diff options
Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus/histogram.go')
| -rw-r--r-- | vendor/github.com/prometheus/client_golang/prometheus/histogram.go | 94 |
1 files changed, 63 insertions, 31 deletions
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/histogram.go b/vendor/github.com/prometheus/client_golang/prometheus/histogram.go index 6cc6e68..331783a 100644 --- a/vendor/github.com/prometheus/client_golang/prometheus/histogram.go +++ b/vendor/github.com/prometheus/client_golang/prometheus/histogram.go @@ -126,23 +126,16 @@ type HistogramOpts struct { // string. Help string - // ConstLabels are used to attach fixed labels to this - // Histogram. Histograms with the same fully-qualified name must have the - // same label names in their ConstLabels. + // ConstLabels are used to attach fixed labels to this metric. Metrics + // with the same fully-qualified name must have the same label names in + // their ConstLabels. // - // Note that in most cases, labels have a value that varies during the - // lifetime of a process. Those labels are usually managed with a - // HistogramVec. ConstLabels serve only special purposes. One is for the - // special case where the value of a label does not change during the - // lifetime of a process, e.g. if the revision of the running binary is - // put into a label. Another, more advanced purpose is if more than one - // Collector needs to collect Histograms with the same fully-qualified - // name. In that case, those Summaries must differ in the values of - // their ConstLabels. See the Collector examples. - // - // If the value of a label never changes (not even between binaries), - // that label most likely should not be a label at all (but part of the - // metric name). + // ConstLabels are only used rarely. In particular, do not use them to + // attach the same labels to all your metrics. Those use cases are + // better covered by target labels set by the scraping Prometheus + // server, or by one specific metric (e.g. a build_info or a + // machine_role metric). See also + // https://prometheus.io/docs/instrumenting/writing_exporters/#target-labels,-not-static-scraped-labels ConstLabels Labels // Buckets defines the buckets into which observations are counted. Each @@ -322,7 +315,7 @@ func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec { // example. // // An error is returned if the number of label values is not the same as the -// number of VariableLabels in Desc. +// number of VariableLabels in Desc (minus any curried labels). // // Note that for more than one label value, this method is prone to mistakes // caused by an incorrect order of arguments. Consider GetMetricWith(Labels) as @@ -330,8 +323,8 @@ func NewHistogramVec(opts HistogramOpts, labelNames []string) *HistogramVec { // latter has a much more readable (albeit more verbose) syntax, but it comes // with a performance overhead (for creating and processing the Labels map). // See also the GaugeVec example. -func (m *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) { - metric, err := m.metricVec.getMetricWithLabelValues(lvs...) +func (v *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) { + metric, err := v.metricVec.getMetricWithLabelValues(lvs...) if metric != nil { return metric.(Observer), err } @@ -345,13 +338,13 @@ func (m *HistogramVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) // are the same as for GetMetricWithLabelValues. // // An error is returned if the number and names of the Labels are inconsistent -// with those of the VariableLabels in Desc. +// with those of the VariableLabels in Desc (minus any curried labels). // // This method is used for the same purpose as // GetMetricWithLabelValues(...string). See there for pros and cons of the two // methods. -func (m *HistogramVec) GetMetricWith(labels Labels) (Observer, error) { - metric, err := m.metricVec.getMetricWith(labels) +func (v *HistogramVec) GetMetricWith(labels Labels) (Observer, error) { + metric, err := v.metricVec.getMetricWith(labels) if metric != nil { return metric.(Observer), err } @@ -359,18 +352,57 @@ func (m *HistogramVec) GetMetricWith(labels Labels) (Observer, error) { } // WithLabelValues works as GetMetricWithLabelValues, but panics where -// GetMetricWithLabelValues would have returned an error. By not returning an -// error, WithLabelValues allows shortcuts like +// GetMetricWithLabelValues would have returned an error. Not returning an +// error allows shortcuts like // myVec.WithLabelValues("404", "GET").Observe(42.21) -func (m *HistogramVec) WithLabelValues(lvs ...string) Observer { - return m.metricVec.withLabelValues(lvs...).(Observer) +func (v *HistogramVec) WithLabelValues(lvs ...string) Observer { + h, err := v.GetMetricWithLabelValues(lvs...) + if err != nil { + panic(err) + } + return h } -// With works as GetMetricWith, but panics where GetMetricWithLabels would have -// returned an error. By not returning an error, With allows shortcuts like -// myVec.With(Labels{"code": "404", "method": "GET"}).Observe(42.21) -func (m *HistogramVec) With(labels Labels) Observer { - return m.metricVec.with(labels).(Observer) +// With works as GetMetricWith but panics where GetMetricWithLabels would have +// returned an error. Not returning an error allows shortcuts like +// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21) +func (v *HistogramVec) With(labels Labels) Observer { + h, err := v.GetMetricWith(labels) + if err != nil { + panic(err) + } + return h +} + +// CurryWith returns a vector curried with the provided labels, i.e. the +// returned vector has those labels pre-set for all labeled operations performed +// on it. The cardinality of the curried vector is reduced accordingly. The +// order of the remaining labels stays the same (just with the curried labels +// taken out of the sequence – which is relevant for the +// (GetMetric)WithLabelValues methods). It is possible to curry a curried +// vector, but only with labels not yet used for currying before. +// +// The metrics contained in the HistogramVec are shared between the curried and +// uncurried vectors. They are just accessed differently. Curried and uncurried +// vectors behave identically in terms of collection. Only one must be +// registered with a given registry (usually the uncurried version). The Reset +// method deletes all metrics, even if called on a curried vector. +func (v *HistogramVec) CurryWith(labels Labels) (ObserverVec, error) { + vec, err := v.curryWith(labels) + if vec != nil { + return &HistogramVec{vec}, err + } + return nil, err +} + +// MustCurryWith works as CurryWith but panics where CurryWith would have +// returned an error. +func (v *HistogramVec) MustCurryWith(labels Labels) ObserverVec { + vec, err := v.CurryWith(labels) + if err != nil { + panic(err) + } + return vec } type constHistogram struct { |