Mercurial > hg
view tests/test-issue672.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 | 99ebde4fec99 |
children | 17e12938f8e7 |
line wrap: on
line source
https://bz.mercurial-scm.org/672 # 0-2-4 # \ \ \ # 1-3-5 # # rename in #1, content change in #4. $ hg init $ touch 1 $ touch 2 $ hg commit -Am init # 0 adding 1 adding 2 $ hg rename 1 1a $ hg commit -m rename # 1 $ hg co -C 0 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo unrelated >> 2 $ hg ci -m unrelated1 # 2 created new head $ hg merge --debug 1 unmatched files in other: 1a all copies found (* = to merge, ! = divergent, % = renamed and deleted): src: '1' -> dst: '1a' checking for directory renames resolving manifests branchmerge: True, force: False, partial: False ancestor: 81f4b099af3d, local: c64f439569a9+, remote: c12dcd37c90a 1: other deleted -> r removing 1 1a: remote created -> g getting 1a 1 files updated, 0 files merged, 1 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg ci -m merge1 # 3 $ hg co -C 2 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ echo hello >> 1 $ hg ci -m unrelated2 # 4 created new head $ hg co -C 3 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg merge -y --debug 4 unmatched files in local: 1a all copies found (* = to merge, ! = divergent, % = renamed and deleted): src: '1' -> dst: '1a' * checking for directory renames resolving manifests branchmerge: True, force: False, partial: False ancestor: c64f439569a9, local: f4a9cff3cd0b+, remote: 746e9549ea96 preserving 1a for resolve of 1a starting 4 threads for background file closing (?) 1a: local copied/moved from 1 -> m (premerge) picked tool ':merge' for 1a (binary False symlink False changedelete False) merging 1a and 1 to 1a my 1a@f4a9cff3cd0b+ other 1@746e9549ea96 ancestor 1@c64f439569a9 premerge successful 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit) $ hg co -C 4 1 files updated, 0 files merged, 1 files removed, 0 files unresolved $ hg merge -y --debug 3 unmatched files in other: 1a all copies found (* = to merge, ! = divergent, % = renamed and deleted): src: '1' -> dst: '1a' * checking for directory renames resolving manifests branchmerge: True, force: False, partial: False ancestor: c64f439569a9, local: 746e9549ea96+, remote: f4a9cff3cd0b preserving 1 for resolve of 1a removing 1 starting 4 threads for background file closing (?) 1a: remote moved from 1 -> m (premerge) picked tool ':merge' for 1a (binary False symlink False changedelete False) merging 1 and 1a to 1a my 1a@746e9549ea96+ other 1a@f4a9cff3cd0b ancestor 1@c64f439569a9 premerge successful 0 files updated, 1 files merged, 0 files removed, 0 files unresolved (branch merge, don't forget to commit)