Function hexStringToID

pkg/util/traceid.go:147–187

(id string, isSpan bool)

}

func hexStringToID(id string, isSpan bool) ([]byte, error) {
	// The encoding/hex package does not handle non-hex characters.
	// Ensure the ID has only the proper characters
	for i, c := range id {
		if (c < 'a' || c > 'f') && (c < 'A' || c > 'F') && (c < '0' || c > '9') {
			return nil, fmt.Errorf("trace IDs can only contain hex characters: invalid character '%c' at position %d", c, i+1)
		}
	}

	// the encoding/hex package does not like odd length strings.
	// just append a bit here
	if len(id)%2 == 1 {
		id = "0" + id
	}

	byteID, err := hex.DecodeString(id)
	if err != nil {
		return nil, err
	}

	size := len(byteID)

	if isSpan {
		if size > 8 {
			return nil, errors.New("span IDs can't be larger than 64 bits")
		}
		// if size < 8 {
		// 	byteID = append(make([]byte, 8-size), byteID...)
		// }
		return byteID, nil
	}

	if size > 16 {
		return nil, errors.New("trace IDs can't be larger than 128 bits")
	}
	if size < 16 {
		byteID = append(make([]byte, 16-size), byteID...)
	}

	return byteID, nil
}