Method first_write_block

include/iocore/eventsystem/IOBuffer.h:1015–1027

Returns a pointer to the first writable block on the block chain. Returns nullptr if there are not currently any writable blocks on the block list. */

    block list.
  */
  IOBufferBlock *
  first_write_block()
  {
    if (_writer) {
      if (_writer->next && !_writer->write_avail()) {
        return _writer->next.get();
      }
      ink_assert(!_writer->next || !_writer->next->read_avail());
      return _writer.get();
    }

    return nullptr;
  }

  char *
  buf()