black: format the codebase with 23.3.0 The CI has moved to 23.3.0, which is the last version that supports 3.7 at runtime, so we should honor this change. # skip-blame mass-reformating only

pytype: work around wrong ImportError flagging As documented in https://github.com/google/pytype/issues/163, newer versions of Pytype do not understand caught `ImportError`, so we temporarily ignore them where applicable.

zeroconf: fix boolean return value This was (wrongly) flagged by Pytype as being undefined since it doesn't seem to understand `try` blocks. However, the caller is expecting a boolean and the fix to appease Pytype is simple, so we do both.

convert: fix various leaked file descriptors Some of these only leaked if an exception occurred between the open and close, but a lot of these leaked unconditionally. A type hint is added to `parsesplicemap` because otherwise this change caused pytype to change the return type from this to `Dict[nothing, nothing]`.

convert: stringify `shlex` class argument The documentation is handwavy, but typeshed says this should be `str`[1]. I'm not sure if this is the correct encoding (vs `fsencode` or "latin1" like the tokens returned by the proxy class). While we're here, we can add a few more type hints that would have caused pytype to flag the problem. [1] https://github.com/python/typeshed/blob/6a9b53e719a139c2d6b41cf265ed0990cf438192/stdlib/shlex.pyi#L51

typing: add trivial type hints to the convert extension's common modules This started as ensuring that the `encoding` and `orig_encoding` attributes has a type other than `Any`, so pytype can catch problems where it needs to be str for stdlib encoding and decoding. It turns out that adding the hint in `mercurial.encoding` is what was needed, but I picked a bunch of low hanging fruit while here. There's definitely more to do, and I see a problem where `shlex.shlex` is being fed bytes instead of str, but there are not enough type hints yet to make pytype notice.

convert: drop a duplicate implementation of `dateutil.makedate()` I noticed this because the signature generated by pytype recently changed to be less specific. When the method was introduced back in 337d728e644f, `util.makedate()` didn't take an optional timestamp arg. But now it does, and the methods are the same (except the `dateutil` version validates that the timestamp isn't a negative value). I left the old method in place in case anyone has custom convert code that monkey patches it.

