rsync -z compress blocks of each file without regard to the previous file, or is the compression dictionary reset for each file so that it is handled independently?
As an example, consider a compressible file
one.txt and its identical copy being transferred to a remote server, where neither file yet exists:
cp -p one.txt two.txt rsync -az one.txt two.txt remote:
zlib compression layer treat
two.txt independently, or is the data transfer at that level simply a continuous stream, so it will have learned a useful compression dictionary for
one.txt that it can apply to
Alternatively, have I completely misunderstood the
zlib compression algorithm, such that (for example) the dictionary is always reset for each new block?
I've tried looking at the
rsync debug output
rsync -avvvvz --debug=IO1,IO2,IO3,IO4 --msgs2stderr but I can't see anything that specifically relates to the compression layer.
(This is following up a comment thread on an answer of mine on ServerFault.)