Cache hash code for closures.

runtime/vm/object.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 "vm/object.h"
 
 #include "include/dart_api.h"
 #include "platform/assert.h"
 #include "vm/assembler.h"
 #include "vm/become.h"
@@ skipping 6827 matching lines @@
   const Instance& result = Instance::Handle(Closure::New(*this, context));
   if (cls.IsGeneric()) {
     const TypeArguments& type_arguments =
         TypeArguments::Handle(receiver.GetTypeArguments());
     result.SetTypeArguments(type_arguments);
   }
   return result.raw();
 }
 
 
+RawSmi* Function::GetClosureHashCode() const {
+  ASSERT(IsClosureFunction());
+  const Object& obj = Object::Handle(raw_ptr()->data_);
+  ASSERT(!obj.IsNull());
+  if (ClosureData::Cast(obj).hash() != Object::null()) {
+    ASSERT(Object::Handle(ClosureData::Cast(obj).hash()).IsSmi());
+    return Smi::New(Smi::Value(Smi::RawCast(ClosureData::Cast(obj).hash())));

[Cutch, 2016/12/21 15:39:45]

this can just be Smi::RawCast(ClosureData::Cast(obj).hash()))

[Florian Schneider, 2016/12/21 15:49:40]

Done.

+  }
+  // Hash not yet computed. Compute and cache it.
+  const Class& cls = Class::Handle(Owner());
+  intptr_t result = String::Handle(name()).Hash();
+  result += String::Handle(Signature()).Hash();
+  result += String::Handle(cls.Name()).Hash();
+  // Finalize hash value like for strings so that it fits into a smi.
+  result += result << 3;
+  result ^= result >> 11;
+  result += result << 15;
+  result &= ((static_cast<intptr_t>(1) << String::kHashBits) - 1);
+  ClosureData::Cast(obj).set_hash(result);
+  return Smi::New(result);
+}
+
+
 RawString* Function::BuildSignature(bool instantiate,
                                     NameVisibility name_visibility,
                                     const TypeArguments& instantiator) const {
   Thread* thread = Thread::Current();
   Zone* zone = thread->zone();
   GrowableHandlePtrArray<const String> pieces(zone, 4);
   String& name = String::Handle(zone);
   if (!instantiate && !is_static() && (name_visibility == kInternalName)) {
     // Prefix the signature with its scope class and type parameters, if any
     // (e.g. "Map<K, V>(K) => bool"). In case of a function type alias, the
@@ skipping 356 matching lines @@
 }
 
 
 void ClosureData::set_implicit_static_closure(const Instance& closure) const {
   ASSERT(!closure.IsNull());
   ASSERT(raw_ptr()->closure_ == Instance::null());
   StorePointer(&raw_ptr()->closure_, closure.raw());
 }
 
 
+void ClosureData::set_hash(intptr_t value) const {
+  StorePointer(&raw_ptr()->hash_, static_cast<RawObject*>(Smi::New(value)));
+}
+
+
 void ClosureData::set_parent_function(const Function& value) const {
   StorePointer(&raw_ptr()->parent_function_, value.raw());
 }
 
 
 void ClosureData::set_signature_type(const Type& value) const {
   StorePointer(&raw_ptr()->signature_type_, value.raw());
 }
 
 
@@ skipping 15638 matching lines @@
   return UserTag::null();
 }
 
 
 const char* UserTag::ToCString() const {
   const String& tag_label = String::Handle(label());
   return tag_label.ToCString();
 }
 
 }  // namespace dart