Dependencies for the affinity router and the
affinity routing daemon.
Change-Id: Icda72c3594ef7f8f0bc0c33dc03087a4c25529ca
diff --git a/vendor/github.com/prometheus/common/model/signature.go b/vendor/github.com/prometheus/common/model/signature.go
new file mode 100644
index 0000000..8762b13
--- /dev/null
+++ b/vendor/github.com/prometheus/common/model/signature.go
@@ -0,0 +1,144 @@
+// 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
+}