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Merge pull request #365 from prometheus/beorn7/vec 

Allow currying of metric vec's
This commit is contained in:
Björn Rabenstein 2017-12-24 17:04:06 +01:00 committed by GitHub
parent 661e31bf84 9ac0bad606
commit 180b8fdc22
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GPG Key ID: 4AEE18F83AFDEB23
13 changed files with 992 additions and 380 deletions
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67
prometheus/counter.go
View File

@ -111,7 +111,7 @@ func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
// Counter with the same label values is created later.
//
// 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
@ -119,8 +119,8 @@ func NewCounterVec(opts CounterOpts, labelNames []string) *CounterVec {
// 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 *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
metric, err := m.metricVec.getMetricWithLabelValues(lvs...)
func (v *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Counter), err
}
@ -134,13 +134,13 @@ func (m *CounterVec) GetMetricWithLabelValues(lvs ...string) (Counter, error) {
// 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 *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
metric, err := m.metricVec.getMetricWith(labels)
func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
metric, err := v.metricVec.getMetricWith(labels)
if metric != nil {
return metric.(Counter), err
}
@ -148,18 +148,57 @@ func (m *CounterVec) GetMetricWith(labels Labels) (Counter, 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").Add(42)
func (m *CounterVec) WithLabelValues(lvs ...string) Counter {
return m.metricVec.withLabelValues(lvs...).(Counter)
func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
c, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return c
}
// 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"}).Add(42)
func (m *CounterVec) With(labels Labels) Counter {
return m.metricVec.with(labels).(Counter)
// returned an error. Not returning an error allows shortcuts like
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
func (v *CounterVec) With(labels Labels) Counter {
c, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return c
}
// 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 CounterVec 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 *CounterVec) CurryWith(labels Labels) (*CounterVec, error) {
vec, err := v.curryWith(labels)
if vec != nil {
return &CounterVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *CounterVec) MustCurryWith(labels Labels) *CounterVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
// CounterFunc is a Counter whose value is determined at collect time by calling a

3
prometheus/desc.go
View File

@ -73,8 +73,7 @@ type Desc struct {
// and therefore not part of the Desc. (They are managed within the Metric.)
//
// For constLabels, the label values are constant. Therefore, they are fully
// specified in the Desc. See the Opts documentation for the implications of
// constant labels.
// specified in the Desc. See the Collector example for a usage pattern.
func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *Desc {
d := &Desc{
fqName: fqName,

67
prometheus/gauge.go
View File

@ -98,15 +98,15 @@ func NewGaugeVec(opts GaugeOpts, labelNames []string) *GaugeVec {
// 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
// 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).
func (m *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
metric, err := m.metricVec.getMetricWithLabelValues(lvs...)
func (v *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Gauge), err
}
@ -120,13 +120,13 @@ func (m *GaugeVec) GetMetricWithLabelValues(lvs ...string) (Gauge, error) {
// 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 *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
metric, err := m.metricVec.getMetricWith(labels)
func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
metric, err := v.metricVec.getMetricWith(labels)
if metric != nil {
return metric.(Gauge), err
}
@ -134,18 +134,57 @@ func (m *GaugeVec) GetMetricWith(labels Labels) (Gauge, 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").Add(42)
func (m *GaugeVec) WithLabelValues(lvs ...string) Gauge {
return m.metricVec.withLabelValues(lvs...).(Gauge)
func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
g, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return g
}
// 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"}).Add(42)
func (m *GaugeVec) With(labels Labels) Gauge {
return m.metricVec.with(labels).(Gauge)
// returned an error. Not returning an error allows shortcuts like
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Add(42)
func (v *GaugeVec) With(labels Labels) Gauge {
g, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return g
}
// 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 GaugeVec 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 *GaugeVec) CurryWith(labels Labels) (*GaugeVec, error) {
vec, err := v.curryWith(labels)
if vec != nil {
return &GaugeVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *GaugeVec) MustCurryWith(labels Labels) *GaugeVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
// GaugeFunc is a Gauge whose value is determined at collect time by calling a

94
prometheus/histogram.go
View File

@ -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 {

2
prometheus/http_test.go
View File

@ -128,7 +128,7 @@ func TestInstrumentHandler(t *testing.T) {
}
out.Reset()
if want, got := 1, len(reqCnt.children); want != got {
if want, got := 1, len(reqCnt.metricMap.metrics); want != got {
t.Errorf("want %d children in reqCnt, got %d", want, got)
}
cnt, err := reqCnt.GetMetricWithLabelValues("get", "418")

20
prometheus/metric.go
View File

@ -79,20 +79,12 @@ type Opts struct {
// 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 metric
// vector collector (like CounterVec, GaugeVec, UntypedVec). 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 Metrics with the same fully-qualified name. In that
// case, those Metrics 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
}

2
prometheus/observer.go
View File

@ -45,6 +45,8 @@ type ObserverVec interface {
GetMetricWithLabelValues(lvs ...string) (Observer, error)
With(Labels) Observer
WithLabelValues(...string) Observer
CurryWith(Labels) (ObserverVec, error)
MustCurryWith(Labels) ObserverVec
Collector
}

11
prometheus/promhttp/instrument_client.go
View File

@ -45,12 +45,11 @@ func InstrumentRoundTripperInFlight(gauge prometheus.Gauge, next http.RoundTripp
// InstrumentRoundTripperCounter is a middleware that wraps the provided
// http.RoundTripper to observe the request result with the provided CounterVec.
// The CounterVec must have zero, one, or two labels. The only allowed label
// names are "code" and "method". The function panics if any other instance
// labels are provided. Partitioning of the CounterVec happens by HTTP status
// code and/or HTTP method if the respective instance label names are present
// in the CounterVec. For unpartitioned counting, use a CounterVec with
// zero labels.
// The CounterVec must have zero, one, or two non-const non-curried labels. For
// those, the only allowed label names are "code" and "method". The function
// panics otherwise. Partitioning of the CounterVec happens by HTTP status code
// and/or HTTP method if the respective instance label names are present in the
// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
//
// If the wrapped RoundTripper panics or returns a non-nil error, the Counter
// is not incremented.

