Waybar/src/modules/backlight.cpp

283 lines
8.6 KiB
C++

#include "modules/backlight.hpp"
#include <algorithm>
#include <chrono>
#include <memory>
#include <libudev.h>
#include <sys/epoll.h>
#include <unistd.h>
#include <fmt/format.h>
namespace {
class FileDescriptor {
public:
explicit FileDescriptor(int fd) : fd_(fd) {}
FileDescriptor(const FileDescriptor &other) = delete;
FileDescriptor(FileDescriptor &&other) noexcept = delete;
FileDescriptor &operator=(const FileDescriptor &other) = delete;
FileDescriptor &operator=(FileDescriptor &&other) noexcept = delete;
~FileDescriptor() {
if (fd_ != -1) {
if (close(fd_) != 0) {
fmt::print(stderr, "Failed to close fd: {}\n", errno);
}
}
}
int get() const { return fd_; }
private:
int fd_;
};
struct UdevDeleter {
void operator()(udev *ptr) { udev_unref(ptr); }
};
struct UdevDeviceDeleter {
void operator()(udev_device *ptr) { udev_device_unref(ptr); }
};
struct UdevEnumerateDeleter {
void operator()(udev_enumerate *ptr) { udev_enumerate_unref(ptr); }
};
struct UdevMonitorDeleter {
void operator()(udev_monitor *ptr) { udev_monitor_unref(ptr); }
};
void check_eq(int rc, int expected, const char *message = "eq, rc was: ") {
if (rc != expected) {
throw std::runtime_error(fmt::format(message, rc));
}
}
void check_neq(int rc, int bad_rc, const char *message = "neq, rc was: ") {
if (rc == bad_rc) {
throw std::runtime_error(fmt::format(message, rc));
}
}
void check0(int rc, const char *message = "rc wasn't 0") {
check_eq(rc, 0, message);
}
void check_gte(int rc, int gte, const char *message = "rc was: ") {
if (rc < gte) {
throw std::runtime_error(fmt::format(message, rc));
}
}
void check_nn(const void *ptr, const char *message = "ptr was null") {
if (ptr == nullptr) {
throw std::runtime_error(message);
}
}
} // namespace
waybar::modules::Backlight::BacklightDev::BacklightDev(std::string name,
int actual, int max)
: name_(std::move(name)), actual_(actual), max_(max) {}
std::string_view waybar::modules::Backlight::BacklightDev::name() const {
return name_;
}
int waybar::modules::Backlight::BacklightDev::get_actual() const {
return actual_;
}
void waybar::modules::Backlight::BacklightDev::set_actual(int actual) {
actual_ = actual;
}
int waybar::modules::Backlight::BacklightDev::get_max() const { return max_; }
void waybar::modules::Backlight::BacklightDev::set_max(int max) { max_ = max; }
waybar::modules::Backlight::Backlight(const std::string &name,
const Json::Value &config)
: ALabel(config, "{percent}%", 2), name_(name),
preferred_device_(
config["device"].isString() ? config["device"].asString() : "") {
label_.set_name("backlight");
udev_thread_ = [this] {
std::unique_ptr<udev, UdevDeleter> udev{udev_new()};
check_nn(udev.get(), "Udev new failed");
std::unique_ptr<udev_monitor, UdevMonitorDeleter> mon{
udev_monitor_new_from_netlink(udev.get(), "udev")};
check_nn(mon.get(), "udev monitor new failed");
check_gte(udev_monitor_filter_add_match_subsystem_devtype(
mon.get(), "backlight", nullptr),
0, "udev failed to add monitor filter: ");
udev_monitor_enable_receiving(mon.get());
auto udev_fd = udev_monitor_get_fd(mon.get());
auto epoll_fd = FileDescriptor{epoll_create1(0)};
check_neq(epoll_fd.get(), -1, "epoll init failed: ");
epoll_event ctl_event;
ctl_event.events = EPOLLIN;
ctl_event.data.fd = udev_fd;
check0(
epoll_ctl(epoll_fd.get(), EPOLL_CTL_ADD, ctl_event.data.fd, &ctl_event),
"epoll_ctl failed: {}");
epoll_event events[EPOLL_MAX_EVENTS];
// Get initial state
{
decltype(devices_) devices;
{
std::scoped_lock<std::mutex> lock(udev_thread_mutex_);
devices = devices_;
}
enumerate_devices(devices.begin(), devices.end(),
std::back_inserter(devices), udev.get());
{
std::scoped_lock<std::mutex> lock(udev_thread_mutex_);
devices_ = devices;
}
dp.emit();
}
while (udev_thread_.isRunning()) {
