diff options
Diffstat (limited to 'vendor/github.com/prometheus/client_golang/prometheus/summary.go')
-rw-r--r-- | vendor/github.com/prometheus/client_golang/prometheus/summary.go | 84 |
1 files changed, 59 insertions, 25 deletions
diff --git a/vendor/github.com/prometheus/client_golang/prometheus/summary.go b/vendor/github.com/prometheus/client_golang/prometheus/summary.go index 82b8850..21c031e 100644 --- a/vendor/github.com/prometheus/client_golang/prometheus/summary.go +++ b/vendor/github.com/prometheus/client_golang/prometheus/summary.go @@ -36,7 +36,10 @@ const quantileLabel = "quantile" // // A typical use-case is the observation of request latencies. By default, a // Summary provides the median, the 90th and the 99th percentile of the latency -// as rank estimations. +// as rank estimations. However, the default behavior will change in the +// upcoming v0.10 of the library. There will be no rank estiamtions at all by +// default. For a sane transition, it is recommended to set the desired rank +// estimations explicitly. // // Note that the rank estimations cannot be aggregated in a meaningful way with // the Prometheus query language (i.e. you cannot average or add them). If you @@ -78,8 +81,10 @@ const ( ) // SummaryOpts bundles the options for creating a Summary metric. It is -// mandatory to set Name and Help to a non-empty string. All other fields are -// optional and can safely be left at their zero value. +// mandatory to set Name and Help to a non-empty string. While all other fields +// are optional and can safely be left at their zero value, it is recommended to +// explicitly set the Objectives field to the desired value as the default value +// will change in the upcoming v0.10 of the library. type SummaryOpts struct { // Namespace, Subsystem, and Name are components of the fully-qualified // name of the Summary (created by joining these components with @@ -399,12 +404,11 @@ func (s quantSort) Less(i, j int) bool { // (e.g. HTTP request latencies, partitioned by status code and method). Create // instances with NewSummaryVec. type SummaryVec struct { - *MetricVec + *metricVec } // NewSummaryVec creates a new SummaryVec based on the provided SummaryOpts and -// partitioned by the given label names. At least one label name must be -// provided. +// partitioned by the given label names. func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec { desc := NewDesc( BuildFQName(opts.Namespace, opts.Subsystem, opts.Name), @@ -413,30 +417,60 @@ func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec { opts.ConstLabels, ) return &SummaryVec{ - MetricVec: newMetricVec(desc, func(lvs ...string) Metric { + metricVec: newMetricVec(desc, func(lvs ...string) Metric { return newSummary(desc, opts, lvs...) }), } } -// GetMetricWithLabelValues replaces the method of the same name in -// MetricVec. The difference is that this method returns a Summary and not a -// Metric so that no type conversion is required. -func (m *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Summary, error) { - metric, err := m.MetricVec.GetMetricWithLabelValues(lvs...) +// GetMetricWithLabelValues returns the Summary for the given slice of label +// values (same order as the VariableLabels in Desc). If that combination of +// label values is accessed for the first time, a new Summary is created. +// +// It is possible to call this method without using the returned Summary to only +// create the new Summary but leave it at its starting value, a Summary without +// any observations. +// +// Keeping the Summary for later use is possible (and should be considered if +// performance is critical), but keep in mind that Reset, DeleteLabelValues and +// Delete can be used to delete the Summary from the SummaryVec. In that case, the +// Summary will still exist, but it will not be exported anymore, even if a +// Summary with the same label values is created later. See also the CounterVec +// example. +// +// An error is returned if the number of label values is not the same as the +// number of VariableLabels in Desc. +// +// 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 +// an alternative to avoid that type of mistake. For higher label numbers, the +// 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 *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) { + metric, err := m.metricVec.getMetricWithLabelValues(lvs...) if metric != nil { - return metric.(Summary), err + return metric.(Observer), err } return nil, err } -// GetMetricWith replaces the method of the same name in MetricVec. The -// difference is that this method returns a Summary and not a Metric so that no -// type conversion is required. -func (m *SummaryVec) GetMetricWith(labels Labels) (Summary, error) { - metric, err := m.MetricVec.GetMetricWith(labels) +// GetMetricWith returns the Summary for the given Labels map (the label names +// must match those of the VariableLabels in Desc). If that label map is +// accessed for the first time, a new Summary is created. Implications of +// creating a Summary without using it and keeping the Summary for later use 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. +// +// This method is used for the same purpose as +// GetMetricWithLabelValues(...string). See there for pros and cons of the two +// methods. +func (m *SummaryVec) GetMetricWith(labels Labels) (Observer, error) { + metric, err := m.metricVec.getMetricWith(labels) if metric != nil { - return metric.(Summary), err + return metric.(Observer), err } return nil, err } @@ -445,15 +479,15 @@ func (m *SummaryVec) GetMetricWith(labels Labels) (Summary, error) { // GetMetricWithLabelValues would have returned an error. By not returning an // error, WithLabelValues allows shortcuts like // myVec.WithLabelValues("404", "GET").Observe(42.21) -func (m *SummaryVec) WithLabelValues(lvs ...string) Summary { - return m.MetricVec.WithLabelValues(lvs...).(Summary) +func (m *SummaryVec) WithLabelValues(lvs ...string) Observer { + return m.metricVec.withLabelValues(lvs...).(Observer) } // 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 *SummaryVec) With(labels Labels) Summary { - return m.MetricVec.With(labels).(Summary) +func (m *SummaryVec) With(labels Labels) Observer { + return m.metricVec.with(labels).(Observer) } type constSummary struct { @@ -514,8 +548,8 @@ func NewConstSummary( quantiles map[float64]float64, labelValues ...string, ) (Metric, error) { - if len(desc.variableLabels) != len(labelValues) { - return nil, errInconsistentCardinality + if err := validateLabelValues(labelValues, len(desc.variableLabels)); err != nil { + return nil, err } return &constSummary{ desc: desc, |