telegraf/plugins/parsers/influx/escape.go

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package influx
import (
"bytes"
"reflect"
"strconv"
"strings"
"unsafe"
)
const (
escapes = " ,="
nameEscapes = " ,"
stringFieldEscapes = `\"`
)
var (
unescaper = strings.NewReplacer(
`\,`, `,`,
`\"`, `"`, // ???
`\ `, ` `,
`\=`, `=`,
)
nameUnescaper = strings.NewReplacer(
`\,`, `,`,
`\ `, ` `,
)
stringFieldUnescaper = strings.NewReplacer(
`\"`, `"`,
`\\`, `\`,
)
)
func unescape(b []byte) string {
if bytes.ContainsAny(b, escapes) {
return unescaper.Replace(unsafeBytesToString(b))
} else {
return string(b)
}
}
func nameUnescape(b []byte) string {
if bytes.ContainsAny(b, nameEscapes) {
return nameUnescaper.Replace(unsafeBytesToString(b))
} else {
return string(b)
}
}
func stringFieldUnescape(b []byte) string {
if bytes.ContainsAny(b, stringFieldEscapes) {
return stringFieldUnescaper.Replace(unsafeBytesToString(b))
} else {
return string(b)
}
}
// parseIntBytes is a zero-alloc wrapper around strconv.ParseInt.
func parseIntBytes(b []byte, base int, bitSize int) (i int64, err error) {
s := unsafeBytesToString(b)
return strconv.ParseInt(s, base, bitSize)
}
// parseFloatBytes is a zero-alloc wrapper around strconv.ParseFloat.
func parseFloatBytes(b []byte, bitSize int) (float64, error) {
s := unsafeBytesToString(b)
return strconv.ParseFloat(s, bitSize)
}
// parseBoolBytes is a zero-alloc wrapper around strconv.ParseBool.
func parseBoolBytes(b []byte) (bool, error) {
return strconv.ParseBool(unsafeBytesToString(b))
}
// unsafeBytesToString converts a []byte to a string without a heap allocation.
//
// It is unsafe, and is intended to prepare input to short-lived functions
// that require strings.
func unsafeBytesToString(in []byte) string {
src := *(*reflect.SliceHeader)(unsafe.Pointer(&in))
dst := reflect.StringHeader{
Data: src.Data,
Len: src.Len,
}
s := *(*string)(unsafe.Pointer(&dst))
return s
}