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Differential D9303

copies-rust: move is_ancestor caching within the rust code
ClosedPublic

Authored by marmoute on Nov 12 2020, 10:16 AM.

Details

Reviewers
Alphare
pulkit
Group Reviewers
hg-reviewers
Commits
rHG8b99c473aae2: copies-rust: move is_ancestor caching within the rust code
Summary

Now that the OrdMap merging is fast, smaller things start to matters.

We move the caching of is_ancestor call within the Rust code. This avoid
round-trip to Python and help us to shave more time on our slower case:

Repo Cases Source-Rev Dest-Rev Old-Time New-Time Difference Factor

pypy x0000_revs_x_added_0_copies d1defd0dc478 c9cb1334cc78 : 2.780174 s, 2.137894 s, -0.642280 s, × 0.7690
mozilla-try x0000_revs_xx000_added_x000_copies 89294cd501d9 7ccb2fc7ccb5 : 9.843481 s, 8.100385 s, -1.743096 s, × 0.8229

Note: I would happily have used native code for ancestors computation, however
I failed (did not tried hard) to created a rust version that goes as fast as
the current C version.

Below are full tables for:

  • this change compared to the previous change
  • this change compared to filelog performance

Repo Cases Source-Rev Dest-Rev Old-Time New-Time Difference Factor

mercurial x_revs_x_added_0_copies ad6b123de1c7 39cfcef4f463 : 0.000049 s, 0.000047 s, -0.000002 s, × 0.9592
mercurial x_revs_x_added_x_copies 2b1c78674230 0c1d10351869 : 0.000182 s, 0.000181 s, -0.000001 s, × 0.9945
mercurial x000_revs_x000_added_x_copies 81f8ff2a9bf2 dd3267698d84 : 0.005872 s, 0.005852 s, -0.000020 s, × 0.9966
pypy x_revs_x_added_0_copies aed021ee8ae8 099ed31b181b : 0.000229 s, 0.000229 s, +0.000000 s, × 1.0000
pypy x_revs_x000_added_0_copies 4aa4e1f8e19a 359343b9ac0e : 0.000058 s, 0.000058 s, +0.000000 s, × 1.0000
pypy x_revs_x_added_x_copies ac52eb7bbbb0 72e022663155 : 0.000148 s, 0.000146 s, -0.000002 s, × 0.9865
pypy x_revs_x00_added_x_copies c3b14617fbd7 ace7255d9a26 : 0.001205 s, 0.001206 s, +0.000001 s, × 1.0008
pypy x_revs_x000_added_x000_copies df6f7a526b60 a83dc6a2d56f : 0.025662 s, 0.025275 s, -0.000387 s, × 0.9849
pypy x000_revs_xx00_added_0_copies 89a76aede314 2f22446ff07e : 0.080113 s, 0.080303 s, +0.000190 s, × 1.0024
pypy x000_revs_x000_added_x_copies 8a3b5bfd266e 2c68e87c3efe : 0.153030 s, 0.152641 s, -0.000389 s, × 0.9975
pypy x000_revs_x000_added_x000_copies 89a76aede314 7b3dda341c84 : 0.098774 s, 0.099107 s, +0.000333 s, × 1.0034
pypy x0000_revs_x_added_0_copies d1defd0dc478 c9cb1334cc78 : 2.780174 s, 2.137894 s, -0.642280 s, × 0.7690
pypy x0000_revs_xx000_added_0_copies bf2c629d0071 4ffed77c095c : 0.022218 s, 0.022202 s, -0.000016 s, × 0.9993
pypy x0000_revs_xx000_added_x000_copies 08ea3258278e d9fa043f30c0 : 0.252125 s, 0.228946 s, -0.023179 s, × 0.9081
netbeans x_revs_x_added_0_copies fb0955ffcbcd a01e9239f9e7 : 0.000186 s, 0.000186 s, +0.000000 s, × 1.0000
netbeans x_revs_x000_added_0_copies 6f360122949f 20eb231cc7d0 : 0.000133 s, 0.000133 s, +0.000000 s, × 1.0000
netbeans x_revs_x_added_x_copies 1ada3faf6fb6 5a39d12eecf4 : 0.000320 s, 0.000320 s, +0.000000 s, × 1.0000
netbeans x_revs_x00_added_x_copies 35be93ba1e2c 9eec5e90c05f : 0.001336 s, 0.001339 s, +0.000003 s, × 1.0022
netbeans x000_revs_xx00_added_0_copies eac3045b4fdd 51d4ae7f1290 : 0.015573 s, 0.015694 s, +0.000121 s, × 1.0078
netbeans x000_revs_x000_added_x_copies e2063d266acd 6081d72689dc : 0.018667 s, 0.018457 s, -0.000210 s, × 0.9888
netbeans x000_revs_x000_added_x000_copies ff453e9fee32 411350406ec2 : 0.112534 s, 0.111691 s, -0.000843 s, × 0.9925
