Previously we used a global variable to track if the incoming connection was
from a shallow remote (based on if the network command was a *_shallow command).
This is hacky and overall a bad idea. The new implementation stores the shallow
flag as a bundlecapability passed to the getbundle command.
A side effect of this is remotefilelog won't work with versions of mercurial
that don't use the getbundle command.
The previous algorithm thought that if the system cache had the file rev, it was
guaranteed to be valid. This isn't true in the case of a machine in which
multiple people share the cache (one person may have pulled a rev but the other
hasn't).
The new algorithm is more explicit. It checks:
- system cache
- local cache
- local cache fallbacks
- remote cache
- master server
Adds a cache client implementation using the opensource python-memcached
library. It's more of an educational example than a production ready one since
it doesn't perform the requests asynchronously. It does however split up large
files into smaller chunks for you.
The remotefilelog extension currently doesn't work with tags. Adding include and
exclude patterns allows users to specify which files they want to treat as
shallow and which the want to download the entire history for. By excluding
.hgtags from being shallow, this enables tags to work in a mostly shallow repo.
This also enables largefile like scenarios where most files are full and only a
few large ones are kept remote.
A rare bug can occur where the local file blob might not exist, but a valid old
version of that blob does exist. This refactor the linknode logic in ancestormap
to check the old versions if the server fetch fails to find the blob.
It still prints an ugly warning message from the server, but this whole issue is
quite rare anyway.
When the cache is stored on a filesystem, excessive stat calls can slow
mercurial updates down dramatically. This reduces it to a single open call for
the cache location and if that fails, a single open call for the local location.
A workingctx produces manifest entries with nullid+'a' or nullid+'m'
for any added or modified files. The extension was trying to prefetch
these but they didn't exist and caused an error. Luckily they are length
42 so we can check for them and not prefetch them.
