Modernize invertergui: MQTT write support, HA integration, UI updates

vendor/github.com/prometheus/client_golang/NOTICE

@@ -16,8 +16,3 @@ Go support for Protocol Buffers - Google's data interchange format
 http://github.com/golang/protobuf/
 Copyright 2010 The Go Authors
 See source code for license details.
-
-Support for streaming Protocol Buffer messages for the Go language (golang).
-https://github.com/matttproud/golang_protobuf_extensions
-Copyright 2013 Matt T. Proud
-Licensed under the Apache License, Version 2.0

vendor/github.com/prometheus/client_golang/prometheus/desc.go

@@ -95,7 +95,8 @@ func (v2) NewDesc(fqName, help string, variableLabels ConstrainableLabels, const
 		help:           help,
 		variableLabels: variableLabels.compile(),
 	}
-	if !model.IsValidMetricName(model.LabelValue(fqName)) {
+	//nolint:staticcheck // TODO: Don't use deprecated model.NameValidationScheme.
+	if !model.NameValidationScheme.IsValidMetricName(fqName) {
 		d.err = fmt.Errorf("%q is not a valid metric name", fqName)
 		return d
 	}
@@ -189,12 +190,15 @@ func (d *Desc) String() string {
 			fmt.Sprintf("%s=%q", lp.GetName(), lp.GetValue()),
 		)
 	}
-	vlStrings := make([]string, 0, len(d.variableLabels.names))
-	for _, vl := range d.variableLabels.names {
-		if fn, ok := d.variableLabels.labelConstraints[vl]; ok && fn != nil {
-			vlStrings = append(vlStrings, fmt.Sprintf("c(%s)", vl))
-		} else {
-			vlStrings = append(vlStrings, vl)
+	vlStrings := []string{}
+	if d.variableLabels != nil {
+		vlStrings = make([]string, 0, len(d.variableLabels.names))
+		for _, vl := range d.variableLabels.names {
+			if fn, ok := d.variableLabels.labelConstraints[vl]; ok && fn != nil {
+				vlStrings = append(vlStrings, fmt.Sprintf("c(%s)", vl))
+			} else {
+				vlStrings = append(vlStrings, vl)
+			}
 		}
 	}
 	return fmt.Sprintf(

vendor/github.com/prometheus/client_golang/prometheus/go_collector.go

@@ -22,13 +22,13 @@ import (
 // goRuntimeMemStats provides the metrics initially provided by runtime.ReadMemStats.
 // From Go 1.17 those similar (and better) statistics are provided by runtime/metrics, so
 // while eval closure works on runtime.MemStats, the struct from Go 1.17+ is
-// populated using runtime/metrics.
+// populated using runtime/metrics. Those are the defaults we can't alter.
 func goRuntimeMemStats() memStatsMetrics {
 	return memStatsMetrics{
 		{
 			desc: NewDesc(
 				memstatNamespace("alloc_bytes"),
-				"Number of bytes allocated and still in use.",
+				"Number of bytes allocated in heap and currently in use. Equals to /memory/classes/heap/objects:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Alloc) },
@@ -36,7 +36,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("alloc_bytes_total"),
-				"Total number of bytes allocated, even if freed.",
+				"Total number of bytes allocated in heap until now, even if released already. Equals to /gc/heap/allocs:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.TotalAlloc) },
@@ -44,23 +44,16 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("sys_bytes"),
-				"Number of bytes obtained from system.",
+				"Number of bytes obtained from system. Equals to /memory/classes/total:byte.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Sys) },
 			valType: GaugeValue,
-		}, {
-			desc: NewDesc(
-				memstatNamespace("lookups_total"),
-				"Total number of pointer lookups.",
-				nil, nil,
-			),
-			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Lookups) },
-			valType: CounterValue,
 		}, {
 			desc: NewDesc(
 				memstatNamespace("mallocs_total"),
-				"Total number of mallocs.",
+				// TODO(bwplotka): We could add go_memstats_heap_objects, probably useful for discovery. Let's gather more feedback, kind of a waste of bytes for everybody for compatibility reasons to keep both, and we can't really rename/remove useful metric.
+				"Total number of heap objects allocated, both live and gc-ed. Semantically a counter version for go_memstats_heap_objects gauge. Equals to /gc/heap/allocs:objects + /gc/heap/tiny/allocs:objects.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Mallocs) },
@@ -68,7 +61,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("frees_total"),
-				"Total number of frees.",
+				"Total number of heap objects frees. Equals to /gc/heap/frees:objects + /gc/heap/tiny/allocs:objects.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.Frees) },
@@ -76,7 +69,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("heap_alloc_bytes"),
-				"Number of heap bytes allocated and still in use.",
+				"Number of heap bytes allocated and currently in use, same as go_memstats_alloc_bytes. Equals to /memory/classes/heap/objects:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapAlloc) },
@@ -84,7 +77,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("heap_sys_bytes"),
-				"Number of heap bytes obtained from system.",
+				"Number of heap bytes obtained from system. Equals to /memory/classes/heap/objects:bytes + /memory/classes/heap/unused:bytes + /memory/classes/heap/released:bytes + /memory/classes/heap/free:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapSys) },
@@ -92,7 +85,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("heap_idle_bytes"),
-				"Number of heap bytes waiting to be used.",
+				"Number of heap bytes waiting to be used. Equals to /memory/classes/heap/released:bytes + /memory/classes/heap/free:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapIdle) },
@@ -100,7 +93,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("heap_inuse_bytes"),
-				"Number of heap bytes that are in use.",
+				"Number of heap bytes that are in use. Equals to /memory/classes/heap/objects:bytes + /memory/classes/heap/unused:bytes",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapInuse) },
@@ -108,7 +101,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("heap_released_bytes"),
-				"Number of heap bytes released to OS.",
+				"Number of heap bytes released to OS. Equals to /memory/classes/heap/released:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapReleased) },
@@ -116,7 +109,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("heap_objects"),
-				"Number of allocated objects.",
+				"Number of currently allocated objects. Equals to /gc/heap/objects:objects.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.HeapObjects) },
@@ -124,7 +117,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("stack_inuse_bytes"),
-				"Number of bytes in use by the stack allocator.",
+				"Number of bytes obtained from system for stack allocator in non-CGO environments. Equals to /memory/classes/heap/stacks:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackInuse) },
@@ -132,7 +125,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("stack_sys_bytes"),
-				"Number of bytes obtained from system for stack allocator.",
+				"Number of bytes obtained from system for stack allocator. Equals to /memory/classes/heap/stacks:bytes + /memory/classes/os-stacks:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.StackSys) },
@@ -140,7 +133,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("mspan_inuse_bytes"),
-				"Number of bytes in use by mspan structures.",
+				"Number of bytes in use by mspan structures. Equals to /memory/classes/metadata/mspan/inuse:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanInuse) },
@@ -148,7 +141,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("mspan_sys_bytes"),
-				"Number of bytes used for mspan structures obtained from system.",
+				"Number of bytes used for mspan structures obtained from system. Equals to /memory/classes/metadata/mspan/inuse:bytes + /memory/classes/metadata/mspan/free:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MSpanSys) },
@@ -156,7 +149,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("mcache_inuse_bytes"),
-				"Number of bytes in use by mcache structures.",
+				"Number of bytes in use by mcache structures. Equals to /memory/classes/metadata/mcache/inuse:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheInuse) },
@@ -164,7 +157,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("mcache_sys_bytes"),
-				"Number of bytes used for mcache structures obtained from system.",
+				"Number of bytes used for mcache structures obtained from system. Equals to /memory/classes/metadata/mcache/inuse:bytes + /memory/classes/metadata/mcache/free:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.MCacheSys) },
@@ -172,7 +165,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("buck_hash_sys_bytes"),
-				"Number of bytes used by the profiling bucket hash table.",
+				"Number of bytes used by the profiling bucket hash table. Equals to /memory/classes/profiling/buckets:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.BuckHashSys) },
@@ -180,7 +173,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("gc_sys_bytes"),
-				"Number of bytes used for garbage collection system metadata.",
+				"Number of bytes used for garbage collection system metadata. Equals to /memory/classes/metadata/other:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.GCSys) },
@@ -188,7 +181,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("other_sys_bytes"),
-				"Number of bytes used for other system allocations.",
+				"Number of bytes used for other system allocations. Equals to /memory/classes/other:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.OtherSys) },
@@ -196,7 +189,7 @@ func goRuntimeMemStats() memStatsMetrics {
 		}, {
 			desc: NewDesc(
 				memstatNamespace("next_gc_bytes"),
-				"Number of heap bytes when next garbage collection will take place.",
+				"Number of heap bytes when next garbage collection will take place. Equals to /gc/heap/goal:bytes.",
 				nil, nil,
 			),
 			eval:    func(ms *runtime.MemStats) float64 { return float64(ms.NextGC) },
@@ -225,7 +218,7 @@ func newBaseGoCollector() baseGoCollector {
 			nil, nil),
 		gcDesc: NewDesc(
 			"go_gc_duration_seconds",
-			"A summary of the pause duration of garbage collection cycles.",
+			"A summary of the wall-time pause (stop-the-world) duration in garbage collection cycles.",
 			nil, nil),
 		gcLastTimeDesc: NewDesc(
 			"go_memstats_last_gc_time_seconds",

