py3: add a missing b'' prefix in contrib/perf.py # skip-blame because just b'' prefixes This fixes test-contrib-perf.t on Python 3 which started failing. Differential Revision: https://phab.mercurial-scm.org/D5421

py3: use '%d' for integers instead of '%s' This should fix test-rebase-inmemory.t which started failing on Python 3 after recent changes. Differential Revision: https://phab.mercurial-scm.org/D5420

py3: whitelist another passing test caught by buildbot Differential Revision: https://phab.mercurial-scm.org/D5419

py3: fix bad escapes of sub() replacement pattern in test-template-basic.t Python 3.7 starts complaining about it. We have to double the backslash or '\x5c' to get around.

perfdiscovery: benching findcommonheads() This works between the local repo and any peer given by its path, and should be useful for further work on discovery Differential Revision: https://phab.mercurial-scm.org/D5418

windows: ensure pure posixfile fd doesn't escape by entering context manager There are tests in test-revlog-mmapindex.t and test-rebase-mq-skip.t that are fixed by this, but we usually don't use --pure on Windows. For whatever reason, the remaining --pure failures are various errors like $ENOTDIR$ and "Access is denied" have a trailing '.'.

vfs: ensure closewrapbase fh doesn't escape by entering context manager I'm not sure if there's a problem in practice here, as there's no test failure either way. The __exit__() and close() methods raise an exception, so maybe __exit__() and close() are being called directly on the underlying handle when delayclosedfile is used on a context manager? I doubt that was intended.

windows: ensure mixedfilemodewrapper fd doesn't escape by entering context mgr Otherwise it seems that the special read and write handling would be bypassed.

py3: ensure the proxied Windows fd doesn't escape by entering context manager The purpose of the proxy class is to provide the `name` attribute which contains the file path. But in tests that used a context manager, it still blew up complaining that 'int' doesn't have a 'startswith' function.

merge with stable

templatefuncs: specialize "no match" value of search() to allow % operation If Python had Maybe or Option, the type of the search() result would be Option<Mapping>, which can be considered as a 0/1 container of a Mapping. So it makes sense that {search(r'no match pattern', x) % "whatever"} is mapped to an empty string.

templatefuncs: add regexp search() function that extracts substring This can be used to extract an issue number from a commit message, for example: {search(r'\(issue([0-9]*)\)', desc) % '{1}'}

rust: changed Graph.parents to return [Revision; 2] This will allow for simple iteration on parent revisions, such as: for parent in graph.parents(rev)?.iter().cloned() This seems to be a zero overhead abstraction once built in release mode. Differential Revision: https://phab.mercurial-scm.org/D5415

rust: improved docstring In the previous wording, rustfmt wanted to cut at the == which is not very readable in my taste. Differential Revision: https://phab.mercurial-scm.org/D5414

revset: move subscript relation functions to its own dict This will help adding more relation functions in extensions. We skip short names (that consist of one letter) while raising UnknownIdentifier because such names cannot be suggested anyway: the similarity cutoff in dispatch._getsimilar() is currently 0.6.

py3: teach run-tests.py to handle exe with spaces when --local isn't specified This was the reason that no amount of quoting worked in test-hghave.t. `os.popen()` needed to be swapped out because while the added quoting around line 3124 worked on py3, it failed on py2. See 38d51371792b. The problem with `os.system()` was wrongly splitting the command on the space in 'Program Files', regardless of quoting. It looks like there are a few other instances of `os.system()` in core code, so presumably those should be replaced?

rust: adapted hg-core tests for iteration over Result Now AncestorsIterator iters on Result<Revision, GraphError>

win32: close the handles associated with a spawned child process Probably not a big deal because at this point, the call is only used when spawning a daemonized server. In that case, the parent process goes away first, so it won't prevent the child from being cleaned up.

rust: remove comment about error handling of AncestorsIterator To be align with 443eb4bc41af "rust: propagate error of index_get_parents() properly." Spotted by Georges Racinet.

