Update dependencies

vendor/github.com/prometheus/common/model/alert.go

@@ -14,6 +14,7 @@
 package model
 
 import (
+	"errors"
 	"fmt"
 	"time"
 )
@@ -64,7 +65,7 @@ func (a *Alert) Resolved() bool {
 	return a.ResolvedAt(time.Now())
 }
 
-// ResolvedAt returns true off the activity interval ended before
+// ResolvedAt returns true iff the activity interval ended before
 // the given timestamp.
 func (a *Alert) ResolvedAt(ts time.Time) bool {
 	if a.EndsAt.IsZero() {
@@ -75,7 +76,12 @@ func (a *Alert) ResolvedAt(ts time.Time) bool {
 
 // Status returns the status of the alert.
 func (a *Alert) Status() AlertStatus {
-	if a.Resolved() {
+	return a.StatusAt(time.Now())
+}
+
+// StatusAt returns the status of the alert at the given timestamp.
+func (a *Alert) StatusAt(ts time.Time) AlertStatus {
+	if a.ResolvedAt(ts) {
 		return AlertResolved
 	}
 	return AlertFiring
@@ -84,19 +90,19 @@ func (a *Alert) Status() AlertStatus {
 // Validate checks whether the alert data is inconsistent.
 func (a *Alert) Validate() error {
 	if a.StartsAt.IsZero() {
-		return fmt.Errorf("start time missing")
+		return errors.New("start time missing")
 	}
 	if !a.EndsAt.IsZero() && a.EndsAt.Before(a.StartsAt) {
-		return fmt.Errorf("start time must be before end time")
+		return errors.New("start time must be before end time")
 	}
 	if err := a.Labels.Validate(); err != nil {
-		return fmt.Errorf("invalid label set: %s", err)
+		return fmt.Errorf("invalid label set: %w", err)
 	}
 	if len(a.Labels) == 0 {
-		return fmt.Errorf("at least one label pair required")
+		return errors.New("at least one label pair required")
 	}
 	if err := a.Annotations.Validate(); err != nil {
-		return fmt.Errorf("invalid annotations: %s", err)
+		return fmt.Errorf("invalid annotations: %w", err)
 	}
 	return nil
 }
@@ -127,6 +133,17 @@ func (as Alerts) HasFiring() bool {
 	return false
 }
 
+// HasFiringAt returns true iff one of the alerts is not resolved
+// at the time ts.
+func (as Alerts) HasFiringAt(ts time.Time) bool {
+	for _, a := range as {
+		if !a.ResolvedAt(ts) {
+			return true
+		}
+	}
+	return false
+}
+
 // Status returns StatusFiring iff at least one of the alerts is firing.
 func (as Alerts) Status() AlertStatus {
 	if as.HasFiring() {
@@ -134,3 +151,12 @@ func (as Alerts) Status() AlertStatus {
 	}
 	return AlertResolved
 }
+
+// StatusAt returns StatusFiring iff at least one of the alerts is firing
+// at the time ts.
+func (as Alerts) StatusAt(ts time.Time) AlertStatus {
+	if as.HasFiringAt(ts) {
+		return AlertFiring
+	}
+	return AlertResolved
+}

vendor/github.com/prometheus/common/model/labels.go

@@ -22,7 +22,7 @@ import (
 )
 
 const (
-	// AlertNameLabel is the name of the label containing the an alert's name.
+	// AlertNameLabel is the name of the label containing the alert's name.
 	AlertNameLabel = "alertname"
 
 	// ExportedLabelPrefix is the prefix to prepend to the label names present in
@@ -32,6 +32,12 @@ const (
 	// MetricNameLabel is the label name indicating the metric name of a
 	// timeseries.
 	MetricNameLabel = "__name__"
+	// MetricTypeLabel is the label name indicating the metric type of
+	// timeseries as per the PROM-39 proposal.
+	MetricTypeLabel = "__type__"
+	// MetricUnitLabel is the label name indicating the metric unit of
+	// timeseries as per the PROM-39 proposal.
+	MetricUnitLabel = "__unit__"
 
 	// SchemeLabel is the name of the label that holds the scheme on which to
 	// scrape a target.
@@ -97,19 +103,24 @@ var LabelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
 // therewith.
 type LabelName string
 
-// IsValid is true iff the label name matches the pattern of LabelNameRE. This
-// method, however, does not use LabelNameRE for the check but a much faster
-// hardcoded implementation.
+// IsValid returns true iff the name matches the pattern of LabelNameRE when
+// NameValidationScheme is set to LegacyValidation, or valid UTF-8 if
+// NameValidationScheme is set to UTF8Validation.
+//
+// Deprecated: This method should not be used and may be removed in the future.
+// Use [ValidationScheme.IsValidLabelName] instead.
 func (ln LabelName) IsValid() bool {
-	if len(ln) == 0 {
-		return false
-	}
-	for i, b := range ln {
-		if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || (b >= '0' && b <= '9' && i > 0)) {
-			return false
-		}
-	}
-	return true
+	return NameValidationScheme.IsValidLabelName(string(ln))
+}
+
+// IsValidLegacy returns true iff name matches the pattern of LabelNameRE for
+// legacy names. It does not use LabelNameRE for the check but a much faster
+// hardcoded implementation.
+//
+// Deprecated: This method should not be used and may be removed in the future.
+// Use [LegacyValidation.IsValidLabelName] instead.
+func (ln LabelName) IsValidLegacy() bool {
+	return LegacyValidation.IsValidLabelName(string(ln))
 }
 
