pub fn stripe_plan(
blob_bytes: usize,
chunk_bytes: usize,
n_rails: usize,
) -> Vec<Vec<(usize, usize)>>Expand description
Round-robin stripe a blob_bytes transfer into chunk_bytes chunks across
n_rails, returning per-rail lists of (offset, len). The offset is the
chunk’s position in BOTH the (single, contiguous) staging buffer and the peer
arena slot — so whichever rail fetches chunk j, it lands at its true offset
and one memcpy reassembles the blob (the verified inc-6 reassembly fix). The
tail chunk carries the short remainder, never chunk_bytes.