vendor/github.com/prometheus/client_golang/prometheus/go_collector_latest.go

@@ -17,6 +17,7 @@
 package prometheus
 
 import (
+	"fmt"
 	"math"
 	"runtime"
 	"runtime/metrics"
@@ -153,7 +154,8 @@ func defaultGoCollectorOptions() internal.GoCollectorOptions {
 			"/gc/heap/frees-by-size:bytes":  goGCHeapFreesBytes,
 		},
 		RuntimeMetricRules: []internal.GoCollectorRule{
-			//{Matcher: regexp.MustCompile("")},
+			// Recommended metrics we want by default from runtime/metrics.
+			{Matcher: internal.GoCollectorDefaultRuntimeMetrics},
 		},
 	}
 }
@@ -203,6 +205,7 @@ func NewGoCollector(opts ...func(o *internal.GoCollectorOptions)) Collector {
 			// to fail here. This condition is tested in TestExpectedRuntimeMetrics.
 			continue
 		}
+		help := attachOriginalName(d.Description.Description, d.Name)
 
 		sampleBuf = append(sampleBuf, metrics.Sample{Name: d.Name})
 		sampleMap[d.Name] = &sampleBuf[len(sampleBuf)-1]
@@ -214,7 +217,7 @@ func NewGoCollector(opts ...func(o *internal.GoCollectorOptions)) Collector {
 			m = newBatchHistogram(
 				NewDesc(
 					BuildFQName(namespace, subsystem, name),
-					d.Description.Description,
+					help,
 					nil,
 					nil,
 				),
@@ -226,7 +229,7 @@ func NewGoCollector(opts ...func(o *internal.GoCollectorOptions)) Collector {
 				Namespace: namespace,
 				Subsystem: subsystem,
 				Name:      name,
-				Help:      d.Description.Description,
+				Help:      help,
 			},
 			)
 		} else {
@@ -234,7 +237,7 @@ func NewGoCollector(opts ...func(o *internal.GoCollectorOptions)) Collector {
 				Namespace: namespace,
 				Subsystem: subsystem,
 				Name:      name,
-				Help:      d.Description.Description,
+				Help:      help,
 			})
 		}
 		metricSet = append(metricSet, m)
@@ -284,6 +287,10 @@ func NewGoCollector(opts ...func(o *internal.GoCollectorOptions)) Collector {
 	}
 }
 
+func attachOriginalName(desc, origName string) string {
+	return fmt.Sprintf("%s Sourced from %s.", desc, origName)
+}
+
 // Describe returns all descriptions of the collector.
 func (c *goCollector) Describe(ch chan<- *Desc) {
 	c.base.Describe(ch)
@@ -376,13 +383,13 @@ func unwrapScalarRMValue(v metrics.Value) float64 {
 		//
 		// This should never happen because we always populate our metric
 		// set from the runtime/metrics package.
-		panic("unexpected unsupported metric")
+		panic("unexpected bad kind metric")
 	default:
 		// Unsupported metric kind.
 		//
 		// This should never happen because we check for this during initialization
 		// and flag and filter metrics whose kinds we don't understand.
-		panic("unexpected unsupported metric kind")
+		panic(fmt.Sprintf("unexpected unsupported metric: %v", v.Kind()))
 	}
 }
 

vendor/github.com/prometheus/client_golang/prometheus/histogram.go

@@ -14,6 +14,7 @@
 package prometheus
 
 import (
+	"errors"
 	"fmt"
 	"math"
 	"runtime"
@@ -28,6 +29,11 @@ import (
 	"google.golang.org/protobuf/types/known/timestamppb"
 )
 
+const (
+	nativeHistogramSchemaMaximum = 8
+	nativeHistogramSchemaMinimum = -4
+)
+
 // nativeHistogramBounds for the frac of observed values. Only relevant for
 // schema > 0. The position in the slice is the schema. (0 is never used, just
 // here for convenience of using the schema directly as the index.)
@@ -330,11 +336,11 @@ func ExponentialBuckets(start, factor float64, count int) []float64 {
 // used for the Buckets field of HistogramOpts.
 //
 // The function panics if 'count' is 0 or negative, if 'min' is 0 or negative.
-func ExponentialBucketsRange(min, max float64, count int) []float64 {
+func ExponentialBucketsRange(minBucket, maxBucket float64, count int) []float64 {
 	if count < 1 {
 		panic("ExponentialBucketsRange count needs a positive count")
 	}
-	if min <= 0 {
+	if minBucket <= 0 {
 		panic("ExponentialBucketsRange min needs to be greater than 0")
 	}
 
@@ -342,12 +348,12 @@ func ExponentialBucketsRange(min, max float64, count int) []float64 {
 	// max = min*growthFactor^(bucketCount-1)
 
 	// We know max/min and highest bucket. Solve for growthFactor.
-	growthFactor := math.Pow(max/min, 1.0/float64(count-1))
+	growthFactor := math.Pow(maxBucket/minBucket, 1.0/float64(count-1))
 
 	// Now that we know growthFactor, solve for each bucket.
 	buckets := make([]float64, count)
 	for i := 1; i <= count; i++ {
-		buckets[i-1] = min * math.Pow(growthFactor, float64(i-1))
+		buckets[i-1] = minBucket * math.Pow(growthFactor, float64(i-1))
 	}
 	return buckets
 }
@@ -440,7 +446,7 @@ type HistogramOpts struct {
 	// constant (or any negative float value).
 	NativeHistogramZeroThreshold float64
 
-	// The remaining fields define a strategy to limit the number of
+	// The next three fields define a strategy to limit the number of
 	// populated sparse buckets. If NativeHistogramMaxBucketNumber is left
 	// at zero, the number of buckets is not limited. (Note that this might
 	// lead to unbounded memory consumption if the values observed by the
@@ -473,6 +479,22 @@ type HistogramOpts struct {
 	NativeHistogramMinResetDuration time.Duration
 	NativeHistogramMaxZeroThreshold float64
 
+	// NativeHistogramMaxExemplars limits the number of exemplars
+	// that are kept in memory for each native histogram. If you leave it at
+	// zero, a default value of 10 is used. If no exemplars should be kept specifically
+	// for native histograms, set it to a negative value. (Scrapers can
+	// still use the exemplars exposed for classic buckets, which are managed
+	// independently.)
+	NativeHistogramMaxExemplars int
+	// NativeHistogramExemplarTTL is only checked once
+	// NativeHistogramMaxExemplars is exceeded. In that case, the
+	// oldest exemplar is removed if it is older than NativeHistogramExemplarTTL.
+	// Otherwise, the older exemplar in the pair of exemplars that are closest
+	// together (on an exponential scale) is removed.
+	// If NativeHistogramExemplarTTL is left at its zero value, a default value of
+	// 5m is used. To always delete the oldest exemplar, set it to a negative value.
+	NativeHistogramExemplarTTL time.Duration
+
 	// now is for testing purposes, by default it's time.Now.
 	now func() time.Time
 
@@ -532,6 +554,7 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 	if opts.afterFunc == nil {
 		opts.afterFunc = time.AfterFunc
 	}
+
 	h := &histogram{
 		desc:                            desc,
 		upperBounds:                     opts.Buckets,
@@ -556,6 +579,7 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 			h.nativeHistogramZeroThreshold = DefNativeHistogramZeroThreshold
 		} // Leave h.nativeHistogramZeroThreshold at 0 otherwise.
 		h.nativeHistogramSchema = pickSchema(opts.NativeHistogramBucketFactor)
+		h.nativeExemplars = makeNativeExemplars(opts.NativeHistogramExemplarTTL, opts.NativeHistogramMaxExemplars)
 	}
 	for i, upperBound := range h.upperBounds {
 		if i < len(h.upperBounds)-1 {
@@ -725,7 +749,8 @@ type histogram struct {
 	// resetScheduled is protected by mtx. It is true if a reset is
 	// scheduled for a later time (when nativeHistogramMinResetDuration has
 	// passed).
-	resetScheduled bool
+	resetScheduled  bool
+	nativeExemplars nativeExemplars
 
 	// now is for testing purposes, by default it's time.Now.
 	now func() time.Time
@@ -742,6 +767,9 @@ func (h *histogram) Observe(v float64) {
 	h.observe(v, h.findBucket(v))
 }
 
