terraform-provider-gitea/vendor/github.com/vmihailenco/msgpack/v4/intern.go

237 lines
4.6 KiB
Go
Raw Normal View History

2022-04-03 04:07:16 +00:00
package msgpack
import (
"encoding/binary"
"errors"
"fmt"
"math"
"reflect"
"github.com/vmihailenco/msgpack/v4/codes"
)
var internStringExtID int8 = -128
var errUnexpectedCode = errors.New("msgpack: unexpected code")
func encodeInternInterfaceValue(e *Encoder, v reflect.Value) error {
if v.IsNil() {
return e.EncodeNil()
}
v = v.Elem()
if v.Kind() == reflect.String {
return encodeInternStringValue(e, v)
}
return e.EncodeValue(v)
}
func encodeInternStringValue(e *Encoder, v reflect.Value) error {
s := v.String()
if s != "" {
if idx, ok := e.intern[s]; ok {
return e.internStringIndex(idx)
}
if e.intern == nil {
e.intern = make(map[string]int)
}
idx := len(e.intern)
e.intern[s] = idx
}
return e.EncodeString(s)
}
func (e *Encoder) internStringIndex(idx int) error {
if idx < math.MaxUint8 {
if err := e.writeCode(codes.FixExt1); err != nil {
return err
}
if err := e.w.WriteByte(byte(internStringExtID)); err != nil {
return err
}
return e.w.WriteByte(byte(idx))
}
if idx < math.MaxUint16 {
if err := e.writeCode(codes.FixExt2); err != nil {
return err
}
if err := e.w.WriteByte(byte(internStringExtID)); err != nil {
return err
}
if err := e.w.WriteByte(byte(idx >> 8)); err != nil {
return err
}
return e.w.WriteByte(byte(idx))
}
if int64(idx) < math.MaxUint32 {
if err := e.writeCode(codes.FixExt4); err != nil {
return err
}
if err := e.w.WriteByte(byte(internStringExtID)); err != nil {
return err
}
if err := e.w.WriteByte(byte(idx >> 24)); err != nil {
return err
}
if err := e.w.WriteByte(byte(idx >> 16)); err != nil {
return err
}
if err := e.w.WriteByte(byte(idx >> 8)); err != nil {
return err
}
return e.w.WriteByte(byte(idx))
}
return fmt.Errorf("msgpack: intern string index=%d is too large", idx)
}
//------------------------------------------------------------------------------
func decodeInternInterfaceValue(d *Decoder, v reflect.Value) error {
c, err := d.readCode()
if err != nil {
return err
}
s, err := d.internString(c)
if err == nil {
v.Set(reflect.ValueOf(s))
return nil
}
if err != nil && err != errUnexpectedCode {
return err
}
if err := d.s.UnreadByte(); err != nil {
return err
}
return decodeInterfaceValue(d, v)
}
func decodeInternStringValue(d *Decoder, v reflect.Value) error {
if err := mustSet(v); err != nil {
return err
}
c, err := d.readCode()
if err != nil {
return err
}
s, err := d.internString(c)
if err != nil {
if err == errUnexpectedCode {
return fmt.Errorf("msgpack: invalid code=%x decoding intern string", c)
}
return err
}
v.SetString(s)
return nil
}
func (d *Decoder) internString(c codes.Code) (string, error) {
if codes.IsFixedString(c) {
n := int(c & codes.FixedStrMask)
return d.internStringWithLen(n)
}
switch c {
case codes.FixExt1, codes.FixExt2, codes.FixExt4:
typeID, length, err := d.extHeader(c)
if err != nil {
return "", err
}
if typeID != internStringExtID {
err := fmt.Errorf("msgpack: got ext type=%d, wanted %d",
typeID, internStringExtID)
return "", err
}
idx, err := d.internStringIndex(length)
if err != nil {
return "", err
}
return d.internStringAtIndex(idx)
case codes.Str8, codes.Bin8:
n, err := d.uint8()
if err != nil {
return "", err
}
return d.internStringWithLen(int(n))
case codes.Str16, codes.Bin16:
n, err := d.uint16()
if err != nil {
return "", err
}
return d.internStringWithLen(int(n))
case codes.Str32, codes.Bin32:
n, err := d.uint32()
if err != nil {
return "", err
}
return d.internStringWithLen(int(n))
}
return "", errUnexpectedCode
}
func (d *Decoder) internStringIndex(length int) (int, error) {
switch length {
case 1:
c, err := d.s.ReadByte()
if err != nil {
return 0, err
}
return int(c), nil
case 2:
b, err := d.readN(2)
if err != nil {
return 0, err
}
n := binary.BigEndian.Uint16(b)
return int(n), nil
case 4:
b, err := d.readN(4)
if err != nil {
return 0, err
}
n := binary.BigEndian.Uint32(b)
return int(n), nil
}
err := fmt.Errorf("msgpack: unsupported intern string index length=%d", length)
return 0, err
}
func (d *Decoder) internStringAtIndex(idx int) (string, error) {
if idx >= len(d.intern) {
err := fmt.Errorf("msgpack: intern string with index=%d does not exist", idx)
return "", err
}
return d.intern[idx], nil
}
func (d *Decoder) internStringWithLen(n int) (string, error) {
if n <= 0 {
return "", nil
}
s, err := d.stringWithLen(n)
if err != nil {
return "", err
}
d.intern = append(d.intern, s)
return s, nil
}