vendor: bump prometheus/client_golang v1.3.0

full diff: https://github.com/prometheus/client_golang/compare/v1.1.0...v1.3.0

This requires LK4D/vndr v0.1.0 or newer for vendoring; also adds a new
dependency: github.com/cespare/xxhash

Signed-off-by: Sebastiaan van Stijn <github@gone.nl>

vendor/github.com/prometheus/client_golang/README.md

@@ -9,7 +9,7 @@ This is the [Go](http://golang.org) client library for
 instrumenting application code, and one for creating clients that talk to the
 Prometheus HTTP API.
 
-__This library requires Go1.9 or later.__
+__This library requires Go1.9 or later.__ The minimum required patch releases for older Go versions are Go1.9.7 and Go1.10.3.
 
 ## Important note about releases and stability
 

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

@@ -2,10 +2,13 @@ module github.com/prometheus/client_golang
 
 require (
 	github.com/beorn7/perks v1.0.1
+	github.com/cespare/xxhash/v2 v2.1.1
 	github.com/golang/protobuf v1.3.2
-	github.com/json-iterator/go v1.1.7
-	github.com/prometheus/client_model v0.0.0-20190129233127-fd36f4220a90
-	github.com/prometheus/common v0.6.0
-	github.com/prometheus/procfs v0.0.3
-	golang.org/x/sys v0.0.0-20190801041406-cbf593c0f2f3
+	github.com/json-iterator/go v1.1.8
+	github.com/prometheus/client_model v0.1.0
+	github.com/prometheus/common v0.7.0
+	github.com/prometheus/procfs v0.0.8
+	golang.org/x/sys v0.0.0-20191220142924-d4481acd189f
 )
+
+go 1.11

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

@@ -19,6 +19,7 @@ import (
 	"sort"
 	"strings"
 
+	"github.com/cespare/xxhash/v2"
 	"github.com/golang/protobuf/proto"
 	"github.com/prometheus/common/model"
 
@@ -126,24 +127,24 @@ func NewDesc(fqName, help string, variableLabels []string, constLabels Labels) *
 		return d
 	}
 
-	vh := hashNew()
+	xxh := xxhash.New()
 	for _, val := range labelValues {
-		vh = hashAdd(vh, val)
-		vh = hashAddByte(vh, separatorByte)
+		xxh.WriteString(val)
+		xxh.Write(separatorByteSlice)
 	}
-	d.id = vh
+	d.id = xxh.Sum64()
 	// Sort labelNames so that order doesn't matter for the hash.
 	sort.Strings(labelNames)
 	// Now hash together (in this order) the help string and the sorted
 	// label names.
-	lh := hashNew()
-	lh = hashAdd(lh, help)
-	lh = hashAddByte(lh, separatorByte)
+	xxh.Reset()
+	xxh.WriteString(help)
+	xxh.Write(separatorByteSlice)
 	for _, labelName := range labelNames {
-		lh = hashAdd(lh, labelName)
-		lh = hashAddByte(lh, separatorByte)
+		xxh.WriteString(labelName)
+		xxh.Write(separatorByteSlice)
 	}
-	d.dimHash = lh
+	d.dimHash = xxh.Sum64()
 
 	d.constLabelPairs = make([]*dto.LabelPair, 0, len(constLabels))
 	for n, v := range constLabels {

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

@@ -273,9 +273,12 @@ type GaugeFunc interface {
 // NewGaugeFunc creates a new GaugeFunc based on the provided GaugeOpts. The
 // value reported is determined by calling the given function from within the
 // Write method. Take into account that metric collection may happen
-// concurrently. If that results in concurrent calls to Write, like in the case
-// where a GaugeFunc is directly registered with Prometheus, the provided
-// function must be concurrency-safe.
+// concurrently. Therefore, it must be safe to call the provided function
+// concurrently.
+//
+// NewGaugeFunc is a good way to create an “info” style metric with a constant
+// value of 1. Example:
+// https://github.com/prometheus/common/blob/8558a5b7db3c84fa38b4766966059a7bd5bfa2ee/version/info.go#L36-L56
 func NewGaugeFunc(opts GaugeOpts, function func() float64) GaugeFunc {
 	return newValueFunc(NewDesc(
 		BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),