+// ObserveWithExemplar should not be called in a high-frequency setting
+// for a native histogram with configured exemplars. For this case,
+// the implementation isn't lock-free and might suffer from lock contention.
 func (h *histogram) ObserveWithExemplar(v float64, e Labels) {
 	i := h.findBucket(v)
 	h.observe(v, i)
@@ -821,6 +849,13 @@ func (h *histogram) Write(out *dto.Metric) error {
 				Length: proto.Uint32(0),
 			}}
 		}
+
+		if h.nativeExemplars.isEnabled() {
+			h.nativeExemplars.Lock()
+			his.Exemplars = append(his.Exemplars, h.nativeExemplars.exemplars...)
+			h.nativeExemplars.Unlock()
+		}
+
 	}
 	addAndResetCounts(hotCounts, coldCounts)
 	return nil
@@ -829,15 +864,35 @@ func (h *histogram) Write(out *dto.Metric) error {
 // findBucket returns the index of the bucket for the provided value, or
 // len(h.upperBounds) for the +Inf bucket.
 func (h *histogram) findBucket(v float64) int {
-	// TODO(beorn7): For small numbers of buckets (<30), a linear search is
-	// slightly faster than the binary search. If we really care, we could
-	// switch from one search strategy to the other depending on the number
-	// of buckets.
-	//
-	// Microbenchmarks (BenchmarkHistogramNoLabels):
-	// 11 buckets: 38.3 ns/op linear - binary 48.7 ns/op
-	// 100 buckets: 78.1 ns/op linear - binary 54.9 ns/op
-	// 300 buckets: 154 ns/op linear - binary 61.6 ns/op
+	n := len(h.upperBounds)
+	if n == 0 {
+		return 0
+	}
+
+	// Early exit: if v is less than or equal to the first upper bound, return 0
+	if v <= h.upperBounds[0] {
+		return 0
+	}
+
+	// Early exit: if v is greater than the last upper bound, return len(h.upperBounds)
+	if v > h.upperBounds[n-1] {
+		return n
+	}
+
+	// For small arrays, use simple linear search
+	// "magic number" 35 is result of tests on couple different (AWS and baremetal) servers
+	// see more details here: https://github.com/prometheus/client_golang/pull/1662
+	if n < 35 {
+		for i, bound := range h.upperBounds {
+			if v <= bound {
+				return i
+			}
+		}
+		// If v is greater than all upper bounds, return len(h.upperBounds)
+		return n
+	}
+
+	// For larger arrays, use stdlib's binary search
 	return sort.SearchFloat64s(h.upperBounds, v)
 }
 
@@ -1091,8 +1146,10 @@ func (h *histogram) resetCounts(counts *histogramCounts) {
 	deleteSyncMap(&counts.nativeHistogramBucketsPositive)
 }
 
-// updateExemplar replaces the exemplar for the provided bucket. With empty
-// labels, it's a no-op. It panics if any of the labels is invalid.
+// updateExemplar replaces the exemplar for the provided classic bucket.
+// With empty labels, it's a no-op. It panics if any of the labels is invalid.
+// If histogram is native, the exemplar will be cached into nativeExemplars,
+// which has a limit, and will remove one exemplar when limit is reached.
 func (h *histogram) updateExemplar(v float64, bucket int, l Labels) {
 	if l == nil {
 		return
@@ -1102,6 +1159,10 @@ func (h *histogram) updateExemplar(v float64, bucket int, l Labels) {
 		panic(err)
 	}
 	h.exemplars[bucket].Store(e)
+	doSparse := h.nativeHistogramSchema > math.MinInt32 && !math.IsNaN(v)
+	if doSparse {
+		h.nativeExemplars.addExemplar(e)
+	}
 }
 
 // HistogramVec is a Collector that bundles a set of Histograms that all share the
@@ -1336,6 +1397,48 @@ func MustNewConstHistogram(
 	return m
 }
 
+// NewConstHistogramWithCreatedTimestamp does the same thing as NewConstHistogram but sets the created timestamp.
+func NewConstHistogramWithCreatedTimestamp(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	buckets map[float64]uint64,
+	ct time.Time,
+	labelValues ...string,
+) (Metric, error) {
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
+		return nil, err
+	}
+	return &constHistogram{
+		desc:       desc,
+		count:      count,
+		sum:        sum,
+		buckets:    buckets,
+		labelPairs: MakeLabelPairs(desc, labelValues),
+		createdTs:  timestamppb.New(ct),
+	}, nil
+}
+
+// MustNewConstHistogramWithCreatedTimestamp is a version of NewConstHistogramWithCreatedTimestamp that panics where
+// NewConstHistogramWithCreatedTimestamp would have returned an error.
+func MustNewConstHistogramWithCreatedTimestamp(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	buckets map[float64]uint64,
+	ct time.Time,
+	labelValues ...string,
+) Metric {
+	m, err := NewConstHistogramWithCreatedTimestamp(desc, count, sum, buckets, ct, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}
+
 type buckSort []*dto.Bucket
 
