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Diffstat (limited to 'vendor/github.com/prometheus/common/model/labels.go')
-rw-r--r-- | vendor/github.com/prometheus/common/model/labels.go | 210 |
1 files changed, 210 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/common/model/labels.go b/vendor/github.com/prometheus/common/model/labels.go new file mode 100644 index 000000000..41051a01a --- /dev/null +++ b/vendor/github.com/prometheus/common/model/labels.go @@ -0,0 +1,210 @@ +// 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] +} |