perf: factor selection of revisions involved in the merge out We will introduce more performance command around merge. As a first step we factor out pieces of `perfmergecalculate` that can be reused.

perf: allow to specify the base of the merge in perfmergecalculate We can now test the rebase case.

perf: add a --from flag to perfmergecalculate Before this change, `perfmergecalculate` was always benchmarking the merge of the working copy with another revision. We can now benchmark the `mergecalculate` call for any arbitrary pair of revision.

merge with stable

py3: fix test-narrow* which started failing because of recent changes #skip-blame because just r'' prefix Differential Revision: https://phab.mercurial-scm.org/D6447

tests: add test for {file_mods}, {file_adds}, {file_dels} on merge commit Differential Revision: https://phab.mercurial-scm.org/D6368

context: add ctx.files{modified,added,removed}() methods Changeset-centric copy tracing is currently very slow because it often reads manifests. One place it needs the manifest is in _chain(), where it removes a copy X->Y if Y has subsequently gotten removed. I want to speed that up by keeping track directly in the changeset of which files are removed in the changeset. These methods will be similar to ctx.p[12]copies() in that way: they will either read from the changeset or calculate the information from the manifests otherwise. Note that these are different from ctx.{modified,added,removed}() on merge commits. Those functions always compare to p1, but the new ones compare to both parents. filesadded() means "file does not exist in either parent but exists now", filesremoved() means "file existed in either parent but does not exist now", and filesmodified() means "file existed in either parent and still exists". The set of files in ctx.files() is the union of the files from the three new functions (and the three new ones are all disjoint sets). Also note that uncommitted merges are weird as usual. The invariant mentioned above still holds, but the functions compare to p1 (and are thus identical to the existing methods). Differential Revision: https://phab.mercurial-scm.org/D6367

copies: split up _chain() in naive chaining and filtering steps The function now has two clearly defined steps. The first step is the actual chaining. This step is very cheap. The second step is filtering out invalid copies. This step is expensive. For changeset-centric copy tracing, I want to do the filtering step only at the end. This patch prepares for that. Differential Revision: https://phab.mercurial-scm.org/D6418

relnotes: document changed behavior of ui.origbackuppath pointing to file Differential Revision: https://phab.mercurial-scm.org/D6446

templatekw: move showfileadds() close to showfile{mods,dels}() Differential Revision: https://phab.mercurial-scm.org/D6370

py3: use range() instead of xrange() The latter does not exist on Python 3. This makes test-contrib-perf.t pass on Python 3 again. Differential Revision: https://phab.mercurial-scm.org/D6443

narrow: move heads close to common as they are closely related Differential Revision: https://phab.mercurial-scm.org/D6445

narrow: pass binary nodeids to generateellipsesbundle2() We generally work with binary nodeids and it's should be expected that new function gets the nodeids in binary form already. Differential Revision: https://phab.mercurial-scm.org/D6444

match: stabilize _rootsdirsandparents doctest Changeset c4b8f8637d7a tried to stabilize some matcher test by using a set. This did not work because the set order is not stable. To fix it, we post process the result to display a sorted version of the set.

narrow: factor out logic to build ellipses related b2parts in separate fn This will help us switch more cleanly to using wireprotocol commands instead of using exchange.pull() which exchanges more things then required. Differential Revision: https://phab.mercurial-scm.org/D6435

narrow: remove unrequired compat code for old versions of hg As the comment says, that if is only required for servers having hg version 3.1 and 3.2. Any client connecting having hg 3.1 or 3.2 locally and trying to use narrow should already be broken taking in account the changes which have been done since narrow moved to core. Differential Revision: https://phab.mercurial-scm.org/D6434

perf: make sure to explicitly disable any profiler after the first iteration The current code work, because of some edge behavior of the `profile` class. We make it explicit that the profiler is not in effect more than once.

test: add missing 'cd ..' to test case Differential Revision: https://phab.mercurial-scm.org/D6439

match: remove an obsolete comment about util.finddirs() Obsolete since 8e55c0c642c (util: make util.dirs() and util.finddirs() include root directory (API), 2017-05-16). Differential Revision: https://phab.mercurial-scm.org/D6433

match: de-flake test-doctest.py by not depending on util.dirs() order util.dirs() yields directories in arbitrary order, which has made test-doctest.py flaky. I think they have been flaky since d8e55c0c642c (util: make util.dirs() and util.finddirs() include root directory (API), 2017-05-16). Before that commit, I think util.dirs() would return at most one entry, so there was only one iteration order. This patch fixes the problem by making _rootsdirsandparents() return a set (whose __str__() is defined to be in sorted order, I believe). The only caller wanted a set anyway. Differential Revision: https://phab.mercurial-scm.org/D6432

perf: add an option to profile the benchmark section Running a perf command with --profile gather data for the whole command execution, including setup and cleanup. This can significantly alter the data. To work around this we introduce a new option, it trigger the profiling of only one iteration of the benchmarked section.

