class INotify::Notifier

def readpartial(size)
  # Use Ruby's readpartial if possible, to avoid blocking other threads.
  begin
    return to_io.readpartial(size) if self.class.supports_ruby_io?
  rescue Errno::EBADF, IOError
    # If the IO has already been closed, reading from it will cause
    # Errno::EBADF. In JRuby it can raise IOError with invalid or
    # closed file descriptor.
    return nil
  rescue IOError => ex
    return nil if ex.message =~ /stream closed/
    raise
  end
  tries = 0
  begin
    tries += 1
    buffer = FFI::MemoryPointer.new(:char, size)
    size_read = Native.read(fd, buffer, size)
    return buffer.read_string(size_read) if size_read >= 0
  end while FFI.errno == Errno::EINTR::Errno && tries <= 5
  raise SystemCallError.new("Error reading inotify events" +
    case FFI.errno
    when Errno::EAGAIN::Errno; ": no data available for non-blocking I/O"
    when Errno::EBADF::Errno; ": invalid or closed file descriptor"
    when Errno::EFAULT::Errno; ": invalid buffer"
    when Errno::EINVAL::Errno; ": invalid file descriptor"
    when Errno::EIO::Errno; ": I/O error"
    when Errno::EISDIR::Errno; ": file descriptor is a directory"
    else; ""
    end,
    FFI.errno)
end