vendor.github.com.prometheus.common.model.labels.go Maven / Gradle / Ivy
// Copyright 2013 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 (
"encoding/json"
"fmt"
"regexp"
"strings"
"unicode/utf8"
)
const (
// AlertNameLabel is the name of the label containing the an alert's name.
AlertNameLabel = "alertname"
// ExportedLabelPrefix is the prefix to prepend to the label names present in
// exported metrics if a label of the same name is added by the server.
ExportedLabelPrefix = "exported_"
// MetricNameLabel is the label name indicating the metric name of a
// timeseries.
MetricNameLabel = "__name__"
// SchemeLabel is the name of the label that holds the scheme on which to
// scrape a target.
SchemeLabel = "__scheme__"
// AddressLabel is the name of the label that holds the address of
// a scrape target.
AddressLabel = "__address__"
// MetricsPathLabel is the name of the label that holds the path on which to
// scrape a target.
MetricsPathLabel = "__metrics_path__"
// ReservedLabelPrefix is a prefix which is not legal in user-supplied
// label names.
ReservedLabelPrefix = "__"
// MetaLabelPrefix is a prefix for labels that provide meta information.
// Labels with this prefix are used for intermediate label processing and
// will not be attached to time series.
MetaLabelPrefix = "__meta_"
// TmpLabelPrefix is a prefix for temporary labels as part of relabelling.
// Labels with this prefix are used for intermediate label processing and
// will not be attached to time series. This is reserved for use in
// Prometheus configuration files by users.
TmpLabelPrefix = "__tmp_"
// ParamLabelPrefix is a prefix for labels that provide URL parameters
// used to scrape a target.
ParamLabelPrefix = "__param_"
// JobLabel is the label name indicating the job from which a timeseries
// was scraped.
JobLabel = "job"
// InstanceLabel is the label name used for the instance label.
InstanceLabel = "instance"
// BucketLabel is used for the label that defines the upper bound of a
// bucket of a histogram ("le" -> "less or equal").
BucketLabel = "le"
// QuantileLabel is used for the label that defines the quantile in a
// summary.
QuantileLabel = "quantile"
)
// LabelNameRE is a regular expression matching valid label names. Note that the
// IsValid method of LabelName performs the same check but faster than a match
// with this regular expression.
var LabelNameRE = regexp.MustCompile("^[a-zA-Z_][a-zA-Z0-9_]*$")
// A LabelName is a key for a LabelSet or Metric. It has a value associated
// 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.
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
}
// UnmarshalYAML implements the yaml.Unmarshaler interface.
func (ln *LabelName) UnmarshalYAML(unmarshal func(interface{}) error) error {
var s string
if err := unmarshal(&s); err != nil {
return err
}
if !LabelName(s).IsValid() {
return fmt.Errorf("%q is not a valid label name", s)
}
*ln = LabelName(s)
return nil
}
// UnmarshalJSON implements the json.Unmarshaler interface.
func (ln *LabelName) UnmarshalJSON(b []byte) error {
var s string
if err := json.Unmarshal(b, &s); err != nil {
return err
}
if !LabelName(s).IsValid() {
return fmt.Errorf("%q is not a valid label name", s)
}
*ln = LabelName(s)
return nil
}
// LabelNames is a sortable LabelName slice. In implements sort.Interface.
type LabelNames []LabelName
func (l LabelNames) Len() int {
return len(l)
}
func (l LabelNames) Less(i, j int) bool {
return l[i] < l[j]
}
func (l LabelNames) Swap(i, j int) {
l[i], l[j] = l[j], l[i]
}
func (l LabelNames) String() string {
labelStrings := make([]string, 0, len(l))
for _, label := range l {
labelStrings = append(labelStrings, string(label))
}
return strings.Join(labelStrings, ", ")
}
// A LabelValue is an associated value for a LabelName.
type LabelValue string
// IsValid returns true iff the string is a valid UTF8.
func (lv LabelValue) IsValid() bool {
return utf8.ValidString(string(lv))
}
// LabelValues is a sortable LabelValue slice. It implements sort.Interface.
type LabelValues []LabelValue
func (l LabelValues) Len() int {
return len(l)
}
func (l LabelValues) Less(i, j int) bool {
return string(l[i]) < string(l[j])
}
func (l LabelValues) Swap(i, j int) {
l[i], l[j] = l[j], l[i]
}
// LabelPair pairs a name with a value.
type LabelPair struct {
Name LabelName
Value LabelValue
}
// LabelPairs is a sortable slice of LabelPair pointers. It implements
// sort.Interface.
type LabelPairs []*LabelPair
func (l LabelPairs) Len() int {
return len(l)
}
func (l LabelPairs) Less(i, j int) bool {
switch {
case l[i].Name > l[j].Name:
return false
case l[i].Name < l[j].Name:
return true
case l[i].Value > l[j].Value:
return false
case l[i].Value < l[j].Value:
return true
default:
return false
}
}
func (l LabelPairs) Swap(i, j int) {
l[i], l[j] = l[j], l[i]
}