forked from mirror/client_golang
138 lines
3.1 KiB
Go
138 lines
3.1 KiB
Go
// Copyright 2013 Prometheus Team
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package model
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import (
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"encoding/binary"
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"fmt"
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"hash/fnv"
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"sort"
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"strconv"
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)
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// Fingerprint provides a hash-capable representation of a Metric.
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// For our purposes, FNV-1A 64-bit is used.
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type Fingerprint uint64
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func (f Fingerprint) String() string {
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return fmt.Sprintf("%016x", uint64(f))
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}
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// Less implements sort.Interface.
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func (f Fingerprint) Less(o Fingerprint) bool {
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return f < o
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}
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// Equal implements sort.Interface.
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func (f Fingerprint) Equal(o Fingerprint) bool {
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return f == o
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}
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// LoadFromString transforms a string representation into a Fingerprint.
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func (f *Fingerprint) LoadFromString(s string) error {
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num, err := strconv.ParseUint(s, 16, 64)
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if err != nil {
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return err
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}
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*f = Fingerprint(num)
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return nil
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}
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// LoadFromMetric decomposes a Metric into this Fingerprint
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func (f *Fingerprint) LoadFromMetric(m Metric) {
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labelLength := len(m)
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labelNames := make([]string, 0, labelLength)
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for labelName := range m {
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labelNames = append(labelNames, string(labelName))
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}
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sort.Strings(labelNames)
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summer := fnv.New64a()
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for _, labelName := range labelNames {
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labelValue := m[LabelName(labelName)]
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summer.Write([]byte(labelName))
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summer.Write([]byte{0})
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summer.Write([]byte(labelValue))
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}
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*f = Fingerprint(binary.LittleEndian.Uint64(summer.Sum(nil)))
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}
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// Fingerprints represents a collection of Fingerprint subject to a given
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// natural sorting scheme. It implements sort.Interface.
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type Fingerprints []Fingerprint
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// Len implements sort.Interface.
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func (f Fingerprints) Len() int {
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return len(f)
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}
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// Less implements sort.Interface.
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func (f Fingerprints) Less(i, j int) bool {
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return f[i] < f[j]
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}
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// Swap implements sort.Interface.
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func (f Fingerprints) Swap(i, j int) {
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f[i], f[j] = f[j], f[i]
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}
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// FingerprintSet is a set of Fingerprints.
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type FingerprintSet map[Fingerprint]struct{}
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// Equal returns true if both sets contain the same elements (and not more).
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func (s FingerprintSet) Equal(o FingerprintSet) bool {
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if len(s) != len(o) {
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return false
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}
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for k := range s {
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if _, ok := o[k]; !ok {
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return false
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}
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}
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return true
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}
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// Intersection returns the elements contained in both sets.
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func (s FingerprintSet) Intersection(o FingerprintSet) FingerprintSet {
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myLength, otherLength := len(s), len(o)
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if myLength == 0 || otherLength == 0 {
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return FingerprintSet{}
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}
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subSet := s
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superSet := o
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if otherLength < myLength {
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subSet = o
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superSet = s
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}
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out := FingerprintSet{}
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for k := range subSet {
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if _, ok := superSet[k]; ok {
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out[k] = struct{}{}
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}
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}
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return out
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}
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