129
prometheus/promhttp/instrument_server.go
View File

@ -14,6 +14,7 @@
package promhttp
import (
"errors"
"net/http"
"strconv"
"strings"
@ -42,10 +43,10 @@ func InstrumentHandlerInFlight(g prometheus.Gauge, next http.Handler) http.Handl
// InstrumentHandlerDuration is a middleware that wraps the provided
// http.Handler to observe the request duration with the provided ObserverVec.
// The ObserverVec must have zero, one, or two labels. The only allowed label
// names are "code" and "method". The function panics if any other instance
// labels are provided. The Observe method of the Observer in the ObserverVec
// is called with the request duration in seconds. Partitioning happens by HTTP
// The ObserverVec must have zero, one, or two non-const non-curried labels. For
// those, the only allowed label names are "code" and "method". The function
// panics otherwise. The Observe method of the Observer in the ObserverVec is
// called with the request duration in seconds. Partitioning happens by HTTP
// status code and/or HTTP method if the respective instance label names are
// present in the ObserverVec. For unpartitioned observations, use an
// ObserverVec with zero labels. Note that partitioning of Histograms is
@ -77,14 +78,13 @@ func InstrumentHandlerDuration(obs prometheus.ObserverVec, next http.Handler) ht
})
}
// InstrumentHandlerCounter is a middleware that wraps the provided
// http.Handler to observe the request result with the provided CounterVec.
// The CounterVec must have zero, one, or two labels. The only allowed label
// names are "code" and "method". The function panics if any other instance
// labels are provided. Partitioning of the CounterVec happens by HTTP status
// code and/or HTTP method if the respective instance label names are present
// in the CounterVec. For unpartitioned counting, use a CounterVec with
// zero labels.
// InstrumentHandlerCounter is a middleware that wraps the provided http.Handler
// to observe the request result with the provided CounterVec. The CounterVec
// must have zero, one, or two non-const non-curried labels. For those, the only
// allowed label names are "code" and "method". The function panics
// otherwise. Partitioning of the CounterVec happens by HTTP status code and/or
// HTTP method if the respective instance label names are present in the
// CounterVec. For unpartitioned counting, use a CounterVec with zero labels.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
@ -111,14 +111,13 @@ func InstrumentHandlerCounter(counter *prometheus.CounterVec, next http.Handler)
// InstrumentHandlerTimeToWriteHeader is a middleware that wraps the provided
// http.Handler to observe with the provided ObserverVec the request duration
// until the response headers are written. The ObserverVec must have zero, one,
// or two labels. The only allowed label names are "code" and "method". The
// function panics if any other instance labels are provided. The Observe
// method of the Observer in the ObserverVec is called with the request
// duration in seconds. Partitioning happens by HTTP status code and/or HTTP
// method if the respective instance label names are present in the
// ObserverVec. For unpartitioned observations, use an ObserverVec with zero
// labels. Note that partitioning of Histograms is expensive and should be used
// judiciously.
// or two non-const non-curried labels. For those, the only allowed label names
// are "code" and "method". The function panics otherwise. The Observe method of
// the Observer in the ObserverVec is called with the request duration in
// seconds. Partitioning happens by HTTP status code and/or HTTP method if the
// respective instance label names are present in the ObserverVec. For
// unpartitioned observations, use an ObserverVec with zero labels. Note that
// partitioning of Histograms is expensive and should be used judiciously.
//
// If the wrapped Handler panics before calling WriteHeader, no value is
// reported.
@ -140,15 +139,15 @@ func InstrumentHandlerTimeToWriteHeader(obs prometheus.ObserverVec, next http.Ha
}
// InstrumentHandlerRequestSize is a middleware that wraps the provided
// http.Handler to observe the request size with the provided ObserverVec.
// The ObserverVec must have zero, one, or two labels. The only allowed label
// names are "code" and "method". The function panics if any other instance
// labels are provided. The Observe method of the Observer in the ObserverVec
// is called with the request size in bytes. Partitioning happens by HTTP
// status code and/or HTTP method if the respective instance label names are
// present in the ObserverVec. For unpartitioned observations, use an
// ObserverVec with zero labels. Note that partitioning of Histograms is
// expensive and should be used judiciously.
// http.Handler to observe the request size with the provided ObserverVec. The
// ObserverVec must have zero, one, or two non-const non-curried labels. For
// those, the only allowed label names are "code" and "method". The function
// panics otherwise. The Observe method of the Observer in the ObserverVec is
// called with the request size in bytes. Partitioning happens by HTTP status
// code and/or HTTP method if the respective instance label names are present in
// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
// labels. Note that partitioning of Histograms is expensive and should be used
// judiciously.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
@ -175,15 +174,15 @@ func InstrumentHandlerRequestSize(obs prometheus.ObserverVec, next http.Handler)
}
// InstrumentHandlerResponseSize is a middleware that wraps the provided
// http.Handler to observe the response size with the provided ObserverVec.
// The ObserverVec must have zero, one, or two labels. The only allowed label
// names are "code" and "method". The function panics if any other instance
// labels are provided. The Observe method of the Observer in the ObserverVec
// is called with the response size in bytes. Partitioning happens by HTTP
// status code and/or HTTP method if the respective instance label names are
// present in the ObserverVec. For unpartitioned observations, use an
// ObserverVec with zero labels. Note that partitioning of Histograms is
// expensive and should be used judiciously.
// http.Handler to observe the response size with the provided ObserverVec. The
// ObserverVec must have zero, one, or two non-const non-curried labels. For
// those, the only allowed label names are "code" and "method". The function
// panics otherwise. The Observe method of the Observer in the ObserverVec is
// called with the response size in bytes. Partitioning happens by HTTP status
// code and/or HTTP method if the respective instance label names are present in
// the ObserverVec. For unpartitioned observations, use an ObserverVec with zero
// labels. Note that partitioning of Histograms is expensive and should be used
// judiciously.
//
// If the wrapped Handler does not set a status code, a status code of 200 is assumed.
//
@ -204,9 +203,12 @@ func checkLabels(c prometheus.Collector) (code bool, method bool) {
// once Descriptors can have their dimensionality queried.
var (
desc *prometheus.Desc
m prometheus.Metric
pm dto.Metric
lvs []string
)
// Get the Desc from the Collector.
descc := make(chan *prometheus.Desc, 1)
c.Describe(descc)
@ -223,16 +225,22 @@ func checkLabels(c prometheus.Collector) (code bool, method bool) {
close(descc)
if _, err := prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0); err == nil {
return
// Create a ConstMetric with the Desc. Since we don't know how many
// variable labels there are, try for as long as it needs.
for err := errors.New("dummy"); err != nil; lvs = append(lvs, magicString) {
m, err = prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, lvs...)
}
if m, err := prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, magicString); err == nil {
// Write out the metric into a proto message and look at the labels.
// If the value is not the magicString, it is a constLabel, which doesn't interest us.
// If the label is curried, it doesn't interest us.
// In all other cases, only "code" or "method" is allowed.
if err := m.Write(&pm); err != nil {
panic("error checking metric for labels")
}
for _, label := range pm.Label {
name, value := label.GetName(), label.GetValue()
if value != magicString {
if value != magicString || isLabelCurried(c, name) {
continue
}
switch name {
@ -243,29 +251,28 @@ func checkLabels(c prometheus.Collector) (code bool, method bool) {
default:
panic("metric partitioned with non-supported labels")
}
}
return
}
func isLabelCurried(c prometheus.Collector, label string) bool {
// This is even hackier than the label test above.
// We essentially try to curry again and see if it works.
// But for that, we need to type-convert to the two
// types we use here, ObserverVec or *CounterVec.
switch v := c.(type) {
case *prometheus.CounterVec:
if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
return false
}
panic("previously set label not found – this must never happen")
case prometheus.ObserverVec:
if _, err := v.CurryWith(prometheus.Labels{label: "dummy"}); err == nil {
return false
}
if m, err := prometheus.NewConstMetric(desc, prometheus.UntypedValue, 0, magicString, magicString); err == nil {
if err := m.Write(&pm); err != nil {
panic("error checking metric for labels")
default:
panic("unsupported metric vec type")
}
for _, label := range pm.Label {
name, value := label.GetName(), label.GetValue()
if value != magicString {
continue
}
if name == "code" || name == "method" {
continue
}
panic("metric partitioned with non-supported labels")
}
code = true
method = true
return
}
panic("metric partitioned with non-supported labels")
return true
}
// emptyLabels is a one-time allocation for non-partitioned metrics to avoid

