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view tests/test-merge7.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 | 91a0bc50b288 |
children | 69429972ff1f |
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initial $ hg init test-a $ cd test-a $ cat >test.txt <<"EOF" > 1 > 2 > 3 > EOF $ hg add test.txt $ hg commit -m "Initial" clone $ cd .. $ hg clone test-a test-b updating to branch default 1 files updated, 0 files merged, 0 files removed, 0 files unresolved change test-a $ cd test-a $ cat >test.txt <<"EOF" > one > two > three > EOF $ hg commit -m "Numbers as words" change test-b $ cd ../test-b $ cat >test.txt <<"EOF" > 1 > 2.5 > 3 > EOF $ hg commit -m "2 -> 2.5" now pull and merge from test-a $ hg pull ../test-a pulling from ../test-a searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) new changesets 96b70246a118 (run 'hg heads' to see heads, 'hg merge' to merge) $ hg merge merging test.txt warning: conflicts while merging test.txt! (edit, then use 'hg resolve --mark') 0 files updated, 0 files merged, 0 files removed, 1 files unresolved use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon [1] resolve conflict $ cat >test.txt <<"EOF" > one > two-point-five > three > EOF $ rm -f *.orig $ hg resolve -m test.txt (no more unresolved files) $ hg commit -m "Merge 1" change test-a again $ cd ../test-a $ cat >test.txt <<"EOF" > one > two-point-one > three > EOF $ hg commit -m "two -> two-point-one" pull and merge from test-a again $ cd ../test-b $ hg pull ../test-a pulling from ../test-a searching for changes adding changesets adding manifests adding file changes added 1 changesets with 1 changes to 1 files (+1 heads) new changesets 40d11a4173a8 (run 'hg heads' to see heads, 'hg merge' to merge) $ hg merge --debug resolving manifests branchmerge: True, force: False, partial: False ancestor: 96b70246a118, local: 50c3a7e29886+, remote: 40d11a4173a8 preserving test.txt for resolve of test.txt starting 4 threads for background file closing (?) test.txt: versions differ -> m (premerge) picked tool ':merge' for test.txt (binary False symlink False changedelete False) merging test.txt my test.txt@50c3a7e29886+ other test.txt@40d11a4173a8 ancestor test.txt@96b70246a118 test.txt: versions differ -> m (merge) picked tool ':merge' for test.txt (binary False symlink False changedelete False) my test.txt@50c3a7e29886+ other test.txt@40d11a4173a8 ancestor test.txt@96b70246a118 warning: conflicts while merging test.txt! (edit, then use 'hg resolve --mark') 0 files updated, 0 files merged, 0 files removed, 1 files unresolved use 'hg resolve' to retry unresolved file merges or 'hg merge --abort' to abandon [1] $ cat test.txt one <<<<<<< working copy: 50c3a7e29886 - test: Merge 1 two-point-five ======= two-point-one >>>>>>> merge rev: 40d11a4173a8 - test: two -> two-point-one three $ hg debugindex test.txt rev linkrev nodeid p1 p2 0 0 01365c4cca56 000000000000 000000000000 1 1 7b013192566a 01365c4cca56 000000000000 2 2 8fe46a3eb557 01365c4cca56 000000000000 3 3 fc3148072371 7b013192566a 8fe46a3eb557 4 4 d40249267ae3 8fe46a3eb557 000000000000 $ hg log changeset: 4:40d11a4173a8 tag: tip parent: 2:96b70246a118 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: two -> two-point-one changeset: 3:50c3a7e29886 parent: 1:d1e159716d41 parent: 2:96b70246a118 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Merge 1 changeset: 2:96b70246a118 parent: 0:b1832b9d912a user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Numbers as words changeset: 1:d1e159716d41 user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: 2 -> 2.5 changeset: 0:b1832b9d912a user: test date: Thu Jan 01 00:00:00 1970 +0000 summary: Initial $ cd ..