Using Gio::FileMonitor for watching style changes

This commit is contained in:
dpayne 2024-01-21 20:49:13 -08:00
parent d7ed4f1fa8
commit f7eca99496
3 changed files with 58 additions and 190 deletions

View File

@ -1,13 +1,13 @@
#pragma once
#include <atomic>
#include <condition_variable>
#include <functional>
#include <mutex>
#include <string>
#include <thread>
#include <vector>
#include "glibmm/refptr.h"
#include "giomm/file.h"
#include "giomm/filemonitor.h"
struct pollfd;
namespace waybar {
@ -15,12 +15,8 @@ class CssReloadHelper {
public:
CssReloadHelper(std::string cssFile, std::function<void()> callback);
~CssReloadHelper();
virtual void monitorChanges();
void stop();
protected:
std::vector<std::string> parseImports(const std::string& cssFile);
@ -38,12 +34,16 @@ class CssReloadHelper {
virtual std::string findPath(const std::string& filename);
void handleFileChange(
Glib::RefPtr<Gio::File> const& file,
Glib::RefPtr<Gio::File> const& other_type,
Gio::FileMonitorEvent event_type);
private:
std::string m_cssFile;
std::function<void()> m_callback;
std::atomic<bool> m_running = false;
std::thread m_thread;
std::mutex m_mutex;
std::condition_variable m_cv;
std::vector<std::tuple<Glib::RefPtr<Gio::FileMonitor>>> m_fileMonitors;
};
} // namespace waybar

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@ -8,8 +8,11 @@
#include <fstream>
#include <regex>
#include <unordered_map>
#include "glibmm/refptr.h"
#include "giomm/file.h"
#include "config.hpp"
namespace {
const std::regex IMPORT_REGEX(R"(@import\s+(?:url\()?(?:"|')([^"')]+)(?:"|')\)?;)");
}
@ -17,8 +20,6 @@ const std::regex IMPORT_REGEX(R"(@import\s+(?:url\()?(?:"|')([^"')]+)(?:"|')\)?;
waybar::CssReloadHelper::CssReloadHelper(std::string cssFile, std::function<void()> callback)
: m_cssFile(std::move(cssFile)), m_callback(std::move(callback)) {}
waybar::CssReloadHelper::~CssReloadHelper() { stop(); }
std::string waybar::CssReloadHelper::getFileContents(const std::string& filename) {
if (filename.empty()) {
return {};
@ -34,21 +35,56 @@ std::string waybar::CssReloadHelper::getFileContents(const std::string& filename
std::string waybar::CssReloadHelper::findPath(const std::string& filename) {
// try path and fallback to looking relative to the config
std::string result;
if (std::filesystem::exists(filename)) {
return filename;
result = filename;
} else {
result = Config::findConfigPath({filename}).value_or("");
}
return Config::findConfigPath({filename}).value_or("");
// File monitor does not work with symlinks, so resolve them
if (std::filesystem::is_symlink(result)) {
result = std::filesystem::read_symlink(result);
}
return result;
}
void waybar::CssReloadHelper::monitorChanges() {
m_thread = std::thread([this] {
m_running = true;
while (m_running) {
auto files = parseImports(m_cssFile);
watchFiles(files);
auto files = parseImports(m_cssFile);
for (const auto& file : files) {
auto gioFile = Gio::File::create_for_path(file);
if (!gioFile) {
spdlog::error("Failed to create file for path: {}", file);
continue;
}
});
auto fileMonitor = gioFile->monitor_file();
if (!fileMonitor) {
spdlog::error("Failed to create file monitor for path: {}", file);
continue;
}
auto connection = fileMonitor->signal_changed().connect(
sigc::mem_fun(*this, &CssReloadHelper::handleFileChange));
if (!connection.connected()) {
spdlog::error("Failed to connect to file monitor for path: {}", file);
continue;
}
m_fileMonitors.emplace_back(std::move(fileMonitor));
}
}
void waybar::CssReloadHelper::handleFileChange(Glib::RefPtr<Gio::File> const& file,
Glib::RefPtr<Gio::File> const& other_type,
Gio::FileMonitorEvent event_type) {
// Multiple events are fired on file changed (attributes, write, changes done hint, etc.), only
// fire for one
if (event_type == Gio::FileMonitorEvent::FILE_MONITOR_EVENT_CHANGES_DONE_HINT) {
spdlog::debug("Reloading style, file changed: {}", file->get_path());
m_callback();
}
}
std::vector<std::string> waybar::CssReloadHelper::parseImports(const std::string& cssFile) {
@ -106,109 +142,3 @@ void waybar::CssReloadHelper::parseImports(const std::string& cssFile,
imports[cssFile] = true;
}
void waybar::CssReloadHelper::stop() {
if (!m_running) {
return;
}
m_running = false;
m_cv.notify_all();
if (m_thread.joinable()) {
m_thread.join();
}
}
void waybar::CssReloadHelper::watchFiles(const std::vector<std::string>& files) {
auto inotifyFd = inotify_init1(IN_NONBLOCK);
if (inotifyFd < 0) {
spdlog::error("Failed to initialize inotify: {}", strerror(errno));
return;
}
std::vector<int> watchFds;
for (const auto& file : files) {
auto watchFd = inotify_add_watch(inotifyFd, file.c_str(), IN_MODIFY | IN_MOVED_TO);
if (watchFd < 0) {
spdlog::error("Failed to add watch for file: {}", file);
} else {
spdlog::debug("Added watch for file: {}", file);
}
watchFds.push_back(watchFd);
}
auto pollFd = pollfd{inotifyFd, POLLIN, 0};
while (true) {
if (watch(inotifyFd, &pollFd)) {
break;
}
}
for (const auto& watchFd : watchFds) {
inotify_rm_watch(inotifyFd, watchFd);
}
close(inotifyFd);
}
bool waybar::CssReloadHelper::watch(int inotifyFd, pollfd* pollFd) {
auto pollResult = poll(pollFd, 1, 10);
if (pollResult < 0) {
spdlog::error("Failed to poll inotify: {}", strerror(errno));
return true;
}
if (pollResult == 0) {
// check if we should stop
if (!m_running) {
return true;
}
std::unique_lock<std::mutex> lock(m_mutex);
// a condition variable is used to allow the thread to be stopped immediately while still not
// spamming poll
m_cv.wait_for(lock, std::chrono::milliseconds(250), [this] { return !m_running; });
// timeout
return false;
}
if (static_cast<bool>(pollFd->revents & POLLIN)) {
if (handleInotifyEvents(inotifyFd)) {
// after the callback is fired we need to re-parse the imports and setup the watches
// again in case the import list has changed
return true;
}
}
return false;
}
bool waybar::CssReloadHelper::handleInotifyEvents(int inotify_fd) {
// inotify event
auto buffer = std::array<char, 4096>{};
auto readResult = read(inotify_fd, buffer.data(), buffer.size());
if (readResult < 0) {
spdlog::error("Failed to read inotify event: {}", strerror(errno));
return false;
}
auto offset = 0;
auto shouldFireCallback = false;
// read all events on the fd
while (offset < readResult) {
auto* event = reinterpret_cast<inotify_event*>(buffer.data() + offset);
offset += sizeof(inotify_event) + event->len;
shouldFireCallback = true;
}
// we only need to fire the callback once
if (shouldFireCallback) {
m_callback();
return true;
}
return false;
}