 func (s buckSort) Len() int {
@@ -1363,9 +1466,9 @@ func pickSchema(bucketFactor float64) int32 {
 	floor := math.Floor(math.Log2(math.Log2(bucketFactor)))
 	switch {
 	case floor <= -8:
-		return 8
+		return nativeHistogramSchemaMaximum
 	case floor >= 4:
-		return -4
+		return nativeHistogramSchemaMinimum
 	default:
 		return -int32(floor)
 	}
@@ -1575,3 +1678,379 @@ func addAndResetCounts(hot, cold *histogramCounts) {
 	atomic.AddUint64(&hot.nativeHistogramZeroBucket, atomic.LoadUint64(&cold.nativeHistogramZeroBucket))
 	atomic.StoreUint64(&cold.nativeHistogramZeroBucket, 0)
 }
+
+type nativeExemplars struct {
+	sync.Mutex
+
+	// Time-to-live for exemplars, it is set to -1 if exemplars are disabled, that is NativeHistogramMaxExemplars is below 0.
+	// The ttl is used on insertion to remove an exemplar that is older than ttl, if present.
+	ttl time.Duration
+
+	exemplars []*dto.Exemplar
+}
+
+func (n *nativeExemplars) isEnabled() bool {
+	return n.ttl != -1
+}
+
+func makeNativeExemplars(ttl time.Duration, maxCount int) nativeExemplars {
+	if ttl == 0 {
+		ttl = 5 * time.Minute
+	}
+
+	if maxCount == 0 {
+		maxCount = 10
+	}
+
+	if maxCount < 0 {
+		maxCount = 0
+		ttl = -1
+	}
+
+	return nativeExemplars{
+		ttl:       ttl,
+		exemplars: make([]*dto.Exemplar, 0, maxCount),
+	}
+}
+
+func (n *nativeExemplars) addExemplar(e *dto.Exemplar) {
+	if !n.isEnabled() {
+		return
+	}
+
+	n.Lock()
+	defer n.Unlock()
+
+	// When the number of exemplars has not yet exceeded or
+	// is equal to cap(n.exemplars), then
+	// insert the new exemplar directly.
+	if len(n.exemplars) < cap(n.exemplars) {
+		var nIdx int
+		for nIdx = 0; nIdx < len(n.exemplars); nIdx++ {
+			if *e.Value < *n.exemplars[nIdx].Value {
+				break
+			}
+		}
+		n.exemplars = append(n.exemplars[:nIdx], append([]*dto.Exemplar{e}, n.exemplars[nIdx:]...)...)
+		return
+	}
+
+	if len(n.exemplars) == 1 {
+		// When the number of exemplars is 1, then
+		// replace the existing exemplar with the new exemplar.
+		n.exemplars[0] = e
+		return
+	}
+	// From this point on, the number of exemplars is greater than 1.
+
+	// When the number of exemplars exceeds the limit, remove one exemplar.
+	var (
+		ot    = time.Time{} // Oldest timestamp seen. Initial value doesn't matter as we replace it due to otIdx == -1 in the loop.
+		otIdx = -1          // Index of the exemplar with the oldest timestamp.
+
+		md = -1.0 // Logarithm of the delta of the closest pair of exemplars.
+
+		// The insertion point of the new exemplar in the exemplars slice after insertion.
+		// This is calculated purely based on the order of the exemplars by value.
+		// nIdx == len(n.exemplars) means the new exemplar is to be inserted after the end.
+		nIdx = -1
+
+		// rIdx is ultimately the index for the exemplar that we are replacing with the new exemplar.
+		// The aim is to keep a good spread of exemplars by value and not let them bunch up too much.
+		// It is calculated in 3 steps:
+		//   1. First we set rIdx to the index of the older exemplar within the closest pair by value.
+		//      That is the following will be true (on log scale):
+		//      either the exemplar pair on index (rIdx-1, rIdx) or (rIdx, rIdx+1) will have
+		//      the closest values to each other from all pairs.
+		//      For example, suppose the values are distributed like this:
+		//        |-----------x-------------x----------------x----x-----|
+		//                                                   ^--rIdx as this is older.
+		//      Or like this:
+		//        |-----------x-------------x----------------x----x-----|
+		//                                                        ^--rIdx as this is older.
+		//   2. If there is an exemplar that expired, then we simple reset rIdx to that index.
+		//   3. We check if by inserting the new exemplar we would create a closer pair at
+		//      (nIdx-1, nIdx) or (nIdx, nIdx+1) and set rIdx to nIdx-1 or nIdx accordingly to
+		//      keep the spread of exemplars by value; otherwise we keep rIdx as it is.
+		rIdx = -1
+		cLog float64 // Logarithm of the current exemplar.
+		pLog float64 // Logarithm of the previous exemplar.
+	)
+
+	for i, exemplar := range n.exemplars {
+		// Find the exemplar with the oldest timestamp.
+		if otIdx == -1 || exemplar.Timestamp.AsTime().Before(ot) {
+			ot = exemplar.Timestamp.AsTime()
+			otIdx = i
+		}
+
+		// Find the index at which to insert new the exemplar.
+		if nIdx == -1 && *e.Value <= *exemplar.Value {
+			nIdx = i
+		}
+
+		// Find the two closest exemplars and pick the one the with older timestamp.
+		pLog = cLog
+		cLog = math.Log(exemplar.GetValue())
+		if i == 0 {
+			continue
+		}
+		diff := math.Abs(cLog - pLog)
+		if md == -1 || diff < md {
+			// The closest exemplar pair is at index: i-1, i.
+			// Choose the exemplar with the older timestamp for replacement.
+			md = diff
+			if n.exemplars[i].Timestamp.AsTime().Before(n.exemplars[i-1].Timestamp.AsTime()) {
+				rIdx = i
+			} else {
+				rIdx = i - 1
+			}
+		}
+
+	}
+
+	// If all existing exemplar are smaller than new exemplar,
+	// then the exemplar should be inserted at the end.
+	if nIdx == -1 {
+		nIdx = len(n.exemplars)
+	}
+	// Here, we have the following relationships:
+	// n.exemplars[nIdx-1].Value < e.Value (if nIdx > 0)
+	// e.Value <= n.exemplars[nIdx].Value (if nIdx < len(n.exemplars))
+
+	if otIdx != -1 && e.Timestamp.AsTime().Sub(ot) > n.ttl {
+		// If the oldest exemplar has expired, then replace it with the new exemplar.
+		rIdx = otIdx
+	} else {
+		// In the previous for loop, when calculating the closest pair of exemplars,
+		// we did not take into account the newly inserted exemplar.
+		// So we need to calculate with the newly inserted exemplar again.
+		elog := math.Log(e.GetValue())
+		if nIdx > 0 {
+			diff := math.Abs(elog - math.Log(n.exemplars[nIdx-1].GetValue()))
+			if diff < md {
+				// The value we are about to insert is closer to the previous exemplar at the insertion point than what we calculated before in rIdx.
+				//                                            v--rIdx
+				// |-----------x-n-----------x----------------x----x-----|
+				//     nIdx-1--^ ^--new exemplar value
+				// Do not make the spread worse, replace nIdx-1 and not rIdx.
+				md = diff
+				rIdx = nIdx - 1
+			}
+		}
+		if nIdx < len(n.exemplars) {
+			diff := math.Abs(math.Log(n.exemplars[nIdx].GetValue()) - elog)
+			if diff < md {
+				// The value we are about to insert is closer to the next exemplar at the insertion point than what we calculated before in rIdx.
+				//                                            v--rIdx
+				// |-----------x-----------n-x----------------x----x-----|
+				//     new exemplar value--^ ^--nIdx
+				// Do not make the spread worse, replace nIdx-1 and not rIdx.
+				rIdx = nIdx
+			}
+		}
+	}
+
+	// Adjust the slice according to rIdx and nIdx.
+	switch {
+	case rIdx == nIdx:
+		n.exemplars[nIdx] = e
+	case rIdx < nIdx:
+		n.exemplars = append(n.exemplars[:rIdx], append(n.exemplars[rIdx+1:nIdx], append([]*dto.Exemplar{e}, n.exemplars[nIdx:]...)...)...)
+	case rIdx > nIdx:
+		n.exemplars = append(n.exemplars[:nIdx], append([]*dto.Exemplar{e}, append(n.exemplars[nIdx:rIdx], n.exemplars[rIdx+1:]...)...)...)
+	}
+}
+
+type constNativeHistogram struct {
+	desc *Desc
+	dto.Histogram
+	labelPairs []*dto.LabelPair
+}
+
+func validateCount(sum float64, count uint64, negativeBuckets, positiveBuckets map[int]int64, zeroBucket uint64) error {
+	var bucketPopulationSum int64
+	for _, v := range positiveBuckets {
+		bucketPopulationSum += v
+	}
+	for _, v := range negativeBuckets {
+		bucketPopulationSum += v
+	}
+	bucketPopulationSum += int64(zeroBucket)
+
+	// If the sum of observations is NaN, the number of observations must be greater or equal to the sum of all bucket counts.
+	// Otherwise, the number of observations must be equal to the sum of all bucket counts .
+
+	if math.IsNaN(sum) && bucketPopulationSum > int64(count) ||
+		!math.IsNaN(sum) && bucketPopulationSum != int64(count) {
+		return errors.New("the sum of all bucket populations exceeds the count of observations")
+	}
+	return nil
+}
+
+// NewConstNativeHistogram returns a metric representing a Prometheus native histogram with
+// fixed values for the count, sum, and positive/negative/zero bucket counts. As those parameters
+// cannot be changed, the returned value does not implement the Histogram
+// interface (but only the Metric interface). Users of this package will not
+// have much use for it in regular operations. However, when implementing custom
+// OpenTelemetry Collectors, it is useful as a throw-away metric that is generated on the fly
+// to send it to Prometheus in the Collect method.
+//
+// zeroBucket counts all (positive and negative)
+// observations in the zero bucket (with an absolute value less or equal
+// the current threshold).
+// positiveBuckets and negativeBuckets are separate maps for negative and positive
+// observations. The map's value is an int64, counting observations in
+// that bucket. The map's key is the
+// index of the bucket according to the used
+// Schema. Index 0 is for an upper bound of 1 in positive buckets and for a lower bound of -1 in negative buckets.
+// NewConstNativeHistogram returns an error if
+//   - the length of labelValues is not consistent with the variable labels in Desc or if Desc is invalid.
+//   - the schema passed is not between 8 and -4
+//   - the sum of counts in all buckets including the zero bucket does not equal the count if sum is not NaN (or exceeds the count if sum is NaN)
+//
+// See https://opentelemetry.io/docs/specs/otel/compatibility/prometheus_and_openmetrics/#exponential-histograms for more details about the conversion from OTel to Prometheus.
+func NewConstNativeHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	positiveBuckets, negativeBuckets map[int]int64,
+	zeroBucket uint64,
+	schema int32,
+	zeroThreshold float64,
+	createdTimestamp time.Time,
+	labelValues ...string,
+) (Metric, error) {
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
+		return nil, err
+	}
+	if schema > nativeHistogramSchemaMaximum || schema < nativeHistogramSchemaMinimum {
+		return nil, errors.New("invalid native histogram schema")
+	}
+	if err := validateCount(sum, count, negativeBuckets, positiveBuckets, zeroBucket); err != nil {
+		return nil, err
+	}
+
+	NegativeSpan, NegativeDelta := makeBucketsFromMap(negativeBuckets)
+	PositiveSpan, PositiveDelta := makeBucketsFromMap(positiveBuckets)
+	ret := &constNativeHistogram{
+		desc: desc,
+		Histogram: dto.Histogram{
+			CreatedTimestamp: timestamppb.New(createdTimestamp),
+			Schema:           &schema,
+			ZeroThreshold:    &zeroThreshold,
+			SampleCount:      &count,
+			SampleSum:        &sum,
+
+			NegativeSpan:  NegativeSpan,
+			NegativeDelta: NegativeDelta,
+
+			PositiveSpan:  PositiveSpan,
+			PositiveDelta: PositiveDelta,
+
+			ZeroCount: proto.Uint64(zeroBucket),
+		},
+		labelPairs: MakeLabelPairs(desc, labelValues),
+	}
+	if *ret.ZeroThreshold == 0 && *ret.ZeroCount == 0 && len(ret.PositiveSpan) == 0 && len(ret.NegativeSpan) == 0 {
+		ret.PositiveSpan = []*dto.BucketSpan{{
+			Offset: proto.Int32(0),
+			Length: proto.Uint32(0),
+		}}
+	}
+	return ret, nil
+}
+
+// MustNewConstNativeHistogram is a version of NewConstNativeHistogram that panics where
+// NewConstNativeHistogram would have returned an error.
+func MustNewConstNativeHistogram(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	positiveBuckets, negativeBuckets map[int]int64,
+	zeroBucket uint64,
+	nativeHistogramSchema int32,
+	nativeHistogramZeroThreshold float64,
+	createdTimestamp time.Time,
+	labelValues ...string,
+) Metric {
+	nativehistogram, err := NewConstNativeHistogram(desc,
+		count,
+		sum,
+		positiveBuckets,
+		negativeBuckets,
+		zeroBucket,
+		nativeHistogramSchema,
+		nativeHistogramZeroThreshold,
+		createdTimestamp,
+		labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return nativehistogram
+}
+
+func (h *constNativeHistogram) Desc() *Desc {
+	return h.desc
+}
+
+func (h *constNativeHistogram) Write(out *dto.Metric) error {
+	out.Histogram = &h.Histogram
+	out.Label = h.labelPairs
+	return nil
+}
+
+func makeBucketsFromMap(buckets map[int]int64) ([]*dto.BucketSpan, []int64) {
+	if len(buckets) == 0 {
+		return nil, nil
+	}
+	var ii []int
+	for k := range buckets {
+		ii = append(ii, k)
+	}
+	sort.Ints(ii)
+
+	var (
+		spans     []*dto.BucketSpan
+		deltas    []int64
+		prevCount int64
+		nextI     int
+	)
+
+	appendDelta := func(count int64) {
+		*spans[len(spans)-1].Length++
+		deltas = append(deltas, count-prevCount)
+		prevCount = count
+	}
+
+	for n, i := range ii {
+		count := buckets[i]
+		// Multiple spans with only small gaps in between are probably
+		// encoded more efficiently as one larger span with a few empty
+		// buckets. Needs some research to find the sweet spot. For now,
+		// we assume that gaps of one or two buckets should not create
+		// a new span.
+		iDelta := int32(i - nextI)
+		if n == 0 || iDelta > 2 {
+			// We have to create a new span, either because we are
+			// at the very beginning, or because we have found a gap
+			// of more than two buckets.
+			spans = append(spans, &dto.BucketSpan{
+				Offset: proto.Int32(iDelta),
+				Length: proto.Uint32(0),
+			})
+		} else {
+			// We have found a small gap (or no gap at all).
+			// Insert empty buckets as needed.
+			for j := int32(0); j < iDelta; j++ {
+				appendDelta(0)
+			}
+		}
+		appendDelta(count)
+		nextI = i + 1
+	}
+	return spans, deltas
+}

vendor/github.com/prometheus/client_golang/prometheus/internal/difflib.go

@@ -22,17 +22,18 @@ import (
 	"bytes"
 	"fmt"
 	"io"
+	"strconv"
 	"strings"
 )
 
