memory: port parseMeminfo to BSDs

src/modules/memory/common.cpp

@@ -0,0 +1,47 @@
+#include "modules/memory.hpp"
+
+waybar::modules::Memory::Memory(const std::string& id, const Json::Value& config)
+    : ALabel(config, "memory", id, "{}%", 30) {
+  thread_ = [this] {
+    dp.emit();
+    thread_.sleep_for(interval_);
+  };
+}
+
+auto waybar::modules::Memory::update() -> void {
+  parseMeminfo();
+
+  unsigned long memtotal = meminfo_["MemTotal"];
+  unsigned long memfree;
+  if (meminfo_.count("MemAvailable")) {
+    // New kernels (3.4+) have an accurate available memory field.
+    memfree = meminfo_["MemAvailable"];
+  } else {
+    // Old kernel; give a best-effort approximation of available memory.
+    memfree = meminfo_["MemFree"] + meminfo_["Buffers"] + meminfo_["Cached"] +
+              meminfo_["SReclaimable"] - meminfo_["Shmem"];
+  }
+
+  if (memtotal > 0 && memfree >= 0) {
+    auto total_ram_gigabytes = memtotal / std::pow(1024, 2);
+    int  used_ram_percentage = 100 * (memtotal - memfree) / memtotal;
+    auto used_ram_gigabytes = (memtotal - memfree) / std::pow(1024, 2);
+    auto available_ram_gigabytes = memfree / std::pow(1024, 2);
+
+    getState(used_ram_percentage);
+    label_.set_markup(fmt::format(format_,
+                                  used_ram_percentage,
+                                  fmt::arg("total", total_ram_gigabytes),
+                                  fmt::arg("percentage", used_ram_percentage),
+                                  fmt::arg("used", used_ram_gigabytes),
+                                  fmt::arg("avail", available_ram_gigabytes)));
+    if (tooltipEnabled()) {
+      label_.set_tooltip_text(fmt::format("{:.{}f}Gb used", used_ram_gigabytes, 1));
+    }
+    event_box_.show();
+  } else {
+    event_box_.hide();
+  }
+  // Call parent update
+  ALabel::update();
+}