p2phttp: Support serving unauthenticated users while requesting
authentication for operations that need it. Eg, --unauth-readonly can be
combined with --authenv.
Drop locking currently needs authentication so it will prompt for that.
That still needs to be addressed somehow.
I anticipate lots of external special remote programs will neglect
implementing this. Still, it's the right thing to do to assume that some
of them may write files out of order. Probably most external special
remotes will not be used with a proxy. When someone is using one with a
proxy, they can always get it fixed to send ORDERED.
A one second delay made it seem really choppy and slow when the special
remote was sending content fairly steadily but was bottlenecked on
running gpg on 10 mb chunks.
This does not appreciably increase CPU, although of course if the
special remote is very slow it will add up over time.
It would perhaps be better to use inotify, like tailVerify does.
The problem was that when the proxy requests a key be retrieved to its
own temp file, fileRetriever was retriving it to the key's temp
location, and then moving it at the end, which broke streaming.
So, plumb through the path where the key is being retrieved to.
Currently works for special remotes that don't use fileRetriever. Ones that
do will download to another filename and rename it into place, defeating
the streaming.
This actually benchmarks slightly slower when getting a large file from
a fast proxied special remote. However, when the proxied special remote
is slow, it will be a big win.
This bypasses the usual haskell file locking used to prevent opening a
file for read that is being written to.
This is unfortunately a bit of a hack. But it seems fairly unlikely to
get broken by changes to ghc. I hope. Using fdToHandle' will also work.
This does not work on windows because it uses openFd from posix. It
would probably be possible to implement it for windows too, just opening
the FD using the Win32 library instead. However, whether windows will
allow reading from a file that is also being written to I don't know,
and since in the git-annex case the writer could be another process (eg
external special remote), that might be doing its own locking in
windows, that seems a can of worms I'd prefer not to open.
