From 10483f5357134ad6a0d6211e30a06e08512f9dc1 Mon Sep 17 00:00:00 2001
From: Kevin Moore <kevmoo@google.com>
Date: Wed, 10 Jan 2018 17:58:29 -0800
Subject: [PATCH 1/2] Use explicit keys for often accessed closures

---
 lib/src/model.dart       | 10 ++++++----
 lib/src/model_utils.dart |  5 +++--
 2 files changed, 9 insertions(+), 6 deletions(-)

diff --git a/lib/src/model.dart b/lib/src/model.dart
index 90ca35802f..fbd024bdc7 100644
--- a/lib/src/model.dart
+++ b/lib/src/model.dart
@@ -1560,8 +1560,8 @@ abstract class GetterSetterCombo implements ModelElement {
     if (targetClass.name == target.name) {
       return original.replaceAll(constructorName, "${target.linkedName}");
     }
-    return original.replaceAll(
-        "${targetClass.name}.${target.name}", "${targetClass.linkedName}.${target.linkedName}");
+    return original.replaceAll("${targetClass.name}.${target.name}",
+        "${targetClass.linkedName}.${target.linkedName}");
   }
 
   String _constantValueBase() {
@@ -2892,7 +2892,8 @@ abstract class ModelElement extends Canonicalization
   ///
   /// For example: libraryName.className.methodName
   @override
-  String get fullyQualifiedName => _memoizer.memoized(_buildFullyQualifiedName);
+  String get fullyQualifiedName => _memoizer.memoized(_buildFullyQualifiedName,
+      altKey: 'fullyQualifiedName');
 
   String _fullyQualifiedNameWithoutLibrary() {
     // Remember, periods are legal in library names.
@@ -2904,7 +2905,8 @@ abstract class ModelElement extends Canonicalization
   // library.fullyQualifiedName seems somehow to break things.
   //String get fullyQualifiedNameWithoutLibrary => _memoizer.memoized2(fullyQualifiedName.replaceFirst, "${library.fullyQualifiedName}.", '');
   String get fullyQualifiedNameWithoutLibrary =>
-      _memoizer.memoized(_fullyQualifiedNameWithoutLibrary);
+      _memoizer.memoized(_fullyQualifiedNameWithoutLibrary,
+          altKey: 'fullyQualifiedNameWithoutLibrary');
 
   String get sourceFileName => element.source.fullName;
 
diff --git a/lib/src/model_utils.dart b/lib/src/model_utils.dart
index 5dbcfbf622..8a32af1ee3 100644
--- a/lib/src/model_utils.dart
+++ b/lib/src/model_utils.dart
@@ -266,8 +266,9 @@ class Memoizer {
 
   /// Calls and caches the return value of [f]() if not in the cache, then
   /// returns the cached value of [f]().
-  R memoized<R>(Function f) {
-    _HashableList key = new _HashableList([f]);
+  R memoized<R>(Function f, {String altKey}) {
+    Object obj = altKey ?? f;
+    _HashableList key = new _HashableList([obj]);
     return _cacheIfAbsent(key, f);
   }
 

From 5ec1c0eadbc52c065a5406f86d464451279066f7 Mon Sep 17 00:00:00 2001
From: Kevin Moore <kevmoo@google.com>
Date: Wed, 10 Jan 2018 18:28:42 -0800
Subject: [PATCH 2/2] _HashableList: don't use UnodifiableListView

Adds unnecessary overhead in a perf-critical case
Also cache the hashCode
---
 lib/src/model_utils.dart | 18 ++++++++++--------
 1 file changed, 10 insertions(+), 8 deletions(-)

diff --git a/lib/src/model_utils.dart b/lib/src/model_utils.dart
index 8a32af1ee3..b21e9e4e99 100644
--- a/lib/src/model_utils.dart
+++ b/lib/src/model_utils.dart
@@ -172,15 +172,17 @@ String crossdartifySource(
 
 /// An UnmodifiableListView that computes equality and hashCode based on the
 /// equality and hashCode of its contained objects.
-class _HashableList extends UnmodifiableListView<dynamic> {
-  _HashableList(Iterable<dynamic> iterable) : super(iterable);
+class _HashableList {
+  final List _source;
+  int _hashCache;
+  _HashableList(this._source);
 
   @override
   bool operator ==(other) {
     if (other is _HashableList) {
-      if (this.length == other.length) {
-        for (var index = 0; index < length; ++index) {
-          if (this[index] != other[index]) return false;
+      if (_source.length == other._source.length) {
+        for (var index = 0; index < _source.length; ++index) {
+          if (_source[index] != other._source[index]) return false;
         }
         return true;
       }
@@ -189,7 +191,7 @@ class _HashableList extends UnmodifiableListView<dynamic> {
   }
 
   @override
-  get hashCode => hashObjects(this);
+  get hashCode => _hashCache ??= hashObjects(_source);
 }
 
 /// Like [Memoizer], except in checked mode will validate that the value of the
@@ -252,11 +254,11 @@ class ValidatingMemoizer extends Memoizer {
 /// ```
 class Memoizer {
   /// Map of a function and its positional parameters (if any), to a value.
-  Map<_HashableList, dynamic> _memoizationTable = new Map();
+  final Map<_HashableList, dynamic> _memoizationTable = new HashMap();
 
   /// Reset the memoization table, forcing calls of the underlying functions.
   void invalidateMemos() {
-    _memoizationTable = new Map();
+    _memoizationTable.clear();
   }
 
   /// A wrapper around putIfAbsent, exposed to allow overrides.