-func min(a, b int) int {
+func minInt(a, b int) int {
 	if a < b {
 		return a
 	}
 	return b
 }
 
-func max(a, b int) int {
+func maxInt(a, b int) int {
 	if a > b {
 		return a
 	}
@@ -427,12 +428,12 @@ func (m *SequenceMatcher) GetGroupedOpCodes(n int) [][]OpCode {
 	if codes[0].Tag == 'e' {
 		c := codes[0]
 		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
-		codes[0] = OpCode{c.Tag, max(i1, i2-n), i2, max(j1, j2-n), j2}
+		codes[0] = OpCode{c.Tag, maxInt(i1, i2-n), i2, maxInt(j1, j2-n), j2}
 	}
 	if codes[len(codes)-1].Tag == 'e' {
 		c := codes[len(codes)-1]
 		i1, i2, j1, j2 := c.I1, c.I2, c.J1, c.J2
-		codes[len(codes)-1] = OpCode{c.Tag, i1, min(i2, i1+n), j1, min(j2, j1+n)}
+		codes[len(codes)-1] = OpCode{c.Tag, i1, minInt(i2, i1+n), j1, minInt(j2, j1+n)}
 	}
 	nn := n + n
 	groups := [][]OpCode{}
@@ -443,16 +444,16 @@ func (m *SequenceMatcher) GetGroupedOpCodes(n int) [][]OpCode {
 		// there is a large range with no changes.
 		if c.Tag == 'e' && i2-i1 > nn {
 			group = append(group, OpCode{
-				c.Tag, i1, min(i2, i1+n),
-				j1, min(j2, j1+n),
+				c.Tag, i1, minInt(i2, i1+n),
+				j1, minInt(j2, j1+n),
 			})
 			groups = append(groups, group)
 			group = []OpCode{}
-			i1, j1 = max(i1, i2-n), max(j1, j2-n)
+			i1, j1 = maxInt(i1, i2-n), maxInt(j1, j2-n)
 		}
 		group = append(group, OpCode{c.Tag, i1, i2, j1, j2})
 	}
-	if len(group) > 0 && !(len(group) == 1 && group[0].Tag == 'e') {
+	if len(group) > 0 && (len(group) != 1 || group[0].Tag != 'e') {
 		groups = append(groups, group)
 	}
 	return groups
@@ -515,7 +516,7 @@ func (m *SequenceMatcher) QuickRatio() float64 {
 // is faster to compute than either .Ratio() or .QuickRatio().
 func (m *SequenceMatcher) RealQuickRatio() float64 {
 	la, lb := len(m.a), len(m.b)
-	return calculateRatio(min(la, lb), la+lb)
+	return calculateRatio(minInt(la, lb), la+lb)
 }
 
 // Convert range to the "ed" format
@@ -524,7 +525,7 @@ func formatRangeUnified(start, stop int) string {
 	beginning := start + 1 // lines start numbering with one
 	length := stop - start
 	if length == 1 {
-		return fmt.Sprintf("%d", beginning)
+		return strconv.Itoa(beginning)
 	}
 	if length == 0 {
 		beginning-- // empty ranges begin at line just before the range
@@ -567,7 +568,7 @@ func WriteUnifiedDiff(writer io.Writer, diff UnifiedDiff) error {
 	buf := bufio.NewWriter(writer)
 	defer buf.Flush()
 	wf := func(format string, args ...interface{}) error {
-		_, err := buf.WriteString(fmt.Sprintf(format, args...))
+		_, err := fmt.Fprintf(buf, format, args...)
 		return err
 	}
 	ws := func(s string) error {

vendor/github.com/prometheus/client_golang/prometheus/internal/go_collector_options.go

@@ -30,3 +30,5 @@ type GoCollectorOptions struct {
 	RuntimeMetricSumForHist    map[string]string
 	RuntimeMetricRules         []GoCollectorRule
 }
+
+var GoCollectorDefaultRuntimeMetrics = regexp.MustCompile(`/gc/gogc:percent|/gc/gomemlimit:bytes|/sched/gomaxprocs:threads`)

vendor/github.com/prometheus/client_golang/prometheus/internal/go_runtime_metrics.go

@@ -66,7 +66,8 @@ func RuntimeMetricsToProm(d *metrics.Description) (string, string, string, bool)
 		name += "_total"
 	}
 
-	valid := model.IsValidMetricName(model.LabelValue(namespace + "_" + subsystem + "_" + name))
+	// Our current conversion moves to legacy naming, so use legacy validation.
+	valid := model.LegacyValidation.IsValidMetricName(namespace + "_" + subsystem + "_" + name)
 	switch d.Kind {
 	case metrics.KindUint64:
 	case metrics.KindFloat64:

vendor/github.com/prometheus/client_golang/prometheus/labels.go

@@ -184,5 +184,6 @@ func validateLabelValues(vals []string, expectedNumberOfValues int) error {
 }
 
 func checkLabelName(l string) bool {
-	return model.LabelName(l).IsValid() && !strings.HasPrefix(l, reservedLabelPrefix)
+	//nolint:staticcheck // TODO: Don't use deprecated model.NameValidationScheme.
+	return model.NameValidationScheme.IsValidLabelName(l) && !strings.HasPrefix(l, reservedLabelPrefix)
 }

vendor/github.com/prometheus/client_golang/prometheus/metric.go

@@ -108,15 +108,23 @@ func BuildFQName(namespace, subsystem, name string) string {
 	if name == "" {
 		return ""
 	}
-	switch {
-	case namespace != "" && subsystem != "":
-		return strings.Join([]string{namespace, subsystem, name}, "_")
-	case namespace != "":
-		return strings.Join([]string{namespace, name}, "_")
-	case subsystem != "":
-		return strings.Join([]string{subsystem, name}, "_")
+
+	sb := strings.Builder{}
+	sb.Grow(len(namespace) + len(subsystem) + len(name) + 2)
+
+	if namespace != "" {
+		sb.WriteString(namespace)
+		sb.WriteString("_")
 	}
-	return name
+
+	if subsystem != "" {
+		sb.WriteString(subsystem)
+		sb.WriteString("_")
+	}
+
+	sb.WriteString(name)
+
+	return sb.String()
 }
 
 type invalidMetric struct {
@@ -178,21 +186,31 @@ func (m *withExemplarsMetric) Write(pb *dto.Metric) error {
 	case pb.Counter != nil:
 		pb.Counter.Exemplar = m.exemplars[len(m.exemplars)-1]
 	case pb.Histogram != nil:
+		h := pb.Histogram
 		for _, e := range m.exemplars {
-			// pb.Histogram.Bucket are sorted by UpperBound.
-			i := sort.Search(len(pb.Histogram.Bucket), func(i int) bool {
-				return pb.Histogram.Bucket[i].GetUpperBound() >= e.GetValue()
+			if (h.GetZeroThreshold() != 0 || h.GetZeroCount() != 0 ||
+				len(h.PositiveSpan) != 0 || len(h.NegativeSpan) != 0) &&
+				e.GetTimestamp() != nil {
+				h.Exemplars = append(h.Exemplars, e)
+				if len(h.Bucket) == 0 {
+					// Don't proceed to classic buckets if there are none.
+					continue
+				}
+			}
+			// h.Bucket are sorted by UpperBound.
+			i := sort.Search(len(h.Bucket), func(i int) bool {
+				return h.Bucket[i].GetUpperBound() >= e.GetValue()
 			})
-			if i < len(pb.Histogram.Bucket) {
-				pb.Histogram.Bucket[i].Exemplar = e
+			if i < len(h.Bucket) {
+				h.Bucket[i].Exemplar = e
 			} else {
 				// The +Inf bucket should be explicitly added if there is an exemplar for it, similar to non-const histogram logic in https://github.com/prometheus/client_golang/blob/main/prometheus/histogram.go#L357-L365.
 				b := &dto.Bucket{
-					CumulativeCount: proto.Uint64(pb.Histogram.GetSampleCount()),
+					CumulativeCount: proto.Uint64(h.GetSampleCount()),
 					UpperBound:      proto.Float64(math.Inf(1)),
 					Exemplar:        e,
 				}
-				pb.Histogram.Bucket = append(pb.Histogram.Bucket, b)
+				h.Bucket = append(h.Bucket, b)
 			}
 		}
 	default:
@@ -219,6 +237,7 @@ type Exemplar struct {
 // Only last applicable exemplar is injected from the list.
 // For example for Counter it means last exemplar is injected.
 // For Histogram, it means last applicable exemplar for each bucket is injected.
+// For a Native Histogram, all valid exemplars are injected.
 //
 // NewMetricWithExemplars works best with MustNewConstMetric and
 // MustNewConstHistogram, see example.
@@ -234,7 +253,7 @@ func NewMetricWithExemplars(m Metric, exemplars ...Exemplar) (Metric, error) {
 	)
 	for i, e := range exemplars {
 		ts := e.Timestamp
-		if ts == (time.Time{}) {
+		if ts.IsZero() {
 			ts = now
 		}
 		exs[i], err = newExemplar(e.Value, ts, e.Labels)

