Mercurial > hg
view tests/test-fastannotate-renames.t @ 42743:8c9a6adec67a
rust-discovery: using the children cache in add_missing
The DAG range computation often needs to get back to very old
revisions, and turns out to be disproportionately long, given
that the end goal is to remove the descendents of the given
missing revisons from the undecided set.
The fast iteration capabilities available in the Rust case make
it possible to avoid the DAG range entirely, at the cost of
precomputing the children cache, and to simply iterate on
children of the given missing revisions.
This is a case where staying on the same side of the interface
between the two languages has clear benefits.
On discoveries with initial undecided sets
small enough to bypass sampling entirely, the total cost of
computing the children cache and the subsequent iteration
becomes better than the Python + C counterpart, which relies on
reachableroots2.
For example, on a repo with more than one million revisions with
an initial undecided set of 11 elements, we get these figures:
Rust version with simple iteration
addcommons: 57.287us
first undecided computation: 184.278334ms
first children cache computation: 131.056us
addmissings iteration: 42.766us
first addinfo total: 185.24 ms
Python + C version
first addcommons: 0.29 ms
addcommons 0.21 ms
first undecided computation 191.35 ms
addmissings 45.75 ms
first addinfo total: 237.77 ms
On discoveries with large undecided sets, the initial price paid
makes the first addinfo slower than the Python + C version,
but that's more than compensated by the gain in sampling and
subsequent iterations.
Here's an extreme example with an undecided set of a million revisions:
Rust version:
first undecided computation: 293.842629ms
first children cache computation: 407.911297ms
addmissings iteration: 34.312869ms
first addinfo total: 776.02 ms
taking initial sample
query 2: sampling time: 1318.38 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings: 143.062us
Python + C version:
first undecided computation 298.13 ms
addmissings 80.13 ms
first addinfo total: 399.62 ms
taking initial sample
query 2: sampling time: 3957.23 ms
query 2; still undecided: 1005013, sample size is: 200
addmissings 52.88 ms
Differential Revision: https://phab.mercurial-scm.org/D6428
author | Georges Racinet <georges.racinet@octobus.net> |
---|---|
date | Tue, 16 Apr 2019 01:16:39 +0200 |
parents | 1ddb296e0dee |
children |
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$ cat >> $HGRCPATH << EOF > [extensions] > fastannotate= > [fastannotate] > mainbranch=main > EOF $ hg init repo $ cd repo add or rename files on top of the master branch $ echo a1 > a $ echo b1 > b $ hg commit -qAm 1 $ hg bookmark -i main $ hg fastannotate --debug -nf b fastannotate: b: 1 new changesets in the main branch 0 b: b1 $ hg fastannotate --debug -nf a fastannotate: a: 1 new changesets in the main branch 0 a: a1 $ echo a2 >> a $ cat > b << EOF > b0 > b1 > EOF $ hg mv a t $ hg mv b a $ hg mv t b $ hg commit -m 'swap names' existing linelogs are not helpful with such renames in side branches $ hg fastannotate --debug -nf a fastannotate: a: linelog cannot help in annotating this revision 1 a: b0 0 b: b1 $ hg fastannotate --debug -nf b fastannotate: b: linelog cannot help in annotating this revision 0 a: a1 1 b: a2 move main branch forward, rebuild should happen $ hg bookmark -i main -r . -q $ hg fastannotate --debug -nf b fastannotate: b: cache broken and deleted fastannotate: b: 2 new changesets in the main branch 0 a: a1 1 b: a2 $ hg fastannotate --debug -nf b fastannotate: b: using fast path (resolved fctx: True) 0 a: a1 1 b: a2 for rev 0, the existing linelog is still useful for a, but not for b $ hg fastannotate --debug -nf a -r 0 fastannotate: a: using fast path (resolved fctx: True) 0 a: a1 $ hg fastannotate --debug -nf b -r 0 fastannotate: b: linelog cannot help in annotating this revision 0 b: b1 a rebuild can also be triggered if "the main branch last time" mismatches $ echo a3 >> a $ hg commit -m a3 $ cat >> b << EOF > b3 > b4 > EOF $ hg commit -m b4 $ hg bookmark -i main -q $ hg fastannotate --debug -nf a fastannotate: a: cache broken and deleted fastannotate: a: 3 new changesets in the main branch 1 a: b0 0 b: b1 2 a: a3 $ hg fastannotate --debug -nf a fastannotate: a: using fast path (resolved fctx: True) 1 a: b0 0 b: b1 2 a: a3 linelog can be updated without being helpful $ hg mv a t $ hg mv b a $ hg mv t b $ hg commit -m 'swap names again' $ hg fastannotate --debug -nf b fastannotate: b: 1 new changesets in the main branch 1 a: b0 0 b: b1 2 a: a3 $ hg fastannotate --debug -nf b fastannotate: b: linelog cannot help in annotating this revision 1 a: b0 0 b: b1 2 a: a3 move main branch forward again, rebuilds are one-time $ hg bookmark -i main -q $ hg fastannotate --debug -nf a fastannotate: a: cache broken and deleted fastannotate: a: 4 new changesets in the main branch 0 a: a1 1 b: a2 3 b: b3 3 b: b4 $ hg fastannotate --debug -nf b fastannotate: b: cache broken and deleted fastannotate: b: 4 new changesets in the main branch 1 a: b0 0 b: b1 2 a: a3 $ hg fastannotate --debug -nf a fastannotate: a: using fast path (resolved fctx: True) 0 a: a1 1 b: a2 3 b: b3 3 b: b4 $ hg fastannotate --debug -nf b fastannotate: b: using fast path (resolved fctx: True) 1 a: b0 0 b: b1 2 a: a3 list changeset hashes to improve readability $ hg log -T '{rev}:{node}\n' 4:980e1ab8c516350172928fba95b49ede3b643dca 3:14e123fedad9f491f5dde0beca2a767625a0a93a 2:96495c41e4c12218766f78cdf244e768d7718b0f 1:35c2b781234c994896aba36bd3245d3104e023df 0:653e95416ebb5dbcc25bbc7f75568c9e01f7bd2f annotate a revision not in the linelog. linelog cannot be used, but does not get rebuilt either $ hg fastannotate --debug -nf a -r 96495c41e4c12218766f78cdf244e768d7718b0f fastannotate: a: linelog cannot help in annotating this revision 1 a: b0 0 b: b1 2 a: a3 $ hg fastannotate --debug -nf a -r 2 fastannotate: a: linelog cannot help in annotating this revision 1 a: b0 0 b: b1 2 a: a3 $ hg fastannotate --debug -nf a -r . fastannotate: a: using fast path (resolved fctx: True) 0 a: a1 1 b: a2 3 b: b3 3 b: b4 annotate an ancient revision where the path matches. linelog can be used $ hg fastannotate --debug -nf a -r 0 fastannotate: a: using fast path (resolved fctx: True) 0 a: a1 $ hg fastannotate --debug -nf a -r 653e95416ebb5dbcc25bbc7f75568c9e01f7bd2f fastannotate: a: using fast path (resolved fctx: False) 0 a: a1