88 lines
2.5 KiB
Go
88 lines
2.5 KiB
Go
// Copyright 2018 The Prometheus Authors
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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 prometheus
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import (
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"errors"
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"fmt"
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"strings"
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"unicode/utf8"
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"github.com/prometheus/common/model"
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)
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// Labels represents a collection of label name -> value mappings. This type is
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// commonly used with the With(Labels) and GetMetricWith(Labels) methods of
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// metric vector Collectors, e.g.:
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// myVec.With(Labels{"code": "404", "method": "GET"}).Add(42)
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//
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// The other use-case is the specification of constant label pairs in Opts or to
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// create a Desc.
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type Labels map[string]string
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// reservedLabelPrefix is a prefix which is not legal in user-supplied
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// label names.
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const reservedLabelPrefix = "__"
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var errInconsistentCardinality = errors.New("inconsistent label cardinality")
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func makeInconsistentCardinalityError(fqName string, labels, labelValues []string) error {
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return fmt.Errorf(
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"%s: %q has %d variable labels named %q but %d values %q were provided",
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errInconsistentCardinality, fqName,
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len(labels), labels,
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len(labelValues), labelValues,
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)
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}
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func validateValuesInLabels(labels Labels, expectedNumberOfValues int) error {
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if len(labels) != expectedNumberOfValues {
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return fmt.Errorf(
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"%s: expected %d label values but got %d in %#v",
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errInconsistentCardinality, expectedNumberOfValues,
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len(labels), labels,
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)
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}
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for name, val := range labels {
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if !utf8.ValidString(val) {
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return fmt.Errorf("label %s: value %q is not valid UTF-8", name, val)
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}
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}
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return nil
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}
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func validateLabelValues(vals []string, expectedNumberOfValues int) error {
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if len(vals) != expectedNumberOfValues {
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return fmt.Errorf(
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"%s: expected %d label values but got %d in %#v",
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errInconsistentCardinality, expectedNumberOfValues,
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len(vals), vals,
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)
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}
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for _, val := range vals {
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if !utf8.ValidString(val) {
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return fmt.Errorf("label value %q is not valid UTF-8", val)
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}
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}
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return nil
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}
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func checkLabelName(l string) bool {
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return model.LabelName(l).IsValid() && !strings.HasPrefix(l, reservedLabelPrefix)
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}
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