test: fix test-http-bad-server with current python 2.7 https://github.com/python/cpython/pull/2825 changed the exception message for empty http status line. Differential Revision: https://phab.mercurial-scm.org/D5412

perf: add perfprogress command I've noticed that progress bars can add significant overhead to tight loops. Let's add a perf command that attempts to isolate that overhead. With a default hgrc, iteration over 1M items appears to take ~3.75s on my machine. Profiling reveals ~28% of time is spent in ui.configbool() resolving the value of the progress.debug config option. Even if I set progress.disable=true, execution still takes ~2.60s, with ~59% of the time spent in ui.configbool(). Differential Revision: https://phab.mercurial-scm.org/D5407

wireprotov2: unify file revision collection and linknode derivation The old mechanism for choosing which file revisions to send in the haveparents=True case was buggy in multiple ways - the most severe of which being that file revisions were excluded when they shouldn't have been. This commit unifies the logic for deriving the filenodes that will be sent by the "filesdata" command. We now consistently read files data from manifests. The "haveparents" argument now controls whether we iterate ctx.files() or use the full manifest to derive relevant files. The logic here is still woefully lacking to fully support shallow clones. It will require an API break to fully address. This commit should at least make the server APIs emit proper data, which is strictly better than before. Differential Revision: https://phab.mercurial-scm.org/D5406

wireprotov2: send linknodes to emitfilerevisions() Previously, linknodes were calculated within emitfilerevisions() by using filectx.introrev(), which would always use the linkrev/linknode as recorded by storage. This is wrong for cases where the receiver doesn't have the changeset the linknode refers to. This commit changes the logic for linknode emission so the mapping of filenode to linknode is computed by the caller and passed into emitfilerevisions(). As part of the change, linknodes for "filesdata" in the haveparents=False case are now correct: the existing code performed a manifest walk and it was trivial to plug in the correct linknode. However, behavior for the haveparents=True case is still wrong because it relies on filtering linkrevs against the outgoing set in order to determine what to send. This will be fixed in a subsequent commit. The change test test-wireproto-exchangev2-shallow.t is a bit wonky. The test repo has 6 revisions. The changed test is performing a shallow clone with depth=1. So, only file data for revision 5 is present locally. So, the new behavior of associating the linknode with revision 5 for every file revision seems correct. Of course, when backfilling old revisions, we'll want to update the linknode. But this problem requires wire protocol support and we'll cross that bridge later. Differential Revision: https://phab.mercurial-scm.org/D5405

tests: add tests for server-side linknode adjustment with wireprotov2 The current implementation of linknode serving in wireprotov2 simply serves up the linkrev/linknode as stored: it doesn't attempt to adjust the linknode to what the receiver is aware of. This can result in the client seeing a linknode referencing a changeset that is unknown to it. This commit adds test coverage of that scenario. The tests in test-wireproto-command-filesdata.t demonstrate two failures. First, the linknode refers to a changeset not in the available set. Second, the server doesn't send a file revision that it should have (because of linkrev filtering). The test in test-wireproto-exchange.t demonstrates that the lack of a file revision results in a corrupted repository on the client. Differential Revision: https://phab.mercurial-scm.org/D5404

tests: fix empty commit in test This was almost certainly a bug. Differential Revision: https://phab.mercurial-scm.org/D5403

tests: add sparserevlog requirement to test-sqlitestore.t Looks like this test was missed when enabling sparse revlogs by default. Differential Revision: https://phab.mercurial-scm.org/D5402

tests: remove all transitional configuration Now that sparse-revlog is enabled by default, we no longer needs it. Differential Revision: https://phab.mercurial-scm.org/D5346

