Begin implementing V8 bindings for Mojo

mojo/public/bindings/js/v8_core.cc

+// Copyright 2013 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "mojo/public/bindings/js/v8_core.h"
+
+#include "mojo/public/bindings/js/v8_array_buffer.h"
+#include "mojo/public/bindings/js/v8_conversions.h"
+#include "mojo/public/bindings/js/v8_exceptions.h"
+#include "mojo/public/bindings/js/v8_per_isolate_data.h"
+
+namespace mojo {
+namespace js {
+
+namespace {
+
+static WrapperInfo g_handle_wrapper_info = {};
+
+bool ToHandleArray(v8::Isolate* isolate,
+                   v8::Handle<v8::Value> value,
+                   std::vector<mojo::Handle>* handles) {
+  if (!value->IsArray()) {
+    ThrowTypeError(isolate, "Expected array argument.");
+    return false;
+  }
+  if (!ToNativeArray(v8::Handle<v8::Array>::Cast(value), handles)) {
+    ThrowTypeError(isolate, "Expected an array of mojo::Handles.");
+    return false;
+  }
+  return true;
+}
+
+void CloseCallback(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  v8::Isolate* isolate = info.GetIsolate();
+  mojo::Handle handle = Wrapper<Handle>::ToNativeUnchecked(info.Holder());
+
+  MojoResult result = mojo::Close(handle);
+  info.GetReturnValue().Set(Wrapper<MojoResult>::ToObject(isolate, result));
+}
+
+void WaitCallback(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  v8::Isolate* isolate = info.GetIsolate();
+
+  if (info.Length() < 2)
+    return ThrowTypeError(isolate, kInsufficientArguments);
+
+  mojo::Handle handle = Wrapper<Handle>::ToNativeUnchecked(info.Holder());
+  MojoWaitFlags flags = Wrapper<MojoWaitFlags>::ToNative(info[0]);
+  MojoDeadline deadline = Wrapper<MojoDeadline>::ToNative(info[1]);
+
+  MojoResult result = mojo::Wait(handle, flags, deadline);
+  info.GetReturnValue().Set(Wrapper<MojoResult>::ToObject(isolate, result));
+}
+
+void WriteMessageCallback(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  v8::Isolate* isolate = info.GetIsolate();
+
+  if (info.Length() < 3)
+    return ThrowTypeError(isolate, kInsufficientArguments);
+
+  mojo::Handle handle = Wrapper<Handle>::ToNativeUnchecked(info.Holder());
+
+  if (!info[0]->IsArrayBufferView())
+    return ThrowTypeError(isolate, "Expected an ArrayBufferView.");
+  BufferView buffer(isolate, v8::Handle<v8::ArrayBufferView>::Cast(info[0]));
+
+  std::vector<mojo::Handle> handles;
+  if (!ToHandleArray(isolate, info[1], &handles))
+    return;
+
+  MojoWaitFlags flags = Wrapper<MojoWaitFlags>::ToNative(info[2]);
+
+  MojoResult result = mojo::WriteMessage(handle,
+                                         buffer.bytes(),
+                                         buffer.num_bytes(),
+                                         handles.data(),
+                                         handles.size(),
+                                         flags);
+
+  info.GetReturnValue().Set(Wrapper<MojoResult>::ToObject(isolate, result));
+}
+
+void ReadMessageCallback(const v8::FunctionCallbackInfo<v8::Value>& info) {
+  v8::Isolate* isolate = info.GetIsolate();
+
+  if (info.Length() < 3)
+    return ThrowTypeError(isolate, kInsufficientArguments);
+
+  mojo::Handle handle = Wrapper<Handle>::ToNativeUnchecked(info.Holder());
+
+  if (!info[0]->IsArrayBufferView())
+    return ThrowTypeError(isolate, "Expected an ArrayBufferView.");
+  BufferView buffer(isolate, v8::Handle<v8::ArrayBufferView>::Cast(info[0]));
+
+  std::vector<mojo::Handle> handles(info[1]->Uint32Value());
+
+  MojoWaitFlags flags = Wrapper<MojoWaitFlags>::ToNative(info[2]);
+
+  uint32_t num_bytes = buffer.num_bytes();
+  uint32_t num_handles = handles.size();
+  MojoResult result = mojo::ReadMessage(handle,
+                                        buffer.bytes(),
+                                        &num_bytes,
+                                        handles.data(),
+                                        &num_handles,
+                                        flags);
+  handles.resize(num_handles);
+
+  // TODO(abarth): We should benchmark this codepath to make sure it's ok to
+  // allocate all this memory on each read.
