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-rw-r--r--vendor/github.com/prometheus/client_golang/prometheus/summary.go84
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,