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#ifdef FS_EVENTS
#include "macos/FSEventsBackend.hh"
#endif
#ifdef WATCHMAN
#include "watchman/WatchmanBackend.hh"
#endif
#ifdef WINDOWS
#include "windows/WindowsBackend.hh"
#endif
#ifdef INOTIFY
#include "linux/InotifyBackend.hh"
#endif
#ifdef KQUEUE
#include "kqueue/KqueueBackend.hh"
#endif
#ifdef __wasm32__
#include "wasm/WasmBackend.hh"
#endif
#include "shared/BruteForceBackend.hh"
#include "Backend.hh"
#include <unordered_map>
static std::unordered_map<std::string, std::shared_ptr<Backend>> sharedBackends;
std::shared_ptr<Backend> getBackend(std::string backend) {
// Use FSEvents on macOS by default.
// Use watchman by default if available on other platforms.
// Fall back to brute force.
#ifdef FS_EVENTS
if (backend == "fs-events" || backend == "default") {
return std::make_shared<FSEventsBackend>();
}
#endif
#ifdef WATCHMAN
if ((backend == "watchman" || backend == "default") && WatchmanBackend::checkAvailable()) {
return std::make_shared<WatchmanBackend>();
}
#endif
#ifdef WINDOWS
if (backend == "windows" || backend == "default") {
return std::make_shared<WindowsBackend>();
}
#endif
#ifdef INOTIFY
if (backend == "inotify" || backend == "default") {
return std::make_shared<InotifyBackend>();
}
#endif
#ifdef KQUEUE
if (backend == "kqueue" || backend == "default") {
return std::make_shared<KqueueBackend>();
}
#endif
#ifdef __wasm32__
if (backend == "wasm" || backend == "default") {
return std::make_shared<WasmBackend>();
}
#endif
if (backend == "brute-force" || backend == "default") {
return std::make_shared<BruteForceBackend>();
}
return nullptr;
}
std::shared_ptr<Backend> Backend::getShared(std::string backend) {
auto found = sharedBackends.find(backend);
if (found != sharedBackends.end()) {
return found->second;
}
auto result = getBackend(backend);
if (!result) {
return getShared("default");
}
result->run();
sharedBackends.emplace(backend, result);
return result;
}
void removeShared(Backend *backend) {
for (auto it = sharedBackends.begin(); it != sharedBackends.end(); it++) {
if (it->second.get() == backend) {
sharedBackends.erase(it);
break;
}
}
// Free up memory.
if (sharedBackends.size() == 0) {
sharedBackends.rehash(0);
}
}
void Backend::run() {
#ifndef __wasm32__
mThread = std::thread([this] () {
try {
start();
} catch (std::exception &err) {
handleError(err);
}
});
if (mThread.joinable()) {
mStartedSignal.wait();
}
#else
try {
start();
} catch (std::exception &err) {
handleError(err);
}
#endif
}
void Backend::notifyStarted() {
mStartedSignal.notify();
}
void Backend::start() {
notifyStarted();
}
Backend::~Backend() {
#ifndef __wasm32__
// Wait for thread to stop
if (mThread.joinable()) {
// If the backend is being destroyed from the thread itself, detach, otherwise join.
if (mThread.get_id() == std::this_thread::get_id()) {
mThread.detach();
} else {
mThread.join();
}
}
#endif
}
void Backend::watch(WatcherRef watcher) {
std::unique_lock<std::mutex> lock(mMutex);
auto res = mSubscriptions.find(watcher);
if (res == mSubscriptions.end()) {
try {
this->subscribe(watcher);
mSubscriptions.insert(watcher);
} catch (std::exception &err) {
unref();
throw;
}
}
}
void Backend::unwatch(WatcherRef watcher) {
std::unique_lock<std::mutex> lock(mMutex);
size_t deleted = mSubscriptions.erase(watcher);
if (deleted > 0) {
this->unsubscribe(watcher);
unref();
}
}
void Backend::unref() {
if (mSubscriptions.size() == 0) {
removeShared(this);
}
}
void Backend::handleWatcherError(WatcherError &err) {
unwatch(err.mWatcher);
err.mWatcher->notifyError(err);
}
void Backend::handleError(std::exception &err) {
std::unique_lock<std::mutex> lock(mMutex);
for (auto it = mSubscriptions.begin(); it != mSubscriptions.end(); it++) {
(*it)->notifyError(err);
}
removeShared(this);
}
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