netbeans x0000_revs_xx000_added_x000_copies 588c2d1ced70 1aad62e59ddd : 1.231869 s, 1.166017 s, -0.065852 s, × 0.9465
mozilla-central x_revs_x_added_0_copies 3697f962bb7b 7015fcdd43a2 : 0.000197 s, 0.000197 s, +0.000000 s, × 1.0000
mozilla-central x_revs_x000_added_0_copies dd390860c6c9 40d0c5bed75d : 0.000637 s, 0.000626 s, -0.000011 s, × 0.9827
mozilla-central x_revs_x_added_x_copies 8d198483ae3b 14207ffc2b2f : 0.000303 s, 0.000303 s, +0.000000 s, × 1.0000
mozilla-central x_revs_x00_added_x_copies 98cbc58cc6bc 446a150332c3 : 0.001663 s, 0.001679 s, +0.000016 s, × 1.0096
mozilla-central x_revs_x000_added_x000_copies 3c684b4b8f68 0a5e72d1b479 : 0.007008 s, 0.006947 s, -0.000061 s, × 0.9913
mozilla-central x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 0.127385 s, 0.133070 s, +0.005685 s, × 1.0446
mozilla-central x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 0.008740 s, 0.008705 s, -0.000035 s, × 0.9960
mozilla-central x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 0.005783 s, 0.005913 s, +0.000130 s, × 1.0225
mozilla-central x000_revs_x000_added_x000_copies 7c97034feb78 4407bd0c6330 : 0.102184 s, 0.101373 s, -0.000811 s, × 0.9921
mozilla-central x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 0.046220 s, 0.046526 s, +0.000306 s, × 1.0066
mozilla-central x0000_revs_xx000_added_x000_copies f78c615a656c 96a38b690156 : 0.315271 s, 0.313954 s, -0.001317 s, × 0.9958
mozilla-central x00000_revs_x0000_added_x0000_copies 6832ae71433c 4c222a1d9a00 : 3.478747 s, 3.367395 s, -0.111352 s, × 0.9680
mozilla-central x00000_revs_x00000_added_x000_copies 76caed42cf7c 1daa622bbe42 : 4.766435 s, 4.691820 s, -0.074615 s, × 0.9843
mozilla-try x_revs_x_added_0_copies aaf6dde0deb8 9790f499805a : 0.001214 s, 0.001199 s, -0.000015 s, × 0.9876
mozilla-try x_revs_x000_added_0_copies d8d0222927b4 5bb8ce8c7450 : 0.001221 s, 0.001216 s, -0.000005 s, × 0.9959
mozilla-try x_revs_x_added_x_copies 092fcca11bdb 936255a0384a : 0.000613 s, 0.000613 s, +0.000000 s, × 1.0000
mozilla-try x_revs_x00_added_x_copies b53d2fadbdb5 017afae788ec : 0.001904 s, 0.001906 s, +0.000002 s, × 1.0011
mozilla-try x_revs_x000_added_x000_copies 20408ad61ce5 6f0ee96e21ad : 0.093000 s, 0.092766 s, -0.000234 s, × 0.9975
mozilla-try x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 0.132194 s, 0.136074 s, +0.003880 s, × 1.0294
mozilla-try x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 0.009069 s, 0.009067 s, -0.000002 s, × 0.9998
mozilla-try x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 0.006169 s, 0.006243 s, +0.000074 s, × 1.0120
mozilla-try x000_revs_x000_added_x000_copies 1346fd0130e4 4c65cbdabc1f : 0.115540 s, 0.114463 s, -0.001077 s, × 0.9907
mozilla-try x0000_revs_x_added_0_copies 63519bfd42ee a36a2a865d92 : 0.435381 s, 0.433683 s, -0.001698 s, × 0.9961
mozilla-try x0000_revs_x_added_x_copies 9fe69ff0762d bcabf2a78927 : 0.415461 s, 0.411278 s, -0.004183 s, × 0.9899
mozilla-try x0000_revs_xx000_added_x_copies 156f6e2674f2 4d0f2c178e66 : 0.155946 s, 0.155133 s, -0.000813 s, × 0.9948
mozilla-try x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 0.048521 s, 0.048933 s, +0.000412 s, × 1.0085
mozilla-try x0000_revs_xx000_added_x000_copies 89294cd501d9 7ccb2fc7ccb5 : 9.843481 s, 8.100385 s, -1.743096 s, × 0.8229
mozilla-try x0000_revs_x0000_added_x0000_copies e928c65095ed e951f4ad123a : 1.465128 s, 1.446720 s, -0.018408 s, × 0.9874
mozilla-try x00000_revs_x00000_added_0_copies dc8a3ca7010e d16fde900c9c : 1.374283 s, 1.369537 s, -0.004746 s, × 0.9965
mozilla-try x00000_revs_x0000_added_x0000_copies 8d3fafa80d4b eb884023b810 : 5.255158 s, 5.186079 s, -0.069079 s, × 0.9869

