Reduce file writes, add logging capability

app/src/FanGenerator.cxx

@@ -22,7 +22,7 @@ FanGenerator::FindFans(vector<shared_ptr<Sensor>> rpmSensors,
   cout << "Setting all fans to maximum speed" << endl;
   for (auto c : pwmControls) {
     c->EnableManualControl();
-    c->pwm(100);
+    c->Power(100);
   }
 
   // Wait for fans to settle
@@ -41,7 +41,7 @@ FanGenerator::FindFans(vector<shared_ptr<Sensor>> rpmSensors,
   for (auto c : pwmControls) {
     cout << "Setting " << c->toString()
          << " to 50% and wait for it to settle..." << endl;
-    c->pwm(50);
+    c->Power(50);
 
     this_thread::sleep_for(chrono::seconds(SETTLE_TIMEOUT));
 
@@ -53,7 +53,7 @@ FanGenerator::FindFans(vector<shared_ptr<Sensor>> rpmSensors,
     }
 
     cout << "Setting fan back to 100%" << endl;
-    c->pwm(100);
+    c->Power(100);
   }
 
   return mapping;

app/src/fan/HwmonFan.cxx

@@ -19,9 +19,9 @@ HwmonFan::HwmonFan(std::shared_ptr<PWMControl> pwmControl,
 
 void HwmonFan::PWM(int percent) {
   if (percent < mMinPWM) {
-    mPWMControl->pwm(mMinPWM);
+    mPWMControl->Power(mMinPWM);
   } else {
-    mPWMControl->pwm(percent);
+    mPWMControl->Power(percent);
   }
 }
 

app/src/main.cxx

@@ -1,15 +1,27 @@
+#include <boost/log/expressions/formatters/named_scope.hpp>
+#include <csignal>
+#include <iostream>
+
+#include <boost/date_time/posix_time/posix_time_types.hpp>
+#include <boost/log/attributes/named_scope.hpp>
+#include <boost/log/core.hpp>
+#include <boost/log/expressions.hpp>
+#include <boost/log/expressions/message.hpp>
+#include <boost/log/support/date_time.hpp>
+#include <boost/log/trivial.hpp>
+#include <boost/log/utility/setup.hpp>
+#include <boost/log/utility/setup/common_attributes.hpp>
+#include <boost/log/utility/setup/console.hpp>
+#include <boost/program_options.hpp>
 #include <boost/program_options/options_description.hpp>
 #include <boost/program_options/parsers.hpp>
 #include <boost/program_options/value_semantic.hpp>
 #include <boost/program_options/variables_map.hpp>
-#include <csignal>
-#include <iostream>
-
-#include <boost/program_options.hpp>
 
 #include <App.h>
 
 namespace po = boost::program_options;
+namespace logging = boost::log;
 
 App app;
 
@@ -17,18 +29,50 @@ static int doInitialSetup = 0;
 
 void signal_handler(int s) { app.Shutdown(); }
 
+void InitLogging(bool verbose) {
+  logging::add_console_log(
+      std::clog,
+      logging::keywords::format =
+          (logging::expressions::stream
+           << "["
+           << logging::expressions::format_date_time<boost::posix_time::ptime>(
+                  "TimeStamp", "%Y-%m-%d %H:%M:%S")
+           << "]["
+           << logging::expressions::format_named_scope(
+                  "Scope", logging::keywords::format = "%c")
+           << "]"
+           << "[" << logging::trivial::severity << "] "
+           << logging::expressions::smessage));
+
+  logging::add_common_attributes();
+  logging::core::get()->add_global_attribute(
+      "Scope", logging::attributes::named_scope());
+
+  BOOST_LOG_FUNCTION();
+
+  if (!verbose) {
+    logging::core::get()->set_filter(logging::trivial::severity >=
+                                     logging::trivial::info);
+  } else {
+    BOOST_LOG_TRIVIAL(info) << "Verbose logging enabled";
+  }
+}
+
 int main(int argc, char **argv) {
   signal(SIGINT, signal_handler);
 
   po::options_description desc("Allowed options");
-  desc.add_options()("help", "produce help message")("setup", po::bool_switch(),
-                                                     "run initial setup");
+  desc.add_options()("help,h", "produce help message")(
+      "setup,s", po::bool_switch(),
+      "run initial setup")("verbose,v", po::bool_switch(), "print debug info");
 
   po::variables_map vm;
   po::store(po::parse_command_line(argc, argv, desc), vm);
   po::notify(vm);
 
   try {
+    InitLogging(vm["verbose"].as<bool>());
+
     if (vm.count("help")) {
       std::cout << desc << "\n";
       return 0;

app/src/pwm/PWMControl.cxx

@@ -1,8 +1,10 @@
-#include <boost/json/object.hpp>
+#include <boost/log/attributes/named_scope.hpp>
 #include <filesystem>
 #include <fstream>
 #include <iostream>
 
+#include <boost/log/trivial.hpp>
+
 #include <pwm/PWMControl.h>
 
 #define PWM_POSTFIX_ENABLE "_enable"
@@ -22,6 +24,8 @@ PWMControl::PWMControl(string controlPath) : mControlPath(controlPath) {
 
   ifstream istrm;
 
+  mCurrentValue = Power();
+
   istrm.open(mEnablePath);
   istrm >> mInitialEnable;
   istrm.close();
@@ -36,22 +40,31 @@ PWMControl::~PWMControl() {
   Reset();
 }
 
-void PWMControl::pwm(int percent) {
-  int pwmValue = PWM_MAX_VALUE * percent / 100;
+void PWMControl::Power(int percent) {
+  BOOST_LOG_FUNCTION();
 
-  ofstream ostrm(mControlPath, ios::trunc);
-  ostrm << pwmValue;
-  ostrm.close();
+  int pwmValue = PWM_MAX_VALUE * (percent / 100);
+
+  if (percent != mCurrentValue) {
+    BOOST_LOG_TRIVIAL(trace) << "Updating control value to " << percent;
+    ofstream ostrm(mControlPath, ios::trunc);
+    ostrm << pwmValue;
+    ostrm.close();
+
+    mCurrentValue = percent;
+  } else {
+    BOOST_LOG_TRIVIAL(trace) << "Value unchanged, do nothing";
+  }
 }
 
-int PWMControl::pwm() {
+int PWMControl::Power() {
   int value;
   ifstream istrm;
 
   istrm.open(mControlPath);
   istrm >> value;
 
-  return value;
+  return (value / PWM_MAX_VALUE) * 100;
 }
 
 void PWMControl::EnableManualControl() {