i might have gotten through drafting the part that seemed most complex to me, unsure region_mask = aligned_tails[idx:next_idx-1] < aligned_offsets[idx+1:next_idx] region_bounds = region_mask.nonzero()[:,0] region_bounds += idx next_op_ct = op_ct + region_bounds.shape[0] + 1 offset_length_tail_idx_ops[op_ct:next_op_ct-1,TAIL] = aligned_tails[region_bounds] offset_length_tail_idx_ops[next_op_ct-1,TAIL] = aligned_end region_bounds += 1 offset_length_tail_idx_ops[op_ct+1:next_op_ct,OFFSET] = aligned_offsets[region_bounds] offset_length_tail_idx_ops[op_ct,OFFSET] = aligned_start offset_length_tail_idx_ops[op_ct:next_op_ct,OP] = OP_FETCH | OP_PLACE above draft is intended to produce a list of pages that do that consolidation i was talking about, where fetches are merged into surrounding pages (by using aligned bounds) and adjacent pages are merged into a single fetch (by comparing non-overlapping bounds for difference) [.. function not drafted fully yet, maybe 1/3rd done. next is listing all the ranges to output to the user and updating the loop variables over unfetched regions kinda. there's still a loop but the intent is to only loop over sparse and cached file regions (to cache accessed sparse regions)