copies-rust: extract the processing of a single copy information This will make it easy to process copy from both p1 and p2 in the same `add_from_changes` call. Differential Revision: https://phab.mercurial-scm.org/D9648

copies-rust: use matching to select the final copies information This is a bit more idiomatic and this prepare a future refactoring where InternalCopies from both parent would be updated at the same time. Differential Revision: https://phab.mercurial-scm.org/D9647

copies-rust: get the parents' copies earlier This remove some conditional nesting and prepare for future work were we will unify the handling of copies from p1 and p2. Differential Revision: https://phab.mercurial-scm.org/D9646

copies-rust: remove the ancestor Oracle logic We are not doing any `is_ancestor` call anymore. So we can drop that logic and associated arguments. Differential Revision: https://phab.mercurial-scm.org/D9645

copies-rust: track "overwrites" directly within CopySource Overwrite are "rare enough" that explicitly keeping track of them is going to be "cheap", or at least much cheaper that issuing many `is_ancestor` calls. Even a simple implementation using no specific optimisation (eg: using the generic HashSet type) yield good result in most cases. They are interesting optimization to can do on top of that. We will implement them in later changesets. We tried different approach to speed up the overwrite detection and this one seems the most promising. Without further optimization, we already see sizable speedup on various cases. Repo Case Source-Rev Dest-Rev # of revisions old time new time Difference Factor time per rev --------------------------------------------------------------------------------------------------------------------------------------------------------------- mozilla-try x00000_revs_x_added_0_copies 6a320851d377 1ebb79acd503 : 363753 revs, 5.138169 s, 4.482399 s, -0.655770 s, × 0.8724, 12 µs/rev mozilla-try x00000_revs_x_added_x_copies 5173c4b6f97c 95d83ee7242d : 362229 revs, 5.127809 s, 4.480366 s, -0.647443 s, × 0.8737, 12 µs/rev mozilla-try x00000_revs_x000_added_x_copies 9126823d0e9c ca82787bb23c : 359344 revs, 4.971136 s, 4.369070 s, -0.602066 s, × 0.8789, 12 µs/rev mozilla-try x00000_revs_x0000_added_x0000_copies 8d3fafa80d4b eb884023b810 : 192665 revs, 1.741678 s, 1.592506 s, -0.149172 s, × 0.9144, 8 µs/rev However, some of the case doing a lot of overwrite get significantly slower. The one with a really problematic slowdown are the special "head reducing" merge in mozilla-try so I am not too worried about them. In addition, further changeset are going to improve the performance of all this. Repo Case Source-Rev Dest-Rev # of revisions old time new time Difference Factor time per rev --------------------------------------------------------------------------------------------------------------------------------------------------------------- mozilla-try x0000_revs_xx000_added_x000_copies 89294cd501d9 7ccb2fc7ccb5 : 97052 revs, 1.343373 s, 2.119204 s, +0.775831 s, × 1.5775, 21 µs/rev mozilla-try x00000_revs_x00000_added_x0000_copies 1b661134e2ca 1ae03d022d6d : 228985 revs, 40.314822 s, 87.824489 s, +47.509667 s, × 2.1785, 383 µs/rev mozilla-try x00000_revs_x00000_added_x000_copies 9b2a99adc05e 8e29777b48e6 : 382065 revs, 20.048029 s, 43.304637 s, +23.256608 s, × 2.1600, 113 µs/rev Full benchmark below: Repo Case Source-Rev Dest-Rev # of revisions old time new time Difference Factor time per rev --------------------------------------------------------------------------------------------------------------------------------------------------------------- mercurial x_revs_x_added_0_copies ad6b123de1c7 39cfcef4f463 : 1 revs, 0.000042 s, 0.000043 s, +0.000001 s, × 1.0238, 43 µs/rev mercurial x_revs_x_added_x_copies 2b1c78674230 0c1d10351869 : 6 revs, 0.000110 