containerd/vendor/github.com/nats-io/nats/encoders/builtin/default_enc.go

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// Copyright 2012-2015 Apcera Inc. All rights reserved.
package builtin
import (
"bytes"
"fmt"
"reflect"
"strconv"
"unsafe"
)
// DefaultEncoder implementation for EncodedConn.
// This encoder will leave []byte and string untouched, but will attempt to
// turn numbers into appropriate strings that can be decoded. It will also
// propely encoded and decode bools. If will encode a struct, but if you want
// to properly handle structures you should use JsonEncoder.
type DefaultEncoder struct {
// Empty
}
var trueB = []byte("true")
var falseB = []byte("false")
var nilB = []byte("")
// Encode
func (je *DefaultEncoder) Encode(subject string, v interface{}) ([]byte, error) {
switch arg := v.(type) {
case string:
bytes := *(*[]byte)(unsafe.Pointer(&arg))
return bytes, nil
case []byte:
return arg, nil
case bool:
if arg {
return trueB, nil
} else {
return falseB, nil
}
case nil:
return nilB, nil
default:
var buf bytes.Buffer
fmt.Fprintf(&buf, "%+v", arg)
return buf.Bytes(), nil
}
}
// Decode
func (je *DefaultEncoder) Decode(subject string, data []byte, vPtr interface{}) error {
// Figure out what it's pointing to...
sData := *(*string)(unsafe.Pointer(&data))
switch arg := vPtr.(type) {
case *string:
*arg = sData
return nil
case *[]byte:
*arg = data
return nil
case *int:
n, err := strconv.ParseInt(sData, 10, 64)
if err != nil {
return err
}
*arg = int(n)
return nil
case *int32:
n, err := strconv.ParseInt(sData, 10, 64)
if err != nil {
return err
}
*arg = int32(n)
return nil
case *int64:
n, err := strconv.ParseInt(sData, 10, 64)
if err != nil {
return err
}
*arg = int64(n)
return nil
case *float32:
n, err := strconv.ParseFloat(sData, 32)
if err != nil {
return err
}
*arg = float32(n)
return nil
case *float64:
n, err := strconv.ParseFloat(sData, 64)
if err != nil {
return err
}
*arg = float64(n)
return nil
case *bool:
b, err := strconv.ParseBool(sData)
if err != nil {
return err
}
*arg = b
return nil
default:
vt := reflect.TypeOf(arg).Elem()
return fmt.Errorf("nats: Default Encoder can't decode to type %s", vt)
}
}