51 lines
1.3 KiB
Go
51 lines
1.3 KiB
Go
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// Copyright 2017, OpenCensus Authors
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//
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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 internal
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import (
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"strings"
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"unicode"
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)
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const labelKeySizeLimit = 100
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// Sanitize returns a string that is trunacated to 100 characters if it's too
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// long, and replaces non-alphanumeric characters to underscores.
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func Sanitize(s string) string {
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if len(s) == 0 {
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return s
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}
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if len(s) > labelKeySizeLimit {
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s = s[:labelKeySizeLimit]
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}
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s = strings.Map(sanitizeRune, s)
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if unicode.IsDigit(rune(s[0])) {
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s = "key_" + s
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}
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if s[0] == '_' {
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s = "key" + s
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}
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return s
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}
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// converts anything that is not a letter or digit to an underscore
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func sanitizeRune(r rune) rune {
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if unicode.IsLetter(r) || unicode.IsDigit(r) {
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return r
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}
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// Everything else turns into an underscore
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return '_'
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}
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