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Diffstat (limited to 'vendor/github.com/prometheus/common/model/signature.go')
-rw-r--r-- | vendor/github.com/prometheus/common/model/signature.go | 144 |
1 files changed, 0 insertions, 144 deletions
diff --git a/vendor/github.com/prometheus/common/model/signature.go b/vendor/github.com/prometheus/common/model/signature.go deleted file mode 100644 index 8762b13c6..000000000 --- a/vendor/github.com/prometheus/common/model/signature.go +++ /dev/null @@ -1,144 +0,0 @@ -// Copyright 2014 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 ( - "sort" -) - -// SeparatorByte is a byte that cannot occur in valid UTF-8 sequences and is -// used to separate label names, label values, and other strings from each other -// when calculating their combined hash value (aka signature aka fingerprint). -const SeparatorByte byte = 255 - -var ( - // cache the signature of an empty label set. - emptyLabelSignature = hashNew() -) - -// LabelsToSignature returns a quasi-unique signature (i.e., fingerprint) for a -// given label set. (Collisions are possible but unlikely if the number of label -// sets the function is applied to is small.) -func LabelsToSignature(labels map[string]string) uint64 { - if len(labels) == 0 { - return emptyLabelSignature - } - - labelNames := make([]string, 0, len(labels)) - for labelName := range labels { - labelNames = append(labelNames, labelName) - } - sort.Strings(labelNames) - - sum := hashNew() - for _, labelName := range labelNames { - sum = hashAdd(sum, labelName) - sum = hashAddByte(sum, SeparatorByte) - sum = hashAdd(sum, labels[labelName]) - sum = hashAddByte(sum, SeparatorByte) - } - return sum -} - -// labelSetToFingerprint works exactly as LabelsToSignature but takes a LabelSet as -// parameter (rather than a label map) and returns a Fingerprint. -func labelSetToFingerprint(ls LabelSet) Fingerprint { - if len(ls) == 0 { - return Fingerprint(emptyLabelSignature) - } - - labelNames := make(LabelNames, 0, len(ls)) - for labelName := range ls { - labelNames = append(labelNames, labelName) - } - sort.Sort(labelNames) - - sum := hashNew() - for _, labelName := range labelNames { - sum = hashAdd(sum, string(labelName)) - sum = hashAddByte(sum, SeparatorByte) - sum = hashAdd(sum, string(ls[labelName])) - sum = hashAddByte(sum, SeparatorByte) - } - return Fingerprint(sum) -} - -// labelSetToFastFingerprint works similar to labelSetToFingerprint but uses a -// faster and less allocation-heavy hash function, which is more susceptible to -// create hash collisions. Therefore, collision detection should be applied. -func labelSetToFastFingerprint(ls LabelSet) Fingerprint { - if len(ls) == 0 { - return Fingerprint(emptyLabelSignature) - } - - var result uint64 - for labelName, labelValue := range ls { - sum := hashNew() - sum = hashAdd(sum, string(labelName)) - sum = hashAddByte(sum, SeparatorByte) - sum = hashAdd(sum, string(labelValue)) - result ^= sum - } - return Fingerprint(result) -} - -// SignatureForLabels works like LabelsToSignature but takes a Metric as -// parameter (rather than a label map) and only includes the labels with the -// specified LabelNames into the signature calculation. The labels passed in -// will be sorted by this function. -func SignatureForLabels(m Metric, labels ...LabelName) uint64 { - if len(labels) == 0 { - return emptyLabelSignature - } - - sort.Sort(LabelNames(labels)) - - sum := hashNew() - for _, label := range labels { - sum = hashAdd(sum, string(label)) - sum = hashAddByte(sum, SeparatorByte) - sum = hashAdd(sum, string(m[label])) - sum = hashAddByte(sum, SeparatorByte) - } - return sum -} - -// SignatureWithoutLabels works like LabelsToSignature but takes a Metric as -// parameter (rather than a label map) and excludes the labels with any of the -// specified LabelNames from the signature calculation. -func SignatureWithoutLabels(m Metric, labels map[LabelName]struct{}) uint64 { - if len(m) == 0 { - return emptyLabelSignature - } - - labelNames := make(LabelNames, 0, len(m)) - for labelName := range m { - if _, exclude := labels[labelName]; !exclude { - labelNames = append(labelNames, labelName) - } - } - if len(labelNames) == 0 { - return emptyLabelSignature - } - sort.Sort(labelNames) - - sum := hashNew() - for _, labelName := range labelNames { - sum = hashAdd(sum, string(labelName)) - sum = hashAddByte(sum, SeparatorByte) - sum = hashAdd(sum, string(m[labelName])) - sum = hashAddByte(sum, SeparatorByte) - } - return sum -} |