 // UnmarshalYAML implements the yaml.Unmarshaler interface.
@@ -164,7 +175,7 @@ func (l LabelNames) String() string {
 // A LabelValue is an associated value for a LabelName.
 type LabelValue string
 
-// IsValid returns true iff the string is a valid UTF8.
+// IsValid returns true iff the string is a valid UTF-8.
 func (lv LabelValue) IsValid() bool {
 	return utf8.ValidString(string(lv))
 }

vendor/github.com/prometheus/common/model/labelset.go

@@ -17,7 +17,6 @@ import (
 	"encoding/json"
 	"fmt"
 	"sort"
-	"strings"
 )
 
 // A LabelSet is a collection of LabelName and LabelValue pairs.  The LabelSet
@@ -115,10 +114,10 @@ func (ls LabelSet) Clone() LabelSet {
 }
 
 // Merge is a helper function to non-destructively merge two label sets.
-func (l LabelSet) Merge(other LabelSet) LabelSet {
-	result := make(LabelSet, len(l))
+func (ls LabelSet) Merge(other LabelSet) LabelSet {
+	result := make(LabelSet, len(ls))
 
-	for k, v := range l {
+	for k, v := range ls {
 		result[k] = v
 	}
 
@@ -129,16 +128,6 @@ func (l LabelSet) Merge(other LabelSet) LabelSet {
 	return result
 }
 
-func (l LabelSet) String() string {
-	lstrs := make([]string, 0, len(l))
-	for l, v := range l {
-		lstrs = append(lstrs, fmt.Sprintf("%s=%q", l, v))
-	}
-
-	sort.Strings(lstrs)
-	return fmt.Sprintf("{%s}", strings.Join(lstrs, ", "))
-}
-
 // Fingerprint returns the LabelSet's fingerprint.
 func (ls LabelSet) Fingerprint() Fingerprint {
 	return labelSetToFingerprint(ls)
@@ -151,7 +140,7 @@ func (ls LabelSet) FastFingerprint() Fingerprint {
 }
 
 // UnmarshalJSON implements the json.Unmarshaler interface.
-func (l *LabelSet) UnmarshalJSON(b []byte) error {
+func (ls *LabelSet) UnmarshalJSON(b []byte) error {
 	var m map[LabelName]LabelValue
 	if err := json.Unmarshal(b, &m); err != nil {
 		return err
@@ -164,6 +153,6 @@ func (l *LabelSet) UnmarshalJSON(b []byte) error {
 			return fmt.Errorf("%q is not a valid label name", ln)
 		}
 	}
-	*l = LabelSet(m)
+	*ls = LabelSet(m)
 	return nil
 }

vendor/github.com/prometheus/common/model/labelset_string.go

@@ -0,0 +1,43 @@
+// Copyright 2024 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.
+
+package model
+
+import (
+	"bytes"
+	"slices"
+	"strconv"
+)
+
+// String will look like `{foo="bar", more="less"}`. Names are sorted alphabetically.
+func (l LabelSet) String() string {
+	var lna [32]string // On stack to avoid memory allocation for sorting names.
+	labelNames := lna[:0]
+	for name := range l {
+		labelNames = append(labelNames, string(name))
+	}
+	slices.Sort(labelNames)
+	var bytea [1024]byte // On stack to avoid memory allocation while building the output.
+	b := bytes.NewBuffer(bytea[:0])
+	b.WriteByte('{')
+	for i, name := range labelNames {
+		if i > 0 {
+			b.WriteString(", ")
+		}
+		b.WriteString(name)
+		b.WriteByte('=')
+		b.Write(strconv.AppendQuote(b.AvailableBuffer(), string(l[LabelName(name)])))
+	}
+	b.WriteByte('}')
+	return b.String()
+}

vendor/github.com/prometheus/common/model/metadata.go

@@ -0,0 +1,28 @@
+// 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.
+
+package model
+
+// MetricType represents metric type values.
+type MetricType string
+
+const (
+	MetricTypeCounter        = MetricType("counter")
+	MetricTypeGauge          = MetricType("gauge")
+	MetricTypeHistogram      = MetricType("histogram")
+	MetricTypeGaugeHistogram = MetricType("gaugehistogram")
+	MetricTypeSummary        = MetricType("summary")
+	MetricTypeInfo           = MetricType("info")
+	MetricTypeStateset       = MetricType("stateset")
+	MetricTypeUnknown        = MetricType("unknown")
+)

vendor/github.com/prometheus/common/model/metric.go

@@ -14,19 +14,242 @@
 package model
 
 import (
+	"encoding/json"
+	"errors"
 	"fmt"
 	"regexp"
 	"sort"
+	"strconv"
 	"strings"
+	"unicode/utf8"
+
+	dto "github.com/prometheus/client_model/go"
+	"go.yaml.in/yaml/v2"
+	"google.golang.org/protobuf/proto"
 )
 
