65 lines
1.4 KiB
Go
65 lines
1.4 KiB
Go
// Copyright (c) 2013, Prometheus Team
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// All rights reserved.
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//
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package prometheus
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import (
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"hash/fnv"
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"sort"
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"github.com/prometheus/client_golang/model"
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)
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// cache the signature of an empty label set.
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var emptyLabelSignature = fnv.New64a().Sum64()
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// LabelsToSignature provides a way of building a unique signature
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// (i.e., fingerprint) for a given label set sequence.
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func LabelsToSignature(labels map[string]string) uint64 {
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if len(labels) == 0 {
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return emptyLabelSignature
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}
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names := make(model.LabelNames, 0, len(labels))
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for name := range labels {
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names = append(names, model.LabelName(name))
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}
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sort.Sort(names)
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hasher := fnv.New64a()
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for _, name := range names {
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hasher.Write([]byte(name))
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hasher.Write([]byte(labels[string(name)]))
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}
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return hasher.Sum64()
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}
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// LabelValuesToSignature provides a way of building a unique signature
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// (i.e., fingerprint) for a given set of label's values.
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func labelValuesToSignature(labels map[string]string) uint64 {
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if len(labels) == 0 {
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return emptyLabelSignature
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}
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names := make(model.LabelNames, 0, len(labels))
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for name := range labels {
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names = append(names, model.LabelName(name))
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}
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sort.Sort(names)
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hasher := fnv.New64a()
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for _, name := range names {
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hasher.Write([]byte(labels[string(name)]))
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}
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return hasher.Sum64()
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}
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