192
prometheus/promhttp/instrument_server_test.go
View File

@ -23,6 +23,162 @@ import (
"github.com/prometheus/client_golang/prometheus"
)
func TestLabelCheck(t *testing.T) {
scenarios := map[string]struct {
varLabels []string
constLabels []string
curriedLabels []string
ok bool
}{
"empty": {
varLabels: []string{},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"code as single var label": {
varLabels: []string{"code"},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"method as single var label": {
varLabels: []string{"method"},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"cade and method as var labels": {
varLabels: []string{"method", "code"},
constLabels: []string{},
curriedLabels: []string{},
ok: true,
},
"valid case with all labels used": {
varLabels: []string{"code", "method"},
constLabels: []string{"foo", "bar"},
curriedLabels: []string{"dings", "bums"},
ok: true,
},
"unsupported var label": {
varLabels: []string{"foo"},
constLabels: []string{},
curriedLabels: []string{},
ok: false,
},
"mixed var labels": {
varLabels: []string{"method", "foo", "code"},
constLabels: []string{},
curriedLabels: []string{},
ok: false,
},
"unsupported var label but curried": {
varLabels: []string{},
constLabels: []string{},
curriedLabels: []string{"foo"},
ok: true,
},
"mixed var labels but unsupported curried": {
varLabels: []string{"code", "method"},
constLabels: []string{},
curriedLabels: []string{"foo"},
ok: true,
},
"supported label as const and curry": {
varLabels: []string{},
constLabels: []string{"code"},
curriedLabels: []string{"method"},
ok: true,
},
"supported label as const and curry with unsupported as var": {
varLabels: []string{"foo"},
constLabels: []string{"code"},
curriedLabels: []string{"method"},
ok: false,
},
}
for name, sc := range scenarios {
t.Run(name, func(t *testing.T) {
constLabels := prometheus.Labels{}
for _, l := range sc.constLabels {
constLabels[l] = "dummy"
}
c := prometheus.NewCounterVec(
prometheus.CounterOpts{
Name: "c",
Help: "c help",
ConstLabels: constLabels,
},
append(sc.varLabels, sc.curriedLabels...),
)
o := prometheus.ObserverVec(prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "c",
Help: "c help",
ConstLabels: constLabels,
},
append(sc.varLabels, sc.curriedLabels...),
))
for _, l := range sc.curriedLabels {
c = c.MustCurryWith(prometheus.Labels{l: "dummy"})
o = o.MustCurryWith(prometheus.Labels{l: "dummy"})
}
func() {
defer func() {
if err := recover(); err != nil {
if sc.ok {
t.Error("unexpected panic:", err)
}
} else if !sc.ok {
t.Error("expected panic")
}
}()
InstrumentHandlerCounter(c, nil)
}()
func() {
defer func() {
if err := recover(); err != nil {
if sc.ok {
t.Error("unexpected panic:", err)
}
} else if !sc.ok {
t.Error("expected panic")
}
}()
InstrumentHandlerDuration(o, nil)
}()
if sc.ok {
// Test if wantCode and wantMethod were detected correctly.
var wantCode, wantMethod bool
for _, l := range sc.varLabels {
if l == "code" {
wantCode = true
}
if l == "method" {
wantMethod = true
}
}
gotCode, gotMethod := checkLabels(c)
if gotCode != wantCode {
t.Errorf("wanted code=%t for counter, got code=%t", wantCode, gotCode)
}
if gotMethod != wantMethod {
t.Errorf("wanted method=%t for counter, got method=%t", wantMethod, gotMethod)
}
gotCode, gotMethod = checkLabels(o)
if gotCode != wantCode {
t.Errorf("wanted code=%t for observer, got code=%t", wantCode, gotCode)
}
if gotMethod != wantMethod {
t.Errorf("wanted method=%t for observer, got method=%t", wantMethod, gotMethod)
}
}
})
}
}
func TestMiddlewareAPI(t *testing.T) {
reg := prometheus.NewRegistry()
@ -159,26 +315,15 @@ func ExampleInstrumentHandlerDuration() {
[]string{"code", "method"},
)
// pushVec and pullVec are partitioned by the HTTP method and use custom
// buckets based on the expected request duration. ConstLabels are used
// to set a handler label to mark pushVec as tracking the durations for
// pushes and pullVec as tracking the durations for pulls. Note that
// Name, Help, and Buckets need to be the same for consistency, so we
// use the same HistogramOpts after just modifying the ConstLabels.
histogramOpts := prometheus.HistogramOpts{
// duration is partitioned by the HTTP method and handler. It uses custom
// buckets based on the expected request duration.
duration := prometheus.NewHistogramVec(
prometheus.HistogramOpts{
Name: "request_duration_seconds",
Help: "A histogram of latencies for requests.",
Buckets: []float64{.25, .5, 1, 2.5, 5, 10},
ConstLabels: prometheus.Labels{"handler": "push"},
}
pushVec := prometheus.NewHistogramVec(
histogramOpts,
[]string{"method"},
)
histogramOpts.ConstLabels = prometheus.Labels{"handler": "pull"}
pullVec := prometheus.NewHistogramVec(
histogramOpts,
[]string{"method"},
},
[]string{"handler", "method"},
)
// responseSize has no labels, making it a zero-dimensional
@ -201,23 +346,20 @@ func ExampleInstrumentHandlerDuration() {
})
// Register all of the metrics in the standard registry.
prometheus.MustRegister(inFlightGauge, counter, pullVec, pushVec, responseSize)
prometheus.MustRegister(inFlightGauge, counter, duration, responseSize)
// Wrap the pushHandler with our shared middleware, but use the
// endpoint-specific pushVec with InstrumentHandlerDuration.
// Instrument the handlers with all the metrics, injecting the "handler"
// label by currying.
pushChain := InstrumentHandlerInFlight(inFlightGauge,
InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "push"}),
InstrumentHandlerCounter(counter,
InstrumentHandlerDuration(pushVec,
InstrumentHandlerResponseSize(responseSize, pushHandler),
),
),
)
// Wrap the pushHandler with the shared middleware, but use the
// endpoint-specific pullVec with InstrumentHandlerDuration.
pullChain := InstrumentHandlerInFlight(inFlightGauge,
InstrumentHandlerDuration(duration.MustCurryWith(prometheus.Labels{"handler": "pull"}),
InstrumentHandlerCounter(counter,
InstrumentHandlerDuration(pullVec,
InstrumentHandlerResponseSize(responseSize, pullHandler),
),
),