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

@@ -138,7 +138,7 @@ type HistogramOpts struct {
 	// 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
+	// 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
@@ -187,7 +187,7 @@ func newHistogram(desc *Desc, opts HistogramOpts, labelValues ...string) Histogr
 		desc:        desc,
 		upperBounds: opts.Buckets,
 		labelPairs:  makeLabelPairs(desc, labelValues),
-		counts:      [2]*histogramCounts{&histogramCounts{}, &histogramCounts{}},
+		counts:      [2]*histogramCounts{{}, {}},
 	}
 	for i, upperBound := range h.upperBounds {
 		if i < len(h.upperBounds)-1 {

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

@@ -18,11 +18,12 @@ import (
 	"time"
 
 	"github.com/golang/protobuf/proto"
+	"github.com/prometheus/common/model"
 
 	dto "github.com/prometheus/client_model/go"
 )
 
-const separatorByte byte = 255
+var separatorByteSlice = []byte{model.SeparatorByte} // For convenient use with xxhash.
 
 // A Metric models a single sample value with its meta data being exported to
 // Prometheus. Implementations of Metric in this package are Gauge, Counter,

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

@@ -62,6 +62,8 @@ func (r *responseWriterDelegator) WriteHeader(code int) {
 }
 
 func (r *responseWriterDelegator) Write(b []byte) (int, error) {
+	// If applicable, call WriteHeader here so that observeWriteHeader is
+	// handled appropriately.
 	if !r.wroteHeader {
 		r.WriteHeader(http.StatusOK)
 	}
@@ -82,12 +84,19 @@ func (d closeNotifierDelegator) CloseNotify() <-chan bool {
 	return d.ResponseWriter.(http.CloseNotifier).CloseNotify()
 }
 func (d flusherDelegator) Flush() {
+	// If applicable, call WriteHeader here so that observeWriteHeader is
+	// handled appropriately.
+	if !d.wroteHeader {
+		d.WriteHeader(http.StatusOK)
+	}
 	d.ResponseWriter.(http.Flusher).Flush()
 }
 func (d hijackerDelegator) Hijack() (net.Conn, *bufio.ReadWriter, error) {
 	return d.ResponseWriter.(http.Hijacker).Hijack()
 }
 func (d readerFromDelegator) ReadFrom(re io.Reader) (int64, error) {
+	// If applicable, call WriteHeader here so that observeWriteHeader is
+	// handled appropriately.
 	if !d.wroteHeader {
 		d.WriteHeader(http.StatusOK)
 	}

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

@@ -25,6 +25,7 @@ import (
 	"sync"
 	"unicode/utf8"
 
+	"github.com/cespare/xxhash/v2"
 	"github.com/golang/protobuf/proto"
 	"github.com/prometheus/common/expfmt"
 
