variable compression feature request

[griffin tucker]

--compress or -z will compress during data transfer

what about a variable compression rate?

--optimal-compress or -za

monitor the speed of the transfer and the cpu throughput and
automatically find the optimum compression in almost-real-time with
the goal of reduced transfer time

i figure you'd have to mark the last block compressed/sent with extra
data indicating new blocks are using a different compression strength,
and it could work for using multiple algorithms, depending on the data

when decompressing, when detecting a new block, it will indicate
corruption in the archive, but the extra data will revert the error
indication - the `corruption' would only be up until the last block,
so the data remains intact, and the new rate/algo can begin after the
`failed' block

finding the type of data that can be compressed better/faster with
different algorithms will also be taken into account

just an idea