writeFromSync method

Implementation

int writeFromSync(List<int> buffer, [int start = 0, int? end]) {
  if (_readOnly) {
    throw Exception('Cannot write to read-only RAM file data');
  }
  final int usedStart = start;
  final int usedEnd = end ?? (start + buffer.length);
  int bufferStartWriteIndex = 0;
  int relativeStart;
  do {
    relativeStart = usedStart + bufferStartWriteIndex;
    final int contentIndex = relativeStart ~/ _subListSize;
    while (contentIndex >= _content.length) {
      _content.add(Uint8List(_subListSize));
    }
    final List<int> contentSubList = _content[contentIndex];
    final int subListStartIndex = relativeStart % _subListSize;
    final int dataLengthToCopy = math.min(
      usedEnd - relativeStart,
      _subListSize - subListStartIndex,
    );
    contentSubList.setRange(
      subListStartIndex,
      subListStartIndex + dataLengthToCopy,
      buffer.getRange(
        bufferStartWriteIndex,
        bufferStartWriteIndex + dataLengthToCopy,
      ),
    );
    bufferStartWriteIndex += dataLengthToCopy;
  } while (relativeStart < usedEnd);
  _length = math.max(usedEnd, _length);
  return usedEnd - start;
}