 var (
-	// MetricNameRE is a regular expression matching valid metric
-	// names. Note that the IsValidMetricName function performs the same
-	// check but faster than a match with this regular expression.
-	MetricNameRE = regexp.MustCompile(`^[a-zA-Z_:][a-zA-Z0-9_:]*$`)
+	// NameValidationScheme determines the global default method of the name
+	// validation to be used by all calls to IsValidMetricName() and LabelName
+	// IsValid().
+	//
+	// Deprecated: This variable should not be used and might be removed in the
+	// far future. If you wish to stick to the legacy name validation use
+	// `IsValidLegacyMetricName()` and `LabelName.IsValidLegacy()` methods
+	// instead. This variable is here as an escape hatch for emergency cases,
+	// given the recent change from `LegacyValidation` to `UTF8Validation`, e.g.,
+	// to delay UTF-8 migrations in time or aid in debugging unforeseen results of
+	// the change. In such a case, a temporary assignment to `LegacyValidation`
+	// value in the `init()` function in your main.go or so, could be considered.
+	//
+	// Historically we opted for a global variable for feature gating different
+	// validation schemes in operations that were not otherwise easily adjustable
+	// (e.g. Labels yaml unmarshaling). That could have been a mistake, a separate
+	// Labels structure or package might have been a better choice. Given the
+	// change was made and many upgraded the common already, we live this as-is
+	// with this warning and learning for the future.
+	NameValidationScheme = UTF8Validation
+
+	// NameEscapingScheme defines the default way that names will be escaped when
+	// presented to systems that do not support UTF-8 names. If the Content-Type
+	// "escaping" term is specified, that will override this value.
+	// NameEscapingScheme should not be set to the NoEscaping value. That string
+	// is used in content negotiation to indicate that a system supports UTF-8 and
+	// has that feature enabled.
+	NameEscapingScheme = UnderscoreEscaping
 )
 
+// ValidationScheme is a Go enum for determining how metric and label names will
+// be validated by this library.
+type ValidationScheme int
+
+const (
+	// UnsetValidation represents an undefined ValidationScheme.
+	// Should not be used in practice.
+	UnsetValidation ValidationScheme = iota
+
+	// LegacyValidation is a setting that requires that all metric and label names
+	// conform to the original Prometheus character requirements described by
+	// MetricNameRE and LabelNameRE.
+	LegacyValidation
+
+	// UTF8Validation only requires that metric and label names be valid UTF-8
+	// strings.
+	UTF8Validation
+)
+
+var _ interface {
+	yaml.Marshaler
+	yaml.Unmarshaler
+	json.Marshaler
+	json.Unmarshaler
+	fmt.Stringer
+} = new(ValidationScheme)
+
+// String returns the string representation of s.
+func (s ValidationScheme) String() string {
+	switch s {
+	case UnsetValidation:
+		return "unset"
+	case LegacyValidation:
+		return "legacy"
+	case UTF8Validation:
+		return "utf8"
+	default:
+		panic(fmt.Errorf("unhandled ValidationScheme: %d", s))
+	}
+}
+
+// MarshalYAML implements the yaml.Marshaler interface.
+func (s ValidationScheme) MarshalYAML() (any, error) {
+	switch s {
+	case UnsetValidation:
+		return "", nil
+	case LegacyValidation, UTF8Validation:
+		return s.String(), nil
+	default:
+		panic(fmt.Errorf("unhandled ValidationScheme: %d", s))
+	}
+}
+
+// UnmarshalYAML implements the yaml.Unmarshaler interface.
+func (s *ValidationScheme) UnmarshalYAML(unmarshal func(any) error) error {
+	var scheme string
+	if err := unmarshal(&scheme); err != nil {
+		return err
+	}
+	return s.Set(scheme)
+}
+
+// MarshalJSON implements the json.Marshaler interface.
+func (s ValidationScheme) MarshalJSON() ([]byte, error) {
+	switch s {
+	case UnsetValidation:
+		return json.Marshal("")
+	case UTF8Validation, LegacyValidation:
+		return json.Marshal(s.String())
+	default:
+		return nil, fmt.Errorf("unhandled ValidationScheme: %d", s)
+	}
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface.
+func (s *ValidationScheme) UnmarshalJSON(bytes []byte) error {
+	var repr string
+	if err := json.Unmarshal(bytes, &repr); err != nil {
+		return err
+	}
+	return s.Set(repr)
+}
+
+// Set implements the pflag.Value interface.
+func (s *ValidationScheme) Set(text string) error {
+	switch text {
+	case "":
+		// Don't change the value.
+	case LegacyValidation.String():
+		*s = LegacyValidation
+	case UTF8Validation.String():
+		*s = UTF8Validation
+	default:
+		return fmt.Errorf("unrecognized ValidationScheme: %q", text)
+	}
+	return nil
+}
+
+// IsValidMetricName returns whether metricName is valid according to s.
+func (s ValidationScheme) IsValidMetricName(metricName string) bool {
+	switch s {
+	case LegacyValidation:
+		if len(metricName) == 0 {
+			return false
+		}
+		for i, b := range metricName {
+			if !isValidLegacyRune(b, i) {
+				return false
+			}
+		}
+		return true
+	case UTF8Validation:
+		if len(metricName) == 0 {
+			return false
+		}
+		return utf8.ValidString(metricName)
+	default:
+		panic(fmt.Sprintf("Invalid name validation scheme requested: %s", s.String()))
+	}
+}
+
+// IsValidLabelName returns whether labelName is valid according to s.
+func (s ValidationScheme) IsValidLabelName(labelName string) bool {
+	switch s {
+	case LegacyValidation:
+		if len(labelName) == 0 {
+			return false
+		}
+		for i, b := range labelName {
+			// TODO: Apply De Morgan's law. Make sure there are tests for this.
+			if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || (b >= '0' && b <= '9' && i > 0)) { //nolint:staticcheck
+				return false
+			}
+		}
+		return true
+	case UTF8Validation:
+		if len(labelName) == 0 {
+			return false
+		}
+		return utf8.ValidString(labelName)
+	default:
+		panic(fmt.Sprintf("Invalid name validation scheme requested: %s", s))
+	}
+}
+
+// Type implements the pflag.Value interface.
+func (ValidationScheme) Type() string {
+	return "validationScheme"
+}
+
+type EscapingScheme int
+
+const (
+	// NoEscaping indicates that a name will not be escaped. Unescaped names that
+	// do not conform to the legacy validity check will use a new exposition
+	// format syntax that will be officially standardized in future versions.
+	NoEscaping EscapingScheme = iota
+
+	// UnderscoreEscaping replaces all legacy-invalid characters with underscores.
+	UnderscoreEscaping
+
+	// DotsEscaping is similar to UnderscoreEscaping, except that dots are
+	// converted to `_dot_` and pre-existing underscores are converted to `__`.
+	DotsEscaping
+
+	// ValueEncodingEscaping prepends the name with `U__` and replaces all invalid
+	// characters with the unicode value, surrounded by underscores. Single
+	// underscores are replaced with double underscores.
+	ValueEncodingEscaping
+)
+
+const (
+	// EscapingKey is the key in an Accept or Content-Type header that defines how
+	// metric and label names that do not conform to the legacy character
+	// requirements should be escaped when being scraped by a legacy prometheus
+	// system. If a system does not explicitly pass an escaping parameter in the
+	// Accept header, the default NameEscapingScheme will be used.
+	EscapingKey = "escaping"
+
+	// Possible values for Escaping Key.
+	AllowUTF8         = "allow-utf-8" // No escaping required.
+	EscapeUnderscores = "underscores"
+	EscapeDots        = "dots"
+	EscapeValues      = "values"
+)
+
+// MetricNameRE is a regular expression matching valid metric
+// names. Note that the IsValidMetricName function performs the same
+// check but faster than a match with this regular expression.
+var MetricNameRE = regexp.MustCompile(`^[a-zA-Z_:][a-zA-Z0-9_:]*$`)
+
 // A Metric is similar to a LabelSet, but the key difference is that a Metric is
 // a singleton and refers to one and only one stream of samples.
 type Metric LabelSet
@@ -86,17 +309,285 @@ func (m Metric) FastFingerprint() Fingerprint {
 	return LabelSet(m).FastFingerprint()
 }
 