96
prometheus/summary.go
View File

@ -101,23 +101,16 @@ type SummaryOpts struct {
// string.
Help string
// ConstLabels are used to attach fixed labels to this
// Summary. Summaries 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
// SummaryVec. 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 Summaries 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
// Objectives defines the quantile rank estimates with their respective
@ -433,13 +426,13 @@ func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
//
// 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
// 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.
// 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
@ -447,8 +440,8 @@ func NewSummaryVec(opts SummaryOpts, labelNames []string) *SummaryVec {
// 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...)
func (v *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
metric, err := v.metricVec.getMetricWithLabelValues(lvs...)
if metric != nil {
return metric.(Observer), err
}
@ -462,13 +455,13 @@ func (m *SummaryVec) GetMetricWithLabelValues(lvs ...string) (Observer, error) {
// 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 *SummaryVec) GetMetricWith(labels Labels) (Observer, error) {
metric, err := m.metricVec.getMetricWith(labels)
func (v *SummaryVec) GetMetricWith(labels Labels) (Observer, error) {
metric, err := v.metricVec.getMetricWith(labels)
if metric != nil {
return metric.(Observer), err
}
@ -476,18 +469,57 @@ func (m *SummaryVec) 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 *SummaryVec) WithLabelValues(lvs ...string) Observer {
return m.metricVec.withLabelValues(lvs...).(Observer)
func (v *SummaryVec) WithLabelValues(lvs ...string) Observer {
s, err := v.GetMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return s
}
// 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) Observer {
return m.metricVec.with(labels).(Observer)
// returned an error. Not returning an error allows shortcuts like
// myVec.With(prometheus.Labels{"code": "404", "method": "GET"}).Observe(42.21)
func (v *SummaryVec) With(labels Labels) Observer {
s, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return s
}
// 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 SummaryVec 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 *SummaryVec) CurryWith(labels Labels) (ObserverVec, error) {
vec, err := v.curryWith(labels)
if vec != nil {
return &SummaryVec{vec}, err
}
return nil, err
}
// MustCurryWith works as CurryWith but panics where CurryWith would have
// returned an error.
func (v *SummaryVec) MustCurryWith(labels Labels) ObserverVec {
vec, err := v.CurryWith(labels)
if err != nil {
panic(err)
}
return vec
}
type constSummary struct {

