d->recent_delta_offsets[2] = d->recent_delta_offsets[1];
d->recent_delta_offsets[1] = d->recent_delta_offsets[0];
d->recent_delta_offsets[0] = d->pending_delta_offset;
d->recent_delta_offsets[2] = d->recent_delta_offsets[1];
d->recent_delta_offsets[1] = d->recent_delta_offsets[0];
d->recent_delta_offsets[0] = d->pending_delta_offset;