Introduced separate load module

The module provides the three system load averages. This is an
improvement compared what you can do with the cpu module: cpu
only provides the one minute sample and the state of the cpu module is
derived from the cpu usage which messes up the formating of the load
average. Also, at least on modern Linux systems, the load of a system
takes much more than the cpu utilization into account and it should
therefore live in a separate module.

include/factory.hpp

@@ -38,6 +38,7 @@
 #endif
 #if defined(HAVE_CPU_LINUX) || defined(HAVE_CPU_BSD)
 #include "modules/cpu.hpp"
+#include "modules/load.hpp"
 #endif
 #include "modules/idle_inhibitor.hpp"
 #if defined(HAVE_MEMORY_LINUX) || defined(HAVE_MEMORY_BSD)

include/modules/load.hpp

@@ -0,0 +1,29 @@
+#pragma once
+
+#include <fmt/format.h>
+
+#include <cstdint>
+#include <fstream>
+#include <numeric>
+#include <string>
+#include <utility>
+#include <vector>
+
+#include "AButton.hpp"
+#include "util/sleeper_thread.hpp"
+
+namespace waybar::modules {
+
+class Load : public AButton {
+ public:
+  Load(const std::string&, const Json::Value&);
+  ~Load() = default;
+  auto update() -> void;
+
+ private:
+  std::tuple<double, double, double> getLoad();
+
+  util::SleeperThread thread_;
+};
+
+}  // namespace waybar::modules

meson.build

@@ -164,6 +164,7 @@ src_files = files(
     'src/modules/disk.cpp',
     'src/modules/idle_inhibitor.cpp',
     'src/modules/image.cpp',
+    'src/modules/load.cpp',
     'src/modules/temperature.cpp',
     'src/modules/user.cpp',
     'src/main.cpp',

src/factory.cpp

@@ -99,6 +99,9 @@ waybar::AModule* waybar::Factory::makeModule(const std::string& name) const {
     if (ref == "cpu") {
       return new waybar::modules::Cpu(id, config_[name]);
     }
+    if (ref == "load") {
+      return new waybar::modules::Load(id, config_[name]);
+    }
 #endif
     if (ref == "clock") {
       return new waybar::modules::Clock(id, config_[name]);

src/modules/load.cpp

@@ -0,0 +1,61 @@
+#include "modules/load.hpp"
+
+// In the 80000 version of fmt library authors decided to optimize imports
+// and moved declarations required for fmt::dynamic_format_arg_store in new
+// header fmt/args.h
+#if (FMT_VERSION >= 80000)
+#include <fmt/args.h>
+#else
+#include <fmt/core.h>
+#endif
+
+waybar::modules::Load::Load(const std::string& id, const Json::Value& config)
+    : AButton(config, "load", id, "{load1}", 10) {
+  thread_ = [this] {
+    dp.emit();
+    thread_.sleep_for(interval_);
+  };
+}
+
+auto waybar::modules::Load::update() -> void {
+  // TODO: as creating dynamic fmt::arg arrays is buggy we have to calc both
+  auto [load1, load5, load15] = getLoad();
+  if (tooltipEnabled()) {
+    auto tooltip = fmt::format("Load 1: {}\nLoad 5: {}\nLoad 15: {}", load1, load5, load15);
+    button_.set_tooltip_text(tooltip);
+  }
+  auto format = format_;
+  auto state = getState(load1);
+  if (!state.empty() && config_["format-" + state].isString()) {
+    format = config_["format-" + state].asString();
+  }
+
+  if (format.empty()) {
+    event_box_.hide();
+  } else {
+    event_box_.show();
+    auto icons = std::vector<std::string>{state};
+    fmt::dynamic_format_arg_store<fmt::format_context> store;
+    store.push_back(fmt::arg("load1", load1));
+    store.push_back(fmt::arg("load5", load5));
+    store.push_back(fmt::arg("load15", load15));
+    store.push_back(fmt::arg("icon1", getIcon(load1, icons)));
+    store.push_back(fmt::arg("icon5", getIcon(load5, icons)));
+    store.push_back(fmt::arg("icon15", getIcon(load15, icons)));
+    label_->set_markup(fmt::vformat(format, store));
+  }
+
+  // Call parent update
+  AButton::update();
+}
+
+std::tuple<double, double, double> waybar::modules::Load::getLoad() {
+  double load[3];
+  if (getloadavg(load, 3) != -1) {
+    double load1 = std::ceil(load[0] * 100.0) / 100.0;
+    double load5 = std::ceil(load[1] * 100.0) / 100.0;
+    double load15 = std::ceil(load[2] * 100.0) / 100.0;
+    return {load1, load5, load15};
+  }
+  throw std::runtime_error("Can't get Cpu load");
+}