s, 0.000114 s, +0.000004 s, × 1.0364, 19 µs/rev mercurial x000_revs_x000_added_x_copies 81f8ff2a9bf2 dd3267698d84 : 1032 revs, 0.004945 s, 0.004937 s, -0.000008 s, × 0.9984, 4 µs/rev pypy x_revs_x_added_0_copies aed021ee8ae8 099ed31b181b : 9 revs, 0.000192 s, 0.000339 s, +0.000147 s, × 1.7656, 37 µs/rev pypy x_revs_x000_added_0_copies 4aa4e1f8e19a 359343b9ac0e : 1 revs, 0.000049 s, 0.000049 s, +0.000000 s, × 1.0000, 49 µs/rev pypy x_revs_x_added_x_copies ac52eb7bbbb0 72e022663155 : 7 revs, 0.000112 s, 0.000202 s, +0.000090 s, × 1.8036, 28 µs/rev pypy x_revs_x00_added_x_copies c3b14617fbd7 ace7255d9a26 : 1 revs, 0.000323 s, 0.000409 s, +0.000086 s, × 1.2663, 409 µs/rev pypy x_revs_x000_added_x000_copies df6f7a526b60 a83dc6a2d56f : 6 revs, 0.010042 s, 0.011984 s, +0.001942 s, × 1.1934, 1997 µs/rev pypy x000_revs_xx00_added_0_copies 89a76aede314 2f22446ff07e : 4785 revs, 0.049813 s, 0.050820 s, +0.001007 s, × 1.0202, 10 µs/rev pypy x000_revs_x000_added_x_copies 8a3b5bfd266e 2c68e87c3efe : 6780 revs, 0.079937 s, 0.087953 s, +0.008016 s, × 1.1003, 12 µs/rev pypy x000_revs_x000_added_x000_copies 89a76aede314 7b3dda341c84 : 5441 revs, 0.059412 s, 0.062902 s, +0.003490 s, × 1.0587, 11 µs/rev pypy x0000_revs_x_added_0_copies d1defd0dc478 c9cb1334cc78 : 43645 revs, 0.533769 s, 0.679234 s, +0.145465 s, × 1.2725, 15 µs/rev pypy x0000_revs_xx000_added_0_copies bf2c629d0071 4ffed77c095c : 2 revs, 0.013147 s, 0.013095 s, -0.000052 s, × 0.9960, 6547 µs/rev pypy x0000_revs_xx000_added_x000_copies 08ea3258278e d9fa043f30c0 : 11316 revs, 0.110680 s, 0.120910 s, +0.010230 s, × 1.0924, 10 µs/rev netbeans x_revs_x_added_0_copies fb0955ffcbcd a01e9239f9e7 : 2 revs, 0.000085 s, 0.000087 s, +0.000002 s, × 1.0235, 43 µs/rev netbeans x_revs_x000_added_0_copies 6f360122949f 20eb231cc7d0 : 2 revs, 0.000107 s, 0.000107 s, +0.000000 s, × 1.0000, 53 µs/rev netbeans x_revs_x_added_x_copies 1ada3faf6fb6 5a39d12eecf4 : 3 revs, 0.000175 s, 0.000186 s, +0.000011 s, × 1.0629, 62 µs/rev netbeans x_revs_x00_added_x_copies 35be93ba1e2c 9eec5e90c05f : 9 revs, 0.000720 s, 0.000754 s, +0.000034 s, × 1.0472, 83 µs/rev netbeans x000_revs_xx00_added_0_copies eac3045b4fdd 51d4ae7f1290 : 1421 revs, 0.010019 s, 0.010443 s, +0.000424 s, × 1.0423, 7 µs/rev netbeans x000_revs_x000_added_x_copies e2063d266acd 6081d72689dc : 1533 revs, 0.015602 s, 0.015697 s, +0.000095 s, × 1.0061, 10 µs/rev netbeans x000_revs_x000_added_x000_copies ff453e9fee32 411350406ec2 : 5750 revs, 0.058759 s, 0.063528 s, +0.004769 s, × 1.0812, 11 µs/rev netbeans x0000_revs_xx000_added_x000_copies 588c2d1ced70 1aad62e59ddd : 66949 revs, 0.491550 s, 0.545515 s, +0.053965 s, × 1.1098, 8 µs/rev mozilla-central x_revs_x_added_0_copies 3697f962bb7b 7015fcdd43a2 : 2 revs, 0.000087 s, 0.000089 s, +0.000002 s, × 1.0230, 44 µs/rev mozilla-central x_revs_x000_added_0_copies dd390860c6c9 40d0c5bed75d : 8 revs, 0.000268 s, 0.000265 s, -0.000003 s, × 0.9888, 33 µs/rev mozilla-central x_revs_x_added_x_copies 8d198483ae3b 14207ffc2b2f : 9 revs, 0.000181 s, 0.000381 s, +0.000200 s, × 2.1050, 42 µs/rev mozilla-central x_revs_x00_added_x_copies 98cbc58cc6bc 446a150332c3 : 7 revs, 0.000661 s, 0.000672 s, +0.000011 s, × 1.0166, 96 µs/rev mozilla-central x_revs_x000_added_x000_copies 3c684b4b8f68 0a5e72d1b479 : 3 revs, 0.003256 s, 0.003497 s, +0.000241 s, × 1.0740, 1165 µs/rev mozilla-central x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 6 revs, 0.066749 s, 0.073204 s, +0.006455 s, × 1.0967, 12200 µs/rev mozilla-central x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 1593 revs, 0.006462 s, 0.006482 s, +0.000020 s, × 1.0031, 4 µs/rev mozilla-central x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 41 revs, 0.004919 s, 0.005066 s, +0.000147 s, × 1.0299, 123 µs/rev mozilla-central x000_revs_x000_added_x000_copies 7c97034feb78 4407bd0c6330 : 7839 revs, 0.062421 