vendor/github.com/prometheus/client_golang/prometheus/process_collector.go

@@ -22,14 +22,16 @@ import (
 )
 
 type processCollector struct {
-	collectFn       func(chan<- Metric)
-	pidFn           func() (int, error)
-	reportErrors    bool
-	cpuTotal        *Desc
-	openFDs, maxFDs *Desc
-	vsize, maxVsize *Desc
-	rss             *Desc
-	startTime       *Desc
+	collectFn         func(chan<- Metric)
+	describeFn        func(chan<- *Desc)
+	pidFn             func() (int, error)
+	reportErrors      bool
+	cpuTotal          *Desc
+	openFDs, maxFDs   *Desc
+	vsize, maxVsize   *Desc
+	rss               *Desc
+	startTime         *Desc
+	inBytes, outBytes *Desc
 }
 
 // ProcessCollectorOpts defines the behavior of a process metrics collector
@@ -100,6 +102,16 @@ func NewProcessCollector(opts ProcessCollectorOpts) Collector {
 			"Start time of the process since unix epoch in seconds.",
 			nil, nil,
 		),
+		inBytes: NewDesc(
+			ns+"process_network_receive_bytes_total",
+			"Number of bytes received by the process over the network.",
+			nil, nil,
+		),
+		outBytes: NewDesc(
+			ns+"process_network_transmit_bytes_total",
+			"Number of bytes sent by the process over the network.",
+			nil, nil,
+		),
 	}
 
 	if opts.PidFn == nil {
@@ -111,24 +123,23 @@ func NewProcessCollector(opts ProcessCollectorOpts) Collector {
 	// Set up process metric collection if supported by the runtime.
 	if canCollectProcess() {
 		c.collectFn = c.processCollect
+		c.describeFn = c.describe
 	} else {
-		c.collectFn = func(ch chan<- Metric) {
-			c.reportError(ch, nil, errors.New("process metrics not supported on this platform"))
-		}
+		c.collectFn = c.errorCollectFn
+		c.describeFn = c.errorDescribeFn
 	}
 
 	return c
 }
 
-// Describe returns all descriptions of the collector.
-func (c *processCollector) Describe(ch chan<- *Desc) {
-	ch <- c.cpuTotal
-	ch <- c.openFDs
-	ch <- c.maxFDs
-	ch <- c.vsize
-	ch <- c.maxVsize
-	ch <- c.rss
-	ch <- c.startTime
+func (c *processCollector) errorCollectFn(ch chan<- Metric) {
+	c.reportError(ch, nil, errors.New("process metrics not supported on this platform"))
+}
+
+func (c *processCollector) errorDescribeFn(ch chan<- *Desc) {
+	if c.reportErrors {
+		ch <- NewInvalidDesc(errors.New("process metrics not supported on this platform"))
+	}
 }
 
 // Collect returns the current state of all metrics of the collector.
@@ -136,6 +147,11 @@ func (c *processCollector) Collect(ch chan<- Metric) {
 	c.collectFn(ch)
 }
 
+// Describe returns all descriptions of the collector.
+func (c *processCollector) Describe(ch chan<- *Desc) {
+	c.describeFn(ch)
+}
+
 func (c *processCollector) reportError(ch chan<- Metric, desc *Desc, err error) {
 	if !c.reportErrors {
 		return

vendor/github.com/prometheus/client_golang/prometheus/process_collector_js.go

@@ -1,26 +0,0 @@
-// Copyright 2019 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-//go:build js
-// +build js
-
-package prometheus
-
-func canCollectProcess() bool {
-	return false
-}
-
-func (c *processCollector) processCollect(ch chan<- Metric) {
-	// noop on this platform
-	return
-}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_other.go

@@ -1,66 +0,0 @@
-// Copyright 2019 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-//go:build !windows && !js && !wasip1
-// +build !windows,!js,!wasip1
-
-package prometheus
-
-import (
-	"github.com/prometheus/procfs"
-)
-
-func canCollectProcess() bool {
-	_, err := procfs.NewDefaultFS()
-	return err == nil
-}
-
-func (c *processCollector) processCollect(ch chan<- Metric) {
-	pid, err := c.pidFn()
-	if err != nil {
-		c.reportError(ch, nil, err)
-		return
-	}
-
-	p, err := procfs.NewProc(pid)
-	if err != nil {
-		c.reportError(ch, nil, err)
-		return
-	}
-
-	if stat, err := p.Stat(); err == nil {
-		ch <- MustNewConstMetric(c.cpuTotal, CounterValue, stat.CPUTime())
-		ch <- MustNewConstMetric(c.vsize, GaugeValue, float64(stat.VirtualMemory()))
-		ch <- MustNewConstMetric(c.rss, GaugeValue, float64(stat.ResidentMemory()))
-		if startTime, err := stat.StartTime(); err == nil {
-			ch <- MustNewConstMetric(c.startTime, GaugeValue, startTime)
-		} else {
-			c.reportError(ch, c.startTime, err)
-		}
-	} else {
-		c.reportError(ch, nil, err)
-	}
-
-	if fds, err := p.FileDescriptorsLen(); err == nil {
-		ch <- MustNewConstMetric(c.openFDs, GaugeValue, float64(fds))
-	} else {
-		c.reportError(ch, c.openFDs, err)
-	}
-
-	if limits, err := p.Limits(); err == nil {
-		ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(limits.OpenFiles))
-		ch <- MustNewConstMetric(c.maxVsize, GaugeValue, float64(limits.AddressSpace))
-	} else {
-		c.reportError(ch, nil, err)
-	}
-}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_wasip1.go

@@ -1,26 +0,0 @@
-// Copyright 2023 The Prometheus Authors
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-// http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
-
-//go:build wasip1
-// +build wasip1
-
-package prometheus
-
-func canCollectProcess() bool {
-	return false
-}
-
-func (*processCollector) processCollect(chan<- Metric) {
-	// noop on this platform
-	return
-}

vendor/github.com/prometheus/client_golang/prometheus/process_collector_windows.go

@@ -79,14 +79,10 @@ func getProcessHandleCount(handle windows.Handle) (uint32, error) {
 }
 
 func (c *processCollector) processCollect(ch chan<- Metric) {
-	h, err := windows.GetCurrentProcess()
-	if err != nil {
-		c.reportError(ch, nil, err)
-		return
-	}
+	h := windows.CurrentProcess()
 
 	var startTime, exitTime, kernelTime, userTime windows.Filetime
-	err = windows.GetProcessTimes(h, &startTime, &exitTime, &kernelTime, &userTime)
+	err := windows.GetProcessTimes(h, &startTime, &exitTime, &kernelTime, &userTime)
 	if err != nil {
 		c.reportError(ch, nil, err)
 		return
@@ -111,6 +107,19 @@ func (c *processCollector) processCollect(ch chan<- Metric) {
 	ch <- MustNewConstMetric(c.maxFDs, GaugeValue, float64(16*1024*1024)) // Windows has a hard-coded max limit, not per-process.
 }
 
+// describe returns all descriptions of the collector for windows.
+// Ensure that this list of descriptors is kept in sync with the metrics collected
+// in the processCollect method. Any changes to the metrics in processCollect
+// (such as adding or removing metrics) should be reflected in this list of descriptors.
+func (c *processCollector) describe(ch chan<- *Desc) {
+	ch <- c.cpuTotal
+	ch <- c.openFDs
+	ch <- c.maxFDs
+	ch <- c.vsize
+	ch <- c.rss
+	ch <- c.startTime
+}
+
 func fileTimeToSeconds(ft windows.Filetime) float64 {
 	return float64(uint64(ft.HighDateTime)<<32+uint64(ft.LowDateTime)) / 1e7
 }

vendor/github.com/prometheus/client_golang/prometheus/promhttp/delegator.go

@@ -76,6 +76,12 @@ func (r *responseWriterDelegator) Write(b []byte) (int, error) {
 	return n, err
 }
 