-// IsValidMetricName returns true iff name matches the pattern of MetricNameRE.
+// IsValidMetricName returns true iff name matches the pattern of MetricNameRE
+// for legacy names, and iff it's valid UTF-8 if the UTF8Validation scheme is
+// selected.
+//
+// Deprecated: This function should not be used and might be removed in the future.
+// Use [ValidationScheme.IsValidMetricName] instead.
+func IsValidMetricName(n LabelValue) bool {
+	return NameValidationScheme.IsValidMetricName(string(n))
+}
+
+// IsValidLegacyMetricName is similar to IsValidMetricName but always uses the
+// legacy validation scheme regardless of the value of NameValidationScheme.
 // This function, however, does not use MetricNameRE for the check but a much
 // faster hardcoded implementation.
-func IsValidMetricName(n LabelValue) bool {
-	if len(n) == 0 {
-		return false
+//
+// Deprecated: This function should not be used and might be removed in the future.
+// Use [LegacyValidation.IsValidMetricName] instead.
+func IsValidLegacyMetricName(n string) bool {
+	return LegacyValidation.IsValidMetricName(n)
+}
+
+// EscapeMetricFamily escapes the given metric names and labels with the given
+// escaping scheme. Returns a new object that uses the same pointers to fields
+// when possible and creates new escaped versions so as not to mutate the
+// input.
+func EscapeMetricFamily(v *dto.MetricFamily, scheme EscapingScheme) *dto.MetricFamily {
+	if v == nil {
+		return nil
 	}
-	for i, b := range n {
-		if !((b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || b == ':' || (b >= '0' && b <= '9' && i > 0)) {
-			return false
+
+	if scheme == NoEscaping {
+		return v
+	}
+
+	out := &dto.MetricFamily{
+		Help: v.Help,
+		Type: v.Type,
+		Unit: v.Unit,
+	}
+
+	// If the name is nil, copy as-is, don't try to escape.
+	if v.Name == nil || IsValidLegacyMetricName(v.GetName()) {
+		out.Name = v.Name
+	} else {
+		out.Name = proto.String(EscapeName(v.GetName(), scheme))
+	}
+	for _, m := range v.Metric {
+		if !metricNeedsEscaping(m) {
+			out.Metric = append(out.Metric, m)
+			continue
+		}
+
+		escaped := &dto.Metric{
+			Gauge:       m.Gauge,
+			Counter:     m.Counter,
+			Summary:     m.Summary,
+			Untyped:     m.Untyped,
+			Histogram:   m.Histogram,
+			TimestampMs: m.TimestampMs,
+		}
+
+		for _, l := range m.Label {
+			if l.GetName() == MetricNameLabel {
+				if l.Value == nil || IsValidLegacyMetricName(l.GetValue()) {
+					escaped.Label = append(escaped.Label, l)
+					continue
+				}
+				escaped.Label = append(escaped.Label, &dto.LabelPair{
+					Name:  proto.String(MetricNameLabel),
+					Value: proto.String(EscapeName(l.GetValue(), scheme)),
+				})
+				continue
+			}
+			if l.Name == nil || IsValidLegacyMetricName(l.GetName()) {
+				escaped.Label = append(escaped.Label, l)
+				continue
+			}
+			escaped.Label = append(escaped.Label, &dto.LabelPair{
+				Name:  proto.String(EscapeName(l.GetName(), scheme)),
+				Value: l.Value,
+			})
+		}
+		out.Metric = append(out.Metric, escaped)
+	}
+	return out
+}
+
+func metricNeedsEscaping(m *dto.Metric) bool {
+	for _, l := range m.Label {
+		if l.GetName() == MetricNameLabel && !IsValidLegacyMetricName(l.GetValue()) {
+			return true
+		}
+		if !IsValidLegacyMetricName(l.GetName()) {
+			return true
 		}
 	}
-	return true
+	return false
+}
+
+// EscapeName escapes the incoming name according to the provided escaping
+// scheme. Depending on the rules of escaping, this may cause no change in the
+// string that is returned. (Especially NoEscaping, which by definition is a
+// noop). This function does not do any validation of the name.
+func EscapeName(name string, scheme EscapingScheme) string {
+	if len(name) == 0 {
+		return name
+	}
+	var escaped strings.Builder
+	switch scheme {
+	case NoEscaping:
+		return name
+	case UnderscoreEscaping:
+		if IsValidLegacyMetricName(name) {
+			return name
+		}
+		for i, b := range name {
+			if isValidLegacyRune(b, i) {
+				escaped.WriteRune(b)
+			} else {
+				escaped.WriteRune('_')
+			}
+		}
+		return escaped.String()
+	case DotsEscaping:
