/*
* 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.
*/
#include "event.h"
#include <atomic>
#include <memory>
namespace facebook::yoga {
const char* LayoutPassReasonToString(const LayoutPassReason value) {
switch (value) {
case LayoutPassReason::kInitial:
return "initial";
case LayoutPassReason::kAbsLayout:
return "abs_layout";
case LayoutPassReason::kStretch:
return "stretch";
case LayoutPassReason::kMultilineStretch:
return "multiline_stretch";
case LayoutPassReason::kFlexLayout:
return "flex_layout";
case LayoutPassReason::kMeasureChild:
return "measure";
case LayoutPassReason::kAbsMeasureChild:
return "abs_measure";
case LayoutPassReason::kFlexMeasure:
return "flex_measure";
default:
return "unknown";
}
}
namespace {
struct Node {
std::function<Event::Subscriber> subscriber = nullptr;
Node* next = nullptr;
explicit Node(std::function<Event::Subscriber>&& subscriber)
: subscriber{std::move(subscriber)} {}
};
std::atomic<Node*> subscribers{nullptr};
Node* push(Node* newHead) {
Node* oldHead = nullptr;
do {
oldHead = subscribers.load(std::memory_order_relaxed);
if (newHead != nullptr) {
newHead->next = oldHead;
}
} while (!subscribers.compare_exchange_weak(
oldHead, newHead, std::memory_order_release, std::memory_order_relaxed));
return oldHead;
}
} // namespace
void Event::reset() {
auto head = push(nullptr);
while (head != nullptr) {
auto current = head;
head = head->next;
delete current;
}
}
void Event::subscribe(std::function<Subscriber>&& subscriber) {
push(new Node{std::move(subscriber)});
}
void Event::publish(
YGNodeConstRef node,
Type eventType,
const Data& eventData) {
for (auto subscriber = subscribers.load(std::memory_order_relaxed);
subscriber != nullptr;
subscriber = subscriber->next) {
subscriber->subscriber(node, eventType, eventData);
}
}
} // namespace facebook::yoga