func unmarshalVector()

in marshal.go [1764:1821]
58 lines of code
15 McCabe index (conditional complexity)

func unmarshalVector(info VectorType, data []byte, value interface{}) error {
	rv := reflect.ValueOf(value)
	if rv.Kind() != reflect.Ptr {
		return unmarshalErrorf("can not unmarshal into non-pointer %T", value)
	}
	rv = rv.Elem()
	t := rv.Type()
	k := t.Kind()
	switch k {
	case reflect.Slice, reflect.Array:
		if data == nil {
			if k == reflect.Array {
				return unmarshalErrorf("unmarshal vector: can not store nil in array value")
			}
			if rv.IsNil() {
				return nil
			}
			rv.Set(reflect.Zero(t))
			return nil
		}
		if k == reflect.Array {
			if rv.Len() != info.Dimensions {
				return unmarshalErrorf("unmarshal vector: array of size %d cannot store vector of %d dimensions", rv.Len(), info.Dimensions)
			}
		} else {
			rv.Set(reflect.MakeSlice(t, info.Dimensions, info.Dimensions))
		}
		elemSize := len(data) / info.Dimensions
		for i := 0; i < info.Dimensions; i++ {
			offset := 0
			if isVectorVariableLengthType(info.SubType) {
				m, p, err := readUnsignedVInt(data)
				if err != nil {
					return err
				}
				elemSize = int(m)
				offset = p
			}
			if offset > 0 {
				data = data[offset:]
			}
			var unmarshalData []byte
			if elemSize >= 0 {
				if len(data) < elemSize {
					return unmarshalErrorf("unmarshal vector: unexpected eof")
				}
				unmarshalData = data[:elemSize]
				data = data[elemSize:]
			}
			err := Unmarshal(info.SubType, unmarshalData, rv.Index(i).Addr().Interface())
			if err != nil {
				return unmarshalErrorf("failed to unmarshal %s into %T: %s", info.SubType, unmarshalData, err.Error())
			}
		}
		return nil
	}
	return unmarshalErrorf("can not unmarshal %s into %T. Accepted types: slice, array.", info, value)
}