Test and support 1.19 (#1160)

* Add new Go 1.19 metrics

Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>

* Format files with the latest formatter

Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>

Signed-off-by: Kemal Akkoyun <kakkoyun@gmail.com>

.circleci/config.yml

@@ -54,6 +54,10 @@ workflows:
           name: go-1-18
           go_version: "1.18"
           run_lint: true
+      - test:
+          name: go-1-19
+          go_version: "1.19"
+          run_lint: true
           # Style and unused/missing packages are only checked against
           # the latest supported Go version.
           run_style_and_unused: true

api/prometheus/v1/api.go

@@ -335,6 +335,7 @@ type RuleGroup struct {
 // that rules are returned in by the API.
 //
 // Rule types can be determined using a type switch:
+//
 //	switch v := rule.(type) {
 //	case RecordingRule:
 //		fmt.Print("got a recording rule")

prometheus/counter.go

@@ -246,6 +246,7 @@ func (v *CounterVec) GetMetricWith(labels Labels) (Counter, error) {
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
 // GetMetricWithLabelValues would have returned an error. Not returning an
 // error allows shortcuts like
+//
 //	myVec.WithLabelValues("404", "GET").Add(42)
 func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
 	c, err := v.GetMetricWithLabelValues(lvs...)
@@ -257,6 +258,7 @@ func (v *CounterVec) WithLabelValues(lvs ...string) Counter {
 
 // 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"}).Add(42)
 func (v *CounterVec) With(labels Labels) Counter {
 	c, err := v.GetMetricWith(labels)

prometheus/doc.go

@@ -21,7 +21,7 @@
 // All exported functions and methods are safe to be used concurrently unless
 // specified otherwise.
 //
-// A Basic Example
+// # A Basic Example
 //
 // As a starting point, a very basic usage example:
 //
@@ -75,13 +75,12 @@
 //		log.Fatal(http.ListenAndServe(":8080", nil))
 //	}
 //
-//
 // This is a complete program that exports two metrics, a Gauge and a Counter,
 // the latter with a label attached to turn it into a (one-dimensional) vector.
 // It register the metrics using a custom registry and exposes them via an HTTP server
 // on the /metrics endpoint.
 //
-// Metrics
+// # Metrics
 //
 // The number of exported identifiers in this package might appear a bit
 // overwhelming. However, in addition to the basic plumbing shown in the example
@@ -112,7 +111,7 @@
 // To create instances of Metrics and their vector versions, you need a suitable
 // …Opts struct, i.e. GaugeOpts, CounterOpts, SummaryOpts, or HistogramOpts.
 //
-// Custom Collectors and constant Metrics
+// # Custom Collectors and constant Metrics
 //
 // While you could create your own implementations of Metric, most likely you
 // will only ever implement the Collector interface on your own. At a first
@@ -153,7 +152,7 @@
 // a metric, GaugeFunc, CounterFunc, or UntypedFunc might be interesting
 // shortcuts.
 //
-// Advanced Uses of the Registry
+// # Advanced Uses of the Registry
 //
 // While MustRegister is the by far most common way of registering a Collector,
 // sometimes you might want to handle the errors the registration might cause.
@@ -188,23 +187,23 @@
 // NewProcessCollector). With a custom registry, you are in control and decide
 // yourself about the Collectors to register.
 //
-// HTTP Exposition
+// # HTTP Exposition
 //
 // The Registry implements the Gatherer interface. The caller of the Gather
 // method can then expose the gathered metrics in some way. Usually, the metrics
 // are served via HTTP on the /metrics endpoint. That's happening in the example
 // above. The tools to expose metrics via HTTP are in the promhttp sub-package.
 //
-// Pushing to the Pushgateway
+// # Pushing to the Pushgateway
 //
 // Function for pushing to the Pushgateway can be found in the push sub-package.
 //
-// Graphite Bridge
+// # Graphite Bridge
 //
 // Functions and examples to push metrics from a Gatherer to Graphite can be
 // found in the graphite sub-package.
 //
-// Other Means of Exposition
+// # Other Means of Exposition
 //
 // More ways of exposing metrics can easily be added by following the approaches
 // of the existing implementations.

prometheus/gauge.go

@@ -210,6 +210,7 @@ func (v *GaugeVec) GetMetricWith(labels Labels) (Gauge, error) {
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
 // GetMetricWithLabelValues would have returned an error. Not returning an
 // error allows shortcuts like
+//
 //	myVec.WithLabelValues("404", "GET").Add(42)
 func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
 	g, err := v.GetMetricWithLabelValues(lvs...)
@@ -221,6 +222,7 @@ func (v *GaugeVec) WithLabelValues(lvs ...string) Gauge {
 
 // 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"}).Add(42)
 func (v *GaugeVec) With(labels Labels) Gauge {
 	g, err := v.GetMetricWith(labels)

prometheus/internal/difflib.go

@@ -201,9 +201,12 @@ func (m *SequenceMatcher) isBJunk(s string) bool {
 // If IsJunk is not defined:
 //
 // Return (i,j,k) such that a[i:i+k] is equal to b[j:j+k], where
+//
 //	alo <= i <= i+k <= ahi
 //	blo <= j <= j+k <= bhi
+//
 // and for all (i',j',k') meeting those conditions,
+//
 //	k >= k'
 //	i <= i'
 //	and if i == i', j <= j'

prometheus/labels.go

@@ -25,6 +25,7 @@ import (
 // Labels represents a collection of label name -> value mappings. This type is
 // commonly used with the With(Labels) and GetMetricWith(Labels) methods of
 // metric vector Collectors, e.g.:
+//
 //	myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
 //
 // The other use-case is the specification of constant label pairs in Opts or to

prometheus/summary.go

@@ -603,6 +603,7 @@ func (v *SummaryVec) GetMetricWith(labels Labels) (Observer, error) {
 // WithLabelValues works as GetMetricWithLabelValues, but panics where
 // GetMetricWithLabelValues would have returned an error. Not returning an
 // error allows shortcuts like
+//
 //	myVec.WithLabelValues("404", "GET").Observe(42.21)
 func (v *SummaryVec) WithLabelValues(lvs ...string) Observer {
 	s, err := v.GetMetricWithLabelValues(lvs...)
@@ -614,6 +615,7 @@ func (v *SummaryVec) WithLabelValues(lvs ...string) 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 *SummaryVec) With(labels Labels) Observer {
 	s, err := v.GetMetricWith(labels)
@@ -701,6 +703,7 @@ func (s *constSummary) Write(out *dto.Metric) error {
 //
 // quantiles maps ranks to quantile values. For example, a median latency of
 // 0.23s and a 99th percentile latency of 0.56s would be expressed as:
+//
 //	map[float64]float64{0.5: 0.23, 0.99: 0.56}
 //
 // NewConstSummary returns an error if the length of labelValues is not

prometheus/timer.go

@@ -25,6 +25,7 @@ type Timer struct {
 // NewTimer creates a new Timer. The provided Observer is used to observe a
 // duration in seconds. Timer is usually used to time a function call in the
 // following way:
+//
 //	func TimeMe() {
 //	    timer := NewTimer(myHistogram)
 //	    defer timer.ObserveDuration()