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view tests/test-merge-revert2.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 | ce3a133f71b3 |
children | 55c6ebd11cb9 |
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$ hg init $ echo "added file1" > file1 $ echo "another line of text" >> file1 $ echo "added file2" > file2 $ hg add file1 file2 $ hg commit -m "added file1 and file2" $ echo "changed file1" >> file1 $ hg commit -m "changed file1" $ hg -q log 1:dfab7f3c2efb 0:c3fa057dd86f $ hg id dfab7f3c2efb tip $ hg update -C 0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg id c3fa057dd86f $ echo "changed file1" >> file1 $ hg id c3fa057dd86f+ $ hg revert --no-backup --all reverting file1 $ hg diff $ hg status $ hg id c3fa057dd86f $ hg update 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg diff $ hg status $ hg id dfab7f3c2efb tip $ hg update -C 0 1 files updated, 0 files merged, 0 files removed, 0 files unresolved $ echo "changed file1 different" >> file1 $ hg update merging file1 warning: conflicts while merging file1! (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 [1] $ hg diff --nodates diff -r dfab7f3c2efb file1 --- a/file1 +++ b/file1 @@ -1,3 +1,7 @@ added file1 another line of text +<<<<<<< working copy: c3fa057dd86f - test: added file1 and file2 +changed file1 different +======= changed file1 +>>>>>>> destination: dfab7f3c2efb - test: changed file1 $ hg status M file1 ? file1.orig $ hg id dfab7f3c2efb+ tip $ hg revert --no-backup --all reverting file1 $ hg diff $ hg status ? file1.orig $ hg id dfab7f3c2efb tip $ hg revert -r tip --no-backup --all $ hg diff $ hg status ? file1.orig $ hg id dfab7f3c2efb tip $ hg update -C 0 files updated, 0 files merged, 0 files removed, 0 files unresolved $ hg diff $ hg status ? file1.orig $ hg id dfab7f3c2efb tip