Mercurial > hg
view tests/test-sparse-revlog.t @ 42619:20d0e59be79b
tests: show the files fields of changelogs for many merges
I don't think there's coverage for many of the subtle cases, and I
found it hard to understand what the code is doing by reading it. The
test takes 40s to run on a laptop, or 9s with --chg.
I have yet to find a description of what the files field is supposed
to be for merges. I thought it could be one of:
1. the files added/modified/removed relative to p1 (wouldn't seem
useful, but `hg diff -c -r mergerev` has this behavior)
2. the files with filelog nodes not in either parent (i.e., what is
needed to create a bundle out of a commit)
3. the files added/removed/modified files by merge itself [1]
It's clearly not 1, because file contents merges are symmetric. It's
clearly not 2 because removed files and exec bit changes are
listed. It's also not 3 but I think it's intended to be 3 and the
differences are bugs.
Assuming 3, the test shows that, for merges, the list of files both
overapproximates and underapproximates. All the cases involve file
changes not in the filelog but in the manifest (existence of file
at revision, exec bit and file vs symlink).
I didn't look at all underapproximations, but they looked minor. The
two overapproximations are problematic though because they both cause
potentially long lists of files when merging cleanly.
[1] even what it means for the merge commit itself to change a file is
not completely trivial. A file in the merge being the same as in one
of the parent is too lax as it would consider that merges change
nothing when they revert all the changes done on one side. The
criteria used in the test and in the next commit for "merge didn't
touch a file" is:
- the parents and the merge all have the same file
- or, one parent didn't touch the file and the other parent contains
the same file as the merge
Differential Revision: https://phab.mercurial-scm.org/D6612
author | Valentin Gatien-Baron <valentin.gatienbaron@gmail.com> |
---|---|
date | Tue, 02 Jul 2019 12:55:51 -0400 |
parents | 688fc33e105d |
children | 58a814d062ca |
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==================================== Test delta choice with sparse revlog ==================================== Sparse-revlog usually shows the most gain on Manifest. However, it is simpler to general an appropriate file, so we test with a single file instead. The goal is to observe intermediate snapshot being created. We need a large enough file. Part of the content needs to be replaced repeatedly while some of it changes rarely. $ bundlepath="$TESTDIR/artifacts/cache/big-file-churn.hg" $ expectedhash=`cat "$bundlepath".md5` #if slow $ if [ ! -f "$bundlepath" ]; then > "$TESTDIR"/artifacts/scripts/generate-churning-bundle.py > /dev/null > fi #else $ if [ ! -f "$bundlepath" ]; then > echo 'skipped: missing artifact, run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"' > exit 80 > fi #endif $ currenthash=`f -M "$bundlepath" | cut -d = -f 2` $ if [ "$currenthash" != "$expectedhash" ]; then > echo 'skipped: outdated artifact, md5 "'"$currenthash"'" expected "'"$expectedhash"'" run "'"$TESTDIR"'/artifacts/scripts/generate-churning-bundle.py"' > exit 80 > fi $ cat >> $HGRCPATH << EOF > [format] > sparse-revlog = yes > maxchainlen = 15 > [storage] > revlog.optimize-delta-parent-choice = yes > revlog.reuse-external-delta = no > EOF $ hg init sparse-repo $ cd sparse-repo $ hg unbundle $bundlepath adding changesets adding manifests adding file changes added 5001 changesets with 5001 changes to 1 files (+89 heads) new changesets 9706f5af64f4:d9032adc8114 (5001 drafts) (run 'hg heads' to see heads, 'hg merge' to merge) $ hg up 1 files updated, 0 files merged, 0 files removed, 0 files unresolved updated to "d9032adc8114: commit #5000" 89 other heads for branch "default" $ hg log --stat -r 0:3 changeset: 0:9706f5af64f4 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: initial commit SPARSE-REVLOG-TEST-FILE | 10500 ++++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 10500 insertions(+), 0 deletions(-) changeset: 1:724907deaa5e user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: commit #1 SPARSE-REVLOG-TEST-FILE | 1068 +++++++++++++++++++++++----------------------- 1 files changed, 534 insertions(+), 534 deletions(-) changeset: 2:62c41bce3e5d user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: commit #2 SPARSE-REVLOG-TEST-FILE | 1068 +++++++++++++++++++++++----------------------- 1 files changed, 534 insertions(+), 534 deletions(-) changeset: 3:348a9cbd6959 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: commit #3 SPARSE-REVLOG-TEST-FILE | 1068 +++++++++++++++++++++++----------------------- 1 files changed, 534 insertions(+), 534 deletions(-) $ f -s .hg/store/data/*.d .hg/store/data/_s_p_a_r_s_e-_r_e_v_l_o_g-_t_e_s_t-_f_i_l_e.d: size=63327412 $ hg debugrevlog * format : 1 flags : generaldelta revisions : 5001 merges : 625 (12.50%) normal : 4376 (87.50%) revisions : 5001 empty : 0 ( 0.00%) text : 0 (100.00%) delta : 0 (100.00%) snapshot : 383 ( 7.66%) lvl-0 : 3 ( 0.06%) lvl-1 : 20 ( 0.40%) lvl-2 : 68 ( 1.36%) lvl-3 : 112 ( 2.24%) lvl-4 : 180 ( 3.60%) deltas : 4618 (92.34%) revision size : 63327412 snapshot : 9886710 (15.61%) lvl-0 : 603104 ( 0.95%) lvl-1 : 1559991 ( 2.46%) lvl-2 : 2295592 ( 3.62%) lvl-3 : 2531199 ( 4.00%) lvl-4 : 2896824 ( 4.57%) deltas : 53440702 (84.39%) chunks : 5001 0x78 (x) : 5001 (100.00%) chunks size : 63327412 0x78 (x) : 63327412 (100.00%) avg chain length : 9 max chain length : 15 max chain reach : 28248745 compression ratio : 27 uncompressed data size (min/max/avg) : 346468 / 346472 / 346471 full revision size (min/max/avg) : 201008 / 201050 / 201034 inter-snapshot size (min/max/avg) : 11596 / 168150 / 24430 level-1 (min/max/avg) : 16653 / 168150 / 77999 level-2 (min/max/avg) : 12951 / 85595 / 33758 level-3 (min/max/avg) : 11608 / 43029 / 22599 level-4 (min/max/avg) : 11596 / 21632 / 16093 delta size (min/max/avg) : 10649 / 107163 / 11572 deltas against prev : 3910 (84.67%) where prev = p1 : 3910 (100.00%) where prev = p2 : 0 ( 0.00%) other : 0 ( 0.00%) deltas against p1 : 648 (14.03%) deltas against p2 : 60 ( 1.30%) deltas against other : 0 ( 0.00%)