electron/shell/common/gin_helper/persistent_dictionary.h
Charles Kerr 7e9eb9e3f1
perf: avoid duplicate calculations in gin_helper::Dictionary getters (#43073)
* perf: cache the dictionary handle

* refactor: prefer result.IsJust() over !result.IsNothing()

for consistency

* refactor: prefer maybe.FromMaybe() over maybe.IsJust() && maybe.FromJust()

the inlined code is simpler

* refactor: simplify Get() impl

* refactor: add private helper Dictionary::MakeKey()

refactor: add private helper Dictionary::MakeHiddenKey()
2024-07-29 12:43:28 -05:00

67 lines
2.1 KiB
C++

// Copyright 2014 Cheng Zhao. All rights reserved.
// Use of this source code is governed by MIT license that can be found in the
// LICENSE file.
#ifndef ELECTRON_SHELL_COMMON_GIN_HELPER_PERSISTENT_DICTIONARY_H_
#define ELECTRON_SHELL_COMMON_GIN_HELPER_PERSISTENT_DICTIONARY_H_
#include "base/memory/raw_ptr.h"
#include "gin/converter.h"
#include "v8/include/v8-context.h"
#include "v8/include/v8-isolate.h"
#include "v8/include/v8-local-handle.h"
#include "v8/include/v8-object.h"
namespace gin_helper {
// Like Dictionary, but stores object in persistent handle so you can keep it
// safely on heap.
//
// TODO(zcbenz): The only user of this class is ElectronTouchBar, we should
// migrate away from this class.
class PersistentDictionary {
public:
PersistentDictionary();
PersistentDictionary(v8::Isolate* isolate, v8::Local<v8::Object> object);
PersistentDictionary(const PersistentDictionary& other);
~PersistentDictionary();
PersistentDictionary& operator=(const PersistentDictionary& other);
v8::Local<v8::Object> GetHandle() const;
template <typename K, typename V>
bool Get(const K& key, V* out) const {
const auto handle = GetHandle();
v8::Local<v8::Context> context = isolate_->GetCurrentContext();
v8::Local<v8::Value> v8_key = gin::ConvertToV8(isolate_, key);
v8::Local<v8::Value> value;
return handle->Has(context, v8_key).FromMaybe(false) &&
handle->Get(context, v8_key).ToLocal(&value) &&
gin::ConvertFromV8(isolate_, value, out);
}
private:
raw_ptr<v8::Isolate> isolate_ = nullptr;
v8::Global<v8::Object> handle_;
};
} // namespace gin_helper
namespace gin {
template <>
struct Converter<gin_helper::PersistentDictionary> {
static bool FromV8(v8::Isolate* isolate,
v8::Local<v8::Value> val,
gin_helper::PersistentDictionary* out) {
if (!val->IsObject())
return false;
*out = gin_helper::PersistentDictionary(isolate, val.As<v8::Object>());
return true;
}
};
} // namespace gin
#endif // ELECTRON_SHELL_COMMON_GIN_HELPER_PERSISTENT_DICTIONARY_H_