420
prometheus/vec.go
View File

@ -23,88 +23,31 @@ import (
// metricVec is a Collector to bundle metrics of the same name that differ in
// their label values. metricVec is not used directly (and therefore
// unexported). It is used as a building block for implementations of vectors of
// a given metric type, like GaugeVec, CounterVec, SummaryVec, HistogramVec, and
// UntypedVec.
// a given metric type, like GaugeVec, CounterVec, SummaryVec, and HistogramVec.
// It also handles label currying. It uses basicMetricVec internally.
type metricVec struct {
mtx sync.RWMutex // Protects the children.
children map[uint64][]metricWithLabelValues
desc *Desc
*metricMap
newMetric func(labelValues ...string) Metric
hashAdd func(h uint64, s string) uint64 // replace hash function for testing collision handling
curry []curriedLabelValue
// hashAdd and hashAddByte can be replaced for testing collision handling.
hashAdd func(h uint64, s string) uint64
hashAddByte func(h uint64, b byte) uint64
}
// newMetricVec returns an initialized metricVec.
func newMetricVec(desc *Desc, newMetric func(lvs ...string) Metric) *metricVec {
return &metricVec{
children: map[uint64][]metricWithLabelValues{},
metricMap: &metricMap{
metrics: map[uint64][]metricWithLabelValues{},
desc: desc,
newMetric: newMetric,
},
hashAdd: hashAdd,
hashAddByte: hashAddByte,
}
}
// metricWithLabelValues provides the metric and its label values for
// disambiguation on hash collision.
type metricWithLabelValues struct {
values []string
metric Metric
}
// Describe implements Collector. The length of the returned slice
// is always one.
func (m *metricVec) Describe(ch chan<- *Desc) {
ch <- m.desc
}
// Collect implements Collector.
func (m *metricVec) Collect(ch chan<- Metric) {
m.mtx.RLock()
defer m.mtx.RUnlock()
for _, metrics := range m.children {
for _, metric := range metrics {
ch <- metric.metric
}
}
}
func (m *metricVec) getMetricWithLabelValues(lvs ...string) (Metric, error) {
h, err := m.hashLabelValues(lvs)
if err != nil {
return nil, err
}
return m.getOrCreateMetricWithLabelValues(h, lvs), nil
}
func (m *metricVec) getMetricWith(labels Labels) (Metric, error) {
h, err := m.hashLabels(labels)
if err != nil {
return nil, err
}
return m.getOrCreateMetricWithLabels(h, labels), nil
}
func (m *metricVec) withLabelValues(lvs ...string) Metric {
metric, err := m.getMetricWithLabelValues(lvs...)
if err != nil {
panic(err)
}
return metric
}
func (m *metricVec) with(labels Labels) Metric {
metric, err := m.getMetricWith(labels)
if err != nil {
panic(err)
}
return metric
}
// DeleteLabelValues removes the metric where the variable labels are the same
// as those passed in as labels (same order as the VariableLabels in Desc). It
// returns true if a metric was deleted.
@ -121,14 +64,12 @@ func (m *metricVec) with(labels Labels) Metric {
// with a performance overhead (for creating and processing the Labels map).
// See also the CounterVec example.
func (m *metricVec) DeleteLabelValues(lvs ...string) bool {
m.mtx.Lock()
defer m.mtx.Unlock()
h, err := m.hashLabelValues(lvs)
if err != nil {
return false
}
return m.deleteByHashWithLabelValues(h, lvs)
return m.metricMap.deleteByHashWithLabelValues(h, lvs, m.curry)
}
// Delete deletes the metric where the variable labels are the same as those
@ -142,35 +83,190 @@ func (m *metricVec) DeleteLabelValues(lvs ...string) bool {
// This method is used for the same purpose as DeleteLabelValues(...string). See
// there for pros and cons of the two methods.
func (m *metricVec) Delete(labels Labels) bool {
m.mtx.Lock()
defer m.mtx.Unlock()
h, err := m.hashLabels(labels)
if err != nil {
return false
}
return m.deleteByHashWithLabels(h, labels)
return m.metricMap.deleteByHashWithLabels(h, labels, m.curry)
}
func (m *metricVec) curryWith(labels Labels) (*metricVec, error) {
var (
newCurry []curriedLabelValue
oldCurry = m.curry
iCurry int
)
for i, label := range m.desc.variableLabels {
val, ok := labels[label]
if iCurry < len(oldCurry) && oldCurry[iCurry].index == i {
if ok {
return nil, fmt.Errorf("label name %q is already curried", label)
}
newCurry = append(newCurry, oldCurry[iCurry])
iCurry++
} else {
if !ok {
continue // Label stays uncurried.
}
newCurry = append(newCurry, curriedLabelValue{i, val})
}
}
if l := len(oldCurry) + len(labels) - len(newCurry); l > 0 {
return nil, fmt.Errorf("%d unknown label(s) found during currying", l)
}
return &metricVec{
metricMap: m.metricMap,
curry: newCurry,
hashAdd: m.hashAdd,
hashAddByte: m.hashAddByte,
}, nil
}
func (m *metricVec) getMetricWithLabelValues(lvs ...string) (Metric, error) {
h, err := m.hashLabelValues(lvs)
if err != nil {
return nil, err
}
return m.metricMap.getOrCreateMetricWithLabelValues(h, lvs, m.curry), nil
}
func (m *metricVec) getMetricWith(labels Labels) (Metric, error) {
h, err := m.hashLabels(labels)
if err != nil {
return nil, err
}
return m.metricMap.getOrCreateMetricWithLabels(h, labels, m.curry), nil
}
func (m *metricVec) hashLabelValues(vals []string) (uint64, error) {
if err := validateLabelValues(vals, len(m.desc.variableLabels)-len(m.curry)); err != nil {
return 0, err
}
var (
h = hashNew()
curry = m.curry
iVals, iCurry int
)
for i := 0; i < len(m.desc.variableLabels); i++ {
if iCurry < len(curry) && curry[iCurry].index == i {
h = m.hashAdd(h, curry[iCurry].value)
iCurry++
} else {
h = m.hashAdd(h, vals[iVals])
iVals++
}
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
func (m *metricVec) hashLabels(labels Labels) (uint64, error) {
