electron/atom/browser/net/js_asker.cc
2015-08-12 13:30:19 +08:00

106 lines
3.8 KiB
C++

// Copyright (c) 2015 GitHub, Inc.
// Use of this source code is governed by the MIT license that can be
// found in the LICENSE file.
#include "atom/browser/net/js_asker.h"
#include "atom/common/native_mate_converters/callback.h"
#include "atom/common/native_mate_converters/v8_value_converter.h"
#include "native_mate/function_template.h"
namespace atom {
namespace internal {
namespace {
struct CallbackHolder {
ResponseCallback callback;
};
// Cached JavaScript version of |HandlerCallback|.
v8::Persistent<v8::FunctionTemplate> g_handler_callback_;
// Cached C++ version of |Function.prototype.bind|.
base::Callback<v8::Local<v8::Value>(
v8::Local<v8::Value>, v8::Local<v8::Value>, v8::Local<v8::Value>)> g_bind;
// The callback which is passed to |handler|.
void HandlerCallback(v8::Local<v8::External> external, mate::Arguments* args) {
scoped_ptr<CallbackHolder> holder(
static_cast<CallbackHolder*>(external->Value()));
CHECK(holder);
v8::Local<v8::Value> value;
if (!args->GetNext(&value)) {
holder->callback.Run(false, nullptr);
return;
}
V8ValueConverter converter;
v8::Local<v8::Context> context = args->isolate()->GetCurrentContext();
scoped_ptr<base::Value> options(converter.FromV8Value(value, context));
holder->callback.Run(true, options.Pass());
}
// func.bind(...).
template<typename... ArgTypes>
v8::Local<v8::Value> BindFunctionWith(v8::Isolate* isolate,
v8::Local<v8::Context> context,
v8::Local<v8::Function> func,
ArgTypes... args) {
v8::MaybeLocal<v8::Value> bind = func->Get(mate::StringToV8(isolate, "bind"));
CHECK(!bind.IsEmpty());
v8::Local<v8::Function> bind_func =
v8::Local<v8::Function>::Cast(bind.ToLocalChecked());
std::vector<v8::Local<v8::Value>> converted = {
func, mate::ConvertToV8(isolate, args)...,
};
return bind_func->Call(
context, func, converted.size(), &converted.front()).ToLocalChecked();
}
// Generate the callback that will be passed to |handler|.
v8::MaybeLocal<v8::Value> GenerateCallback(v8::Isolate* isolate,
v8::Local<v8::Context> context,
const ResponseCallback& callback) {
// The FunctionTemplate is cached.
if (g_handler_callback_.IsEmpty())
g_handler_callback_.Reset(
isolate,
mate::CreateFunctionTemplate(isolate, base::Bind(&HandlerCallback)));
v8::Local<v8::FunctionTemplate> handler_callback =
v8::Local<v8::FunctionTemplate>::New(isolate, g_handler_callback_);
CallbackHolder* holder = new CallbackHolder;
holder->callback = callback;
return BindFunctionWith(isolate, context,
handler_callback->GetFunction(),
v8::External::New(isolate, holder));
}
} // namespace
void AskForOptions(v8::Isolate* isolate,
const JavaScriptHandler& handler,
net::URLRequest* request,
const ResponseCallback& callback) {
DCHECK_CURRENTLY_ON(content::BrowserThread::UI);
v8::Locker locker(isolate);
v8::HandleScope handle_scope(isolate);
v8::Local<v8::Context> context = isolate->GetCurrentContext();
v8::Context::Scope context_scope(context);
// We don't convert the callback to C++ directly because creating
// FunctionTemplate will cause memory leak since V8 never releases it. So we
// have to create the function object in JavaScript to work around it.
v8::MaybeLocal<v8::Value> wrapped_callback = GenerateCallback(
isolate, context, callback);
if (wrapped_callback.IsEmpty()) {
callback.Run(false, nullptr);
return;
}
handler.Run(request, wrapped_callback.ToLocalChecked());
}
} // namespace internal
} // namespace atom