Mercurial > hg
view tests/helpers-testrepo.sh @ 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 | 152f1b47e0ad |
children |
line wrap: on
line source
# In most cases, the mercurial repository can be read by the bundled hg, but # that isn't always true because third-party extensions may change the store # format, for example. In which case, the system hg installation is used. # # We want to use the hg version being tested when interacting with the test # repository, and the system hg when interacting with the mercurial source code # repository. # # The mercurial source repository was typically orignally cloned with the # system mercurial installation, and may require extensions or settings from # the system installation. if [ -n "$HGTESTEXTRAEXTENSIONS" ]; then for extension in $HGTESTEXTRAEXTENSIONS; do extraoptions="$extraoptions --config extensions.$extension=!" done fi syshg () { ( syshgenv exec hg "$@" ) } # Revert the environment so that running "hg" runs the system hg # rather than the test hg installation. syshgenv () { . "$HGTEST_RESTOREENV" HGPLAIN=1 export HGPLAIN } # The test-repo is a live hg repository which may have evolution markers # created, e.g. when a ~/.hgrc enabled evolution. # # Tests may be run using a custom HGRCPATH, which do not enable evolution # markers by default. # # If test-repo includes evolution markers, and we do not enable evolution # markers, hg will occasionally complain when it notices them, which disrupts # tests resulting in sporadic failures. # # Since we aren't performing any write operations on the test-repo, there's # no harm in telling hg that we support evolution markers, which is what the # following lines for the hgrc file do: cat >> "$HGRCPATH" << EOF [experimental] evolution = createmarkers EOF # Use the system hg command if the bundled hg can't read the repository with # no warning nor error. if [ -n "`hg id -R "$TESTDIR/.." 2>&1 >/dev/null`" ]; then alias testrepohg=syshg alias testrepohgenv=syshgenv else alias testrepohg="hg $extraoptions" alias testrepohgenv=: fi