revlog: use mmap by default is pre-population is available Using mmap has a great impact of memory usage on server, and a good impact on performance in multiple case. Now that we pre-populate memory mapping by default, there is case where it using mmap is slower. So we use it by default (if pre-population is available). Further work to reduce the performance impact of the pre-population will be done later. Some benchmark below (using the same setup as 522b4d729e89): As for 522b4d729e89 the impact on small repository like Mercurial or Pypy is tiny, ~1% best. However for large repositories we see some performance improvement without seeing the performance regression that we could have without pre-populate. ##### For netbeans ### data-env-vars.name = netbeans-2018-08-01-zstd-sparse-revlog ## benchmark.name = hg.command.log # bin-env-vars.hg.flavor = rust # benchmark.variants.limit-rev = 1 # benchmark.variants.patch = yes no-mmap: 0.171579 mmap: 0.166311 (-3.07%, -0.01) # bin-env-vars.hg.flavor = default no-mmap: 0.170716 mmap: 0.165218 (-3.22%, -0.01) # benchmark.variants.patch = no # benchmark.variants.rev = tip no-mmap: 0.140862 mmap: 0.137566 (-2.34%, -0.00) ## benchmark.name = hg.command.unbundle # bin-env-vars.hg.flavor = rust # benchmark.variants.issue6528 = disabled # benchmark.variants.reuse-external-delta-parent = yes # benchmark.variants.revs = any-1-extra-rev # benchmark.variants.source = unbundle no-mmap: 0.238038 mmap: 0.239912 no-populate: 0.cbd4c9 (+11.71%, +0.03) #### For Mozilla ### data-env-vars.name = mozilla-try-2019-02-18-ds2-pnm # benchmark.name = hg.command.log # bin-env-vars.hg.flavor = rust # bin-env-vars.hg.py-re2-module = default # benchmark.variants.limit-rev = 1 # benchmark.variants.patch = yes no-mmap: 0.258440 mmap: 0.237813 (-7.98%, -0.02) # benchmark.variants.limit-rev = 10 no-mmap: 1.235323 mmap: 1.213578 (-1.76%, -0.02) ## benchmark.name = hg.command.push # bin-env-vars.hg.flavor = rust # bin-env-vars.hg.py-re2-module = default # benchmark.variants.explicit-rev = none # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.reuse-external-delta-parent = yes # benchmark.variants.revs = any-1-extra-rev no-mmap: 4.790135 mmap: 4.668971 (-2.53%, -0.12) no-populate: 4.841141 (+1.06%, +0.05) ### data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog ## benchmark.name = hg.command.log # bin-env-vars.hg.flavor = default # benchmark.variants.limit-rev = 1000 # benchmark.variants.rev = tip no-mmap: 0.206187 mmap: 0.197348 (-4.29%, -0.01) ## benchmark.name = hg.command.push # bin-env-vars.hg.flavor = default # benchmark.variants.explicit-rev = none # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.reuse-external-delta-parent = yes # benchmark.variants.revs = any-1-extra-rev no-mmap: 4.768259 mmap: 4.798632 no-populate: 4.953295 (+3.88%, +0.19) # benchmark.variants.revs = any-100-extra-rev no-mmap: 4.785946 mmap: 4.903618 no-populate: 5.014963 (+4.79%, +0.23) ## benchmark.name = hg.command.unbundle # bin-env-vars.hg.flavor = default # benchmark.variants.issue6528 = disabled # benchmark.variants.reuse-external-delta-parent = yes # benchmark.variants.revs = any-1-extra-rev # benchmark.variants.source = unbundle no-mmap: 1.400121 mmap: 1.423411 no-populate: 1.585365 (+13.23%, +0.19)

revlog: use an explicit config option to enable mmap usage for index We replace the `experimental.mmapindexthreshold` with two options: The `storage.revlog.mmap.index` is a boolean option to enable or disable the feature. The `storage.revlog.mmap.index:size-threshold` is a bytes option that control when we will be using mmap instead of plain reading.

