rust: create wrapper struct to reduce `regex` contention issues Explanations inline.

tags-fnode-cache: skip building a changectx in getfnode Building a changectx object is costly, doing it just to retrieve the revision number is suboptimal. Directly fetching the revision number from the changelog provide a sizeable speedup to `hg debugupdatecache`. ### data-env-vars.name = mercurial-2018-08-01-zstd-sparse-revlog # benchmark.name = debug-update-cache # benchmark.variants.pre-state = warm before: 0.213229 seconds after: 0.165577 seconds (-22.35%) # data-env-vars.name = mercurial-filtered-2019-11-22-zstd-sparse-revlog before: 1.200383 seconds after: 1.071618 seconds (-10.73%) # data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog before: 1.465735 seconds after: 0.923128 seconds (-37.02%) # data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog before: 6.511771 seconds after: 4.507316 seconds (-30.78%) # data-env-vars.name = netbeans-2018-08-01-zstd-sparse-revlog before: 1.023007 seconds after: 0.645026 seconds (-36.95%) # data-env-vars.name = pypy-2018-08-01-zstd-sparse-revlog before: 0.381141 seconds after: 0.268654 seconds (-29.51%)

tags-fnode-cache: do not repeatedly open the filelog in a loop While getting multiple hgtagsfnodecache entries, we were opening (and closing) the `.hgtags` filelog for each iteration. The meant repeatedly reading and parsing the version same information from disk. A quite costly operation. We no longer do this, leading to a sizable improvement in `hg debugupdatecache` run for an already warm repositories. ### data-env-vars.name = mercurial-2018-08-01-zstd-sparse-revlog # benchmark.name = debug-update-cache # benchmark.variants.pre-state = warm before: 1.711778 seconds after: 0.213229 seconds (-87.54%) # data-env-vars.name = pypy-2018-08-01-zstd-sparse-revlog before: 4.010817 seconds after: 0.381141 seconds (-90.50%) # data-env-vars.name = netbeans-2018-08-01-zstd-sparse-revlog before: 13.574141 after: 1.023007 seconds (-92.46%) # data-env-vars.name = mozilla-central-2018-08-01-zstd-sparse-revlog before: 18.884656 after: 1.465735 seconds (-92.24%) # data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog before: 88.924823 after: 6.511771 seconds (-92.68%)

profile: prevent a crash when line number is unknown For some unknown reason, `self.lineno` can be None. The previous code crashed in such case, we now ignore the case, as we do for other error in this function. We also fallback to using `-1` in the output when this lack of line number makes it to the display code. The reason of unknown line-numbers is… unknown.

configitems: enable pullbundles by default The use of pullbundles is already protected: they are only used when a pullbundles.manifest file is created on the server. Having an additional flag doesn't really make sense and can confuse users (as indicated in the mercurial mailing list on the topic "Can't get pull-bundles working").

upgrade: byteify requirement changes written to output ui.write() expects bytes, and internally uses `b''` as the default when getting the `label` keyword from `*args`. So either we're missing test coverage, or there's some very subtle conversion from unicode somewhere. Also, slip in a type hint to flag this in the future.

typing: add basic type hints to stringutil.py

vfs: make the default opener mode binary The default was already binary for `abstractvfs`, and the `vfs` implementation adds binary mode if the caller didn't supply it. Therefore, it should be safe for all vfs objects (and I don't think we want text reads anyway).

typing: add basic type hints to vfs.py Again, there's a lot more that could be done, but this sticks to the obviously correct stuff that is related to primitives or `vfs` objects. Hopefully this helps smoke out more path related bytes vs str issues in TortoiseHg. PyCharm seems smart enough to apply hints from annotated superclass functions, but pytype isn't (according to the *.pyi file generated), so those are annotated too. There was some discussion about changing the default path arg from `None` to `b''` in order to avoid the more verbose `Optional` declarations. This would be more in line with `os.path.join()` (which rejects `None`, but ignores empty strings), and still not change the behavior for callers still passing `None` (because the check is `if path` instead of an explicit check for `None`). But I didn't want to hold this up while discussing that, so this documents what _is_.

util: implement `writelines()` on atomictempfile With typehints on the vfs objects, pytype will flag this: FAILED: /mnt/c/Users/Matt/hg/.pytype/pyi/mercurial/patch.pyi /usr/bin/python3.8 -m pytype.single --imports_info /mnt/c/Users/Matt/hg/.pytype/imports/mercurial.patch.imports --module-name mercurial.patch -V 3.7 -o /mnt/c/Users/Matt/hg/.pytype/pyi/mercurial/patch.pyi --analyze-annotated --nofail --quick /mnt/c/Users/Matt/hg/mercurial/patch.py File "/mnt/c/Users/Matt/hg/mercurial/patch.py", line 535, in writerej: No attribute 'writelines' on mercurial.util.atomictempfile [attribute-error] In Union[ mercurial.util.atomictempfile, mercurial.vfs.checkambigatclosing, mercurial.vfs.delayclosedfile, mercurial.windows.fdproxy, mercurial.windows.mixedfilemodewrapper ] It's not a real problem there (atomictempfile is only created by passing different args), but it's reasonable for this to implement the function and behave like a normal file. There are other functions missing that can be added if/when needed.