s, 0.065707 s, +0.003286 s, × 1.0526, 8 µs/rev mozilla-central x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 615 revs, 0.026633 s, 0.026800 s, +0.000167 s, × 1.0063, 43 µs/rev mozilla-central x0000_revs_xx000_added_x000_copies f78c615a656c 96a38b690156 : 30263 revs, 0.197792 s, 0.203856 s, +0.006064 s, × 1.0307, 6 µs/rev mozilla-central x00000_revs_x0000_added_x0000_copies 6832ae71433c 4c222a1d9a00 : 153721 revs, 1.259970 s, 1.293394 s, +0.033424 s, × 1.0265, 8 µs/rev mozilla-central x00000_revs_x00000_added_x000_copies 76caed42cf7c 1daa622bbe42 : 204976 revs, 1.689184 s, 1.698239 s, +0.009055 s, × 1.0054, 8 µs/rev mozilla-try x_revs_x_added_0_copies aaf6dde0deb8 9790f499805a : 2 revs, 0.000865 s, 0.000875 s, +0.000010 s, × 1.0116, 437 µs/rev mozilla-try x_revs_x000_added_0_copies d8d0222927b4 5bb8ce8c7450 : 2 revs, 0.000893 s, 0.000891 s, -0.000002 s, × 0.9978, 445 µs/rev mozilla-try x_revs_x_added_x_copies 092fcca11bdb 936255a0384a : 4 revs, 0.000172 s, 0.000292 s, +0.000120 s, × 1.6977, 73 µs/rev mozilla-try x_revs_x00_added_x_copies b53d2fadbdb5 017afae788ec : 2 revs, 0.001159 s, 0.003939 s, +0.002780 s, × 3.3986, 1969 µs/rev mozilla-try x_revs_x000_added_x000_copies 20408ad61ce5 6f0ee96e21ad : 1 revs, 0.031621 s, 0.033027 s, +0.001406 s, × 1.0445, 33027 µs/rev mozilla-try x_revs_x0000_added_x0000_copies effb563bb7e5 c07a39dc4e80 : 6 revs, 0.068571 s, 0.073703 s, +0.005132 s, × 1.0748, 12283 µs/rev mozilla-try x000_revs_xx00_added_0_copies 6100d773079a 04a55431795e : 1593 revs, 0.006452 s, 0.006469 s, +0.000017 s, × 1.0026, 4 µs/rev mozilla-try x000_revs_x000_added_x_copies 9f17a6fc04f9 2d37b966abed : 41 revs, 0.005443 s, 0.005278 s, -0.000165 s, × 0.9697, 128 µs/rev mozilla-try x000_revs_x000_added_x000_copies 1346fd0130e4 4c65cbdabc1f : 6657 revs, 0.063180 s, 0.064995 s, +0.001815 s, × 1.0287, 9 µs/rev mozilla-try x0000_revs_x_added_0_copies 63519bfd42ee a36a2a865d92 : 40314 revs, 0.293564 s, 0.301041 s, +0.007477 s, × 1.0255, 7 µs/rev mozilla-try x0000_revs_x_added_x_copies 9fe69ff0762d bcabf2a78927 : 38690 revs, 0.286595 s, 0.285575 s, -0.001020 s, × 0.9964, 7 µs/rev mozilla-try x0000_revs_xx000_added_x_copies 156f6e2674f2 4d0f2c178e66 : 8598 revs, 0.083256 s, 0.085597 s, +0.002341 s, × 1.0281, 9 µs/rev mozilla-try x0000_revs_xx000_added_0_copies 9eec5917337d 67118cc6dcad : 615 revs, 0.027282 s, 0.027118 s, -0.000164 s, × 0.9940, 44 µs/rev mozilla-try x0000_revs_xx000_added_x000_copies 89294cd501d9 7ccb2fc7ccb5 : 97052 revs, 1.343373 s, 2.119204 s, +0.775831 s, × 1.5775, 21 µs/rev mozilla-try x0000_revs_x0000_added_x0000_copies e928c65095ed e951f4ad123a : 52031 revs, 0.665737 s, 0.701479 s, +0.035742 s, × 1.0537, 13 µs/rev mozilla-try x00000_revs_x_added_0_copies 6a320851d377 1ebb79acd503 : 363753 revs, 5.138169 s, 4.482399 s, -0.655770 s, × 0.8724, 12 µs/rev mozilla-try x00000_revs_x00000_added_0_copies dc8a3ca7010e d16fde900c9c : 34414 revs, 0.573276 s, 0.574082 s, +0.000806 s, × 1.0014, 16 µs/rev mozilla-try x00000_revs_x_added_x_copies 5173c4b6f97c 95d83ee7242d : 362229 revs, 5.127809 s, 4.480366 s, -0.647443 s, × 0.8737, 12 µs/rev mozilla-try x00000_revs_x000_added_x_copies 9126823d0e9c ca82787bb23c : 359344 revs, 4.971136 s, 4.369070 s, -0.602066 s, × 0.8789, 12 µs/rev mozilla-try x00000_revs_x0000_added_x0000_copies 8d3fafa80d4b eb884023b810 : 192665 revs, 1.741678 s, 1.592506 s, -0.149172 s, × 0.9144, 8 µs/rev mozilla-try x00000_revs_x00000_added_x0000_copies 1b661134e2ca 1ae03d022d6d : 228985 revs, 40.314822 s, 87.824489 s, +47.509667 s, × 2.1785, 383 µs/rev mozilla-try x00000_revs_x00000_added_x000_copies 9b2a99adc05e 8e29777b48e6 : 382065 revs, 20.048029 s, 43.304637 s, +23.256608 s, × 2.1600, 113 µs/rev private : 459513 revs, 37.179470 s, 33.853687 s, -3.325783 s, × 0.9105, 73 µs/rev Differential Revision: https://phab.mercurial-scm.org/D9644