Repo Case Source-Rev Dest-Rev filelog sidedata Difference Factor

mercurial x_revs_x_added_0_copies ad6b123de1c7 39cfcef4f463 : 0.000892 s, 0.000047 s, -0.000845 s, × 0.052691
mercurial x_revs_x_added_x_copies 2b1c78674230 0c1d10351869 : 0.001823 s, 0.000181 s, -0.001642 s, × 0.099287
mercurial x000_revs_x000_added_x_copies 81f8ff2a9bf2 dd3267698d84 : 0.018063 s, 0.005852 s, -0.012211 s, × 0.323977
pypy x_revs_x_added_0_copies aed021ee8ae8 099ed31b181b : 0.001505 s, 0.000229 s, -0.001276 s, × 0.152159
pypy x_revs_x000_added_0_copies 4aa4e1f8e19a 359343b9ac0e : 0.205895 s, 0.000058 s, -0.205837 s, × 0.000282
pypy x_revs_x_added_x_copies ac52eb7bbbb0 72e022663155 : 0.017021 s, 0.000146 s, -0.016875 s, × 0.008578
pypy x_revs_x00_added_x_copies c3b14617fbd7 ace7255d9a26 : 0.019422 s, 0.001206 s, -0.018216 s, × 0.062095
pypy x_revs_x000_added_x000_copies df6f7a526b60 a83dc6a2d56f : 0.767740 s, 0.025275 s, -0.742465 s, × 0.032921
pypy x000_revs_xx00_added_0_copies 89a76aede314 2f22446ff07e : 1.188515 s, 0.080303 s, -1.108212 s, × 0.067566
pypy x000_revs_x000_added_x_copies 8a3b5bfd266e 2c68e87c3efe : 1.251968 s, 0.152641 s, -1.099327 s, × 0.121921
pypy x000_revs_x000_added_x000_copies 89a76aede314 7b3dda341c84 : 1.616799 s, 0.099107 s, -1.517692 s, × 0.061298
pypy x0000_revs_x_added_0_copies d1defd0dc478 c9cb1334cc78 : 0.001057 s, 2.137894 s, +2.136837 s, × 2022.605487
pypy x0000_revs_xx000_added_0_copies bf2c629d0071 4ffed77c095c : 1.069485 s, 0.022202 s, -1.047283 s, × 0.020760
pypy x0000_revs_xx000_added_x000_copies 08ea3258278e d9fa043f30c0 : 1.350162 s, 0.228946 s, -1.121216 s, × 0.169569
netbeans x_revs_x_added_0_copies fb0955ffcbcd a01e9239f9e7 : 0.028008 s, 0.000186 s, -0.027822 s, × 0.006641
netbeans x_revs_x000_added_0_copies 6f360122949f 20eb231cc7d0 : 0.132281 s, 0.000133 s, -0.132148 s, × 0.001005
netbeans x_revs_x_added_x_copies 1ada3faf6fb6 5a39d12eecf4 : 0.025311 s, 0.000320 s, -0.024991 s, × 0.012643
netbeans x_revs_x00_added_x_copies 35be93ba1e2c 9eec5e90c05f : 0.052957 s, 0.001339 s, -0.051618 s, × 0.025285
netbeans x000_revs_xx00_added_0_copies eac3045b4fdd 51d4ae7f1290 : 0.038011 s, 0.015694 s, -0.022317 s, × 0.412880
netbeans x000_revs_x000_added_x_copies e2063d266acd 6081d72689dc : 0.198639 s, 0.018457 s, -0.180182 s, × 0.092917
netbeans x000_revs_x000_added_x000_copies ff453e9fee32 411350406ec2 : 0.955713 s, 0.111691 s, -0.844022 s, × 0.116867
netbeans x0000_revs_xx000_added_x000_copies 588c2d1ced70 1aad62e59ddd : 3.838886 s, 1.166017 s, -2.672869 s, × 0.303738
mozilla-central x_revs_x_added_0_copies 3697f962bb7b 7015fcdd43a2 : 0.024548 s, 0.000197 s, -0.024351 s, × 0.008025
mozilla-central x_revs_x000_added_0_copies dd390860c6c9 40d0c5bed75d : 0.143394 s, 0.000626 s, -0.142768 s, × 0.004366
mozilla-central x_revs_x_added_x_copies 8d198483ae3b 14207ffc2b2f : 0.026046 s, 0.000303 s, -0.025743 s, × 0.011633
mozilla-central x_revs_x00_added_x_copies 98cbc58cc6bc 446a150332c3 : 0.085440 s, 0.001679 s, -0.083761 s, × 0.019651
mozilla-central x_revs_x000_added_x000_copies 3c684b4b8f68 0a5e72d1b479 : 0.195656 s, 0.006947 s, -0.188709 s, × 0.035506
mozilla-central x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 2.190874 s, 0.133070 s, -2.057804 s, × 0.060738
