Mercurial > hg
view tests/test-wireproto.py @ 40393:229d23cdb203
exchangev2: support fetching shallow files history
This commit teaches the exchangev2 client code to handle fetching shallow
files data.
Only shallow fetching of files data is supported: shallow fetching of
changeset and manifest data is explicitly not yet supported.
Previously, we would fetch file revisions for changesets that were received
by the current pull operation. In the new model, we calculate the set of
"relevant" changesets given the pull depth and only fetch files data for
those changesets.
We also teach the "filesdata" command invocation to vary parameters as needed.
The implementation here is far from complete or optimal. Subsequent pulls will
end up re-fetching a lot of files data. But the application of this data should
mostly be a no-op on the client, so it isn't a big deal.
Depending on the order file revisions are fetched in, revisions could get
inserted with the wrong revision number relationships. I think the best way
to deal with this is to remove revision numbers from storage and to either
dynamically derive them (by reconstructing a DAG from nodes/parents) or remove
revision numbers from the file storage interface completely.
A missing API that we'll likely want to write pretty soon is "ensure files
for revision(s) are present." We can kind of cajole exchangev2.pull() to do
this. But it isn't very efficient. For example, in simple cases like
widening the store to obtain data for a single revision, it is probably
more efficient to walk the manifest and find exactly which file revisions
are missing and to make explicit requests for just their data. In more
advanced cases, asking the server for all files data may be more efficient,
even though it requires sending data the client already has. There is tons
of room for future experimentation here. And TBH I'm not sure what the
final state will be.
Anyway, this commit gets us pretty close to being able to have shallow
and narrow checkouts with exchangev2/sqlite storage. Close enough that a
minimal extension should be able to provide fill in the gaps until the code
in core stabilizes and there is a user-facing way to trigger the
narrow/shallow bits from `hg clone` without also implying using of the
narrow extension...
Differential Revision: https://phab.mercurial-scm.org/D5169
author | Gregory Szorc <gregory.szorc@gmail.com> |
---|---|
date | Fri, 19 Oct 2018 12:30:49 +0200 |
parents | 32bc3815efae |
children | d6569f1e9b37 |
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from __future__ import absolute_import, print_function import sys from mercurial import ( error, pycompat, ui as uimod, util, wireprototypes, wireprotov1peer, wireprotov1server, ) from mercurial.utils import ( stringutil, ) stringio = util.stringio class proto(object): def __init__(self, args): self.args = args self.name = 'dummyproto' def getargs(self, spec): args = self.args args.setdefault(b'*', {}) names = spec.split() return [args[n] for n in names] def checkperm(self, perm): pass wireprototypes.TRANSPORTS['dummyproto'] = { 'transport': 'dummy', 'version': 1, } class clientpeer(wireprotov1peer.wirepeer): def __init__(self, serverrepo, ui): self.serverrepo = serverrepo self.ui = ui def url(self): return b'test' def local(self): return None def peer(self): return self def canpush(self): return True def close(self): pass def capabilities(self): return [b'batch'] def _call(self, cmd, **args): args = pycompat.byteskwargs(args) res = wireprotov1server.dispatch(self.serverrepo, proto(args), cmd) if isinstance(res, wireprototypes.bytesresponse): return res.data elif isinstance(res, bytes): return res else: raise error.Abort('dummy client does not support response type') def _callstream(self, cmd, **args): return stringio(self._call(cmd, **args)) @wireprotov1peer.batchable def greet(self, name): f = wireprotov1peer.future() yield {b'name': mangle(name)}, f yield unmangle(f.value) class serverrepo(object): def greet(self, name): return b"Hello, " + name def filtered(self, name): return self def mangle(s): return b''.join(pycompat.bytechr(ord(c) + 1) for c in pycompat.bytestr(s)) def unmangle(s): return b''.join(pycompat.bytechr(ord(c) - 1) for c in pycompat.bytestr(s)) def greet(repo, proto, name): return mangle(repo.greet(unmangle(name))) wireprotov1server.commands[b'greet'] = (greet, b'name') srv = serverrepo() clt = clientpeer(srv, uimod.ui()) def printb(data, end=b'\n'): out = getattr(sys.stdout, 'buffer', sys.stdout) out.write(data + end) out.flush() printb(clt.greet(b"Foobar")) with clt.commandexecutor() as e: fgreet1 = e.callcommand(b'greet', {b'name': b'Fo, =;:<o'}) fgreet2 = e.callcommand(b'greet', {b'name': b'Bar'}) printb(stringutil.pprint([f.result() for f in (fgreet1, fgreet2)], bprefix=True))