scope oshi_calcProcessCPUUsage.

sbool #debug;

sclass #Data {
  S characteristics; // for identifying the process
  long cpuTime, timestamp;
  
  toString { ret "cpuTime=" + cpuTime + ", timestamp=" + timestamp + ", characteristics=" + characteristics; }
}

// key: pid; TODO: delete dead processes from map
static Map<Int, Data> #map = synchroMap();

// call this in proper interval (1 to 3 seconds) to work properly
static double oshi_calcProcessCPUUsage(OSProcess p) {
  if (p == null) ret 0;
  int pid = p.getProcessID();
  Data data = map.get(pid);
  S characteristics = oshi_immutableProcessCharacteristics(p);
  if (data == null || neq(data.characteristics, characteristics)) {
    if (debug && data != null) print("Dropping data for " + pid + " (" + data.characteristics + " vs " + characteristics + ")");
    map.put(pid, data = new Data);
  }
  if (data.characteristics == null) data.characteristics = characteristics;
  
  long cpuTime = p.getKernelTime() + p.getUserTime();

  double result = 0;
  long now = sysNow();
  if (debug)
    print("oshi cpu: " + pid + " / " + cpuTime + " / " + data);
  if (data.timestamp != 0)
		result = percentRatio(cpuTime-data.cpuTime, now-data.timestamp);
  data.timestamp = now;
	data.cpuTime = cpuTime;
	ret result;
}

end scope