DockerCLI/vendor/github.com/prometheus/common/model/labelset_string.go

46 lines
1.3 KiB
Go

// Copyright 2024 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.
//go:build go1.21
package model
import (
"bytes"
"slices"
"strconv"
)
// String will look like `{foo="bar", more="less"}`. Names are sorted alphabetically.
func (l LabelSet) String() string {
var lna [32]string // On stack to avoid memory allocation for sorting names.
labelNames := lna[:0]
for name := range l {
labelNames = append(labelNames, string(name))
}
slices.Sort(labelNames)
var bytea [1024]byte // On stack to avoid memory allocation while building the output.
b := bytes.NewBuffer(bytea[:0])
b.WriteByte('{')
for i, name := range labelNames {
if i > 0 {
b.WriteString(", ")
}
b.WriteString(name)
b.WriteByte('=')
b.Write(strconv.AppendQuote(b.AvailableBuffer(), string(l[LabelName(name)])))
}
b.WriteByte('}')
return b.String()
}