stole a trick from btop to measure power

include/cpu.hpp

@@ -1,6 +1,7 @@
 #ifndef CPU_HPP
 #define CPU_HPP
 
+#include <chrono>
 #include <cstdint>
 #include <filesystem>
 #include <log.hpp>
@@ -34,4 +35,4 @@ void update(cpuSensors* g);
 
 }  // namespace cpu
 
-#endif
+#endif

src/cpu.cpp

@@ -17,6 +17,8 @@ void detectHwmon(cpuSensors* target, std::string pci) {
 }
 
 void update(cpuSensors* c) {
+    static std::chrono::time_point<std::chrono::steady_clock> previous_ts;
+    static uint64_t previous_usage = 0;
     // commented out unused values so its faster
     if (c->hwmon == "") return;  // break if no module
     if (c->zenpower) {
@@ -31,6 +33,12 @@ void update(cpuSensors* c) {
     } else {
         c->tctl = std::stoi(readFile(c->hwmon + "/temp1_input", 2));
         c->tccd1 = std::stoi(readFile(c->hwmon + "/temp3_input", 2));
+        // read power from intel-rapl? works on amd too, btop uses this trick, seems accurate
+        auto current_ts = std::chrono::steady_clock::now();
+        auto current_usage = std::stoul(readFile("/sys/class/powercap/intel-rapl:0/energy_uj", 24));
+        c->ptotal = (float)(current_usage - previous_usage) / (float)(std::chrono::duration_cast<std::chrono::microseconds>(current_ts - previous_ts).count());
+        previous_ts = current_ts;
+        previous_usage = current_usage;
     }
 
     // lots of reads but still faster than reading /proc/cpuinfo
@@ -42,4 +50,4 @@ void update(cpuSensors* c) {
     c->avg_freq /= N_CPU;
 }
 
-}  // namespace cpu
+}  // namespace cpu