perf: add a `pre-run` option sometimes, the initial run is necessary to warm some cache that are not relevant for the current measurement. We add a new `perf.pre-run` option to specify a number of run of the benchmark logic that will happens before measurement are taken.

narrow: consider empty commits to be "inside the narrow spec" for templates It doesn't seem useful to exclude them, or harmful to include them. Users writing log templates using outsidenarrow as a predicate might consider it unexpected if their locally created empty drafts are treated as if they contained something outside the clone. Differential Revision: https://phab.mercurial-scm.org/D6414

rust-python3: useless python2 specific import This python27_sys import prevents building with python3, it had been previously removed in a5fa9140ce4c, but that has been since pruned Differential Revision: https://phab.mercurial-scm.org/D6415

rust-python3: compatibility fix for incoming PyLong On Python3, PyInt is PyLong and it doesn't have the `value()` method. Re upcasting to PythonObj as done here works, but we might prefer taking a PythonObj from the onset (would require more testing) Differential Revision: https://phab.mercurial-scm.org/D6397

py3: add one new passing test found by buildbot Differential Revision: https://phab.mercurial-scm.org/D6412

discovery: slowly increase sampling size Some pathological discovery runs can requires many roundtrip. When this happens things can get very slow. To make the algorithm more resilience again such pathological case. We slowly increase the sample size with each roundtrip (+5%). This will have a negligible impact on "normal" discovery with few roundtrips, but a large positive impact of case with many roundtrips. Asking more question per roundtrip helps to reduce the undecided set faster. Instead of reducing the undecided set a linear speed (in the worst case), we reduce it as a guaranteed (small) exponential rate. The data below show this slow ramp up in sample size: round trip | 1 | 5 | 10 | 20 | 50 | 100 | 130 | sample size | 200 | 254 | 321 | 517 | 2 199 | 25 123 | 108 549 | covered nodes | 200 | 1 357 | 2 821 | 7 031 | 42 658 | 524 530 | 2 276 755 | To be a bit more concrete, lets take a very pathological case as an example. We are doing discovery from a copy of Mozilla-try to a more recent version of mozilla-unified. Mozilla-unified heads are unknown to the mozilla-try repo and there are over 1 million "missing" changesets. (the discovery is "local" to avoid network interference) Without this change, the discovery: - last 1858 seconds (31 minutes), - does 1700 round trip, - asking about 340 000 nodes. With this change, the discovery: - last 218 seconds (3 minutes, 38 seconds a -88% improvement), - does 94 round trip (-94%), - asking about 344 211 nodes (+1%). Of course, this is an extreme case (and 3 minutes is still slow). However this give a good example of how this sample size increase act as a safety net catching any bad situations. We could image a steeper increase than 5%. For example 10% would give the following number: round trip | 1 | 5 | 10 | 20 | 50 | 75 | 100 | sample size | 200 | 321 | 514 | 1 326 | 23 060 | 249 812 | 2 706 594 | covered nodes | 200 | 1 541 | 3 690 | 12 671 | 251 871 | 2 746 254 | 29 770 966 | In parallel, it is useful to understand these pathological cases and improve them. However the current change provides a general purpose safety net to smooth the impact of pathological cases. To avoid issue with older http server, the increase in sample size only occurs if the protocol has not limit on command argument size.

tests: make the grep pattern in remotefilelog-gcrepack portable (issue6122) test-remotefilelog-gcrepack was using "\" to escape "|" in the grep pattern. The most of implementations ignore "\" when it is followed by "|", so the regex works. However, OpenBSD doesn't ignore "\" and considers "|" part of the text instead of create two branches. Neither of both behaviors violate POSIX. This change removes the unnecessary escape character and changes grep to egrep, so the extended regular expression works on every unix. This is part of the bug 6122. Tested on OpenBSD, GNU, FreeBSD, NetBSD, Solaris 11 and BusyBox. Credits to Todd C. Miller, Paul de Weerd and Ingo Schwarze for helping me with it.

help: document new "bookmarksinstore" requirement in internals.requirements Differential Revision: https://phab.mercurial-scm.org/D6413

absorb: fix interactive mode I didn't know existed While investigating a bug in `hg absorb -e` I unintentionally discovered `hg absorb --interactive` and its brokenness. This adds a test and restores the functionality. Note that this interface is still marked experimental, so we can change this to be more sophisticated in the future. Differential Revision: https://phab.mercurial-scm.org/D6411