func DecodeAttributeValue()

in dax/internal/cbor/attrval.go [140:282]
142 lines of code
40 McCabe index (conditional complexity)

func DecodeAttributeValue(reader *Reader) (*dynamodb.AttributeValue, error) {
	hdr, err := reader.PeekHeader()
	if err != nil {
		return nil, err
	}
	major := hdr & MajorTypeMask
	minor := hdr & MinorTypeMask

	switch major {
	case Utf:
		s, err := reader.ReadString()
		if err != nil {
			return nil, err
		}
		return &dynamodb.AttributeValue{S: &s}, nil
	case Bytes:
		b, err := reader.ReadBytes()
		if err != nil {
			return nil, err
		}
		return &dynamodb.AttributeValue{B: b}, nil
	case Array:
		len, err := reader.ReadArrayLength()
		if err != nil {
			return nil, err
		}
		as := make([]*dynamodb.AttributeValue, len)
		for i := 0; i < len; i++ {
			a, err := DecodeAttributeValue(reader)
			if err != nil {
				return nil, err
			}
			as[i] = a
		}
		return &dynamodb.AttributeValue{L: as}, nil
	case Map:
		len, err := reader.ReadMapLength()
		if err != nil {
			return nil, err
		}
		m := make(map[string]*dynamodb.AttributeValue, len)
		for i := 0; i < len; i++ {
			k, err := reader.ReadString()
			if err != nil {
				return nil, err
			}
			v, err := DecodeAttributeValue(reader)
			if err != nil {
				return nil, err
			}
			m[k] = v
		}
		return &dynamodb.AttributeValue{M: m}, nil
	case PosInt, NegInt:
		s, err := reader.ReadCborIntegerToString()
		if err != nil {
			return nil, err
		}
		return &dynamodb.AttributeValue{N: &s}, nil
	case Simple:
		if _, _, err := reader.readTypeHeader(); err != nil {
			return nil, err
		}
		switch hdr {
		case False:
			return &dynamodb.AttributeValue{BOOL: aws.Bool(false)}, nil
		case True:
			return &dynamodb.AttributeValue{BOOL: aws.Bool(true)}, nil
		case Nil:
			return &dynamodb.AttributeValue{NULL: aws.Bool(true)}, nil
		default:
			return nil, awserr.New(request.ErrCodeSerialization, fmt.Sprintf("unknown minor type %d for simple major type", minor), nil)
		}
	case Tag:
		switch minor {
		case TagPosBigInt, TagNegBigInt:
			i, err := reader.ReadBigInt()
			if err != nil {
				return nil, err
			}
			return &dynamodb.AttributeValue{N: aws.String(i.String())}, nil
		case TagDecimal:
			d, err := reader.ReadDecimal()
			if err != nil {
				return nil, err
			}
			return &dynamodb.AttributeValue{N: aws.String(d.String())}, nil
		default:
			_, tag, err := reader.readTypeHeader()
			if err != nil {
				return nil, err
			}
			switch tag {
			case tagStringSet:
				len, err := reader.ReadArrayLength()
				if err != nil {
					return nil, err
				}
				ss := make([]*string, len)
				for i := 0; i < len; i++ {
					s, err := reader.ReadString()
					if err != nil {
						return nil, err
					}
					ss[i] = &s
				}
				return &dynamodb.AttributeValue{SS: ss}, nil
			case tagNumberSet:
				len, err := reader.ReadArrayLength()
				if err != nil {
					return nil, err
				}
				ss := make([]*string, len)
				for i := 0; i < len; i++ {
					av, err := DecodeAttributeValue(reader)
					if err != nil {
						return nil, err
					}
					ss[i] = av.N
				}
				return &dynamodb.AttributeValue{NS: ss}, nil
			case tagBinarySet:
				len, err := reader.ReadArrayLength()
				if err != nil {
					return nil, err
				}
				bs := make([][]byte, len)
				for i := 0; i < len; i++ {
					b, err := reader.ReadBytes()
					if err != nil {
						return nil, err
					}
					bs[i] = b
				}
				return &dynamodb.AttributeValue{BS: bs}, nil
			default:
				return nil, awserr.New(request.ErrCodeSerialization, fmt.Sprintf("unknown minor type %d or tag %d", minor, tag), nil)
			}
		}
	default:
		return nil, awserr.New(request.ErrCodeSerialization, fmt.Sprintf("unknown major type %d", major), nil)
	}
}