copies-rust: add methods to build and update CopySource Having explicit method with clear semantic help to clarify the code and prepare an update to the underlying documentation without too much disruption. Differential Revision: https://phab.mercurial-scm.org/D9643

copies-rust: fix reverted argument when merging tiny minor or major The argument where not passed in the right other. This is not caught by the test (yet) because it is a sub case of a special case. Am I adding this to my list of things to test. Using test directly in Rust would be appropriate here. However we don't have the ability to test this code that way yet, and I am focussing on other part of that work right now. Differential Revision: https://phab.mercurial-scm.org/D9657

copies-rust: rename TimeStampedPathCopy to CopySource Same rational as the previous changesets. CopySource is a clear descriptive name that does not depends on an implementation details that we are about to the change. Differential Revision: https://phab.mercurial-scm.org/D9642

copies-rust: rename TimeStampedPathCopies to InternalPathCopies We are looking into moving away from TimeStampedPathCopy (that use is_ancestors call to detect overwrite) in favor of an approach that does not requires is_ancestors calls. Yet we will still need an internal representation that differs from the returned result. So we call it "InternalPathCopies" which is generic but clear. Differential Revision: https://phab.mercurial-scm.org/D9641

copies: detect case when a merge decision overwrite previous data We now detect and record when a merge case required special logic (eg: thing that append during the merge, ambiguity leading to picking p1 data, etc) and we explicitly mark the result as superseding the previous data. This fixes the family of test we previously added. Differential Revision: https://phab.mercurial-scm.org/D9613

