Track Source objects in PackageNames.

lib/src/source.dart

 // Copyright (c) 2012, 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:async';
 
 import 'package:pub_semver/pub_semver.dart';
 
 import 'package.dart';
 import 'pubspec.dart';
@@ skipping 106 matching lines @@
   /// [description2] for this source.
   ///
   /// This method should be light-weight. It doesn't need to validate that
   /// either package exists.
   ///
   /// Note that either description may be a reference description or an ID
   /// description; they need not be the same type. ID descriptions should be
   /// considered equal to the reference descriptions that produced them.
   bool descriptionsEqual(description1, description2);
 
+  /// Returns a hash code for [description].
+  ///
+  /// Descriptions that compare equal using [descriptionsEqual] should return
+  /// the same hash code.
+  int hashDescription(description);
+
   /// Returns the source's name.
   String toString() => name;
 }
 
 /// A source bound to a [SystemCache].
 abstract class BoundSource {
   /// The unbound source that produced [this]. 
   Source get source;
 
   /// The system cache to which [this] is bound.
   SystemCache get systemCache;
 
   /// Get the IDs of all versions that match [ref].
   ///
   /// Note that this does *not* require the packages to be downloaded locally,
   /// which is the point. This is used during version resolution to determine
   /// which package versions are available to be downloaded (or already
   /// downloaded).
   ///
   /// By default, this assumes that each description has a single version and
   /// uses [describe] to get that version.
   ///
   /// Sources should not override this. Instead, they implement [doGetVersions].
   Future<List<PackageId>> getVersions(PackageRef ref) {
     if (ref.isRoot) {
       throw new ArgumentError("Cannot get versions for the root package.");
     }
-    if (ref.source != source.name) {
+    if (ref.source != source) {
       throw new ArgumentError("Package $ref does not use source ${source.name}.");
     }
 
     return doGetVersions(ref);
   }
 
   /// Get the IDs of all versions that match [ref].
   ///
   /// Note that this does *not* require the packages to be downloaded locally,
   /// which is the point. This is used during version resolution to determine
@@ skipping 15 matching lines @@
   ///
   /// This may be called for packages that have not yet been downloaded during
   /// the version resolution process. Its results are automatically memoized.
   ///
   /// Throws a [DataException] if the pubspec's version doesn't match [id]'s
   /// version.
   ///
   /// Sources should not override this. Instead, they implement [doDescribe].
   Future<Pubspec> describe(PackageId id) async {
     if (id.isRoot) throw new ArgumentError("Cannot describe the root package.");
-    if (id.source != source.name) {
-      throw new ArgumentError("Package $id does not use source ${source.name}.");
+    if (id.source != source) {
+      throw new ArgumentError(
+          "Package $id does not use source ${source.name}.");
     }
 
     var pubspec = _pubspecs[id];
     if (pubspec != null) return pubspec;
 
     // Delegate to the overridden one.
     pubspec = await doDescribe(id);
     if (pubspec.version != id.version) {
       dataError("The pubspec for $id has version ${pubspec.version}.");
     }
@@ skipping 21 matching lines @@
   /// If the source is cached, this will be a path in the system cache.
   String getDirectory(PackageId id);
 
   /// Stores [pubspec] so it's returned when [describe] is called with [id].
   ///
   /// This is notionally protected; it should only be called by subclasses.
   void memoizePubspec(PackageId id, Pubspec pubspec) {
     _pubspecs[id] = pubspec;
   }
 }