pub fn byte_range_reader(
path: &Path,
index: usize,
peers: usize,
) -> Option<(BufReader<File>, u64)>Expand description
Open a byte-range slice of path for worker index out of peers.
Returns Some((reader, bytes_to_read)) on success. The reader is
pre-seeked to the start of the worker’s range (aligned to the next
line boundary for non-zero workers). The caller should read up to
bytes_to_read bytes, stopping at the first complete line beyond
that budget.
Returns None on I/O error (logged to stderr).