copies: rearrange all value comparison conditional To properly handle the newly tested case (chaining of merges) we will need to detect more accurately when an actualy merging of the copy information (and superseed the two existing data). Before starting to do so, we need to reorganise the values comparison to introduce different conditional branches when such actual merging is needed/detected. To avoid mixing too many change in this complicated code, we do the reorganisation before adding the "overwrite detection" logic in the next changesets. Differential Revision: https://phab.mercurial-scm.org/D9612

test-copies: introduce merge chains test for the P/Q merges This is similar to the chaining test we have for the A/E merges. The current result of this tests is wrong, as for the other test of the same familly. This will be fixed by a later changesets. Differential Revision: https://phab.mercurial-scm.org/D10059

test-copies: add a case involving the `b` and a new `r` branch That case involve a branch overwriting copies information from the other one. It is similar to the `mBFm` / `mFBm` case except this case actual content merge is involved too. Differential Revision: https://phab.mercurial-scm.org/D10058

test-copies: introduce case combining the `p` and `q` branch That case involves conflicting copies information from each branch. It is similar to the `mAEm` / `mEAm` case except this case actual content merge is involved too. Differential Revision: https://phab.mercurial-scm.org/D10057

test-copies: add a `q` branch similar to the `e` but on the new files This branch will be used to create merge case that mirror ones involving the `e` branch. Differential Revision: https://phab.mercurial-scm.org/D10056

test-copies: add a `p` branch similar to the `a` but on the new files This branch will be used to create merge case that mirror ones involving the `a` branch. Differential Revision: https://phab.mercurial-scm.org/D10055

test-copies: move the new files in the `i` branch The initial branch is moving some of the "same content" file around. We do the same for the "different content" before start to implement more tests. The new files have harmless impact of various existing tests. Differential Revision: https://phab.mercurial-scm.org/D10054

test-copies: add 3 new files with their own content The new `p`, `q` and `r` file mirror the `a`, `b` and `h` but with different content for each files. This will be used to create "mirror" test case that involve actual merge happening. For now, we only add the file to keep patches small and easier to review. Differential Revision: https://phab.mercurial-scm.org/D10053

test-copies: introduce merge chaing test for the A/E + change tests This is similar to the chaining test we have for the A/E merges (without change). The current result of this tests is wrong, as for they "without change counter part". This will be fixed by a later changesets. Differential Revision: https://phab.mercurial-scm.org/D10052

test-copies: add a "change during merge" variant to the A+E test Checks inline comment for details.

test-copies: filter out the linkrev part of `debugindex` It is not really useful for the tests and is a large source of churn when adding more revisions to the tests. Differential Revision: https://phab.mercurial-scm.org/D10050

test-copies: use "case-id" instead of revision number when listing sidedata The revision number are not very informative and can change when new changeset are added, creating unnecessary churn. We change the template before adding more test to improve clarify of the over changesets. Differential Revision: https://phab.mercurial-scm.org/D10049

test-copies: remove revision number from log Differential Revision: https://phab.mercurial-scm.org/D10048

test-copies: add test chaining multiple merge Right now, the copy tracing logic take the right decision for merges, but it does not keep track of the right information about these decision and can fall into later traps. We start with highlighting this possibility by adding new tests, and we will fix them later. Check the inline test documentation for details. Differential Revision: https://phab.mercurial-scm.org/D9611

test-copies: add test chaining multiple merges Right now, the copy tracing logic take the right decision for merges, but it does not keep track of the right information about these decision and can fall into later traps. We start with highlighting this possibility by adding new tests, and we will fix them later. Check the inline test documentation for details. Differential Revision: https://phab.mercurial-scm.org/D9610

test-copies: add test chaining multiple merges Right now, the copy tracing logic take the right decision for merges, but it does not keep track of the right information about these decision and can fall into later traps. We start with highlighting this possibility by adding new tests, and we will fix them later. Check the inline test documentation for details. Differential Revision: https://phab.mercurial-scm.org/D9609

test-copies: add subcase titles for various "conflicting" information variant This make the transitions between case clearer. Differential Revision: https://phab.mercurial-scm.org/D10047

test-copies: improve description of the B+F case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10046

test-copies: improve description of the C+H case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10045

test-copies: improve description of the B+C "revert/restore" case This will make its role clearer. Differential Revision: https://phab.mercurial-scm.org/D10044