mirror of
https://github.com/facebook/react-native.git
synced 2025-11-01 09:14:26 +00:00
David Vacca
8f6aee0df5
Summary: Fabric uses a cache where it stores the result of the text measurement in C++ (to avoid unnecessary text measurement that are very costly). This cache has a "max size" of 256 and this size is not enough to store all the texts we have in the screen In my tests, the amount of texts being measured are ~290 and after scrolling many times they increase to 611. This diff increases the size of the TextMeasure to 1024 for users in the experiment. As a result this improves performance of HoverEvents by +5x times (see test plan) changelog: [internal] internal Reviewed By: JoshuaGross Differential Revision: D33112788 fbshipit-source-id: e15feecf0f54da62b252892d37a64fb4ead29e22
77 lines
1.9 KiB
C++
77 lines
1.9 KiB
C++
/*
|
|
* Copyright (c) Facebook, Inc. and its affiliates.
|
|
*
|
|
* This source code is licensed under the MIT license found in the
|
|
* LICENSE file in the root directory of this source tree.
|
|
*/
|
|
|
|
#include <functional>
|
|
#include <memory>
|
|
#include <mutex>
|
|
|
|
#include <better/optional.h>
|
|
#include <folly/container/EvictingCacheMap.h>
|
|
|
|
namespace facebook {
|
|
namespace react {
|
|
|
|
/*
|
|
* Simple thread-safe LRU cache.
|
|
*/
|
|
template <typename KeyT, typename ValueT, int maxSize>
|
|
class SimpleThreadSafeCache {
|
|
public:
|
|
SimpleThreadSafeCache() : map_{maxSize} {}
|
|
SimpleThreadSafeCache(unsigned long size) : map_{size} {}
|
|
|
|
/*
|
|
* Returns a value from the map with a given key.
|
|
* If the value wasn't found in the cache, constructs the value using given
|
|
* generator function, stores it inside a cache and returns it.
|
|
* Can be called from any thread.
|
|
*/
|
|
ValueT get(const KeyT &key, std::function<ValueT(const KeyT &key)> generator)
|
|
const {
|
|
std::lock_guard<std::mutex> lock(mutex_);
|
|
auto iterator = map_.find(key);
|
|
if (iterator == map_.end()) {
|
|
auto value = generator(key);
|
|
map_.set(key, value);
|
|
return value;
|
|
}
|
|
|
|
return iterator->second;
|
|
}
|
|
|
|
/*
|
|
* Returns a value from the map with a given key.
|
|
* If the value wasn't found in the cache, returns empty optional.
|
|
* Can be called from any thread.
|
|
*/
|
|
better::optional<ValueT> get(const KeyT &key) const {
|
|
std::lock_guard<std::mutex> lock(mutex_);
|
|
auto iterator = map_.find(key);
|
|
if (iterator == map_.end()) {
|
|
return {};
|
|
}
|
|
|
|
return iterator->second;
|
|
}
|
|
|
|
/*
|
|
* Sets a key-value pair in the LRU cache.
|
|
* Can be called from any thread.
|
|
*/
|
|
void set(const KeyT &key, const ValueT &value) const {
|
|
std::lock_guard<std::mutex> lock(mutex_);
|
|
map_.set(std::move(key), std::move(value));
|
|
}
|
|
|
|
private:
|
|
mutable folly::EvictingCacheMap<KeyT, ValueT> map_;
|
|
mutable std::mutex mutex_;
|
|
};
|
|
|
|
} // namespace react
|
|
} // namespace facebook
|