mozilla-central x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 0.090208 s, 0.008705 s, -0.081503 s, × 0.096499
mozilla-central x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 0.747367 s, 0.005913 s, -0.741454 s, × 0.007912
mozilla-central x000_revs_x000_added_x000_copies 7c97034feb78 4407bd0c6330 : 1.152863 s, 0.101373 s, -1.051490 s, × 0.087932
mozilla-central x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 6.598336 s, 0.046526 s, -6.551810 s, × 0.007051
mozilla-central x0000_revs_xx000_added_x000_copies f78c615a656c 96a38b690156 : 3.255015 s, 0.313954 s, -2.941061 s, × 0.096452
mozilla-central x00000_revs_x0000_added_x0000_copies 6832ae71433c 4c222a1d9a00 : 15.668041 s, 3.367395 s, -12.300646 s, × 0.214921
mozilla-central x00000_revs_x00000_added_x000_copies 76caed42cf7c 1daa622bbe42 : 20.439638 s, 4.691820 s, -15.747818 s, × 0.229545
mozilla-try x_revs_x_added_0_copies aaf6dde0deb8 9790f499805a : 0.080923 s, 0.001199 s, -0.079724 s, × 0.014817
mozilla-try x_revs_x000_added_0_copies d8d0222927b4 5bb8ce8c7450 : 0.498456 s, 0.001216 s, -0.497240 s, × 0.002440
mozilla-try x_revs_x_added_x_copies 092fcca11bdb 936255a0384a : 0.020798 s, 0.000613 s, -0.020185 s, × 0.029474
mozilla-try x_revs_x00_added_x_copies b53d2fadbdb5 017afae788ec : 0.226930 s, 0.001906 s, -0.225024 s, × 0.008399
mozilla-try x_revs_x000_added_x000_copies 20408ad61ce5 6f0ee96e21ad : 1.113005 s, 0.092766 s, -1.020239 s, × 0.083347
mozilla-try x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 2.230671 s, 0.136074 s, -2.094597 s, × 0.061001
mozilla-try x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 0.089672 s, 0.009067 s, -0.080605 s, × 0.101113
mozilla-try x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 0.740221 s, 0.006243 s, -0.733978 s, × 0.008434
mozilla-try x000_revs_x000_added_x000_copies 1346fd0130e4 4c65cbdabc1f : 1.185881 s, 0.114463 s, -1.071418 s, × 0.096521
mozilla-try x0000_revs_x_added_0_copies 63519bfd42ee a36a2a865d92 : 0.086072 s, 0.433683 s, +0.347611 s, × 5.038607
mozilla-try x0000_revs_x_added_x_copies 9fe69ff0762d bcabf2a78927 : 0.081321 s, 0.411278 s, +0.329957 s, × 5.057464
mozilla-try x0000_revs_xx000_added_x_copies 156f6e2674f2 4d0f2c178e66 : 7.528370 s, 0.155133 s, -7.373237 s, × 0.020606
mozilla-try x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 6.757368 s, 0.048933 s, -6.708435 s, × 0.007241
mozilla-try x0000_revs_xx000_added_x000_copies 89294cd501d9 7ccb2fc7ccb5 : 7.643752 s, 8.100385 s, +0.456633 s, × 1.059739
mozilla-try x0000_revs_x0000_added_x0000_copies e928c65095ed e951f4ad123a : 9.704242 s, 1.446720 s, -8.257522 s, × 0.149081
mozilla-try x00000_revs_x_added_0_copies 6a320851d377 1ebb79acd503 : 0.092845 s, killed
mozilla-try x00000_revs_x00000_added_0_copies dc8a3ca7010e d16fde900c9c : 26.626870 s, 1.369537 s, -25.257333 s, × 0.051434
mozilla-try x00000_revs_x_added_x_copies 5173c4b6f97c 95d83ee7242d : 0.092953 s, killed
mozilla-try x00000_revs_x000_added_x_copies 9126823d0e9c ca82787bb23c : 0.227131 s, killed
mozilla-try x00000_revs_x0000_added_x0000_copies 8d3fafa80d4b eb884023b810 : 18.884666 s, 5.186079 s, -13.698587 s, × 0.274619
mozilla-try x00000_revs_x00000_added_x0000_copies 1b661134e2ca 1ae03d022d6d : 21.451622 s, killed
mozilla-try x00000_revs_x00000_added_x000_copies 9b2a99adc05e 8e29777b48e6 : 25.152558 s, killed

