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Diffstat (limited to 'vendor/github.com/prometheus/common/model/labelset.go')
-rw-r--r-- | vendor/github.com/prometheus/common/model/labelset.go | 169 |
1 files changed, 169 insertions, 0 deletions
diff --git a/vendor/github.com/prometheus/common/model/labelset.go b/vendor/github.com/prometheus/common/model/labelset.go new file mode 100644 index 000000000..6eda08a73 --- /dev/null +++ b/vendor/github.com/prometheus/common/model/labelset.go @@ -0,0 +1,169 @@ +// 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" + "sort" + "strings" +) + +// A LabelSet is a collection of LabelName and LabelValue pairs. The LabelSet +// may be fully-qualified down to the point where it may resolve to a single +// Metric in the data store or not. All operations that occur within the realm +// of a LabelSet can emit a vector of Metric entities to which the LabelSet may +// match. +type LabelSet map[LabelName]LabelValue + +// Validate checks whether all names and values in the label set +// are valid. +func (ls LabelSet) Validate() error { + for ln, lv := range ls { + if !ln.IsValid() { + return fmt.Errorf("invalid name %q", ln) + } + if !lv.IsValid() { + return fmt.Errorf("invalid value %q", lv) + } + } + return nil +} + +// Equal returns true iff both label sets have exactly the same key/value pairs. +func (ls LabelSet) Equal(o LabelSet) bool { + if len(ls) != len(o) { + return false + } + for ln, lv := range ls { + olv, ok := o[ln] + if !ok { + return false + } + if olv != lv { + return false + } + } + return true +} + +// Before compares the metrics, using the following criteria: +// +// If m has fewer labels than o, it is before o. If it has more, it is not. +// +// If the number of labels is the same, the superset of all label names is +// sorted alphanumerically. The first differing label pair found in that order +// determines the outcome: If the label does not exist at all in m, then m is +// before o, and vice versa. Otherwise the label value is compared +// alphanumerically. +// +// If m and o are equal, the method returns false. +func (ls LabelSet) Before(o LabelSet) bool { + if len(ls) < len(o) { + return true + } + if len(ls) > len(o) { + return false + } + + lns := make(LabelNames, 0, len(ls)+len(o)) + for ln := range ls { + lns = append(lns, ln) + } + for ln := range o { + lns = append(lns, ln) + } + // It's probably not worth it to de-dup lns. + sort.Sort(lns) + for _, ln := range lns { + mlv, ok := ls[ln] + if !ok { + return true + } + olv, ok := o[ln] + if !ok { + return false + } + if mlv < olv { + return true + } + if mlv > olv { + return false + } + } + return false +} + +// Clone returns a copy of the label set. +func (ls LabelSet) Clone() LabelSet { + lsn := make(LabelSet, len(ls)) + for ln, lv := range ls { + lsn[ln] = lv + } + return lsn +} + +// Merge is a helper function to non-destructively merge two label sets. +func (l LabelSet) Merge(other LabelSet) LabelSet { + result := make(LabelSet, len(l)) + + for k, v := range l { + result[k] = v + } + + for k, v := range other { + result[k] = v + } + + 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) +} + +// FastFingerprint returns the LabelSet's Fingerprint calculated by a faster hashing +// algorithm, which is, however, more susceptible to hash collisions. +func (ls LabelSet) FastFingerprint() Fingerprint { + return labelSetToFastFingerprint(ls) +} + +// UnmarshalJSON implements the json.Unmarshaler interface. +func (l *LabelSet) UnmarshalJSON(b []byte) error { + var m map[LabelName]LabelValue + if err := json.Unmarshal(b, &m); err != nil { + return err + } + // encoding/json only unmarshals maps of the form map[string]T. It treats + // LabelName as a string and does not call its UnmarshalJSON method. + // Thus, we have to replicate the behavior here. + for ln := range m { + if !ln.IsValid() { + return fmt.Errorf("%q is not a valid label name", ln) + } + } + *l = LabelSet(m) + return nil +} |