refactor collectors into subpackage

connector/collector/proc.go

@@ -0,0 +1,42 @@
+package collector
+
+import (
+	linuxproc "github.com/c9s/goprocinfo/linux"
+	"github.com/opencontainers/runc/libcontainer/system"
+)
+
+var sysMemTotal = getSysMemTotal()
+var clockTicksPerSecond = uint64(system.GetClockTicks())
+
+const nanoSecondsPerSecond = 1e9
+
+func getSysMemTotal() int64 {
+	stat, err := linuxproc.ReadMemInfo("/proc/meminfo")
+	if err != nil {
+		log.Errorf("error reading system stats: %s", err)
+		return 0
+	}
+	return int64(stat.MemTotal * 1024)
+}
+
+// return cumulative system cpu usage in nanoseconds
+func getSysCPUUsage() uint64 {
+	stat, err := linuxproc.ReadStat("/proc/stat")
+	if err != nil {
+		log.Errorf("error reading system stats: %s", err)
+		return 0
+	}
+
+	sum := stat.CPUStatAll.User +
+		stat.CPUStatAll.Nice +
+		stat.CPUStatAll.System +
+		stat.CPUStatAll.Idle +
+		stat.CPUStatAll.IOWait +
+		stat.CPUStatAll.IRQ +
+		stat.CPUStatAll.SoftIRQ +
+		stat.CPUStatAll.Steal +
+		stat.CPUStatAll.Guest +
+		stat.CPUStatAll.GuestNice
+
+	return (sum * nanoSecondsPerSecond) / clockTicksPerSecond
+}