mmap: populate the mapping by default Without pre-population, accessing all data through a mmap can result in many pagefault, reducing performance significantly. If the mmap is prepopulated, the performance can no longer get slower than a full read. (See benchmark number below) In some cases were very few data is read, prepopulating can be overkill and slower than populating on access (through page fault). So that behavior can be controlled when the caller can pre-determine the best behavior. (See benchmark number below) In addition, testing with populating in a secondary thread yield great result combining the best of each approach. This might be implemented in later changesets. In all cases, using mmap has a great effect on memory usage when many processes run in parallel on the same machine. ### Benchmarks # What did I run A couple of month back I ran a large benchmark campaign to assess the impact of various approach for using mmap with the revlog (and other files), it highlighted a few benchmarks that capture the impact of the changes well. So to validate this change I checked the following: - log command displaying various revisions (read the changelog index) - log command displaying the patch of listed revisions (read the changelog index, the manifest index and a few files indexes) - unbundling a few revisions (read and write changelog, manifest and few files indexes, and walk the graph to update some cache) - pushing a few revisions (read and write changelog, manifest and few files indexes, walk the graph to update some cache, performs various accesses locally and remotely during discovery) Benchmarks were run using the default module policy (c+py) and the rust one. No significant difference were found between the two implementation, so we will present result using the default policy (unless otherwise specified). I ran them on a few repositories : - mercurial: a "public changeset only" copy of mercurial from 2018-08-01 using zstd compression and sparse-revlog - pypy: a copy of pypy from 2018-08-01 using zstd compression and sparse-revlog - netbeans: a copy of netbeans from 2018-08-01 using zstd compression and sparse-revlog - mozilla-try: a copy of mozilla-try from 2019-02-18 using zstd compression and sparse-revlog - mozilla-try persistent-nodemap: Same as the above but with a persistent nodemap. Used for the log --patch benchmark only # Results For the smaller repositories (mercurial, pypy), the impact of mmap is almost imperceptible, other cost dominating the operation. The impact of prepopulating is undiscernible in the benchmark we ran. For larger repositories the benchmark support explanation given above: On netbeans, the log can be about 1% faster without repopulation (for a difference < 100ms) but unbundle becomes a bit slower, even when small. ### data-env-vars.name = netbeans-2018-08-01-zstd-sparse-revlog # benchmark.name = hg.command.unbundle # benchmark.variants.issue6528 = disabled # benchmark.variants.reuse-external-delta-parent = yes # benchmark.variants.revs = any-1-extra-rev # benchmark.variants.source = unbundle # benchmark.variants.verbosity = quiet with-populate: 0.240157 no-populate: 0.265087 (+10.38%, +0.02) # benchmark.variants.revs = any-100-extra-rev with-populate: 1.459518 no-populate: 1.481290 (+1.49%, +0.02) ## benchmark.name = hg.command.push # benchmark.variants.explicit-rev = none # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.reuse-external-delta-parent = yes # benchmark.variants.revs = any-1-extra-rev with-populate: 0.771919 no-populate: 0.792025 (+2.60%, +0.02) # benchmark.variants.revs = any-100-extra-rev with-populate: 1.459518 no-populate: 1.481290 (+1.49%, +0.02) For mozilla-try, the "slow down" from pre-populate for small `hg log` is more visible, but still small in absolute time. (using rust value for the persistent nodemap value to be relevant). ### data-env-vars.name = mozilla-try-2019-02-18-ds2-pnm # benchmark.name = hg.command.log # bin-env-vars.hg.flavor = rust # benchmark.variants.patch = yes # benchmark.variants.limit-rev = 1 with-populate: 0.237813 no-populate: 0.229452 (-3.52%, -0.01) # benchmark.variants.limit-rev = 10 # benchmark.variants.patch = yes with-populate: 1.213578 no-populate: 1.205189 ### data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog # benchmark.variants.limit-rev = 1000 # benchmark.variants.patch = no # benchmark.variants.rev = tip with-populate: 0.198607 no-populate: 0.195038 (-1.80%, -0.00) However pre-populating provide a significant boost on more complex operations like unbundle or push: ### data-env-vars.name = mozilla-try-2019-02-18-zstd-sparse-revlog # benchmark.name = hg.command.push # benchmark.variants.explicit-rev = none # benchmark.variants.issue6528 = disabled # benchmark.variants.protocol = ssh # benchmark.variants.reuse-external-delta-parent = yes # benchmark.variants.revs = any-1-extra-rev with-populate: 4.798632 no-populate: 4.953295 (+3.22%, +0.15) # benchmark.variants.revs = any-100-extra-rev with-populate: 4.903618 no-populate: 5.014963 (+2.27%, +0.11) ## benchmark.name = hg.command.unbundle # benchmark.variants.revs = any-1-extra-rev with-populate: 1.423411 no-populate: 1.585365 (+11.38%, +0.16) # benchmark.variants.revs = any-100-extra-rev with-populate: 1.537909 no-populate: 1.688489 (+9.79%, +0.15)

win32mbcs: use str for encoding value This was reported to the TortoiseHg tracker as: https://foss.heptapod.net/mercurial/tortoisehg/thg/-/issues/5980 It doesn't look like we have any tests for this extension, but the explicit type hints are enough to convince pytype that the module level `_encoding` attr is str. The `encode()` and `decode()` methods are too complex to add type hints for them.

typing: add a trivial type hint to `mercurial/vfs.py` Since hg 3dbc7b1ecaba, pytype stopped seeing the return value of `rmtree` as `None`, and substituted `Any`.