+// Unwrap lets http.ResponseController get the underlying http.ResponseWriter,
+// by implementing the [rwUnwrapper](https://cs.opensource.google/go/go/+/refs/tags/go1.21.4:src/net/http/responsecontroller.go;l=42-44) interface.
+func (r *responseWriterDelegator) Unwrap() http.ResponseWriter {
+	return r.ResponseWriter
+}
+
 type (
 	closeNotifierDelegator struct{ *responseWriterDelegator }
 	flusherDelegator       struct{ *responseWriterDelegator }

vendor/github.com/prometheus/client_golang/prometheus/promhttp/http.go

@@ -38,13 +38,14 @@ import (
 	"io"
 	"net/http"
 	"strconv"
-	"strings"
 	"sync"
 	"time"
 
 	"github.com/prometheus/common/expfmt"
 
+	"github.com/prometheus/client_golang/internal/github.com/golang/gddo/httputil"
 	"github.com/prometheus/client_golang/prometheus"
+	"github.com/prometheus/client_golang/prometheus/promhttp/internal"
 )
 
 const (
@@ -54,6 +55,24 @@ const (
 	processStartTimeHeader = "Process-Start-Time-Unix"
 )
 
+// Compression represents the content encodings handlers support for the HTTP
+// responses.
+type Compression string
+
+const (
+	Identity Compression = "identity"
+	Gzip     Compression = "gzip"
+	Zstd     Compression = "zstd"
+)
+
+func defaultCompressionFormats() []Compression {
+	if internal.NewZstdWriter != nil {
+		return []Compression{Identity, Gzip, Zstd}
+	} else {
+		return []Compression{Identity, Gzip}
+	}
+}
+
 var gzipPool = sync.Pool{
 	New: func() interface{} {
 		return gzip.NewWriter(nil)
@@ -122,6 +141,18 @@ func HandlerForTransactional(reg prometheus.TransactionalGatherer, opts HandlerO
 		}
 	}
 
+	// Select compression formats to offer based on default or user choice.
+	var compressions []string
+	if !opts.DisableCompression {
+		offers := defaultCompressionFormats()
+		if len(opts.OfferedCompressions) > 0 {
+			offers = opts.OfferedCompressions
+		}
+		for _, comp := range offers {
+			compressions = append(compressions, string(comp))
+		}
+	}
+
 	h := http.HandlerFunc(func(rsp http.ResponseWriter, req *http.Request) {
 		if !opts.ProcessStartTime.IsZero() {
 			rsp.Header().Set(processStartTimeHeader, strconv.FormatInt(opts.ProcessStartTime.Unix(), 10))
@@ -165,22 +196,30 @@ func HandlerForTransactional(reg prometheus.TransactionalGatherer, opts HandlerO
 		} else {
 			contentType = expfmt.Negotiate(req.Header)
 		}
-		header := rsp.Header()
-		header.Set(contentTypeHeader, string(contentType))
+		rsp.Header().Set(contentTypeHeader, string(contentType))
 
-		w := io.Writer(rsp)
-		if !opts.DisableCompression && gzipAccepted(req.Header) {
-			header.Set(contentEncodingHeader, "gzip")
-			gz := gzipPool.Get().(*gzip.Writer)
-			defer gzipPool.Put(gz)
-
-			gz.Reset(w)
-			defer gz.Close()
-
-			w = gz
+		w, encodingHeader, closeWriter, err := negotiateEncodingWriter(req, rsp, compressions)
+		if err != nil {
+			if opts.ErrorLog != nil {
+				opts.ErrorLog.Println("error getting writer", err)
+			}
+			w = io.Writer(rsp)
+			encodingHeader = string(Identity)
 		}
 
-		enc := expfmt.NewEncoder(w, contentType)
+		defer closeWriter()
+
+		// Set Content-Encoding only when data is compressed
+		if encodingHeader != string(Identity) {
+			rsp.Header().Set(contentEncodingHeader, encodingHeader)
+		}
+
+		var enc expfmt.Encoder
+		if opts.EnableOpenMetricsTextCreatedSamples {
+			enc = expfmt.NewEncoder(w, contentType, expfmt.WithCreatedLines())
+		} else {
+			enc = expfmt.NewEncoder(w, contentType)
+		}
 
 		// handleError handles the error according to opts.ErrorHandling
 		// and returns true if we have to abort after the handling.
@@ -343,9 +382,19 @@ type HandlerOpts struct {
 	// no effect on the HTTP status code because ErrorHandling is set to
 	// ContinueOnError.
 	Registry prometheus.Registerer
-	// If DisableCompression is true, the handler will never compress the
-	// response, even if requested by the client.
+	// DisableCompression disables the response encoding (compression) and
+	// encoding negotiation. If true, the handler will
+	// never compress the response, even if requested
+	// by the client and the OfferedCompressions field is set.
 	DisableCompression bool
+	// OfferedCompressions is a set of encodings (compressions) handler will
+	// try to offer when negotiating with the client. This defaults to identity, gzip
+	// and zstd.
+	// NOTE: If handler can't agree with the client on the encodings or
+	// unsupported or empty encodings are set in OfferedCompressions,
+	// handler always fallbacks to no compression (identity), for
+	// compatibility reasons. In such cases ErrorLog will be used if set.
+	OfferedCompressions []Compression
 	// The number of concurrent HTTP requests is limited to
 	// MaxRequestsInFlight. Additional requests are responded to with 503
 	// Service Unavailable and a suitable message in the body. If
@@ -371,6 +420,21 @@ type HandlerOpts struct {
 	// (which changes the identity of the resulting series on the Prometheus
 	// server).
 	EnableOpenMetrics bool
+	// EnableOpenMetricsTextCreatedSamples specifies if this handler should add, extra, synthetic
+	// Created Timestamps for counters, histograms and summaries, which for the current
+	// version of OpenMetrics are defined as extra series with the same name and "_created"
+	// suffix. See also the OpenMetrics specification for more details
+	// https://github.com/prometheus/OpenMetrics/blob/v1.0.0/specification/OpenMetrics.md#counter-1
+	//
+	// Created timestamps are used to improve the accuracy of reset detection,
+	// but the way it's designed in OpenMetrics 1.0 it also dramatically increases cardinality
+	// if the scraper does not handle those metrics correctly (converting to created timestamp
+	// instead of leaving those series as-is). New OpenMetrics versions might improve
+	// this situation.
+	//
+	// Prometheus introduced the feature flag 'created-timestamp-zero-ingestion'
+	// in version 2.50.0 to handle this situation.
+	EnableOpenMetricsTextCreatedSamples bool
 	// ProcessStartTime allows setting process start timevalue that will be exposed
 	// with "Process-Start-Time-Unix" response header along with the metrics
 	// payload. This allow callers to have efficient transformations to cumulative
@@ -381,19 +445,6 @@ type HandlerOpts struct {
 	ProcessStartTime time.Time
 }
 
-// gzipAccepted returns whether the client will accept gzip-encoded content.
-func gzipAccepted(header http.Header) bool {
-	a := header.Get(acceptEncodingHeader)
-	parts := strings.Split(a, ",")
-	for _, part := range parts {
-		part = strings.TrimSpace(part)
-		if part == "gzip" || strings.HasPrefix(part, "gzip;") {
-			return true
-		}
-	}
-	return false
-}
-
 // httpError removes any content-encoding header and then calls http.Error with
 // the provided error and http.StatusInternalServerError. Error contents is
 // supposed to be uncompressed plain text. Same as with a plain http.Error, this
@@ -406,3 +457,36 @@ func httpError(rsp http.ResponseWriter, err error) {
 		http.StatusInternalServerError,
 	)
 }
+
+// negotiateEncodingWriter reads the Accept-Encoding header from a request and
+// selects the right compression based on an allow-list of supported
+// compressions. It returns a writer implementing the compression and an the
+// correct value that the caller can set in the response header.
+func negotiateEncodingWriter(r *http.Request, rw io.Writer, compressions []string) (_ io.Writer, encodingHeaderValue string, closeWriter func(), _ error) {
+	if len(compressions) == 0 {
+		return rw, string(Identity), func() {}, nil
+	}
+
+	// TODO(mrueg): Replace internal/github.com/gddo once https://github.com/golang/go/issues/19307 is implemented.
+	selected := httputil.NegotiateContentEncoding(r, compressions)
+
+	switch selected {
+	case "zstd":
+		if internal.NewZstdWriter == nil {
+			// The content encoding was not implemented yet.
+			return nil, "", func() {}, fmt.Errorf("content compression format not recognized: %s. Valid formats are: %s", selected, defaultCompressionFormats())
+		}
+		writer, closeWriter, err := internal.NewZstdWriter(rw)
+		return writer, selected, closeWriter, err
+	case "gzip":
+		gz := gzipPool.Get().(*gzip.Writer)
+		gz.Reset(rw)
+		return gz, selected, func() { _ = gz.Close(); gzipPool.Put(gz) }, nil
+	case "identity":
+		// This means the content is not compressed.
+		return rw, selected, func() {}, nil
+	default:
+		// The content encoding was not implemented yet.
+		return nil, "", func() {}, fmt.Errorf("content compression format not recognized: %s. Valid formats are: %s", selected, defaultCompressionFormats())
+	}
+}

vendor/github.com/prometheus/client_golang/prometheus/promhttp/instrument_server.go