+
+  v8::Handle<v8::Object> object = v8::Object::New();
+  object->Set(v8::String::NewSymbol("result"),
+              Wrapper<MojoResult>::ToObject(isolate, result));
+  object->Set(v8::String::NewSymbol("bytesRead"),
+              Wrapper<uint32_t>::ToObject(isolate, num_bytes));
+  object->Set(v8::String::NewSymbol("handles"),
+              ToObjectArray(isolate, handles));
+  info.GetReturnValue().Set(object);
+}
+
+void CreateMessagePipeCallback(
+    const v8::FunctionCallbackInfo<v8::Value>& info) {
+  v8::Isolate* isolate = info.GetIsolate();
+
+  mojo::Handle handle_0;
+  mojo::Handle handle_1;
+  MojoResult result = mojo::CreateMessagePipe(&handle_0, &handle_1);
+
+  // TODO(abarth): We should benchmark this codepath to make sure it's ok to
+  // allocate all this memory on each read.
+
+  v8::Handle<v8::Object> object = v8::Object::New();
+  object->Set(v8::String::NewSymbol("result"),
+              Wrapper<MojoResult>::ToObject(isolate, result));
+  object->Set(v8::String::NewSymbol("handle0"),
+              Wrapper<mojo::Handle>::ToObject(isolate, handle_0));
+  object->Set(v8::String::NewSymbol("handle1"),
+              Wrapper<mojo::Handle>::ToObject(isolate, handle_0));
+  info.GetReturnValue().Set(object);
+}
+
+}
+
+v8::Local<v8::ObjectTemplate> Wrapper<mojo::Handle>::CreateTemplate() {
+  v8::Local<v8::ObjectTemplate> handle_template = v8::ObjectTemplate::New();
+  handle_template->SetInternalFieldCount(kNumberOfInternalFields);
+  handle_template->Set(v8::String::NewSymbol("close"),
+                       v8::FunctionTemplate::New(CloseCallback));
+  handle_template->Set(v8::String::NewSymbol("wait"),
+                       v8::FunctionTemplate::New(WaitCallback));
+  handle_template->Set(v8::String::NewSymbol("writeMessage"),
+                       v8::FunctionTemplate::New(WriteMessageCallback));
+  handle_template->Set(v8::String::NewSymbol("readMessage"),
+                       v8::FunctionTemplate::New(ReadMessageCallback));
+  return handle_template;
+}
+
+bool Wrapper<mojo::Handle>::HasInstance(v8::Handle<v8::Object> object) {
+  return WrapperInfo::From(object) == &g_handle_wrapper_info;
+}
+
+v8::Handle<v8::Object> Wrapper<mojo::Handle>::ToObject(
+    v8::Isolate* isolate, mojo::Handle handle) {
+  V8PerIsolateData* data = V8PerIsolateData::From(isolate);
+  v8::Local<v8::Object> object = data->handle_template()->NewInstance();
+  object->SetAlignedPointerInInternalField(
+      kWrapperInfoIndex, &g_handle_wrapper_info);
+  object->SetInternalField(
+      kEncodedValueIndex, v8::Integer::NewFromUnsigned(handle.value, isolate));
+  return object;
+}
+
+mojo::Handle Wrapper<mojo::Handle>::ToNative(
+    v8::Handle<v8::Object> object) {
+  if (!HasInstance(object))
+    return mojo::kInvalidHandle;
+  return ToNativeUnchecked(object);
+}
+
+mojo::Handle Wrapper<mojo::Handle>::ToNativeUnchecked(
+    v8::Handle<v8::Object> object) {
+  v8::Handle<v8::Value> field = object->GetInternalField(kEncodedValueIndex);
+  mojo::Handle handle = { field->Uint32Value() };
+  return handle;
+}
+
+}  // namespace js
+}  // namespace mojo