fix(cpu): show correct load

feat(cpu): show cores in tooltip

include/modules/cpu.hpp

@@ -1,7 +1,9 @@
 #pragma once
 
 #include <fmt/format.h>
-#include <sys/sysinfo.h>
+#include <fstream>
+#include <vector>
+#include <numeric>
 #include "util/chrono.hpp"
 #include "ALabel.hpp"
 
@@ -12,6 +14,9 @@ class Cpu : public ALabel {
     Cpu(const Json::Value&);
     auto update() -> void;
   private:
+    static inline const std::string data_dir_ = "/proc/stat";
+    std::vector< std::tuple<size_t, size_t> > parseCpuinfo();
+    std::vector< std::tuple<size_t, size_t> > prevTimes_;
     waybar::util::SleeperThread thread_;
 };
 

src/modules/cpu.cpp

@@ -13,10 +13,52 @@ waybar::modules::Cpu::Cpu(const Json::Value& config)
 
 auto waybar::modules::Cpu::update() -> void
 {
-  struct sysinfo info = {};
-  if (sysinfo(&info) == 0) {
-    float f_load = 1.f / (1u << SI_LOAD_SHIFT);
-    uint16_t load = info.loads[0] * f_load * 100 / get_nprocs();
+  if (prevTimes_.size() < 1) {
+    prevTimes_ = parseCpuinfo();
+    std::this_thread::sleep_for(chrono::milliseconds(100));
+  }
+  std::vector< std::tuple<size_t, size_t> > currTimes = parseCpuinfo();
+  std::string tooltip;
+  for (size_t i = 0; i < currTimes.size(); ++i) {
+    auto [currIdle, currTotal] = currTimes[i];
+    auto [prevIdle, prevTotal] = prevTimes_[i];
+    const float deltaIdle = currIdle - prevIdle;
+    const float deltaTotal = currTotal - prevTotal;
+    uint16_t load = 100 * (1 - deltaIdle / deltaTotal);
+    if (i == 0) {
       label_.set_text(fmt::format(format_, load));
+      tooltip = fmt::format("Total: {}%", load);
+    } else {
+      tooltip = tooltip + fmt::format("\nCore{}: {}%", i - 1, load);
     } 
   }
+  label_.set_tooltip_text(tooltip);
+  prevTimes_ = currTimes;
+}
+
+std::vector< std::tuple<size_t, size_t> > waybar::modules::Cpu::parseCpuinfo()
+{
+  std::ifstream info(data_dir_);
+  if (!info.is_open()) {
+    throw std::runtime_error("Can't open " + data_dir_);
+  }
+  std::vector< std::tuple<size_t, size_t> > cpuinfo;
+  std::string line;
+  while (getline(info, line)) {    
+    if (line.substr(0,3).compare("cpu") != 0) {
+      break;
+    }
+    std::stringstream sline(line.substr(5));
+    std::vector<size_t> times;
+    for (size_t time; sline >> time; times.push_back(time));
+
+    size_t idle_time = 0;
+    size_t total_time = 0;
+    if (times.size() >= 4) {
+      idle_time = times[3];
+      total_time = std::accumulate(times.begin(), times.end(), 0);
+    }
+    cpuinfo.push_back( {idle_time, total_time} );
+  }
+  return cpuinfo;
+}