terraform/vendor/github.com/vmihailenco/msgpack/encode.go

171 lines
3.3 KiB
Go

package msgpack
import (
"bytes"
"io"
"reflect"
"time"
"github.com/vmihailenco/msgpack/codes"
)
type writer interface {
io.Writer
WriteByte(byte) error
WriteString(string) (int, error)
}
type byteWriter struct {
io.Writer
buf []byte
bootstrap [64]byte
}
func newByteWriter(w io.Writer) *byteWriter {
bw := &byteWriter{
Writer: w,
}
bw.buf = bw.bootstrap[:]
return bw
}
func (w *byteWriter) WriteByte(c byte) error {
w.buf = w.buf[:1]
w.buf[0] = c
_, err := w.Write(w.buf)
return err
}
func (w *byteWriter) WriteString(s string) (int, error) {
w.buf = append(w.buf[:0], s...)
return w.Write(w.buf)
}
// Marshal returns the MessagePack encoding of v.
func Marshal(v interface{}) ([]byte, error) {
var buf bytes.Buffer
err := NewEncoder(&buf).Encode(v)
return buf.Bytes(), err
}
type Encoder struct {
w writer
buf []byte
sortMapKeys bool
structAsArray bool
useJSONTag bool
useCompact bool
}
// NewEncoder returns a new encoder that writes to w.
func NewEncoder(w io.Writer) *Encoder {
bw, ok := w.(writer)
if !ok {
bw = newByteWriter(w)
}
return &Encoder{
w: bw,
buf: make([]byte, 9),
}
}
// SortMapKeys causes the Encoder to encode map keys in increasing order.
// Supported map types are:
// - map[string]string
// - map[string]interface{}
func (e *Encoder) SortMapKeys(flag bool) *Encoder {
e.sortMapKeys = flag
return e
}
// StructAsArray causes the Encoder to encode Go structs as MessagePack arrays.
func (e *Encoder) StructAsArray(flag bool) *Encoder {
e.structAsArray = flag
return e
}
// UseJSONTag causes the Encoder to use json struct tag as fallback option
// if there is no msgpack tag.
func (e *Encoder) UseJSONTag(flag bool) *Encoder {
e.useJSONTag = flag
return e
}
// UseCompactEncoding causes the Encoder to chose the most compact encoding.
// For example, it allows to encode Go int64 as msgpack int8 saving 7 bytes.
func (e *Encoder) UseCompactEncoding(flag bool) *Encoder {
e.useCompact = flag
return e
}
func (e *Encoder) Encode(v interface{}) error {
switch v := v.(type) {
case nil:
return e.EncodeNil()
case string:
return e.EncodeString(v)
case []byte:
return e.EncodeBytes(v)
case int:
return e.encodeInt64Cond(int64(v))
case int64:
return e.encodeInt64Cond(v)
case uint:
return e.encodeUint64Cond(uint64(v))
case uint64:
return e.encodeUint64Cond(v)
case bool:
return e.EncodeBool(v)
case float32:
return e.EncodeFloat32(v)
case float64:
return e.EncodeFloat64(v)
case time.Duration:
return e.encodeInt64Cond(int64(v))
case time.Time:
return e.EncodeTime(v)
}
return e.EncodeValue(reflect.ValueOf(v))
}
func (e *Encoder) EncodeMulti(v ...interface{}) error {
for _, vv := range v {
if err := e.Encode(vv); err != nil {
return err
}
}
return nil
}
func (e *Encoder) EncodeValue(v reflect.Value) error {
fn := getEncoder(v.Type())
return fn(e, v)
}
func (e *Encoder) EncodeNil() error {
return e.writeCode(codes.Nil)
}
func (e *Encoder) EncodeBool(value bool) error {
if value {
return e.writeCode(codes.True)
}
return e.writeCode(codes.False)
}
func (e *Encoder) writeCode(c codes.Code) error {
return e.w.WriteByte(byte(c))
}
func (e *Encoder) write(b []byte) error {
_, err := e.w.Write(b)
return err
}
func (e *Encoder) writeString(s string) error {
_, err := e.w.WriteString(s)
return err
}