Added documentation and optimized util

246 ▸   for p < size {¬
247 ▸   ▸   chunks[p] = 1048576¬
248 ▸   ▸   pp = p¬
249 ▸   ▸   p += chunks[p]¬
250 ▸   }¬
251 ¬
If the above for loop chunk did not get executed since size == 131072, then it can happen.
I would prefer it to be cleaned up since its not a readable code.

252 ▸   chunks[pp] = size - pp¬
253 ▸   if chunks[pp] == 0 {¬
254 ▸   ▸   delete(chunks, pp)¬
255 ▸   }¬