if err := validateValuesInLabels(labels, len(m.desc.variableLabels)-len(m.curry)); err != nil {
return 0, err
}
var (
h = hashNew()
curry = m.curry
iCurry int
)
for i, label := range m.desc.variableLabels {
val, ok := labels[label]
if iCurry < len(curry) && curry[iCurry].index == i {
if ok {
return 0, fmt.Errorf("label name %q is already curried", label)
}
h = m.hashAdd(h, curry[iCurry].value)
iCurry++
} else {
if !ok {
return 0, fmt.Errorf("label name %q missing in label map", label)
}
h = m.hashAdd(h, val)
}
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
// metricWithLabelValues provides the metric and its label values for
// disambiguation on hash collision.
type metricWithLabelValues struct {
values []string
metric Metric
}
// curriedLabelValue sets the curried value for a label at the given index.
type curriedLabelValue struct {
index int
value string
}
// metricMap is a helper for metricVec and shared between differently curried
// metricVecs.
type metricMap struct {
mtx sync.RWMutex // Protects metrics.
metrics map[uint64][]metricWithLabelValues
desc *Desc
newMetric func(labelValues ...string) Metric
}
// Describe implements Collector. It will send exactly one Desc to the provided
// channel.
func (m *metricMap) Describe(ch chan<- *Desc) {
ch <- m.desc
}
// Collect implements Collector.
func (m *metricMap) Collect(ch chan<- Metric) {
m.mtx.RLock()
defer m.mtx.RUnlock()
for _, metrics := range m.metrics {
for _, metric := range metrics {
ch <- metric.metric
}
}
}
// Reset deletes all metrics in this vector.
func (m *metricMap) Reset() {
m.mtx.Lock()
defer m.mtx.Unlock()
for h := range m.metrics {
delete(m.metrics, h)
}
}
// deleteByHashWithLabelValues removes the metric from the hash bucket h. If
// there are multiple matches in the bucket, use lvs to select a metric and
// remove only that metric.
func (m *metricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool {
metrics, ok := m.children[h]
func (m *metricMap) deleteByHashWithLabelValues(
h uint64, lvs []string, curry []curriedLabelValue,
) bool {
m.mtx.Lock()
defer m.mtx.Unlock()
metrics, ok := m.metrics[h]
if !ok {
return false
}
i := m.findMetricWithLabelValues(metrics, lvs)
i := findMetricWithLabelValues(metrics, lvs, curry)
if i >= len(metrics) {
return false
}
if len(metrics) > 1 {
m.children[h] = append(metrics[:i], metrics[i+1:]...)
m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
} else {
delete(m.children, h)
delete(m.metrics, h)
}
return true
}
@ -178,71 +274,35 @@ func (m *metricVec) deleteByHashWithLabelValues(h uint64, lvs []string) bool {
// deleteByHashWithLabels removes the metric from the hash bucket h. If there
// are multiple matches in the bucket, use lvs to select a metric and remove
// only that metric.
func (m *metricVec) deleteByHashWithLabels(h uint64, labels Labels) bool {
metrics, ok := m.children[h]
func (m *metricMap) deleteByHashWithLabels(
h uint64, labels Labels, curry []curriedLabelValue,
) bool {
metrics, ok := m.metrics[h]
if !ok {
return false
}
i := m.findMetricWithLabels(metrics, labels)
i := findMetricWithLabels(m.desc, metrics, labels, curry)
if i >= len(metrics) {
return false
}
if len(metrics) > 1 {
m.children[h] = append(metrics[:i], metrics[i+1:]...)
m.metrics[h] = append(metrics[:i], metrics[i+1:]...)
} else {
delete(m.children, h)
delete(m.metrics, h)
}
return true
}
// Reset deletes all metrics in this vector.
func (m *metricVec) Reset() {
m.mtx.Lock()
defer m.mtx.Unlock()
for h := range m.children {
delete(m.children, h)
}
}
func (m *metricVec) hashLabelValues(vals []string) (uint64, error) {
if err := validateLabelValues(vals, len(m.desc.variableLabels)); err != nil {
return 0, err
}
h := hashNew()
for _, val := range vals {
h = m.hashAdd(h, val)
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
func (m *metricVec) hashLabels(labels Labels) (uint64, error) {
if err := validateValuesInLabels(labels, len(m.desc.variableLabels)); err != nil {
return 0, err
}
h := hashNew()
for _, label := range m.desc.variableLabels {
val, ok := labels[label]
if !ok {
return 0, fmt.Errorf("label name %q missing in label map", label)
}
h = m.hashAdd(h, val)
h = m.hashAddByte(h, model.SeparatorByte)
}
return h, nil
}
// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
// or creates it and returns the new one.
//
// This function holds the mutex.
func (m *metricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string) Metric {
func (m *metricMap) getOrCreateMetricWithLabelValues(
hash uint64, lvs []string, curry []curriedLabelValue,
) Metric {
m.mtx.RLock()
metric, ok := m.getMetricWithHashAndLabelValues(hash, lvs)
metric, ok := m.getMetricWithHashAndLabelValues(hash, lvs, curry)
m.mtx.RUnlock()
if ok {
return metric
@ -250,13 +310,11 @@ func (m *metricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string)
m.mtx.Lock()
defer m.mtx.Unlock()
metric, ok = m.getMetricWithHashAndLabelValues(hash, lvs)
metric, ok = m.getMetricWithHashAndLabelValues(hash, lvs, curry)
if !ok {
// Copy to avoid allocation in case wo don't go down this code path.
copiedLVs := make([]string, len(lvs))
copy(copiedLVs, lvs)
metric = m.newMetric(copiedLVs...)
m.children[hash] = append(m.children[hash], metricWithLabelValues{values: copiedLVs, metric: metric})
inlinedLVs := inlineLabelValues(lvs, curry)
metric = m.newMetric(inlinedLVs...)
m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: inlinedLVs, metric: metric})
}
return metric
}
