Optimize getField by caching a closure generated from eval.

runtime/lib/mirrors.cc

 // 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.
 
 #include "lib/invocation_mirror.h"
 #include "vm/bootstrap_natives.h"
 #include "vm/class_finalizer.h"
 #include "vm/compiler.h"
 #include "vm/dart_entry.h"
 #include "vm/exceptions.h"
@@ skipping 1283 matching lines @@
                            Instance::null_instance());
 }
 
 
 DEFINE_NATIVE_ENTRY(TypeVariableMirror_upper_bound, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(TypeParameter, param, arguments->NativeArgAt(0));
   return param.bound();
 }
 
 
+DEFINE_NATIVE_ENTRY(Mirrors_evalInLibraryWithPrivateKey, 2) {
+  GET_NON_NULL_NATIVE_ARGUMENT(String, expression, arguments->NativeArgAt(0));
+  GET_NATIVE_ARGUMENT(String, private_key, arguments->NativeArgAt(1));
+
+  const GrowableObjectArray& libraries =
+      GrowableObjectArray::Handle(isolate->object_store()->libraries());
+  const int num_libraries = libraries.Length();
+  Library& each_library = Library::Handle();
+  Library& ctxt_library = Library::Handle();
+  String& library_key = String::Handle();
+
+  for (int i = 0; i < num_libraries; i++) {
+    each_library ^= libraries.At(i);
+    library_key = each_library.private_key();
+    if (library_key.Equals(private_key)) {
+      ctxt_library = each_library.raw();
+      break;
+    }
+  }
+  if (ctxt_library.IsNull()) {
+    ctxt_library = Library::CoreLibrary();
+  }
+  return ctxt_library.Evaluate(expression);
+}
+
 DEFINE_NATIVE_ENTRY(TypedefMirror_declaration, 1) {
   GET_NON_NULL_NATIVE_ARGUMENT(Type, type, arguments->NativeArgAt(0));
   const Class& cls = Class::Handle(type.type_class());
   // We represent typedefs as non-canonical signature classes.
   ASSERT(cls.IsSignatureClass() && !cls.IsCanonicalSignatureClass());
   return CreateTypedefMirror(cls,
                              AbstractType::Handle(cls.DeclarationType()),
                              Bool::True(),  // is_declaration
                              Object::null_instance());
 }
@@ skipping 748 matching lines @@
 
 DEFINE_NATIVE_ENTRY(VariableMirror_type, 2) {
   GET_NON_NULL_NATIVE_ARGUMENT(MirrorReference, ref, arguments->NativeArgAt(0));
   const Field& field = Field::Handle(ref.GetFieldReferent());
   GET_NATIVE_ARGUMENT(AbstractType, instantiator, arguments->NativeArgAt(1));
   const AbstractType& type = AbstractType::Handle(field.type());
   return InstantiateType(type, instantiator);
 }
 
 }  // namespace dart