void _finalizeData()

in lib/src/hash_sink.dart [133:173]
26 lines of code
4 McCabe index (conditional complexity)

  void _finalizeData() {
    // Pad out the data with 0x80, eight or sixteen 0s, and as many more 0s
    // as we need to land cleanly on a chunk boundary.
    _pendingData.add(0x80);

    final contentsLength = _lengthInBytes + 1 /* 0x80 */ + _signatureBytes;
    final finalizedLength =
        _roundUp(contentsLength, _currentChunk.lengthInBytes);

    for (var i = 0; i < finalizedLength - contentsLength; i++) {
      _pendingData.add(0);
    }

    if (_lengthInBytes > _maxMessageLengthInBytes) {
      throw UnsupportedError(
          'Hashing is unsupported for messages with more than 2^53 bits.');
    }

    var lengthInBits = _lengthInBytes * bitsPerByte;

    // Add the full length of the input data as a 64-bit value at the end of the
    // hash. Note: we're only writing out 64 bits, so skip ahead 8 if the
    // signature is 128-bit.
    final offset = _pendingData.length + (_signatureBytes - 8);

    _pendingData.addAll(Uint8List(_signatureBytes));
    var byteData = _pendingData.buffer.asByteData();

    // We're essentially doing byteData.setUint64(offset, lengthInBits, _endian)
    // here, but that method isn't supported on dart2js so we implement it
    // manually instead.
    var highBits = lengthInBits >> 32;
    var lowBits = lengthInBits & mask32;
    if (_endian == Endian.big) {
      byteData.setUint32(offset, highBits, _endian);
      byteData.setUint32(offset + bytesPerWord, lowBits, _endian);
    } else {
      byteData.setUint32(offset, lowBits, _endian);
      byteData.setUint32(offset + bytesPerWord, highBits, _endian);
    }
  }