downloads still need the old copy code because they aren't
parallel in the same way uploads are. revert all the code
that removed the parallel copy, only use the non-parallel
copy for uploads, and add back the parallelism and chunk
size flags and have them set the maximum concurrent pieces
flags to values based on each other when only one is set
for backwards compatibility.
mostly reverts 54ef1c8ca2
Change-Id: I8b5f62bf18a6548fa60865c6c61b5f34fbcec14c
the parallelism and parallelism-chunk-size flags
which used to control how many parts to split a
segment into and many to perform in parallel
are now deprecated and replaced by
maximum-concurrent-pieces and long-tail-margin.
now, for an individual transfer, the total number
of piece uploads that transfer will perform is
controlled by maximum-concurrent-pieces, and
segments within that transfer will automatically
be performed in parallel. so if you used to set
your parallelism to n, a good value for the pieces
might be something approximately like 130*n, and
the parallelism-chunk-size is unnecessary.
Change-Id: Ibe724ca70b07eba89dad551eb612a1db988b18b9
This changes allows fetching the file size more easily (for supported
files) in order to afterwards calculate the multipart part size
accordingly.
Change-Id: Idabba4c2ee794ee471973889f5843174a7acad35
