Remove hard limit from mirrors accessor caches.

runtime/lib/mirrors_impl.dart

Index: runtime/lib/mirrors_impl.dart
diff --git a/runtime/lib/mirrors_impl.dart b/runtime/lib/mirrors_impl.dart
index 89b7f0581bd505f1084e83d346642d45da5d043f..8a928713afc2acb3d33bfd1881bdaccf0a36aa20 100644
--- a/runtime/lib/mirrors_impl.dart
+++ b/runtime/lib/mirrors_impl.dart
@@ -5,7 +5,7 @@
 // VM-specific implementation of the dart:mirrors library.
 
 import "dart:collection" show UnmodifiableListView, UnmodifiableMapView;
-import "dart:_internal" show LRUMap;
+import "dart:_internal" show Cache;
 
 final emptyList = new UnmodifiableListView([]);
 final emptyMap = new UnmodifiableMapView({});
@@ -299,40 +299,30 @@ class _LocalInstanceMirror extends _LocalObjectMirror
     return identityHashCode(_reflectee) ^ 0x36363636;
   }
 
-  static var _getFieldClosures = new LRUMap.withShift(9);
-  static var _setFieldClosures = new LRUMap.withShift(9);
-  static var _getFieldCallCounts = new LRUMap.withShift(10);
-  static var _setFieldCallCounts = new LRUMap.withShift(10);
-  static const _closureThreshold = 20;
+  static var _getFieldClosures = new Cache.withInitialShift(4);
+  static var _setFieldClosures = new Cache.withInitialShift(4);
+
+  _createGetterClosure(unwrapped) {
+    var atPosition = unwrapped.indexOf('@');
+    if (atPosition == -1) {
+      // Public symbol.
+      return  _eval('(x) => x.$unwrapped', null);
+    } else {
+      // Private symbol.
+      var withoutKey = unwrapped.substring(0, atPosition);
+      var privateKey = unwrapped.substring(atPosition);
+      return _eval('(x) => x.$withoutKey', privateKey);
+    }
+  }
 
   _getFieldSlow(unwrapped) {
     // Slow path factored out to give the fast path a better chance at being
     // inlined.
-    var callCount = _getFieldCallCounts[unwrapped];
-    if (callCount == null) {
-      callCount = 0;
-    }
-    if (callCount == _closureThreshold) {
-      // We've seen a successful setter invocation a few times: time to invest
-      // in a closure.
-      var f;
-      var atPosition = unwrapped.indexOf('@');
-      if (atPosition == -1) {
-        // Public symbol.
-        f = _eval('(x) => x.$unwrapped', null);
-      } else {
-        // Private symbol.
-        var withoutKey = unwrapped.substring(0, atPosition);
-        var privateKey = unwrapped.substring(atPosition);
-        f = _eval('(x) => x.$withoutKey', privateKey);
-      }
-      _getFieldClosures[unwrapped] = f;
-      return reflect(f(_reflectee));
-    }
     var result = reflect(_invokeGetter(_reflectee, unwrapped));
-    // Only update call count if we don't throw to avoid creating closures for
-    // non-existent getters.
-    _getFieldCallCounts[unwrapped] = callCount + 1;
+    // Wait until success to avoid creating closures for non-existent getters.
+    _getFieldClosures[unwrapped] = (r) {
+      return (_getFieldClosures[unwrapped] = _createGetterClosure(unwrapped))(r);

[Ivan Posva, 2014/08/06 23:05:14]

Long line?

+    };
     return result;
   }
 
@@ -342,35 +332,28 @@ class _LocalInstanceMirror extends _LocalObjectMirror
     return (f == null) ? _getFieldSlow(unwrapped) : reflect(f(_reflectee));
   }
 
+  _createSetterClosure(unwrapped) {
+    var atPosition = unwrapped.indexOf('@');
+    if (atPosition == -1) {
+      // Public symbol.
+      return _eval('(x, v) => x.$unwrapped = v', null);
+    } else {
+      // Private symbol.
+      var withoutKey = unwrapped.substring(0, atPosition);
+      var privateKey = unwrapped.substring(atPosition);
+      return _eval('(x, v) => x.$withoutKey = v', privateKey);
+    }
+  }
+
   _setFieldSlow(unwrapped, arg) {
     // Slow path factored out to give the fast path a better chance at being
     // inlined.
-    var callCount = _setFieldCallCounts[unwrapped];
-    if (callCount == null) {
-      callCount = 0;
-    }
-    if (callCount == _closureThreshold) {
-      // We've seen a successful getter invocation a few times: time to invest
-      // in a closure.
-      var f;
-      var atPosition = unwrapped.indexOf('@');
-      if (atPosition == -1) {
-        // Public symbol.
-        f = _eval('(x, v) => x.$unwrapped = v', null);
-      } else {
-        // Private symbol.
-        var withoutKey = unwrapped.substring(0, atPosition);
-        var privateKey = unwrapped.substring(atPosition);
-        f = _eval('(x, v) => x.$withoutKey = v', privateKey);
-      }
-      _setFieldClosures[unwrapped] = f;
-      return reflect(f(_reflectee, arg));
-    }
     _invokeSetter(_reflectee, unwrapped, arg);
     var result = reflect(arg);
-    // Only update call count if we don't throw to avoid creating closures for
-    // non-existent setters.
-    _setFieldCallCounts[unwrapped] = callCount + 1;
+    // Wait until success to avoid creating closures for non-existent setters.
+    _setFieldClosures[unwrapped] = (r, v) {
+      return (_setFieldClosures[unwrapped] = _createSetterClosure(unwrapped))(r, v);
+    };
     return result;
   }