+		// Do not early return for legacy valid names, we still escape underscores.
+		for i, b := range name {
+			switch {
+			case b == '_':
+				escaped.WriteString("__")
+			case b == '.':
+				escaped.WriteString("_dot_")
+			case isValidLegacyRune(b, i):
+				escaped.WriteRune(b)
+			default:
+				escaped.WriteString("__")
+			}
+		}
+		return escaped.String()
+	case ValueEncodingEscaping:
+		if IsValidLegacyMetricName(name) {
+			return name
+		}
+		escaped.WriteString("U__")
+		for i, b := range name {
+			switch {
+			case b == '_':
+				escaped.WriteString("__")
+			case isValidLegacyRune(b, i):
+				escaped.WriteRune(b)
+			case !utf8.ValidRune(b):
+				escaped.WriteString("_FFFD_")
+			default:
+				escaped.WriteRune('_')
+				escaped.WriteString(strconv.FormatInt(int64(b), 16))
+				escaped.WriteRune('_')
+			}
+		}
+		return escaped.String()
+	default:
+		panic(fmt.Sprintf("invalid escaping scheme %d", scheme))
+	}
+}
+
+// lower function taken from strconv.atoi.
+func lower(c byte) byte {
+	return c | ('x' - 'X')
+}
+
+// UnescapeName unescapes the incoming name according to the provided escaping
+// scheme if possible. Some schemes are partially or totally non-roundtripable.
+// If any error is enountered, returns the original input.
+func UnescapeName(name string, scheme EscapingScheme) string {
+	if len(name) == 0 {
+		return name
+	}
+	switch scheme {
+	case NoEscaping:
+		return name
+	case UnderscoreEscaping:
+		// It is not possible to unescape from underscore replacement.
+		return name
+	case DotsEscaping:
+		name = strings.ReplaceAll(name, "_dot_", ".")
+		name = strings.ReplaceAll(name, "__", "_")
+		return name
+	case ValueEncodingEscaping:
+		escapedName, found := strings.CutPrefix(name, "U__")
+		if !found {
+			return name
+		}
+
+		var unescaped strings.Builder
+	TOP:
+		for i := 0; i < len(escapedName); i++ {
+			// All non-underscores are treated normally.
+			if escapedName[i] != '_' {
+				unescaped.WriteByte(escapedName[i])
+				continue
+			}
+			i++
+			if i >= len(escapedName) {
+				return name
+			}
+			// A double underscore is a single underscore.
+			if escapedName[i] == '_' {
+				unescaped.WriteByte('_')
+				continue
+			}
+			// We think we are in a UTF-8 code, process it.
+			var utf8Val uint
+			for j := 0; i < len(escapedName); j++ {
+				// This is too many characters for a utf8 value based on the MaxRune
+				// value of '\U0010FFFF'.
+				if j >= 6 {
+					return name
+				}
+				// Found a closing underscore, convert to a rune, check validity, and append.
+				if escapedName[i] == '_' {
+					utf8Rune := rune(utf8Val)
+					if !utf8.ValidRune(utf8Rune) {
+						return name
+					}
+					unescaped.WriteRune(utf8Rune)
+					continue TOP
+				}
+				r := lower(escapedName[i])
+				utf8Val *= 16
+				switch {
+				case r >= '0' && r <= '9':
+					utf8Val += uint(r) - '0'
+				case r >= 'a' && r <= 'f':
+					utf8Val += uint(r) - 'a' + 10
+				default:
+					return name
+				}
+				i++
+			}
+			// Didn't find closing underscore, invalid.
+			return name
+		}
+		return unescaped.String()
+	default:
+		panic(fmt.Sprintf("invalid escaping scheme %d", scheme))
+	}
+}
+
+func isValidLegacyRune(b rune, i int) bool {
+	return (b >= 'a' && b <= 'z') || (b >= 'A' && b <= 'Z') || b == '_' || b == ':' || (b >= '0' && b <= '9' && i > 0)
+}
+
+func (e EscapingScheme) String() string {
+	switch e {
+	case NoEscaping:
+		return AllowUTF8
+	case UnderscoreEscaping:
+		return EscapeUnderscores
+	case DotsEscaping:
+		return EscapeDots
+	case ValueEncodingEscaping:
+		return EscapeValues
+	default:
+		panic(fmt.Sprintf("unknown format scheme %d", e))
+	}
+}
+
+func ToEscapingScheme(s string) (EscapingScheme, error) {
+	if s == "" {
+		return NoEscaping, errors.New("got empty string instead of escaping scheme")
+	}
+	switch s {
+	case AllowUTF8:
+		return NoEscaping, nil
+	case EscapeUnderscores:
+		return UnderscoreEscaping, nil
+	case EscapeDots:
+		return DotsEscaping, nil
+	case EscapeValues:
+		return ValueEncodingEscaping, nil
+	default:
+		return NoEscaping, fmt.Errorf("unknown format scheme %s", s)
+	}
 }

