func()

in map.go [163:228]

• 51 lines of code
• 12 McCabe index (conditional complexity)

func (d *Decoder) decMapByValue(value reflect.Value) error {
	var (
		tag        byte
		err        error
		entryKey   interface{}
		entryValue interface{}
	)

	// tag, _ = d.readBufByte()
	tag, err = d.ReadByte()
	// check error
	if err != nil {
		return perrors.WithStack(err)
	}

	switch tag {
	case BC_NULL:
		// null map tag check
		return nil
	case BC_REF:
		refObj, decErr := d.decRef(int32(tag))
		if decErr != nil {
			return perrors.WithStack(decErr)
		}
		SetValue(value, EnsurePackValue(refObj))
		return nil
	case BC_MAP:
		d.decString(TAG_READ) // read map type , ignored
	case BC_MAP_UNTYPED:
		// do nothing
	default:
		return perrors.Errorf("expect map header, but get %x", tag)
	}

	m := reflect.MakeMap(UnpackPtrType(value.Type()))
	// pack with pointer, so that to ref the same map
	m = PackPtr(m)
	d.appendRefs(m)

	// read key and value
	for {
		entryKey, err = d.DecodeValue()
		if err != nil {
			// EOF means the end flag 'Z' of map is already read
			if perrors.Is(err, io.EOF) {
				break
			} else {
				return perrors.WithStack(err)
			}
		}
		if entryKey == nil {
			break
		}
		entryValue, err = d.DecodeValue()
		// fix: check error
		if err != nil {
			return perrors.WithStack(err)
		}

		m.Elem().SetMapIndex(EnsurePackValue(entryKey), EnsureRawValue(entryValue))
	}

	SetValue(value, m)

	return nil
}