@ -265,9 +323,11 @@ func (m *metricVec) getOrCreateMetricWithLabelValues(hash uint64, lvs []string)
// or creates it and returns the new one.
//
// This function holds the mutex.
func (m *metricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metric {
func (m *metricMap) getOrCreateMetricWithLabels(
hash uint64, labels Labels, curry []curriedLabelValue,
) Metric {
m.mtx.RLock()
metric, ok := m.getMetricWithHashAndLabels(hash, labels)
metric, ok := m.getMetricWithHashAndLabels(hash, labels, curry)
m.mtx.RUnlock()
if ok {
return metric
@ -275,21 +335,23 @@ func (m *metricVec) getOrCreateMetricWithLabels(hash uint64, labels Labels) Metr
m.mtx.Lock()
defer m.mtx.Unlock()
metric, ok = m.getMetricWithHashAndLabels(hash, labels)
metric, ok = m.getMetricWithHashAndLabels(hash, labels, curry)
if !ok {
lvs := m.extractLabelValues(labels)
lvs := extractLabelValues(m.desc, labels, curry)
metric = m.newMetric(lvs...)
m.children[hash] = append(m.children[hash], metricWithLabelValues{values: lvs, metric: metric})
m.metrics[hash] = append(m.metrics[hash], metricWithLabelValues{values: lvs, metric: metric})
}
return metric
}
// getMetricWithHashAndLabelValues gets a metric while handling possible
// collisions in the hash space. Must be called while holding the read mutex.
func (m *metricVec) getMetricWithHashAndLabelValues(h uint64, lvs []string) (Metric, bool) {
metrics, ok := m.children[h]
func (m *metricMap) getMetricWithHashAndLabelValues(
h uint64, lvs []string, curry []curriedLabelValue,
) (Metric, bool) {
metrics, ok := m.metrics[h]
if ok {
if i := m.findMetricWithLabelValues(metrics, lvs); i < len(metrics) {
if i := findMetricWithLabelValues(metrics, lvs, curry); i < len(metrics) {
return metrics[i].metric, true
}
}
@ -298,10 +360,12 @@ func (m *metricVec) getMetricWithHashAndLabelValues(h uint64, lvs []string) (Met
// getMetricWithHashAndLabels gets a metric while handling possible collisions in
// the hash space. Must be called while holding read mutex.
func (m *metricVec) getMetricWithHashAndLabels(h uint64, labels Labels) (Metric, bool) {
metrics, ok := m.children[h]
func (m *metricMap) getMetricWithHashAndLabels(
h uint64, labels Labels, curry []curriedLabelValue,
) (Metric, bool) {
metrics, ok := m.metrics[h]
if ok {
if i := m.findMetricWithLabels(metrics, labels); i < len(metrics) {
if i := findMetricWithLabels(m.desc, metrics, labels, curry); i < len(metrics) {
return metrics[i].metric, true
}
}
@ -310,9 +374,11 @@ func (m *metricVec) getMetricWithHashAndLabels(h uint64, labels Labels) (Metric,
// findMetricWithLabelValues returns the index of the matching metric or
// len(metrics) if not found.
func (m *metricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, lvs []string) int {
func findMetricWithLabelValues(
metrics []metricWithLabelValues, lvs []string, curry []curriedLabelValue,
) int {
for i, metric := range metrics {
if m.matchLabelValues(metric.values, lvs) {
if matchLabelValues(metric.values, lvs, curry) {
return i
}
}
@ -321,32 +387,51 @@ func (m *metricVec) findMetricWithLabelValues(metrics []metricWithLabelValues, l
// findMetricWithLabels returns the index of the matching metric or len(metrics)
// if not found.
func (m *metricVec) findMetricWithLabels(metrics []metricWithLabelValues, labels Labels) int {
func findMetricWithLabels(
desc *Desc, metrics []metricWithLabelValues, labels Labels, curry []curriedLabelValue,
) int {
for i, metric := range metrics {
if m.matchLabels(metric.values, labels) {
if matchLabels(desc, metric.values, labels, curry) {
return i
}
}
return len(metrics)
}
func (m *metricVec) matchLabelValues(values []string, lvs []string) bool {
if len(values) != len(lvs) {
func matchLabelValues(values []string, lvs []string, curry []curriedLabelValue) bool {
if len(values) != len(lvs)+len(curry) {
return false
}
var iLVs, iCurry int
for i, v := range values {
if v != lvs[i] {
if iCurry < len(curry) && curry[iCurry].index == i {
if v != curry[iCurry].value {
return false
}
iCurry++
continue
}
if v != lvs[iLVs] {
return false
}
iLVs++
}
return true
}
func (m *metricVec) matchLabels(values []string, labels Labels) bool {
if len(labels) != len(values) {
func matchLabels(desc *Desc, values []string, labels Labels, curry []curriedLabelValue) bool {
if len(values) != len(labels)+len(curry) {
return false
}
for i, k := range m.desc.variableLabels {
iCurry := 0
for i, k := range desc.variableLabels {
if iCurry < len(curry) && curry[iCurry].index == i {
if values[i] != curry[iCurry].value {
return false
}
iCurry++
continue
}
if values[i] != labels[k] {
return false
}
@ -354,10 +439,31 @@ func (m *metricVec) matchLabels(values []string, labels Labels) bool {
return true
}
func (m *metricVec) extractLabelValues(labels Labels) []string {
labelValues := make([]string, len(labels))
for i, k := range m.desc.variableLabels {
func extractLabelValues(desc *Desc, labels Labels, curry []curriedLabelValue) []string {
labelValues := make([]string, len(labels)+len(curry))
iCurry := 0
for i, k := range desc.variableLabels {
if iCurry < len(curry) && curry[iCurry].index == i {
labelValues[i] = curry[iCurry].value
iCurry++
continue
}
labelValues[i] = labels[k]
}
return labelValues
}
func inlineLabelValues(lvs []string, curry []curriedLabelValue) []string {
labelValues := make([]string, len(lvs)+len(curry))
var iCurry, iLVs int
for i := range labelValues {
if iCurry < len(curry) && curry[iCurry].index == i {
labelValues[i] = curry[iCurry].value
iCurry++
continue
}
labelValues[i] = lvs[iLVs]
iLVs++
}
return labelValues
}