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

marmoute created this revision.Nov 12 2020, 10:16 AM
Alphare accepted this revision.Nov 13 2020, 6:45 AM
Alphare added a subscriber: Alphare.
Alphare added inline comments.
rust/hg-core/src/copy_tracing.rs
116

'a is useless here.

marmoute updated this revision to Diff 23497.Nov 13 2020, 7:05 PM
Alphare updated this revision to Diff 23726.Nov 27 2020, 11:11 AM
marmoute updated this revision to Diff 23799.Nov 28 2020, 6:20 PM
pulkit accepted this revision.Nov 29 2020, 2:04 PM
This revision is now accepted and ready to land.Nov 29 2020, 2:04 PM

Revision Contents
Changeset List

PathPackages
Mmercurial/copies.py (4 lines)
Mrust/hg-core/src/copy_tracing.rs (54 lines)

Diff 23857

mercurial/copies.py

def _changesetforwardcopies(a, b, match): def _changesetforwardcopies(a, b, match):
if a.rev() in (node.nullrev, b.rev()): if a.rev() in (node.nullrev, b.rev()):
return {} return {}
repo = a.repo().unfiltered() repo = a.repo().unfiltered()
children = {} children = {}
cl = repo.changelog cl = repo.changelog
isancestor = cached_is_ancestor(cl.isancestorrev) isancestor = cl.isancestorrev
missingrevs = cl.findmissingrevs(common=[a.rev()], heads=[b.rev()]) missingrevs = cl.findmissingrevs(common=[a.rev()], heads=[b.rev()])
mrset = set(missingrevs) mrset = set(missingrevs)
roots = set() roots = set()
for r in missingrevs: for r in missingrevs:
for p in cl.parentrevs(r): for p in cl.parentrevs(r):
if p == node.nullrev: if p == node.nullrev:
continue continue
if p not in children: if p not in children:
alwaysmatch = match.always() alwaysmatch = match.always()
if rustmod is not None and alwaysmatch: if rustmod is not None and alwaysmatch:
return rustmod.combine_changeset_copies( return rustmod.combine_changeset_copies(
list(revs), children, targetrev, revinfo, isancestor list(revs), children, targetrev, revinfo, isancestor
) )
isancestor = cached_is_ancestor(isancestor)
all_copies = {} all_copies = {}
for r in revs: for r in revs:
copies = all_copies.pop(r, None) copies = all_copies.pop(r, None)
if copies is None: if copies is None:
# this is a root # this is a root
copies = {} copies = {}
for i, c in enumerate(children[r]): for i, c in enumerate(children[r]):
p1, p2, changes = revinfo(c) p1, p2, changes = revinfo(c)

