Mercurial > hg
view tests/test-fastannotate-protocol.t @ 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 | d8a7690ccc74 |
children | 7116fc614cfc |
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$ cat >> $HGRCPATH << EOF > [ui] > ssh = "$PYTHON" "$TESTDIR/dummyssh" > [extensions] > fastannotate= > [fastannotate] > mainbranch=@ > EOF $ HGMERGE=true; export HGMERGE setup the server repo $ hg init repo-server $ cd repo-server $ cat >> .hg/hgrc << EOF > [fastannotate] > server=1 > EOF $ for i in 1 2 3 4; do > echo $i >> a > hg commit -A -m $i a > done $ [ -d .hg/fastannotate ] [1] $ hg bookmark @ $ cd .. setup the local repo $ hg clone 'ssh://user@dummy/repo-server' repo-local -q $ cd repo-local $ cat >> .hg/hgrc << EOF > [fastannotate] > client=1 > clientfetchthreshold=0 > EOF $ [ -d .hg/fastannotate ] [1] $ hg fastannotate a --debug running * (glob) sending hello command sending between command remote: * (glob) (?) remote: capabilities: * (glob) remote: * (glob) (?) sending protocaps command fastannotate: requesting 1 files sending getannotate command fastannotate: writing 112 bytes to fastannotate/default/a.l fastannotate: writing 94 bytes to fastannotate/default/a.m fastannotate: a: using fast path (resolved fctx: True) 0: 1 1: 2 2: 3 3: 4 the cache could be reused and no download is necessary $ hg fastannotate a --debug fastannotate: a: using fast path (resolved fctx: True) 0: 1 1: 2 2: 3 3: 4 if the client agrees where the head of the master branch is, no re-download happens even if the client has more commits $ echo 5 >> a $ hg commit -m 5 $ hg bookmark -r 3 @ -f $ hg fastannotate a --debug 0: 1 1: 2 2: 3 3: 4 4: 5 if the client has a different "@" (head of the master branch) and "@" is ahead of the server, the server can detect things are unchanged and does not return full contents (not that there is no "writing ... to fastannotate"), but the client can also build things up on its own (causing diverge) $ hg bookmark -r 4 @ -f $ hg fastannotate a --debug running * (glob) sending hello command sending between command remote: * (glob) (?) remote: capabilities: * (glob) remote: * (glob) (?) sending protocaps command fastannotate: requesting 1 files sending getannotate command fastannotate: a: 1 new changesets in the main branch 0: 1 1: 2 2: 3 3: 4 4: 5 if the client has a different "@" which is behind the server. no download is necessary $ hg fastannotate a --debug --config fastannotate.mainbranch=2 fastannotate: a: using fast path (resolved fctx: True) 0: 1 1: 2 2: 3 3: 4 4: 5 define fastannotate on-disk paths $ p1=.hg/fastannotate/default $ p2=../repo-server/.hg/fastannotate/default revert bookmark change so the client is behind the server $ hg bookmark -r 2 @ -f in the "fctx" mode with the "annotate" command, the client also downloads the cache. but not in the (default) "fastannotate" mode. $ rm $p1/a.l $p1/a.m $ hg annotate a --debug | grep 'fastannotate: writing' [1] $ hg annotate a --config fastannotate.modes=fctx --debug | grep 'fastannotate: writing' | sort fastannotate: writing 112 bytes to fastannotate/default/a.l fastannotate: writing 94 bytes to fastannotate/default/a.m the fastannotate cache (built server-side, downloaded client-side) in two repos have the same content (because the client downloads from the server) $ diff $p1/a.l $p2/a.l $ diff $p1/a.m $p2/a.m in the "fctx" mode, the client could also build the cache locally $ hg annotate a --config fastannotate.modes=fctx --debug --config fastannotate.mainbranch=4 | grep fastannotate fastannotate: requesting 1 files fastannotate: a: 1 new changesets in the main branch the server would rebuild broken cache automatically $ cp $p2/a.m $p2/a.m.bak $ echo BROKEN1 > $p1/a.m $ echo BROKEN2 > $p2/a.m $ hg fastannotate a --debug | grep 'fastannotate: writing' | sort fastannotate: writing 112 bytes to fastannotate/default/a.l fastannotate: writing 94 bytes to fastannotate/default/a.m $ diff $p1/a.m $p2/a.m $ diff $p2/a.m $p2/a.m.bak use the "debugbuildannotatecache" command to build annotate cache $ rm -rf $p1 $p2 $ hg --cwd ../repo-server debugbuildannotatecache a --debug fastannotate: a: 4 new changesets in the main branch $ hg --cwd ../repo-local debugbuildannotatecache a --debug running * (glob) sending hello command sending between command remote: * (glob) (?) remote: capabilities: * (glob) remote: * (glob) (?) sending protocaps command fastannotate: requesting 1 files sending getannotate command fastannotate: writing * (glob) fastannotate: writing * (glob) $ diff $p1/a.l $p2/a.l $ diff $p1/a.m $p2/a.m with the clientfetchthreshold config option, the client can build up the cache without downloading from the server $ rm -rf $p1 $ hg fastannotate a --debug --config fastannotate.clientfetchthreshold=10 fastannotate: a: 3 new changesets in the main branch 0: 1 1: 2 2: 3 3: 4 4: 5 if the fastannotate directory is not writable, the fctx mode still works $ rm -rf $p1 $ touch $p1 $ hg annotate a --debug --traceback --config fastannotate.modes=fctx fastannotate: a: cache broken and deleted fastannotate: prefetch failed: * (glob) fastannotate: a: cache broken and deleted fastannotate: falling back to the vanilla annotate: * (glob) 0: 1 1: 2 2: 3 3: 4 4: 5 with serverbuildondemand=False, the server will not build anything $ cat >> ../repo-server/.hg/hgrc <<EOF > [fastannotate] > serverbuildondemand=False > EOF $ rm -rf $p1 $p2 $ hg fastannotate a --debug | grep 'fastannotate: writing' [1]