View File

@ -124,65 +124,3 @@ TEST_CASE_METHOD(CssReloadHelperTest, "parse_imports", "[util][css_reload_helper
REQUIRE(files.empty());
}
}
TEST_CASE("file_watcher", "[util][css_reload_helper]")
{
SECTION("file does not exist")
{
std::atomic<int> count;
std::string f1 = std::tmpnam(nullptr);
waybar::CssReloadHelper helper(f1, [&count](){++count;});
helper.monitorChanges();
std::this_thread::sleep_for(std::chrono::milliseconds(100));
CHECK(count == 0);
helper.stop();
std::remove(f1.c_str());
}
SECTION("file exists")
{
std::atomic<int> count;
std::string f1 = std::tmpnam(nullptr);
std::ofstream(f1) << "body { color: red; }";
waybar::CssReloadHelper helper(f1, [&count](){++count;});
helper.monitorChanges();
std::this_thread::sleep_for(std::chrono::milliseconds(100));
CHECK(count == 0);
std::this_thread::sleep_for(std::chrono::milliseconds(100));
std::ofstream(f1) << "body { color: blue; }";
std::this_thread::sleep_for(std::chrono::milliseconds(100));
CHECK(count == 1);
helper.stop();
std::remove(f1.c_str());
}
SECTION("multiple files")
{
std::atomic<int> count;
std::string f1 = std::tmpnam(nullptr);
std::string f2 = std::tmpnam(nullptr);
std::ofstream(f1) << ("@import '" + f2 + " ';");
std::ofstream(f2) << "body { color: red; }";
waybar::CssReloadHelper helper(f1, [&count](){++count;});
helper.monitorChanges();
std::this_thread::sleep_for(std::chrono::milliseconds(100));
CHECK(count == 0);
std::this_thread::sleep_for(std::chrono::milliseconds(100));
std::ofstream(f2) << "body { color: blue; }";
std::this_thread::sleep_for(std::chrono::milliseconds(100));
CHECK(count == 1);
helper.stop();
std::remove(f1.c_str());
std::remove(f2.c_str());
}
}