cpu: Show cpu summary and reuse cpuinfo content

cpu/cpu.go

@@ -92,12 +92,13 @@ const (
 
 // Holds all cpu information including previous, current counts and estimated values for percent time spent in each.
 type CpuInfo struct {
- Cores int
- Mhz float64
- Siblings int // this is threads
- Stats []*CpuTime
- OldStats []*CpuTime
- calcstats *calculatedstats
+ Cores int
+ Mhz float64
+ Siblings int // this is threads
+ Stats []*CpuTime
+ OldStats []*CpuTime
+ calcstats *calculatedstats
+ SummaryStats *CpuStat
 }
 
 // This will be a heap to quickly get cpu sorted by user time
@@ -144,24 +145,30 @@ func (cpu *CpuInfo) estimate() {
  c.steal = float32((cur[i].steal - prev[i].steal)) / denom
  c.guest = float32((cur[i].guest - prev[i].guest)) / denom
  c.guest_nice = float32((cur[i].guest_nice - prev[i].guest_nice)) / denom
- heap.Push(cpu.calcstats, c)
+ if i == 0 {
+ cpu.SummaryStats = c
+ } else {
+ heap.Push(cpu.calcstats, c)
+ }
  }
 }
 
+// TODO - update this to string representation of CpuInfo
 func (cpu *CpuInfo) InfoPrint(num_cpus int) string {
  // clktck, err := sysconf.Sysconf(sysconf.SC_CLK_TCK)
  // if err != nil {
- //  log.Fatal("error getting system clock", err)
+ // log.Fatal("error getting system clock", err)
  // }
- cpu.estimate()
+ num_cpus = min(cpu.Siblings, num_cpus)
  if len(cpu.OldStats) == 0 {
  // TODO: - be smarter than just skipping it the first time through?
  return ""
  }
 
  var sb strings.Builder
  sb.WriteString(fmt.Sprintf("vc:%d\tf: %.2f\n", cpu.Siblings, cpu.Mhz/1000))
-
+ sb.WriteString(fmt.Sprintf("CPU: usr:%.2f sys:%.2f: idle:%.2f\n",
+ cpu.SummaryStats.user, cpu.SummaryStats.sys, cpu.SummaryStats.idle))
  for i := 0; i < num_cpus; i++ {
  c := heap.Pop(cpu.calcstats).(*CpuStat)
  sb.WriteString(
@@ -191,7 +198,7 @@ func get_cpuinfo() (*CpuInfo, error) {
 
  // f2, err := mmap.Open("/proc/cpuinfo")
  // if err != nil {
- //  return nil, err
+ // return nil, err
  // }
  // defer f2.Close()
 
@@ -321,16 +328,23 @@ func getCpuTime(numcpu int) ([]*CpuTime, error) {
 }
 
 func CPUStats(ci *CpuInfo) (*CpuInfo, error) {
- info, err := get_cpuinfo()
- if err != nil {
- return nil, err
+ // only update info if it's empty? is it common enough for num cpu etc to
+ // change for this to be checked everytime?
+ var err error
+ // this seems like a bad idea but the norm in golang?
+ // but also it's nonsesne for a real cpuinfo to have zero cores
+ if ci.Cores == 0 {
+ ci, err = get_cpuinfo()
+ if err != nil {
+ return nil, err
+ }
  }
 
- info.OldStats = ci.Stats
-
- info.Stats, err = getCpuTime(info.Siblings)
+ ci.OldStats = ci.Stats
+ ci.Stats, err = getCpuTime(ci.Siblings)
  if err != nil {
  return nil, err
  }
- return info, nil
+ ci.estimate()
+ return ci, nil
 }