rust/hg-core/src/copy_tracing.rs

merged: HashSet::new(), merged: HashSet::new(),
salvaged: HashSet::new(), salvaged: HashSet::new(),
copied_from_p1: PathCopies::new(), copied_from_p1: PathCopies::new(),
copied_from_p2: PathCopies::new(), copied_from_p2: PathCopies::new(),
} }
} }
} }
/// A struct responsible for answering "is X ancestors of Y" quickly
///
/// The structure will delegate ancestors call to a callback, and cache the
/// result.
#[derive(Debug)]
struct AncestorOracle<'a, A: Fn(Revision, Revision) -> bool> {
inner: &'a A,
pairs: HashMap<(Revision, Revision), bool>,
}
impl<'a, A: Fn(Revision, Revision) -> bool> AncestorOracle<'a, A> {
fn new(func: &'a A) -> Self {
Self {
inner: func,
pairs: HashMap::default(),
}
}
/// returns `true` if `anc` is an ancestors of `desc`, `false` otherwise
fn is_ancestor(&mut self, anc: Revision, desc: Revision) -> bool {
if anc > desc {
false
} else if anc == desc {
true
} else {
if let Some(b) = self.pairs.get(&(anc, desc)) {
*b
} else {
let b = (self.inner)(anc, desc);
self.pairs.insert((anc, desc), b);
b
}
}
}
}
/// Same as mercurial.copies._combine_changeset_copies, but in Rust. /// Same as mercurial.copies._combine_changeset_copies, but in Rust.
/// ///
/// Arguments are: /// Arguments are:
/// ///
/// revs: all revisions to be considered /// revs: all revisions to be considered
/// children: a {parent ? [childrens]} mapping /// children: a {parent ? [childrens]} mapping
/// target_rev: the final revision we are combining copies to /// target_rev: the final revision we are combining copies to
/// rev_info(rev): callback to get revision information: /// rev_info(rev): callback to get revision information:
/// * first parent /// * first parent
/// * second parent /// * second parent
/// * ChangedFiles /// * ChangedFiles
/// isancestors(low_rev, high_rev): callback to check if a revision is an /// isancestors(low_rev, high_rev): callback to check if a revision is an
/// ancestor of another /// ancestor of another
pub fn combine_changeset_copies( pub fn combine_changeset_copies<A: Fn(Revision, Revision) -> bool>(
AlphareUnsubmitted
Not Done

'a is useless here.

