// NewCollector returns a prometheus.Collector for a given stats var.
// It supports all stats var types except String, StringFunc and Rates.
// The returned collector still needs to be registered with prometheus registry.
func NewCollector(opts prometheus.Opts, v expvar.Var) prometheus.Collector {
switch st := v.(type) {
case *stats.Int:
return prometheus.NewGaugeFunc(prometheus.GaugeOpts(opts), func() float64 {
return float64(st.Get())
})
case stats.IntFunc:
return prometheus.NewGaugeFunc(prometheus.GaugeOpts(opts), func() float64 {
return float64(st())
})
case *stats.Duration:
return prometheus.NewGaugeFunc(prometheus.GaugeOpts(opts), func() float64 {
return st.Get().Seconds()
})
case stats.DurationFunc:
return prometheus.NewGaugeFunc(prometheus.GaugeOpts(opts), func() float64 {
return st().Seconds()
})
case *stats.Float:
return prometheus.NewGaugeFunc(prometheus.GaugeOpts(opts), st.Get)
case stats.FloatFunc:
return prometheus.NewGaugeFunc(prometheus.GaugeOpts(opts), st)
case *stats.Counters:
return newCountersCollector(opts, st, "tag")
case stats.CountersFunc:
return newCountersCollector(opts, st, "tag")
case *stats.MultiCounters:
return newCountersCollector(opts, st, st.Labels()...)
case *stats.MultiCountersFunc:
return newCountersCollector(opts, st, st.Labels()...)
case *stats.Histogram:
return newHistogramCollector(opts, st)
case *stats.Timings:
return newTimingsCollector(opts, st, "category")
case *stats.MultiTimings:
return newTimingsCollector(opts, &st.Timings, st.Labels()...)
case *stats.String:
// prometheus can't collect string values
return nil
case stats.StringFunc:
// prometheus can't collect string values
return nil
case *stats.Rates:
// Ignore these, because monitoring tools will calculate
// rates for us.
return nil
default:
log.Warningf("Unsupported type for %s: %T", opts.Name, v)
return nil
}
}
func (m *metric) init() error {
name := m.Measurable.MsName()
mangledName := mangleName(name)
opts := prometheus.Opts{
Name: mangledName,
Help: name,
}
switch m.Measurable.MsType() {
case measurable.CounterType:
mi, ok := m.Measurable.(interface {
MsInt64() int64
})
if !ok {
return errNotSupported
}
m.Metric = prometheus.NewCounterFunc(prometheus.CounterOpts(opts), func() float64 {
return float64(mi.MsInt64())
})
case measurable.GaugeType:
mi, ok := m.Measurable.(interface {
MsInt64() int64
})
if !ok {
return errNotSupported
}
m.Metric = prometheus.NewGaugeFunc(prometheus.GaugeOpts(opts), func() float64 {
return float64(mi.MsInt64())
})
default:
return errNotSupported
}
return nil
}