mirror of
https://github.com/facebook/react-native.git
synced 2025-11-01 09:14:26 +00:00
Samuel Susla
e665a0f995
Summary: changelog: [internal] C++17 has implementation of shared_mutex in standard library. Let's use it instead of folly. Reviewed By: cipolleschi Differential Revision: D43275493 fbshipit-source-id: d766251226aa230110011aca94b4e697fe0d31a1
114 lines
3.1 KiB
C++
114 lines
3.1 KiB
C++
/*
|
|
* Copyright (c) Meta Platforms, Inc. and affiliates.
|
|
*
|
|
* This source code is licensed under the MIT license found in the
|
|
* LICENSE file in the root directory of this source tree.
|
|
*/
|
|
|
|
#pragma once
|
|
|
|
#include <memory>
|
|
#include <mutex>
|
|
#include <optional>
|
|
#include <shared_mutex>
|
|
#include <string>
|
|
|
|
#include <butter/map.h>
|
|
|
|
#include <react/debug/flags.h>
|
|
#include <react/debug/react_native_assert.h>
|
|
|
|
namespace facebook {
|
|
namespace react {
|
|
|
|
/*
|
|
* General purpose dependency injection container.
|
|
* Instance types must be copyable.
|
|
*/
|
|
class ContextContainer final {
|
|
public:
|
|
using Shared = std::shared_ptr<ContextContainer const>;
|
|
|
|
/*
|
|
* Registers an instance of the particular type `T` in the container
|
|
* using the provided `key`. Only one instance can be registered per key.
|
|
* The method does nothing if given `key` already exists in the container.
|
|
*
|
|
* Convention is to use the plain base class name for the key, so for
|
|
* example if the type `T` is `std::shared_ptr<const ReactNativeConfig>`,
|
|
* then one would use `"ReactNativeConfig"` for the `key`, even if the
|
|
* instance is actually a `shared_ptr` of derived class
|
|
*`ReactNativeConfig`.
|
|
*/
|
|
template <typename T>
|
|
void insert(std::string const &key, T const &instance) const {
|
|
std::unique_lock lock(mutex_);
|
|
|
|
instances_.insert({key, std::make_shared<T>(instance)});
|
|
}
|
|
|
|
/*
|
|
* Removes an instance stored for a given `key`.
|
|
* Does nothing if the instance was not found.
|
|
*/
|
|
void erase(std::string const &key) const {
|
|
std::unique_lock lock(mutex_);
|
|
|
|
instances_.erase(key);
|
|
}
|
|
|
|
/*
|
|
* Updates the container with values from a given container.
|
|
* Values with keys that already exist in the container will be replaced with
|
|
* values from the given container.
|
|
*/
|
|
void update(ContextContainer const &contextContainer) const {
|
|
std::unique_lock lock(mutex_);
|
|
|
|
for (auto const &pair : contextContainer.instances_) {
|
|
instances_.erase(pair.first);
|
|
instances_.insert(pair);
|
|
}
|
|
}
|
|
|
|
/*
|
|
* Returns a previously registered instance of the particular type `T`
|
|
* for `key`.
|
|
* Throws an exception if the instance could not be found.
|
|
*/
|
|
template <typename T>
|
|
T at(std::string const &key) const {
|
|
std::shared_lock lock(mutex_);
|
|
|
|
react_native_assert(
|
|
instances_.find(key) != instances_.end() &&
|
|
"ContextContainer doesn't have an instance for given key.");
|
|
return *std::static_pointer_cast<T>(instances_.at(key));
|
|
}
|
|
|
|
/*
|
|
* Returns a (wrapped in an optional) previously registered instance of
|
|
* the particular type `T` for given `key`.
|
|
* Returns an empty optional if the instance could not be found.
|
|
*/
|
|
template <typename T>
|
|
std::optional<T> find(std::string const &key) const {
|
|
std::shared_lock lock(mutex_);
|
|
|
|
auto iterator = instances_.find(key);
|
|
if (iterator == instances_.end()) {
|
|
return {};
|
|
}
|
|
|
|
return *std::static_pointer_cast<T>(iterator->second);
|
|
}
|
|
|
|
private:
|
|
mutable std::shared_mutex mutex_;
|
|
// Protected by mutex_`.
|
|
mutable butter::map<std::string, std::shared_ptr<void>> instances_;
|
|
};
|
|
|
|
} // namespace react
|
|
} // namespace facebook
|