typing: add a few trivial type hints to `mercurial/templater.py` Since hg 3dbc7b1ecaba, pytype started inferring that the second value in the tuple is `BinaryIO`, but still hasn't been able to figure out the rest of `open_template()`. We can be more precise.

typing: add a few type hints to `mercurial/revlog.py` Somewhere between hg 3dbc7b1ecaba and hg 8e3f6b5bf720, pytype stopped being able to infer the type for `_docket_file` and `compress()`. Lock those types in before they get lost.

typing: add a trivial type hint to `mercurial/posix.py` to avoid an @overload Since hg 3dbc7b1ecaba, pytype added an `@overload` for this function, without a type on the parameter. That's wrong, and undermines the hints on the non-trivial functions.

typing: add some trivial type hints to `mercurial/match.py` These were new methods since hg 3dbc7b1ecaba, but surprisingly pytype couldn't figure them out.

typing: add a type hint to `mercurial/hg.py` Somewhere between hg 3dbc7b1ecaba and hg 8e3f6b5bf720, the first value of the tuple changed from bytes to str. Let's lock this in, so that pytype flags it if someone mistakenly adds a tuple with bytes somewhere.

typing: restore `encoding.encoding` and `encoding.encodingmode` to bytes Somewhere between hg 3dbc7b1ecaba and hg 8e3f6b5bf720, pytype determined the signature of these fields changed from `bytes` to `Any`. Not sure why- the type of `environ` then and now is: `Union[WindowsEnviron, Dict[bytes, bytes], os._Environ[bytes]]` That said, PyCharm wasn't able to figure out the type of `environ`, and the `WindowsEnviron` class extends `MutableMapping` without specifying bytes for the key and value types in py3.9. But that's not changed in my setup, so I can't explain it.

typing: add some trivial type hints to `mercurial/bundlecaches.py` The function is meant for extensions, but it wasn't obvious what was expected without looking through the code. Also, pytype couldn't figure it out either.

typing: add some type hints for bundle2 capabilities Somewhere between hg 3dbc7b1ecaba and hg 8e3f6b5bf720, pytype determined the signature of `bundle20.capabilities` changed from `Dict[bytes, Tuple[bytes]]` to `Dict[bytes, Union[List[bytes], Tuple[bytes]]]`. First, I did try to simply be explicit about the previously inferred type, but it does seem to mix and match list/tuple now (e.g. in `writenewbundle()`). I tried changing the new list usage to tuple, but a couple of things complained, (and I think lists of one item are a little more clear to read anyway). So then I typed the dict value as `Sequence[bytes]`, which worked fine. But there's also a module level `capabilities` field, and when that's typed, pytype complains about `Sequence[bytes]` lacking `__add__`[1]. So I gave up, and just assigned it the type it wanted, with an alias. If somebody feels motivated to make the type consistent, it's simple enough to change the alias. The mutable default value to the constructor was removed to appease PyCharm's type checking on the field. (I didn't bother running the code through pytype prior to changing it, because we've previously made an effort to remove this pattern anyway.) I'm not sure why `getrepocaps()` has a default value for `role` that apparently raises an exception. It's just flagged for now so this series can land without risking additional problems. [1] https://foss.heptapod.net/mercurial/mercurial-devel/-/jobs/2466903

typing: add a few type hints to `mercurial/utils/urlutil.py` Somewhere between hg 3dbc7b1ecaba and hg 8e3f6b5bf720, `_pathsuboptions` changed from `Dict[bytes, Tuple[bytes, Any]]` to `Dict[bytes, Tuple[str, Any]]`, and it caught my attention from diffing the local *.pyi files. The change is correct based on the assertion, so let's get pytype to check for this instead of relying on the assertion alone.

typing: add type hints to `mercurial/utils/resourceutil.py` The `except` path requires byte args (because of the byte based manipulation in `_package_path()`), while the `else` case tolerates `AnyStr`. Pytype was unable to figure this out, and we should make sure the interface is the same for all environments.

copyright: update to 2024

branching: merge stable into default for 6.9 cycle