const int event_count =
epoll_wait(epoll_fd.get(), events, EPOLL_MAX_EVENTS,
std::chrono::milliseconds{interval_}.count());
if (!udev_thread_.isRunning()) {
break;
}
decltype(devices_) devices;
{
std::scoped_lock<std::mutex> lock(udev_thread_mutex_);
devices = devices_;
}
for (int i = 0; i < event_count; ++i) {
const auto &event = events[i];
check_eq(event.data.fd, udev_fd, "unexpected udev fd");
std::unique_ptr<udev_device, UdevDeviceDeleter> dev{
udev_monitor_receive_device(mon.get())};
check_nn(dev.get(), "epoll dev was null");
upsert_device(devices.begin(), devices.end(),
std::back_inserter(devices), dev.get());
}
// Refresh state if timed out
if (event_count == 0) {
enumerate_devices(devices.begin(), devices.end(),
std::back_inserter(devices), udev.get());
}
{
std::scoped_lock<std::mutex> lock(udev_thread_mutex_);
devices_ = devices;
}
dp.emit();
}
};
}
waybar::modules::Backlight::~Backlight() = default;
auto waybar::modules::Backlight::update() -> void {
decltype(devices_) devices;
{
std::scoped_lock<std::mutex> lock(udev_thread_mutex_);
devices = devices_;
}
const auto best =
best_device(devices.cbegin(), devices.cend(), preferred_device_);
if (best != nullptr) {
if (previous_best_.has_value() && previous_best_.value() == *best &&
!previous_format_.empty() && previous_format_ == format_) {
return;
}
const auto percent =
best->get_max() == 0 ? 100 : best->get_actual() * 100 / best->get_max();
label_.set_markup(fmt::format(format_,
fmt::arg("percent", std::to_string(percent)),
fmt::arg("icon", getIcon(percent))));
} else {
if (!previous_best_.has_value()) {
return;
}
label_.set_markup("");
}
previous_best_ = best == nullptr ? std::nullopt : std::optional{*best};
previous_format_ = format_;
}
template <class ForwardIt>
const waybar::modules::Backlight::BacklightDev *
waybar::modules::Backlight::best_device(ForwardIt first, ForwardIt last,
std::string_view preferred_device) {
const auto found =
std::find_if(first, last, [preferred_device](const auto &dev) {
return dev.name() == preferred_device;
});
if (found != last) {
return &(*found);
}
const auto max =
std::max_element(first, last, [](const auto &l, const auto &r) {
return l.get_max() < r.get_max();
});
return max == last ? nullptr : &(*max);
}
template <class ForwardIt, class Inserter>
void waybar::modules::Backlight::upsert_device(ForwardIt first, ForwardIt last,
Inserter inserter,
udev_device *dev) {
const char *name = udev_device_get_sysname(dev);
check_nn(name);
const char *actual = udev_device_get_sysattr_value(dev, "actual_brightness");
check_nn(actual);
const int actual_int = std::stoi(actual);
const char *max = udev_device_get_sysattr_value(dev, "max_brightness");
check_nn(max);
const int max_int = std::stoi(max);
auto found = std::find_if(first, last, [name](const auto &device) {
return device.name() == name;
});
if (found != last) {
found->set_actual(actual_int);
found->set_max(max_int);
} else {
*inserter = BacklightDev{name, actual_int, max_int};
++inserter;
}
}
template <class ForwardIt, class Inserter>
void waybar::modules::Backlight::enumerate_devices(ForwardIt first,
ForwardIt last,
Inserter inserter,
udev *udev) {
std::unique_ptr<udev_enumerate, UdevEnumerateDeleter> enumerate{
udev_enumerate_new(udev)};
udev_enumerate_add_match_subsystem(enumerate.get(), "backlight");
udev_enumerate_scan_devices(enumerate.get());
udev_list_entry *enum_devices =
udev_enumerate_get_list_entry(enumerate.get());
udev_list_entry *dev_list_entry;
udev_list_entry_foreach(dev_list_entry, enum_devices) {
const char *path = udev_list_entry_get_name(dev_list_entry);
std::unique_ptr<udev_device, UdevDeviceDeleter> dev{
udev_device_new_from_syspath(udev, path)};
check_nn(dev.get(), "dev new failed");
upsert_device(first, last, inserter, dev.get());
}
}