stream-clone: avoid opening a revlog in case we do not need it
Opening an revlog has a cost, especially if it is inline as we have to scan the
file and construct an index.
To prevent the associated slowdown, we just do a minimal scan to check that an
inline file is still inline, and simply stream the file without creating a
revlog when we can.
This provides a big boost compared to the previous changeset, even if the full
generation is still penalized by the initial gathering of information.
All benchmarks are run on linux with Python 3.10.7.
# benchmark.name = hg.exchange.stream.generate
# benchmark.variants.version = v2
### Compared to the previous changesets
We get a large win all across the board!
# mercurial-2018-08-01-zstd-sparse-revlog
before: 0.250694 seconds
after: 0.105986 seconds (-57.72%)
# pypy-2018-08-01-zstd-sparse-revlog
before: 3.885657 seconds
after: 1.709748 seconds (-56.00%)
# netbeans-2018-08-01-zstd-sparse-revlog
before: 16.679371 seconds
after: 7.687469 seconds (-53.91%)
# mozilla-central-2018-08-01-zstd-sparse-revlog
before: 38.575482 seconds
after: 17.520316 seconds (-54.58%)
# mozilla-try-2019-02-18-zstd-sparse-revlog
before: 81.160994 seconds
after: 37.073753 seconds (-54.32%)
### Compared to 6.4.3
We are still significantly slower than 6.4.3, the extra time is usually twice
slower than the extra time we observe on the locked section, which is a quite
interesting information.
Except for mercurial-central that is much faster. That discrepancy is not really
explained yet.
# mercurial-2018-08-01-zstd-sparse-revlog
6.4.3: 0.072560 seconds
after: 0.105986 seconds (+46.07%) (- 0.03 seconds)
# pypy-2018-08-01-zstd-sparse-revlog
6.4.3: 1.211193 seconds
after: 1.709748 seconds (+41.16%) (-0.45 seconds)
# netbeans-2018-08-01-zstd-sparse-revlog
6.4.3: 4.932843 seconds
after: 7.687469 seconds (+55.84%) (-2.75 seconds)
# mozilla-central-2018-08-01-zstd-sparse-revlog
6.4.3: 34.012226 seconds
after: 17.520316 seconds (-48.49%) (-16.49 seconds)
# mozilla-try-2019-02-18-zstd-sparse-revlog
6.4.3: 23.850555 seconds
after: 37.073753 seconds (+55.44%) (+13.22 seconds)
#!/bin/bash
set -eu
if [[ "$PHABRICATOR_TOKEN" == "NO-PHAB" ]]; then
echo 'Skipping Phabricator Step' >&2
exit 0
fi
revision_in_stack=`hg log \
--rev '.#stack and ::. and topic()' \
-T '\nONE-REV\n' \
| grep 'ONE-REV' | wc -l`
revision_on_phab=`hg log \
--rev '.#stack and ::. and topic() and desc("re:\nDifferential Revision: [^\n]+D\d+$")'\
-T '\nONE-REV\n' \
| grep 'ONE-REV' | wc -l`
if [[ $revision_in_stack -eq 0 ]]; then
echo "stack is empty" >&2
exit 0
fi
if [[ $revision_on_phab -eq 0 ]]; then
echo "no tracked diff in this stack" >&2
exit 0
fi
if [[ $revision_on_phab -lt $revision_in_stack ]]; then
echo "not all stack changesets (${revision_in_stack}) have matching Phabricator Diff (${revision_on_phab})" >&2
exit 2
fi
if [[ "$PHABRICATOR_TOKEN" == "" ]]; then
echo 'missing $PHABRICATOR_TOKEN variable' >&2
echo '(use PHABRICATOR_TOKEN="NO-PHAB" to disable this step)' >&2
exit 2
fi
hg \
--config extensions.phabricator= \
--config phabricator.url=https://phab.mercurial-scm.org/ \
--config phabricator.callsign=HG \
--config auth.phabricator.schemes=https \
--config auth.phabricator.prefix=phab.mercurial-scm.org \
--config auth.phabricator.phabtoken=$PHABRICATOR_TOKEN \
phabsend --rev '.#stack and ::. and topic()' \
"$@"