Issue #2407187 by artem_sylchuk, longwave, Matroskeen, Berdir, Wim Leers,...

Issue #2407187 by artem_sylchuk, longwave, Matroskeen, Berdir, Wim Leers, andypost, abramm: Optimize LibraryDependencyResolver::getMinimalRepresentativeSubset() and win >=4%

(cherry picked from commit 3e64338b)

core/lib/Drupal/Core/Asset/LibraryDependencyResolver.php

@@ -14,6 +14,13 @@ class LibraryDependencyResolver implements LibraryDependencyResolverInterface {
    */
   protected $libraryDiscovery;
 
+  /**
+   * The libraries dependencies.
+   *
+   * @var array
+   */
+  protected $librariesDependencies = [];
+
   /**
    * Constructs a new LibraryDependencyResolver instance.
    *
@@ -28,7 +35,14 @@ public function __construct(LibraryDiscoveryInterface $library_discovery) {
    * {@inheritdoc}
    */
   public function getLibrariesWithDependencies(array $libraries) {
-    return $this->doGetDependencies($libraries);
+    $return = [];
+    foreach ($libraries as $library) {
+      if (!isset($this->librariesDependencies[$library])) {
+        $this->librariesDependencies[$library] = $this->doGetDependencies([$library]);
+      }
+      $return += $this->librariesDependencies[$library];
+    }
+    return array_values($return);
   }
 
   /**
@@ -49,13 +63,13 @@ public function getLibrariesWithDependencies(array $libraries) {
    */
   protected function doGetDependencies(array $libraries_with_unresolved_dependencies, array $final_libraries = []) {
     foreach ($libraries_with_unresolved_dependencies as $library) {
-      if (!in_array($library, $final_libraries)) {
+      if (!isset($final_libraries[$library])) {
         list($extension, $name) = explode('/', $library, 2);
         $definition = $this->libraryDiscovery->getLibraryByName($extension, $name);
         if (!empty($definition['dependencies'])) {
           $final_libraries = $this->doGetDependencies($definition['dependencies'], $final_libraries);
         }
-        $final_libraries[] = $library;
+        $final_libraries[$library] = $library;
       }
     }
     return $final_libraries;
@@ -67,31 +81,15 @@ protected function doGetDependencies(array $libraries_with_unresolved_dependenci
   public function getMinimalRepresentativeSubset(array $libraries) {
     assert(count($libraries) === count(array_unique($libraries)), '$libraries can\'t contain duplicate items.');
 
-    $minimal = [];
-
     // Determine each library's dependencies.
-    $with_deps = [];
+    $all_dependencies = [];
     foreach ($libraries as $library) {
-      $with_deps[$library] = $this->getLibrariesWithDependencies([$library]);
-    }
-
-    foreach ($libraries as $library) {
-      $exists = FALSE;
-      foreach ($with_deps as $other_library => $dependencies) {
-        if ($library == $other_library) {
-          continue;
-        }
-        if (in_array($library, $dependencies)) {
-          $exists = TRUE;
-          break;
-        }
-      }
-      if (!$exists) {
-        $minimal[] = $library;
-      }
+      $with_deps = $this->getLibrariesWithDependencies([$library]);
+      // We don't need library itself listed in the dependencies.
+      $all_dependencies += array_diff($with_deps, [$library]);
     }
 
-    return $minimal;
+    return array_values(array_diff($libraries, array_intersect($all_dependencies, $libraries)));
   }
 
 }