js(on)?$" "")))))}))))))
+        module-fseq))))
+
+(def node-file-seq->libs-spec (memoize node-file-seq->libs-spec*))
+
 (defn index-node-modules-dir
   ([]
    (index-node-modules-dir
      (when env/*compiler*
        (:options @env/*compiler*))))
   ([{:keys [verbose target]}]
-   (letfn [(package-json? [path]
-             (boolean (re-find #"node_modules[/\\](@[^/\\]+?[/\\])?[^/\\]+?[/\\]package\.json$" path)))]
-     (let [module-fseq (util/module-file-seq)
-           pkg-jsons (into {}
-                       (comp
-                         (map #(.getAbsolutePath %))
-                         (filter package-json?)
-                         (map (fn [path]
-                                [path (json/read-str (slurp path))])))
-                       module-fseq)]
-       (into []
-         (comp
-           (map #(.getAbsolutePath %))
-           (map (fn [path]
-                  (merge
-                    {:file path
-                     :module-type :commonjs}
-                    (when-not (package-json? path)
-                      (let [pkg-json-main (some
-                                            (fn [[pkg-json-path {:strs [main name]}]]
-                                              (when-not (nil? main)
-                                                (let [main-path (str (string/replace pkg-json-path #"package\.json$" "")
-                                                                  main)]
-                                                  (when (= main-path path)
-                                                    name))))
-                                            pkg-jsons)]
-                        {:provides (if (some? pkg-json-main)
-                                     [pkg-json-main]
-                                     (let [module-rel-name (string/replace
-                                                             (subs path (.lastIndexOf path "node_modules"))
-                                                             #"node_modules[\\\/]" "")]
-                                       (cond-> [module-rel-name (string/replace module-rel-name #"\.js(on)?$" "")]
-                                         (boolean (re-find #"[\\\/]index\.js(on)?$" module-rel-name))
-                                         (conj (string/replace module-rel-name #"[\\\/]index\.js(on)?$" "")))))}))))))
-         module-fseq)))))
+   (let [module-fseq (util/module-file-seq)]
+     (node-file-seq->libs-spec module-fseq))))
 
 (defn preprocess-js
   "Given js-module map, apply preprocessing defined by :preprocess value in the map."