vendor/github.com/prometheus/common/model/signature.go

@@ -22,10 +22,8 @@ import (
 // when calculating their combined hash value (aka signature aka fingerprint).
 const SeparatorByte byte = 255
 
-var (
-	// cache the signature of an empty label set.
-	emptyLabelSignature = hashNew()
-)
+// cache the signature of an empty label set.
+var emptyLabelSignature = hashNew()
 
 // LabelsToSignature returns a quasi-unique signature (i.e., fingerprint) for a
 // given label set. (Collisions are possible but unlikely if the number of label

vendor/github.com/prometheus/common/model/silence.go

@@ -15,6 +15,7 @@ package model
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"regexp"
 	"time"
@@ -34,7 +35,7 @@ func (m *Matcher) UnmarshalJSON(b []byte) error {
 	}
 
 	if len(m.Name) == 0 {
-		return fmt.Errorf("label name in matcher must not be empty")
+		return errors.New("label name in matcher must not be empty")
 	}
 	if m.IsRegex {
 		if _, err := regexp.Compile(m.Value); err != nil {
@@ -77,30 +78,30 @@ type Silence struct {
 // Validate returns true iff all fields of the silence have valid values.
 func (s *Silence) Validate() error {
 	if len(s.Matchers) == 0 {
-		return fmt.Errorf("at least one matcher required")
+		return errors.New("at least one matcher required")
 	}
 	for _, m := range s.Matchers {
 		if err := m.Validate(); err != nil {
-			return fmt.Errorf("invalid matcher: %s", err)
+			return fmt.Errorf("invalid matcher: %w", err)
 		}
 	}
 	if s.StartsAt.IsZero() {
-		return fmt.Errorf("start time missing")
+		return errors.New("start time missing")
 	}
 	if s.EndsAt.IsZero() {
-		return fmt.Errorf("end time missing")
+		return errors.New("end time missing")
 	}
 	if s.EndsAt.Before(s.StartsAt) {
-		return fmt.Errorf("start time must be before end time")
+		return errors.New("start time must be before end time")
 	}
 	if s.CreatedBy == "" {
-		return fmt.Errorf("creator information missing")
+		return errors.New("creator information missing")
 	}
 	if s.Comment == "" {
-		return fmt.Errorf("comment missing")
+		return errors.New("comment missing")
 	}
 	if s.CreatedAt.IsZero() {
-		return fmt.Errorf("creation timestamp missing")
+		return errors.New("creation timestamp missing")
 	}
 	return nil
 }

vendor/github.com/prometheus/common/model/time.go

@@ -126,14 +126,14 @@ func (t *Time) UnmarshalJSON(b []byte) error {
 	p := strings.Split(string(b), ".")
 	switch len(p) {
 	case 1:
-		v, err := strconv.ParseInt(string(p[0]), 10, 64)
+		v, err := strconv.ParseInt(p[0], 10, 64)
 		if err != nil {
 			return err
 		}
 		*t = Time(v * second)
 
 	case 2:
-		v, err := strconv.ParseInt(string(p[0]), 10, 64)
+		v, err := strconv.ParseInt(p[0], 10, 64)
 		if err != nil {
 			return err
 		}
@@ -143,7 +143,7 @@ func (t *Time) UnmarshalJSON(b []byte) error {
 		if prec < 0 {
 			p[1] = p[1][:dotPrecision]
 		} else if prec > 0 {
-			p[1] = p[1] + strings.Repeat("0", prec)
+			p[1] += strings.Repeat("0", prec)
 		}
 
 		va, err := strconv.ParseInt(p[1], 10, 32)
@@ -170,15 +170,15 @@ func (t *Time) UnmarshalJSON(b []byte) error {
 // This type should not propagate beyond the scope of input/output processing.
 type Duration time.Duration
 