Alphare: `'a` is useless here.
revs: Vec<Revision>, revs: Vec<Revision>,
children: HashMap<Revision, Vec<Revision>>, children: HashMap<Revision, Vec<Revision>>,
target_rev: Revision, target_rev: Revision,
rev_info: &impl Fn(Revision) -> RevInfo, rev_info: &impl Fn(Revision) -> RevInfo,
is_ancestor: &impl Fn(Revision, Revision) -> bool, is_ancestor: &A,
) -> PathCopies { ) -> PathCopies {
let mut all_copies = HashMap::new(); let mut all_copies = HashMap::new();
let mut oracle = AncestorOracle::new(is_ancestor);
for rev in revs { for rev in revs {
// Retrieve data computed in a previous iteration // Retrieve data computed in a previous iteration
let copies = all_copies.remove(&rev); let copies = all_copies.remove(&rev);
let copies = match copies { let copies = match copies {
Some(c) => c, Some(c) => c,
None => TimeStampedPathCopies::default(), // root of the walked set None => TimeStampedPathCopies::default(), // root of the walked set
}; };
} }
Some(other_copies) => { Some(other_copies) => {
let (minor, major) = match parent { let (minor, major) = match parent {
1 => (other_copies, new_copies), 1 => (other_copies, new_copies),
2 => (new_copies, other_copies), 2 => (new_copies, other_copies),
_ => unreachable!(), _ => unreachable!(),
}; };
let merged_copies = let merged_copies =
merge_copies_dict(minor, major, &changes, is_ancestor); merge_copies_dict(minor, major, &changes, &mut oracle);
all_copies.insert(child, merged_copies); all_copies.insert(child, merged_copies);
} }
}; };
} }
} }
// Drop internal information (like the timestamp) and return the final // Drop internal information (like the timestamp) and return the final
// mapping. // mapping.
result result
} }
/// merge two copies-mapping together, minor and major /// merge two copies-mapping together, minor and major
/// ///
/// In case of conflict, value from "major" will be picked, unless in some /// In case of conflict, value from "major" will be picked, unless in some
/// cases. See inline documentation for details. /// cases. See inline documentation for details.
#[allow(clippy::if_same_then_else)] #[allow(clippy::if_same_then_else)]
fn merge_copies_dict( fn merge_copies_dict<A: Fn(Revision, Revision) -> bool>(
minor: TimeStampedPathCopies, minor: TimeStampedPathCopies,
major: TimeStampedPathCopies, major: TimeStampedPathCopies,
changes: &ChangedFiles, changes: &ChangedFiles,
is_ancestor: &impl Fn(Revision, Revision) -> bool, oracle: &mut AncestorOracle<A>,
) -> TimeStampedPathCopies { ) -> TimeStampedPathCopies {
if minor.is_empty() { if minor.is_empty() {
return major; return major;
} else if major.is_empty() { } else if major.is_empty() {
return minor; return minor;
} }
let mut override_minor = Vec::new(); let mut override_minor = Vec::new();
let mut override_major = Vec::new(); let mut override_major = Vec::new();
let mut pick_minor = || (to_major(dest, src_minor)); let mut pick_minor = || (to_major(dest, src_minor));
let mut pick_major = || (to_minor(dest, src_major)); let mut pick_major = || (to_minor(dest, src_major));
if src_major.path == src_minor.path { if src_major.path == src_minor.path {
// we have the same value, but from other source; // we have the same value, but from other source;
if src_major.rev == src_minor.rev { if src_major.rev == src_minor.rev {
// If the two entry are identical, no need to do // If the two entry are identical, no need to do
// anything (but diff should not have yield them) // anything (but diff should not have yield them)
unreachable!(); unreachable!();
} else if is_ancestor(src_major.rev, src_minor.rev) { } else if oracle.is_ancestor(src_major.rev, src_minor.rev)
{
pick_minor(); pick_minor();
} else { } else {
pick_major(); pick_major();
} }
} else if src_major.rev == src_minor.rev { } else if src_major.rev == src_minor.rev {
// We cannot get copy information for both p1 and p2 in the // We cannot get copy information for both p1 and p2 in the
// same rev. So this is the same value. // same rev. So this is the same value.
unreachable!(); unreachable!();
// salvaged by the merge, unconditionnaly preserve the // salvaged by the merge, unconditionnaly preserve the
// major side. // major side.
pick_major(); pick_major();
} else if changes.merged.contains(dest) { } else if changes.merged.contains(dest) {
// If the file was actively merged, copy information from // If the file was actively merged, copy information from
// each side might conflict. The major side will win such // each side might conflict. The major side will win such
// conflict. // conflict.
pick_major(); pick_major();
} else if is_ancestor(src_major.rev, src_minor.rev) { } else if oracle.is_ancestor(src_major.rev, src_minor.rev) {
// If the minor side is strictly newer than the major side, // If the minor side is strictly newer than the major side,
// it should be kept. // it should be kept.
pick_minor(); pick_minor();
} else if src_major.path.is_some() { } else if src_major.path.is_some() {
// without any special case, the "major" value win other // without any special case, the "major" value win other
// the "minor" one. // the "minor" one.
pick_major(); pick_major();
} else if is_ancestor(src_minor.rev, src_major.rev) { } else if oracle.is_ancestor(src_minor.rev, src_major.rev) {
// the "major" rev is a direct ancestors of "minor", any // the "major" rev is a direct ancestors of "minor", any
// different value should overwrite // different value should overwrite
pick_major(); pick_major();
} else { } else {
// major version is None (so the file was deleted on that // major version is None (so the file was deleted on that
// branch) and that branch is independant (neither minor // branch) and that branch is independant (neither minor
// nor major is an ancestors of the other one.) We preserve // nor major is an ancestors of the other one.) We preserve
// the new information about the new file. // the new information about the new file.