@@ -74,7 +75,7 @@ func NewRegistry() *Registry {
 // NewPedanticRegistry returns a registry that checks during collection if each
 // collected Metric is consistent with its reported Desc, and if the Desc has
 // actually been registered with the registry. Unchecked Collectors (those whose
-// Describe methed does not yield any descriptors) are excluded from the check.
+// Describe method does not yield any descriptors) are excluded from the check.
 //
 // Usually, a Registry will be happy as long as the union of all collected
 // Metrics is consistent and valid even if some metrics are not consistent with
@@ -266,7 +267,7 @@ func (r *Registry) Register(c Collector) error {
 		descChan           = make(chan *Desc, capDescChan)
 		newDescIDs         = map[uint64]struct{}{}
 		newDimHashesByName = map[string]uint64{}
-		collectorID        uint64 // Just a sum of all desc IDs.
+		collectorID        uint64 // All desc IDs XOR'd together.
 		duplicateDescErr   error
 	)
 	go func() {
@@ -293,12 +294,12 @@ func (r *Registry) Register(c Collector) error {
 		if _, exists := r.descIDs[desc.id]; exists {
 			duplicateDescErr = fmt.Errorf("descriptor %s already exists with the same fully-qualified name and const label values", desc)
 		}
-		// If it is not a duplicate desc in this collector, add it to
+		// If it is not a duplicate desc in this collector, XOR it to
 		// the collectorID.  (We allow duplicate descs within the same
 		// collector, but their existence must be a no-op.)
 		if _, exists := newDescIDs[desc.id]; !exists {
 			newDescIDs[desc.id] = struct{}{}
-			collectorID += desc.id
+			collectorID ^= desc.id
 		}
 
 		// Are all the label names and the help string consistent with
@@ -360,7 +361,7 @@ func (r *Registry) Unregister(c Collector) bool {
 	var (
 		descChan    = make(chan *Desc, capDescChan)
 		descIDs     = map[uint64]struct{}{}
-		collectorID uint64 // Just a sum of the desc IDs.
+		collectorID uint64 // All desc IDs XOR'd together.
 	)
 	go func() {
 		c.Describe(descChan)
@@ -368,7 +369,7 @@ func (r *Registry) Unregister(c Collector) bool {
 	}()
 	for desc := range descChan {
 		if _, exists := descIDs[desc.id]; !exists {
-			collectorID += desc.id
+			collectorID ^= desc.id
 			descIDs[desc.id] = struct{}{}
 		}
 	}
@@ -875,9 +876,9 @@ func checkMetricConsistency(
 	}
 
 	// Is the metric unique (i.e. no other metric with the same name and the same labels)?
-	h := hashNew()
-	h = hashAdd(h, name)
-	h = hashAddByte(h, separatorByte)
+	h := xxhash.New()
+	h.WriteString(name)
+	h.Write(separatorByteSlice)
 	// Make sure label pairs are sorted. We depend on it for the consistency
 	// check.
 	if !sort.IsSorted(labelPairSorter(dtoMetric.Label)) {
@@ -888,18 +889,19 @@ func checkMetricConsistency(
 		dtoMetric.Label = copiedLabels
 	}
 	for _, lp := range dtoMetric.Label {
-		h = hashAdd(h, lp.GetName())
-		h = hashAddByte(h, separatorByte)
-		h = hashAdd(h, lp.GetValue())
-		h = hashAddByte(h, separatorByte)
+		h.WriteString(lp.GetName())
+		h.Write(separatorByteSlice)
+		h.WriteString(lp.GetValue())
+		h.Write(separatorByteSlice)
 	}
-	if _, exists := metricHashes[h]; exists {
+	hSum := h.Sum64()
+	if _, exists := metricHashes[hSum]; exists {
 		return fmt.Errorf(
 			"collected metric %q { %s} was collected before with the same name and label values",
 			name, dtoMetric,
 		)
 	}
-	metricHashes[h] = struct{}{}
+	metricHashes[hSum] = struct{}{}
 	return nil
 }
 

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

@@ -208,7 +208,7 @@ func newSummary(desc *Desc, opts SummaryOpts, labelValues ...string) Summary {
 		s := &noObjectivesSummary{
 			desc:       desc,
 			labelPairs: makeLabelPairs(desc, labelValues),
-			counts:     [2]*summaryCounts{&summaryCounts{}, &summaryCounts{}},
+			counts:     [2]*summaryCounts{{}, {}},
 		}
 		s.init(s) // Init self-collection.
 		return s

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

@@ -24,7 +24,7 @@ import (
 // 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, and HistogramVec.
-// It also handles label currying. It uses basicMetricVec internally.
+// It also handles label currying.
 type metricVec struct {
 	*metricMap