-// Set implements pflag/flag.Value
+// Set implements pflag/flag.Value.
 func (d *Duration) Set(s string) error {
 	var err error
 	*d, err = ParseDuration(s)
 	return err
 }
 
-// Type implements pflag.Value
-func (d *Duration) Type() string {
+// Type implements pflag.Value.
+func (*Duration) Type() string {
 	return "duration"
 }
 
@@ -201,6 +201,7 @@ var unitMap = map[string]struct {
 
 // ParseDuration parses a string into a time.Duration, assuming that a year
 // always has 365d, a week always has 7d, and a day always has 24h.
+// Negative durations are not supported.
 func ParseDuration(s string) (Duration, error) {
 	switch s {
 	case "0":
@@ -253,18 +254,36 @@ func ParseDuration(s string) (Duration, error) {
 			return 0, errors.New("duration out of range")
 		}
 	}
+
 	return Duration(dur), nil
 }
 
+// ParseDurationAllowNegative is like ParseDuration but also accepts negative durations.
+func ParseDurationAllowNegative(s string) (Duration, error) {
+	if s == "" || s[0] != '-' {
+		return ParseDuration(s)
+	}
+
+	d, err := ParseDuration(s[1:])
+
+	return -d, err
+}
+
 func (d Duration) String() string {
 	var (
-		ms = int64(time.Duration(d) / time.Millisecond)
-		r  = ""
+		ms   = int64(time.Duration(d) / time.Millisecond)
+		r    = ""
+		sign = ""
 	)
+
 	if ms == 0 {
 		return "0s"
 	}
 
+	if ms < 0 {
+		sign, ms = "-", -ms
+	}
+
 	f := func(unit string, mult int64, exact bool) {
 		if exact && ms%mult != 0 {
 			return
@@ -286,7 +305,7 @@ func (d Duration) String() string {
 	f("s", 1000, false)
 	f("ms", 1, false)
 
-	return r
+	return sign + r
 }
 
 // MarshalJSON implements the json.Marshaler interface.

vendor/github.com/prometheus/common/model/value.go

@@ -21,14 +21,12 @@ import (
 	"strings"
 )
 
-var (
-	// ZeroSample is the pseudo zero-value of Sample used to signal a
-	// non-existing sample. It is a Sample with timestamp Earliest, value 0.0,
-	// and metric nil. Note that the natural zero value of Sample has a timestamp
-	// of 0, which is possible to appear in a real Sample and thus not suitable
-	// to signal a non-existing Sample.
-	ZeroSample = Sample{Timestamp: Earliest}
-)
+// ZeroSample is the pseudo zero-value of Sample used to signal a
+// non-existing sample. It is a Sample with timestamp Earliest, value 0.0,
+// and metric nil. Note that the natural zero value of Sample has a timestamp
+// of 0, which is possible to appear in a real Sample and thus not suitable
+// to signal a non-existing Sample.
+var ZeroSample = Sample{Timestamp: Earliest}
 
 // Sample is a sample pair associated with a metric. A single sample must either
 // define Value or Histogram but not both. Histogram == nil implies the Value
@@ -193,7 +191,8 @@ func (ss SampleStream) String() string {
 }
 
 func (ss SampleStream) MarshalJSON() ([]byte, error) {
-	if len(ss.Histograms) > 0 && len(ss.Values) > 0 {
+	switch {
+	case len(ss.Histograms) > 0 && len(ss.Values) > 0:
 		v := struct {
 			Metric     Metric                `json:"metric"`
 			Values     []SamplePair          `json:"values"`
@@ -204,7 +203,7 @@ func (ss SampleStream) MarshalJSON() ([]byte, error) {
 			Histograms: ss.Histograms,
 		}
 		return json.Marshal(&v)
-	} else if len(ss.Histograms) > 0 {
+	case len(ss.Histograms) > 0:
 		v := struct {
 			Metric     Metric                `json:"metric"`
 			Histograms []SampleHistogramPair `json:"histograms"`
@@ -213,7 +212,7 @@ func (ss SampleStream) MarshalJSON() ([]byte, error) {
 			Histograms: ss.Histograms,
 		}
 		return json.Marshal(&v)
-	} else {
+	default:
 		v := struct {
 			Metric Metric       `json:"metric"`
 			Values []SamplePair `json:"values"`
@@ -260,7 +259,7 @@ func (s Scalar) String() string {
 // MarshalJSON implements json.Marshaler.
 func (s Scalar) MarshalJSON() ([]byte, error) {
 	v := strconv.FormatFloat(float64(s.Value), 'f', -1, 64)
-	return json.Marshal([...]interface{}{s.Timestamp, string(v)})
+	return json.Marshal([...]interface{}{s.Timestamp, v})
 }
 
 // UnmarshalJSON implements json.Unmarshaler.
@@ -274,7 +273,7 @@ func (s *Scalar) UnmarshalJSON(b []byte) error {
 
 	value, err := strconv.ParseFloat(f, 64)
 	if err != nil {
-		return fmt.Errorf("error parsing sample value: %s", err)
+		return fmt.Errorf("error parsing sample value: %w", err)
 	}
 	s.Value = SampleValue(value)
 	return nil
@@ -351,9 +350,9 @@ func (m Matrix) Len() int           { return len(m) }
 func (m Matrix) Less(i, j int) bool { return m[i].Metric.Before(m[j].Metric) }
 func (m Matrix) Swap(i, j int)      { m[i], m[j] = m[j], m[i] }
 