sparse-revlog: enabled by default The feature provides large benefits. It now seems mature enough to be enabled by default. * It solves catastrophic issues regarding delta storage in revlog, * It allows for shorter delta chain in all repositories, improving performances. Running benchmark of a wide range of operation did not reveal problematic impact. Performance gains are observed where expected. The format is supported by Mercurial version 4.7. So it seems safe to enable it by default now. Here is a reminder of key numbers regarding this delta strategy effect on repository size and performance. Effect on Size: =============== For repositories with a lot of branches, sparse-revlog significantly improve size, fixing limitation associated with the span of a delta chain. In addition, sparse-revlog, deal well with limitations of the delta chain length. For large repositories, this allows for a stiff reduction of the delta chain without a problematic impact on the repository size. This delta chain length improvement helps all repositories, not just the ones with many branches. As a reminder, here are the default chain limits for each "format": * no-sparse: none * sparse: 1000 Mercurial --------- Manifest Size: limit | none | 1000 ------------|-------------|------------ no-sparse | 6 143 044 | 6 269 496 sparse | 5 798 796 | 5 827 025 Manifest Chain length data limit || none || 1000 value || average | max || average | max ------------||---------|---------||---------|--------- no-sparse || 429 | 1 397 || 397 | 1 000 sparse || 326 | 1 290 || 313 | 1 000 Full Store Size limit | none | 1000 ------------|-------------|------------ no-sparse | 46 944 775 | 47 166 129 sparse | 46 622 445 | 46 723 774 pypy ---- Manifest Size: limit | none | 1000 ------------|-------------|------------ no-sparse | 52 941 760 | 56 200 970 sparse | 26 348 229 | 27 384 133 Manifest Chain length data limit || none || 1000 value || average | max || average | max ------------||---------|---------||---------|--------- no-sparse || 769 | 3 889 || 390 | 1 000 sparse || 1 223 | 3 846 || 495 | 1 000 Full Store Size limit | none | 1000 ------------|-------------|------------ no-sparse | 336 050 203 | 339 309 413 sparse | 338 673 985 | 339 709 889 Mozilla ------- Manifest Size: limit | none | 1000 ------------|----------------|--------------- no-sparse | 215 096 339 | 1 708 853 525 sparse | 188 947 271 | 278 894 170 Manifest Chain length data limit || none || 1000 value || average | max || average | max ------------||---------|---------||---------|-------- no-sparse || 20 454 | 59 562 || 491 | 1 000 sparse || 23 509 | 69 891 || 489 | 1 000 Full Store Size limit | none | 1000 ------------|----------------|--------------- no-sparse | 2 377 578 715 | 3 876 258 798 sparse | 2 441 677 137 | 2 535 997 381 Netbeans -------- Manifest Size: limit | none | 1000 ------------|----------------|--------------- no-sparse | 130 088 982 | 741 590 565 sparse | 118 836 887 | 159 161 207 Manifest Chain length data limit || none || 1000 value || average | max || average | max ------------||---------|---------||---------|--------- no-sparse || 19 321 | 61 397 || 510 | 1 000 sparse || 21 240 | 61 583 || 503 | 1 000 Full Store Size limit | none | 1000 ------------|----------------|--------------- no-sparse | 1 160 013 008 | 1 771 514 591 sparse | 1 164 959 988 | 1 205 284 308 Private repo #1 --------------- Manifest Size: limit | none | 1000 ------------|-----------------|--------------- no-sparse | 33 725 285 081 | 33 724 834 190 sparse | 350 542 420 | 423 470 579 Manifest Chain length data limit || none || 1000 value || average | max || average | max ------------||---------|---------||---------|--------- no-sparse || 282 | 8 885 || 113 | 1 000 snapshot || 3 655 | 8 951 || 530 | 1 000 Full Store Size limit | none | 1000 ------------|----------------|--------------- no-sparse | 41 544 149 652 | 41 543 698 761 sparse | 8 448 037 300 | 8 520 965 459 Effect on speed: ================ Performances are strongly impacted by the delta chain length. Longer chain results in slower revision restoration. For this reason, the 1000 chain limit introduced by sparse-revlog helps repository with previously large chains a lot. In our corpus, this means `netbeans` and `mozilla-central` who suffered from unreasonable manifest delta chain length. Another way sparse revlog helps, is by producing better delta's. For repositories with many branches, the pathological patterns that resulted in many sub-optimal deltas are gone. Smaller delta help with operations where deltas are directly relevant, like bundle. However, the sparse-revlog logic introduces some extra processing and a more throughout testing of possible delta candidates. Adding an extra cost in some cases. This cost is usually counterbalanced by the other performance gain. However, for smaller repositories not affected by delta chain length issues or branching related issues, this might make things a bit slower. However, these are also repository where revlog performance is dwarfed by other costs. Below are the summary of some timing from the performance test suite running at `http://perf.octobus.net/` for