@@ -392,7 +392,7 @@ func isLabelCurried(c prometheus.Collector, label string) bool {
 func labels(code, method bool, reqMethod string, status int, extraMethods ...string) prometheus.Labels {
 	labels := prometheus.Labels{}
 
-	if !(code || method) {
+	if !code && !method {
 		return labels
 	}
 

vendor/github.com/prometheus/client_golang/prometheus/registry.go

@@ -314,16 +314,17 @@ func (r *Registry) Register(c Collector) error {
 			if dimHash != desc.dimHash {
 				return fmt.Errorf("a previously registered descriptor with the same fully-qualified name as %s has different label names or a different help string", desc)
 			}
-		} else {
-			// ...then check the new descriptors already seen.
-			if dimHash, exists := newDimHashesByName[desc.fqName]; exists {
-				if dimHash != desc.dimHash {
-					return fmt.Errorf("descriptors reported by collector have inconsistent label names or help strings for the same fully-qualified name, offender is %s", desc)
-				}
-			} else {
-				newDimHashesByName[desc.fqName] = desc.dimHash
-			}
+			continue
 		}
+
+		// ...then check the new descriptors already seen.
+		if dimHash, exists := newDimHashesByName[desc.fqName]; exists {
+			if dimHash != desc.dimHash {
+				return fmt.Errorf("descriptors reported by collector have inconsistent label names or help strings for the same fully-qualified name, offender is %s", desc)
+			}
+			continue
+		}
+		newDimHashesByName[desc.fqName] = desc.dimHash
 	}
 	// A Collector yielding no Desc at all is considered unchecked.
 	if len(newDescIDs) == 0 {

vendor/github.com/prometheus/client_golang/prometheus/summary.go

@@ -243,6 +243,7 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 
 	s := &summary{
 		desc: desc,
+		now:  opts.now,
 
 		objectives:       opts.Objectives,
 		sortedObjectives: make([]float64, 0, len(opts.Objectives)),
@@ -280,6 +281,8 @@ type summary struct {
 
 	desc *Desc
 
+	now func() time.Time
+
 	objectives       map[float64]float64
 	sortedObjectives []float64
 
@@ -307,7 +310,7 @@ func (s *summary) Observe(v float64) {
 	s.bufMtx.Lock()
 	defer s.bufMtx.Unlock()
 
-	now := time.Now()
+	now := s.now()
 	if now.After(s.hotBufExpTime) {
 		s.asyncFlush(now)
 	}
@@ -326,7 +329,7 @@ func (s *summary) Write(out *dto.Metric) error {
 	s.bufMtx.Lock()
 	s.mtx.Lock()
 	// Swap bufs even if hotBuf is empty to set new hotBufExpTime.
-	s.swapBufs(time.Now())
+	s.swapBufs(s.now())
 	s.bufMtx.Unlock()
 
 	s.flushColdBuf()
@@ -783,3 +786,45 @@ func MustNewConstSummary(
 	}
 	return m
 }
+
+// NewConstSummaryWithCreatedTimestamp does the same thing as NewConstSummary but sets the created timestamp.
+func NewConstSummaryWithCreatedTimestamp(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	quantiles map[float64]float64,
+	ct time.Time,
+	labelValues ...string,
+) (Metric, error) {
+	if desc.err != nil {
+		return nil, desc.err
+	}
+	if err := validateLabelValues(labelValues, len(desc.variableLabels.names)); err != nil {
+		return nil, err
+	}
+	return &constSummary{
+		desc:       desc,
+		count:      count,
+		sum:        sum,
+		quantiles:  quantiles,
+		labelPairs: MakeLabelPairs(desc, labelValues),
+		createdTs:  timestamppb.New(ct),
+	}, nil
+}
+
+// MustNewConstSummaryWithCreatedTimestamp is a version of NewConstSummaryWithCreatedTimestamp that panics where
+// NewConstSummaryWithCreatedTimestamp would have returned an error.
+func MustNewConstSummaryWithCreatedTimestamp(
+	desc *Desc,
+	count uint64,
+	sum float64,
+	quantiles map[float64]float64,
+	ct time.Time,
+	labelValues ...string,
+) Metric {
+	m, err := NewConstSummaryWithCreatedTimestamp(desc, count, sum, quantiles, ct, labelValues...)
+	if err != nil {
+		panic(err)
+	}
+	return m
+}

vendor/github.com/prometheus/client_golang/prometheus/vec.go

@@ -79,7 +79,7 @@ func (m *MetricVec) DeleteLabelValues(lvs ...string) bool {
 		return false
 	}
 
-	return m.metricMap.deleteByHashWithLabelValues(h, lvs, m.curry)
+	return m.deleteByHashWithLabelValues(h, lvs, m.curry)
 }
 
 // Delete deletes the metric where the variable labels are the same as those
@@ -101,7 +101,7 @@ func (m *MetricVec) Delete(labels Labels) bool {
 		return false
 	}
 
-	return m.metricMap.deleteByHashWithLabels(h, labels, m.curry)
+	return m.deleteByHashWithLabels(h, labels, m.curry)
 }
 
 // DeletePartialMatch deletes all metrics where the variable labels contain all of those
@@ -114,7 +114,7 @@ func (m *MetricVec) DeletePartialMatch(labels Labels) int {
 	labels, closer := constrainLabels(m.desc, labels)
 	defer closer()
 
-	return m.metricMap.deleteByLabels(labels, m.curry)
+	return m.deleteByLabels(labels, m.curry)
 }
 
 // Without explicit forwarding of Describe, Collect, Reset, those methods won't
@@ -216,7 +216,7 @@ func (m *MetricVec) GetMetricWithLabelValues(lvs ...string) (Metric, error) {
 		return nil, err
 	}
 
-	return m.metricMap.getOrCreateMetricWithLabelValues(h, lvs, m.curry), nil
+	return m.getOrCreateMetricWithLabelValues(h, lvs, m.curry), nil
 }
 
 // GetMetricWith returns the Metric for the given Labels map (the label names
@@ -244,7 +244,7 @@ func (m *MetricVec) GetMetricWith(labels Labels) (Metric, error) {
 		return nil, err
 	}
 
-	return m.metricMap.getOrCreateMetricWithLabels(h, labels, m.curry), nil
+	return m.getOrCreateMetricWithLabels(h, labels, m.curry), nil
 }
 
 func (m *MetricVec) hashLabelValues(vals []string) (uint64, error) {
@@ -507,7 +507,7 @@ func (m *metricMap) getOrCreateMetricWithLabelValues(
 	return metric
 }
 
-// getOrCreateMetricWithLabelValues retrieves the metric by hash and label value
+// getOrCreateMetricWithLabels retrieves the metric by hash and label value
 // or creates it and returns the new one.
 //
 // This function holds the mutex.

vendor/github.com/prometheus/client_golang/prometheus/wrap.go

@@ -63,7 +63,7 @@ func WrapRegistererWith(labels Labels, reg Registerer) Registerer {
 // metric names that are standardized across applications, as that would break
 // horizontal monitoring, for example the metrics provided by the Go collector
 // (see NewGoCollector) and the process collector (see NewProcessCollector). (In
-// fact, those metrics are already prefixed with “go_” or “process_”,
+// fact, those metrics are already prefixed with "go_" or "process_",
 // respectively.)
 //
 // Conflicts between Collectors registered through the original Registerer with
@@ -78,6 +78,40 @@ func WrapRegistererWithPrefix(prefix string, reg Registerer) Registerer {
 	}
 }
 
+// WrapCollectorWith returns a Collector wrapping the provided Collector. The
+// wrapped Collector will add the provided Labels to all Metrics it collects (as
+// ConstLabels). The Metrics collected by the unmodified Collector must not
+// duplicate any of those labels.
+//
+// WrapCollectorWith can be useful to work with multiple instances of a third
+// party library that does not expose enough flexibility on the lifecycle of its
+// registered metrics.
+// For example, let's say you have a foo.New(reg Registerer) constructor that
+// registers metrics but never unregisters them, and you want to create multiple
+// instances of foo.Foo with different labels.
+// The way to achieve that, is to create a new Registry, pass it to foo.New,
+// then use WrapCollectorWith to wrap that Registry with the desired labels and
+// register that as a collector in your main Registry.
+// Then you can un-register the wrapped collector effectively un-registering the
+// metrics registered by foo.New.
+func WrapCollectorWith(labels Labels, c Collector) Collector {
+	return &wrappingCollector{
+		wrappedCollector: c,
+		labels:           labels,
+	}
+}
+
+// WrapCollectorWithPrefix returns a Collector wrapping the provided Collector. The
+// wrapped Collector will add the provided prefix to the name of all Metrics it collects.
+//
+// See the documentation of WrapCollectorWith for more details on the use case.
+func WrapCollectorWithPrefix(prefix string, c Collector) Collector {
+	return &wrappingCollector{
+		wrappedCollector: c,
+		prefix:           prefix,
+	}
+}
+
 type wrappingRegisterer struct {
 	wrappedRegisterer Registerer
 	prefix            string