From fa8a0613a3ef993ae69ffad683c668d45d432306 Mon Sep 17 00:00:00 2001
From: Zachary Anderson <zra@google.com>
Date: Mon, 14 Dec 2015 11:12:25 -0800
Subject: [PATCH] Fold ApiObjectConverter use into ApiMessageReader

TODO from change on Friday.

R=turnidge@google.com

Review URL: https://codereview.chromium.org/1523013002 .
---
 runtime/vm/dart_api_message.cc       | 36 ++++++++++++++++++++++------
 runtime/vm/dart_api_message.h        | 10 ++++----
 runtime/vm/native_message_handler.cc | 20 ++++------------
 3 files changed, 39 insertions(+), 27 deletions(-)

diff --git a/runtime/vm/dart_api_message.cc b/runtime/vm/dart_api_message.cc
index a4e47bbd971..bec6df921e6 100644
--- a/runtime/vm/dart_api_message.cc
+++ b/runtime/vm/dart_api_message.cc
@@ -18,15 +18,26 @@ ApiMessageReader::ApiMessageReader(const uint8_t* buffer, intptr_t length)
       backward_references_(kNumInitialReferences),
       vm_isolate_references_(kNumInitialReferences),
       vm_symbol_references_(NULL) {
-  // We need to have an enclosing ApiNativeScope.
-  ASSERT(ApiNativeScope::Current() != NULL);
-  zone_ = ApiNativeScope::Current()->zone();
-  ASSERT(zone_ != NULL);
-  Init();
+}
+
+
+ApiMessageReader::ApiMessageReader(Message* msg)
+    : BaseReader(msg->IsRaw() ? reinterpret_cast<uint8_t*>(msg->raw_obj())
+                              : msg->data(),
+                 msg->len()),
+      zone_(NULL),
+      backward_references_(kNumInitialReferences),
+      vm_isolate_references_(kNumInitialReferences),
+      vm_symbol_references_(NULL) {
 }
 
 
 void ApiMessageReader::Init() {
+  // We need to have an enclosing ApiNativeScope.
+  ASSERT(ApiNativeScope::Current() != NULL);
+  zone_ = ApiNativeScope::Current()->zone();
+  ASSERT(zone_ != NULL);
+
   // Initialize marker objects used to handle Lists.
   // TODO(sjesse): Remove this when message serialization format is
   // updated.
@@ -40,8 +51,19 @@ void ApiMessageReader::Init() {
 
 
 Dart_CObject* ApiMessageReader::ReadMessage() {
-  // Read the object out of the message.
-  return ReadObject();
+  Init();
+  if (PendingBytes() > 0) {
+    // Read the object out of the message.
+    return ReadObject();
+  } else {
+    const RawObject* raw_obj =
+        reinterpret_cast<const RawObject*>(CurrentBufferAddress());
+    ASSERT(ApiObjectConverter::CanConvert(raw_obj));
+    Dart_CObject* cobj =
+      reinterpret_cast<Dart_CObject*>(allocator(sizeof(Dart_CObject)));
+    ApiObjectConverter::Convert(raw_obj, cobj);
+    return cobj;
+  }
 }
 
 
diff --git a/runtime/vm/dart_api_message.h b/runtime/vm/dart_api_message.h
index de1b5c3c5b5..f4675c4b384 100644
--- a/runtime/vm/dart_api_message.h
+++ b/runtime/vm/dart_api_message.h
@@ -9,6 +9,7 @@
 #include "platform/utils.h"
 #include "vm/allocation.h"
 #include "vm/dart_api_state.h"
+#include "vm/message.h"
 #include "vm/raw_object.h"
 #include "vm/snapshot.h"
 
@@ -48,6 +49,7 @@ class ApiMessageReader : public BaseReader {
   // Allocation of all C Heap objects is done in the zone associated with
   // the enclosing ApiNativeScope.
   ApiMessageReader(const uint8_t* buffer, intptr_t length);
+  explicit ApiMessageReader(Message* message);
   ~ApiMessageReader() { }
 
   Dart_CObject* ReadMessage();
@@ -212,13 +214,13 @@ class ApiMessageWriter : public BaseWriter {
 // as well.
 class ApiObjectConverter : public AllStatic {
  public:
-  static bool CanConvert(RawObject* raw_obj) {
+  static bool CanConvert(const RawObject* raw_obj) {
     return !raw_obj->IsHeapObject() || (raw_obj == Object::null());
   }
 
-  static bool Convert(RawObject* raw_obj, Dart_CObject* c_obj) {
+  static bool Convert(const RawObject* raw_obj, Dart_CObject* c_obj) {
     if (!raw_obj->IsHeapObject()) {
-      ConvertSmi(reinterpret_cast<RawSmi*>(raw_obj), c_obj);
+      ConvertSmi(reinterpret_cast<const RawSmi*>(raw_obj), c_obj);
     } else if (raw_obj == Object::null()) {
       ConvertNull(c_obj);
     } else {
@@ -228,7 +230,7 @@ class ApiObjectConverter : public AllStatic {
   }
 
  private:
-  static void ConvertSmi(RawSmi* raw_smi, Dart_CObject* c_obj) {
+  static void ConvertSmi(const RawSmi* raw_smi, Dart_CObject* c_obj) {
     ASSERT(!raw_smi->IsHeapObject());
     intptr_t value = Smi::Value(raw_smi);
     if (Utils::IsInt(31, value)) {
diff --git a/runtime/vm/native_message_handler.cc b/runtime/vm/native_message_handler.cc
index e99caa5debe..7779e95c5f3 100644
--- a/runtime/vm/native_message_handler.cc
+++ b/runtime/vm/native_message_handler.cc
@@ -42,22 +42,10 @@ MessageHandler::MessageStatus NativeMessageHandler::HandleMessage(
   // All allocation of objects for decoding the message is done in the
   // zone associated with this scope.
   ApiNativeScope scope;
-
-  if (message->IsRaw()) {
-    // TODO(zra): This should be folded into ApiMessageReader. This will likely
-    // require ApiMessageReader to have a constructor that takes a Message*.
-    ASSERT(ApiObjectConverter::CanConvert(message->raw_obj()));
-    Dart_CObject object;
-    bool success = ApiObjectConverter::Convert(message->raw_obj(), &object);
-    ASSERT(success);
-    (*func())(message->dest_port(), &object);
-  } else {
-    Dart_CObject* object;
-    ApiMessageReader reader(message->data(), message->len());
-    object = reader.ReadMessage();
-    (*func())(message->dest_port(), object);
-  }
-
+  Dart_CObject* object;
+  ApiMessageReader reader(message);
+  object = reader.ReadMessage();
+  (*func())(message->dest_port(), object);
   delete message;
   return kOK;
 }