227
prometheus/vec_test.go
View File

@ -166,7 +166,7 @@ func testMetricVec(t *testing.T, vec *GaugeVec) {
}
var total int
for _, metrics := range vec.children {
for _, metrics := range vec.metricMap.metrics {
for _, metric := range metrics {
total++
copy(pair[:], metric.values)
@ -201,7 +201,7 @@ func testMetricVec(t *testing.T, vec *GaugeVec) {
vec.Reset()
if len(vec.children) > 0 {
if len(vec.metricMap.metrics) > 0 {
t.Fatalf("reset failed")
}
}
@ -239,6 +239,229 @@ func TestCounterVecEndToEndWithCollision(t *testing.T) {
}
}
func TestCurryVec(t *testing.T) {
vec := NewCounterVec(
CounterOpts{
Name: "test",
Help: "helpless",
},
[]string{"one", "two", "three"},
)
testCurryVec(t, vec)
}
func TestCurryVecWithCollisions(t *testing.T) {
vec := NewCounterVec(
CounterOpts{
Name: "test",
Help: "helpless",
},
[]string{"one", "two", "three"},
)
vec.hashAdd = func(h uint64, s string) uint64 { return 1 }
vec.hashAddByte = func(h uint64, b byte) uint64 { return 1 }
testCurryVec(t, vec)
}
func testCurryVec(t *testing.T, vec *CounterVec) {
assertMetrics := func(t *testing.T) {
n := 0
for _, m := range vec.metricMap.metrics {
n += len(m)
}
if n != 2 {
t.Error("expected two metrics, got", n)
}
m := &dto.Metric{}
c1, err := vec.GetMetricWithLabelValues("1", "2", "3")
if err != nil {
t.Fatal("unexpected error getting metric:", err)
}
c1.Write(m)
if want, got := 1., m.GetCounter().GetValue(); want != got {
t.Errorf("want %f as counter value, got %f", want, got)
}
m.Reset()
c2, err := vec.GetMetricWithLabelValues("11", "22", "33")
if err != nil {
t.Fatal("unexpected error getting metric:", err)
}
c2.Write(m)
if want, got := 1., m.GetCounter().GetValue(); want != got {
t.Errorf("want %f as counter value, got %f", want, got)
}
}
assertNoMetric := func(t *testing.T) {
if n := len(vec.metricMap.metrics); n != 0 {
t.Error("expected no metrics, got", n)
}
}
t.Run("zero labels", func(t *testing.T) {
c1 := vec.MustCurryWith(nil)
c2 := vec.MustCurryWith(nil)
c1.WithLabelValues("1", "2", "3").Inc()
c2.With(Labels{"one": "11", "two": "22", "three": "33"}).Inc()
assertMetrics(t)
if !c1.Delete(Labels{"one": "1", "two": "2", "three": "3"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("11", "22", "33") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("first label", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"one": "1"})
c2 := vec.MustCurryWith(Labels{"one": "11"})
c1.WithLabelValues("2", "3").Inc()
c2.With(Labels{"two": "22", "three": "33"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"two": "22", "three": "33"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("2", "3") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"two": "2", "three": "3"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("22", "33") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("middle label", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"two": "2"})
c2 := vec.MustCurryWith(Labels{"two": "22"})
c1.WithLabelValues("1", "3").Inc()
c2.With(Labels{"one": "11", "three": "33"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"one": "11", "three": "33"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("1", "3") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"one": "1", "three": "3"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("11", "33") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("last label", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3"})
c2 := vec.MustCurryWith(Labels{"three": "33"})
c1.WithLabelValues("1", "2").Inc()
c2.With(Labels{"one": "11", "two": "22"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"two": "22", "one": "11"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("1", "2") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"two": "2", "one": "1"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("11", "22") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("two labels", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3", "one": "1"})
c2 := vec.MustCurryWith(Labels{"three": "33", "one": "11"})
c1.WithLabelValues("2").Inc()
c2.With(Labels{"two": "22"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"two": "22"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("2") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"two": "2"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("22") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("all labels", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3", "two": "2", "one": "1"})
c2 := vec.MustCurryWith(Labels{"three": "33", "one": "11", "two": "22"})
c1.WithLabelValues().Inc()
c2.With(nil).Inc()
assertMetrics(t)
if !c1.Delete(Labels{}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues() {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("double curry", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3"}).MustCurryWith(Labels{"one": "1"})
c2 := vec.MustCurryWith(Labels{"three": "33"}).MustCurryWith(Labels{"one": "11"})
c1.WithLabelValues("2").Inc()
c2.With(Labels{"two": "22"}).Inc()
assertMetrics(t)
if c1.Delete(Labels{"two": "22"}) {
t.Error("deletion unexpectedly succeeded")
}
if c2.DeleteLabelValues("2") {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"two": "2"}) {
t.Error("deletion failed")
}
if !c2.DeleteLabelValues("22") {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("use already curried label", func(t *testing.T) {
c1 := vec.MustCurryWith(Labels{"three": "3"})
if _, err := c1.GetMetricWithLabelValues("1", "2", "3"); err == nil {
t.Error("expected error when using already curried label")
}
if _, err := c1.GetMetricWith(Labels{"one": "1", "two": "2", "three": "3"}); err == nil {
t.Error("expected error when using already curried label")
}
assertNoMetric(t)
c1.WithLabelValues("1", "2").Inc()
if c1.Delete(Labels{"one": "1", "two": "2", "three": "3"}) {
t.Error("deletion unexpectedly succeeded")
}
if !c1.Delete(Labels{"one": "1", "two": "2"}) {
t.Error("deletion failed")
}
assertNoMetric(t)
})
t.Run("curry already curried label", func(t *testing.T) {
if _, err := vec.MustCurryWith(Labels{"three": "3"}).CurryWith(Labels{"three": "33"}); err == nil {
t.Error("currying unexpectedly succeeded")
} else if err.Error() != `label name "three" is already curried` {
t.Error("currying returned unexpected error:", err)
}
})
t.Run("unknown label", func(t *testing.T) {
if _, err := vec.CurryWith(Labels{"foo": "bar"}); err == nil {
t.Error("currying unexpectedly succeeded")
} else if err.Error() != "1 unknown label(s) found during currying" {
t.Error("currying returned unexpected error:", err)
}
})
}
func BenchmarkMetricVecWithLabelValuesBasic(b *testing.B) {
benchmarkMetricVecWithLabelValues(b, map[string][]string{
"l1": {"onevalue"},