Cache Uri to Package and Package to node mappings.

pkg/analyzer/lib/src/summary/bazel_summary.dart

 // Copyright (c) 2016, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 import 'dart:convert';
 
 import 'package:analyzer/file_system/file_system.dart';
 import 'package:analyzer/src/generated/engine.dart';
 import 'package:analyzer/src/generated/source.dart';
 import 'package:analyzer/src/generated/utilities_collection.dart';
@@ skipping 92 matching lines @@
   final PackageBundle sdkBundle;
 
   /**
    * Mapping from bundle paths to corresponding [Package]s.  The packages in
    * the map were consistent with their constituent sources at the moment when
    * they were put into the map.
    */
   final Map<Folder, List<Package>> folderToPackagesMap = {};
 
   /**
-   * Mapping from [Uri]s to corresponding [_LinkNode]s.
+   * Mapping from [Uri]s to corresponding [Package]s.
    */
-  final Map<Uri, _LinkNode> uriToNodeMap = {};
+  final Map<Uri, Package> uriToPackageMap = {};
+
+  /**
+   * Mapping from [Package]s to corresponding [_LinkNode]s.
+   */
+  final Map<Package, _LinkNode> packageToNodeMap = {};
 
   SummaryProvider(this.provider, this.getOutputFolder, AnalysisContext context)
       : context = context,
         sdkBundle = context.sourceFactory.dartSdk?.getLinkedBundle();
 
   /**
    * Return the complete list of [Package]s that are required to provide all
    * resolution results for the given [source].
    *
    * The same list of packages is returned for the same [Source], i.e. always
@@ skipping 29 matching lines @@
         .where((package) => package.linked != null)
         .toList();
   }
 
   /**
    * Return the [Package] that contains information about the source with
    * the given [uri], or `null` if such package does not exist.
    */
   @visibleForTesting
   Package getUnlinkedForUri(Uri uri) {
-    Folder outputFolder = getOutputFolder(uri);
-    if (outputFolder != null) {
-      String uriStr = uri.toString();
-      List<Package> packages = _getUnlinkedPackages(outputFolder);
-      for (Package package in packages) {
-        if (package._unitUris.contains(uriStr)) {
-          return package;
+    return uriToPackageMap.putIfAbsent(uri, () {
+      Folder outputFolder = getOutputFolder(uri);
+      if (outputFolder != null) {
+        String uriStr = uri.toString();
+        List<Package> packages = _getUnlinkedPackages(outputFolder);
+        for (Package package in packages) {
+          if (package._unitUris.contains(uriStr)) {
+            return package;
+          }
         }
       }
-    }
-    return null;
+      return null;
+    });
   }
 
   /**
    * Return the hexadecimal string of the MD5 hash of the contents of the
    * given [source] in [context].
    */
   String _computeSourceHashHex(Source source) {
     String text = context.getContents(source).data;
     List<int> bytes = UTF8.encode(text);
     List<int> hashBytes = md5.convert(bytes).bytes;
     return hex.encode(hashBytes);
   }
 
   /**
    * Return the node for the given [uri], or `null` if there is no unlinked
    * bundle that contains [uri].
    */
   _LinkNode _getLinkNodeForUri(Uri uri) {
-    return uriToNodeMap.putIfAbsent(uri, () {
-      Package package = getUnlinkedForUri(uri);
+    Package package = getUnlinkedForUri(uri);
+    return packageToNodeMap.putIfAbsent(package, () {
       if (package == null) {
         return null;
       }
       return new _LinkNode(this, package);
     });
   }
 
   /**
    * Return all consistent unlinked [Package]s in the given [folder].  Some of
    * the returned packages might be already linked.
@@ skipping 196 matching lines @@
       appendDependencies(this);
       if (transitiveDependencies.any((node) => node.failed)) {
         failed = true;
       }
     }
   }
 
   @override
   String toString() => package.toString();
 }