-func (mat Matrix) String() string {
-	matCp := make(Matrix, len(mat))
-	copy(matCp, mat)
+func (m Matrix) String() string {
+	matCp := make(Matrix, len(m))
+	copy(matCp, m)
 	sort.Sort(matCp)
 
 	strs := make([]string, len(matCp))

vendor/github.com/prometheus/common/model/value_float.go

@@ -15,19 +15,18 @@ package model
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"math"
 	"strconv"
 )
 
-var (
-	// ZeroSamplePair is the pseudo zero-value of SamplePair used to signal a
-	// non-existing sample pair. It is a SamplePair with timestamp Earliest and
-	// value 0.0. Note that the natural zero value of SamplePair has a timestamp
-	// of 0, which is possible to appear in a real SamplePair and thus not
-	// suitable to signal a non-existing SamplePair.
-	ZeroSamplePair = SamplePair{Timestamp: Earliest}
-)
+// ZeroSamplePair is the pseudo zero-value of SamplePair used to signal a
+// non-existing sample pair. It is a SamplePair with timestamp Earliest and
+// value 0.0. Note that the natural zero value of SamplePair has a timestamp
+// of 0, which is possible to appear in a real SamplePair and thus not
+// suitable to signal a non-existing SamplePair.
+var ZeroSamplePair = SamplePair{Timestamp: Earliest}
 
 // A SampleValue is a representation of a value for a given sample at a given
 // time.
@@ -41,7 +40,7 @@ func (v SampleValue) MarshalJSON() ([]byte, error) {
 // UnmarshalJSON implements json.Unmarshaler.
 func (v *SampleValue) UnmarshalJSON(b []byte) error {
 	if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
-		return fmt.Errorf("sample value must be a quoted string")
+		return errors.New("sample value must be a quoted string")
 	}
 	f, err := strconv.ParseFloat(string(b[1:len(b)-1]), 64)
 	if err != nil {

vendor/github.com/prometheus/common/model/value_histogram.go

@@ -15,6 +15,7 @@ package model
 
 import (
 	"encoding/json"
+	"errors"
 	"fmt"
 	"strconv"
 	"strings"
@@ -32,7 +33,7 @@ func (v FloatString) MarshalJSON() ([]byte, error) {
 
 func (v *FloatString) UnmarshalJSON(b []byte) error {
 	if len(b) < 2 || b[0] != '"' || b[len(b)-1] != '"' {
-		return fmt.Errorf("float value must be a quoted string")
+		return errors.New("float value must be a quoted string")
 	}
 	f, err := strconv.ParseFloat(string(b[1:len(b)-1]), 64)
 	if err != nil {
@@ -85,22 +86,22 @@ func (s *HistogramBucket) Equal(o *HistogramBucket) bool {
 	return s == o || (s.Boundaries == o.Boundaries && s.Lower == o.Lower && s.Upper == o.Upper && s.Count == o.Count)
 }
 
-func (b HistogramBucket) String() string {
+func (s HistogramBucket) String() string {
 	var sb strings.Builder
-	lowerInclusive := b.Boundaries == 1 || b.Boundaries == 3
-	upperInclusive := b.Boundaries == 0 || b.Boundaries == 3
+	lowerInclusive := s.Boundaries == 1 || s.Boundaries == 3
+	upperInclusive := s.Boundaries == 0 || s.Boundaries == 3
 	if lowerInclusive {
 		sb.WriteRune('[')
 	} else {
 		sb.WriteRune('(')
 	}
-	fmt.Fprintf(&sb, "%g,%g", b.Lower, b.Upper)
+	fmt.Fprintf(&sb, "%g,%g", s.Lower, s.Upper)
 	if upperInclusive {
 		sb.WriteRune(']')
 	} else {
 		sb.WriteRune(')')
 	}
-	fmt.Fprintf(&sb, ":%v", b.Count)
+	fmt.Fprintf(&sb, ":%v", s.Count)
 	return sb.String()
 }
 
@@ -141,7 +142,7 @@ type SampleHistogramPair struct {
 
 func (s SampleHistogramPair) MarshalJSON() ([]byte, error) {
 	if s.Histogram == nil {
-		return nil, fmt.Errorf("histogram is nil")
+		return nil, errors.New("histogram is nil")
 	}
 	t, err := json.Marshal(s.Timestamp)
 	if err != nil {
@@ -164,7 +165,7 @@ func (s *SampleHistogramPair) UnmarshalJSON(buf []byte) error {
 		return fmt.Errorf("wrong number of fields: %d != %d", gotLen, wantLen)
 	}
 	if s.Histogram == nil {
-		return fmt.Errorf("histogram is null")
+		return errors.New("histogram is null")
 	}
 	return nil
 }

vendor/github.com/prometheus/common/model/value_type.go

@@ -66,8 +66,8 @@ func (et *ValueType) UnmarshalJSON(b []byte) error {
 	return nil
 }
 
-func (e ValueType) String() string {
-	switch e {
+func (et ValueType) String() string {
+	switch et {
 	case ValNone:
 		return "<ValNone>"
 	case ValScalar: