/
keys.go
95 lines (80 loc) · 2.35 KB
/
keys.go
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// Copyright 2017 Istio 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 memquota
import (
"fmt"
"sort"
"strconv"
"sync"
"istio.io/istio/mixer/pkg/pool"
)
// we maintain a pool of these for use by the makeKey function
type keyWorkspace struct {
keys []string
}
// pool of reusable keyWorkspace structs
var keyWorkspacePool = sync.Pool{New: func() interface{} { return &keyWorkspace{} }}
// makeKey produces a unique key representing the given labels.
func makeKey(name string, labels map[string]interface{}) string {
ws := keyWorkspacePool.Get().(*keyWorkspace)
keys := ws.keys
buf := pool.GetBuffer()
// ensure stable order
for k := range labels {
keys = append(keys, k)
}
sort.Strings(keys)
buf.WriteString(name) // nolint: gas
for _, k := range keys {
buf.WriteString(";") // nolint: gas
buf.WriteString(k) // nolint: gas
buf.WriteString("=") // nolint: gas
switch v := labels[k].(type) {
case string:
buf.WriteString(v) // nolint: gas
case int64:
var bytes [32]byte
buf.Write(strconv.AppendInt(bytes[:], v, 16)) // nolint: gas
case float64:
var bytes [32]byte
buf.Write(strconv.AppendFloat(bytes[:], v, 'b', -1, 64)) // nolint: gas
case bool:
var bytes [32]byte
buf.Write(strconv.AppendBool(bytes[:], v)) // nolint: gas
case []byte:
buf.Write(v) // nolint: gas
case map[string]string:
ws := keyWorkspacePool.Get().(*keyWorkspace)
mk := ws.keys
// ensure stable order
for k2 := range v {
mk = append(mk, k2)
}
sort.Strings(mk)
for _, k2 := range mk {
buf.WriteString(k2) // nolint: gas
buf.WriteString(v[k2]) // nolint: gas
}
ws.keys = keys[:0]
keyWorkspacePool.Put(ws)
default:
buf.WriteString(v.(fmt.Stringer).String()) // nolint: gas
}
}
result := buf.String()
pool.PutBuffer(buf)
ws.keys = keys[:0]
keyWorkspacePool.Put(ws)
return result
}