a handful of key commands and operation. It is important to keep in mind that most of this command works on the tip part of the repository. The non-sparse and sparse version produce different delta chains and the tip revision can end up at an arbitrary point of these chains. This will impact some performance number listed in this summary. For the record: here is the delta chain length for the tip revision of manifest log in the benchmarked repository: | no-sparse | sparse | mercurial | 94 | 904 | pypy | 23 | 673 | netbeans | 4158 | 258 | mozilla | 63263 | 781 | As you can see, the chain length for mercurial and pypy turn out to be significantly longer. The netbeans and mozilla one get shorter because these repositories benefit from the maximum chain length. Timing for `hg commit`: ----------------------- The time taken by `hg commit` does not varies significantly, no drawback for using sparse here. | no-sparse | sparse | mercurial | 68.1ms | 66.7ms | pypy | 95.0ms | 94.1ms | netbeans | 614.0ms | 611.0ms | mozilla | 1340.0ms | 1.320.0ms | Check the final section for statistics on a wider array of write. Timing for bundling 10 000 changesets ------------------------------------- The repository that benefits from better delta see a good performance boost. The other ones are not significantly affected. | no-sparse | sparse | mercurial | 3.1s | 3.0s | pypy | 25.1s | 7.5s | netbeans | 24.2s | 17.0s | mozilla | 23.7s | 25.0s | Timing for unbundling 1 000 changesets -------------------------------------- Mercurial and mozilla are unaffected. The pypy repository benefit well from the better delta. However, the netbeans repository takes a visible hit. Digging that difference reveals that it comes from the sparse-revlog bundle having to deal with a snapshot that was re-encoded in the bundle. The slow path for adding new a revision had to be triggered for it, slowing things down. The Sparse versions do not have such snapshot to handle similar cases in the tested configuration. | no-sparse | sparse | mercurial | 519ms | 502ms | pypy | 1.270ms | 886ms | netbeans | 1.370ms | 2.250ms | mozilla | 3.230ms | 3.210ms | Netbeans benefits from the better deltas in other dimensions too. For example, the produced bundle is significantly smaller: * netbeans-no-sparse.hg: 2.3MB * netbeans-sparse.hg: 1.9MB Timing to restore the tip most manifest entry: ---------------------------------------------- Nothing surprising here. The timing for mercurial and pypy are within a small range where they won't affect performance much. In our tested case, they are slower as they use a longer chain. Timing for netbeans and mozilla improves a lot. Removing a significant amount of time. | no-sparse | sparse | mercurial | 1.09ms | 3.15ms | pypy | 4.11ms | 10.70ms | netbeans | 239.00ms | 112.00ms | mozilla | 688.00ms | 198.00ms | Reading 100 revision in descending order: ----------------------------------------- We see the same kind of effect when reading the last 100 revisions. Large boost for netbeans and mozilla, as they use much smaller delta chain. Mercurial and pypy longer chain means slower reads, but nothing gets out of control. | no-sparse | sparse | mercurial | 0.089s | 0.268s | pypy | 0.259s | 0.698s | netbeans | 125.000s | 20.600s | mozilla | 23.000s | 11.400s | Writing from full text: statistic for the last 30K revisions ------------------------------------------------------------ This benchmark adds revisions to revlog from their full text. This is similar to the work done during a commit, but for a large amount of revisions so that we get a more relevant view. We see better overall performances with sparse-revlog. The very worst case is usually slower with sparse-revlog, but does not gets out of control. For the vast majorities of the other writes, sparse-revlog is significantly faster for larger repositories. This is reflected in the accumulated rewrite time for netbeans and mozilla. The notable exception is the pypy repository where things get slower. The extra processing is not balanced by shorter delta chain. However, this is to be seen as a blocking issue. First, the overall time spend dealing with revlog for the repository pypy size is small compared to the other costs, so we get slower on operations that matter less than for other larger repository. Second, we still get nice size benefit from using sparse-revlog, smaller repo size brings other usability and speed benefit (eg: bundle size). max time | no-sparse | sparse | mercurial | 0.010143s | 0.045280s | pypy | 0.034924s | 0.243288s | netbeans | 0.605371s | 2.130876s | mozilla | 1.478342s | 3.424541s | 99% time | no-sparse | sparse | mercurial | 0.003774s | 0.003758s | pypy | 0.017387s | 0.025310s | netbeans | 0.576913s | 0.271195s | mozilla | 1.478342s | 0.449661s | 95% time | no-sparse | sparse | mercurial | 0.002069s | 0.002120s | pypy | 0.010141s | 0.014797s | netbeans | 0.540202s | 0.258644s | mozilla | 0.654830s | 0.243440s | full time | no-sparse | sparse | mercurial | 14.15s | 14.87s | pypy | 90.50s | 137.12s | netbeans | 6401.06s | 3411.14s | mozilla | 3086.89s | 1991.97s | Differential Revision: https://phab.mercurial-scm.org/D5345