revlog: drop the CamelCase name for `revlog.revlogrevisiondelta` These CamelCase names popped up this cycle because pytype was getting confused by the zope decorator, and so the decoration was decoupled from the class declaration. We're in the process of switching all of the zope interfaces to `typing.Protocol` classes, but we're up against the code freeze. It would be nice to use CamelCase for protocol classes (or classes in general), but let's reset to a consistent state and buy some more time to think about this. Since we're moving to Protocol classes and I disabled the interface tests back in ef7d85089952, I'm not bothering to re-add the decorator, and re-confuse pytype. But do place the interface next to the class, so that these places can be found with the `grep` when the time comes to subclass.

tests: use pyflakes as a tool, not a python module The usage of pyflakes as a Python module was introduced in e397c6d74652, to work around issue between Python 2 and Python 3. This issues are long behind us now and we can get beck to using pyflakes as a tool, giving us more flexibility about how we install it. The `hghave` requirements is modified to check that we have a tool available, instead of a python module.

clang-format: do not accept version above 19.x This gives me different formatting on latest version available in Debian. So disabling for now.

rust-update: add a config item to disable the Rust update fastpath Explanations inline.

update: add a Rust fast-path when updating from null (and clean) This case is easy to detect and we have all we need to generate a valid working copy and dirstate entirely in Rust, which speeds things up considerably: On my machine updating a repo of ~300k files goes from 10.00s down to 4.2s, all while consuming 50% less system time, with all caches hot. Something to note is that further improvements will probably happen with the upcoming `InnerRevlog` series that does smarter mmap hanlding, especially for filelogs. Here are benchmark numbers on a machine with only 4 cores (and no SMT enabled) ``` ### data-env-vars.name = heptapod-public-2024-03-25-ds2-pnm # benchmark.name = hg.command.update # bin-env-vars.hg.py-re2-module = default # bin-env-vars.hg.changeset.node = <this change> # benchmark.variants.atomic-update = no # benchmark.variants.scenario = null-to-tip # benchmark.variants.worker = default default: 5.328762 ~~~~~ rust: 1.308654 (-75.44%, -4.02) ### data-env-vars.name = mercurial-devel-2024-03-22-ds2-pnm # benchmark.name = hg.command.update # bin-env-vars.hg.py-re2-module = default # bin-env-vars.hg.changeset.node = <this change> # benchmark.variants.atomic-update = no # benchmark.variants.scenario = null-to-tip # benchmark.variants.worker = default default: 1.693271 ~~~~~ rust: 1.151053 (-32.02%, -0.54) ### data-env-vars.name = mozilla-unified-2024-03-22-ds2-pnm # benchmark.name = hg.command.update # bin-env-vars.hg.py-re2-module = default # bin-env-vars.hg.changeset.node = <this change> # benchmark.variants.atomic-update = no # benchmark.variants.scenario = null-to-tip # benchmark.variants.worker = default default: 38.901613 ~~~~~ rust: 11.637880 (-70.08%, -27.26) ### data-env-vars.name = netbsd-xsrc-public-2024-09-19-ds2-pnm # benchmark.name = hg.command.update # bin-env-vars.hg.py-re2-module = default # bin-env-vars.hg.changeset.node = <this change> # benchmark.variants.atomic-update = no # benchmark.variants.scenario = null-to-tip # benchmark.variants.worker = default default: 4.793727 ~~~~~ rust: 1.505905 (-68.59%, -3.29) ```

merge: improve working-copy mtime race handling Explanations inline. This also makes use of `make_mtime_reliable`, which unifies our mtime raciness logic from the status. On top of this, this fixes the handling of the pure dirstate status to better catch racy status, as we've been doing in Rust for a long time now.

merge: move the filtering of ambiguous files to a dedicated function I have multiple reasons: - The body of `_update` is way too long - This adds typing which will help our tooling and brains understand this code more easily - This function will get more nested and complex in the next patch I've taken the liberty of rewrapping and typo-passing the docstring.

timestamp: make the reliable comparison more usable from outside This is going to be used with pre-computed times unlike in status.

timestamp: add type information to the module This is easy to do and helps both Pytype and developpers understand what objects they are dealing with.

rust-dirstate: make the reliable timestamp comparison more usable from outside This is going to be used with pre-computed times unlike in status.

rust-dirstate-map: use a more precise identity This is closer to the behavior of what Python does. So far, we were checking only the inode, but this might not be good enough for the v1 case.

dirstate-map: add a missing debug wait point when accessing the v2 docket fc8e37c380d3 added synchronization points to the dirstate to allow for race condition testing without actually requiring a time-based race condition to happen. This changes adds the `pre-read-file` wait point before we read the docket, since callers might ask for the parents before anything else is read, leading to the first read being done before the wait point. This removes some differences in test output which were presumed to be speed related, but weren't.

rust-parsers: use the same error message as with the higher-level code This can happen at two places, but it's not really enough time to justify it being refactored. Let's ensure we have the same error message, the newer one being slightly more helpful.

rust-pathauditor: make sure we actually test the nested repo case This covers the *on-disk* case, where the path itself does not have a `.hg` component.

rust-pathauditor: match more of Python's behavior and display messages We will make use of the path auditor when running our update fast-path, and we want to output of it to be close enough.

rust-dirstate: pass dirstate tracked key from the requirements We will make use of this with the `hg update` fastpath

rust-files: check for empty manifests caused by narrow Explanations inline

rust-repo: don't use on-disk dirstate parents in v1 This mistake was not causing any problems yet since we were never updating parents from Rust code. This is about to change, so let's fix it.

rust-cpython: add a util to get a `Repo` from a python path I suspect this will not be the last time we need to do something like this.

rust: improve `InvalidRevision` error message I encountered this when debugging earlier and felt like we were losing some information along the way, which we were!

rust-dirstate: use a struct as arguments for the high-level `reset_state` This makes the interface a lot clearer at the call site and prevents silly mistakes, as an API with a bunch of booleans is prone to errors. This refactor adds a `from_empty` parameter for a fast-path when resetting and entry we're sure does not exist. It will be used in the upcoming update Rust fastpath, and was not split to prevent more churn.

rust: implement `From<SparseConfigWarning>` for `HgError` This will be useful in a future patch to avoid a lot of boilerplate.

rust-hg-cpython: add an `HgProgressBar` util This will be the entry point for all progress bars from a Python context in upcoming patches. Like the `Progress` trait, this is subject to change once we have more use cases, but this is good enough for now.

rust: add `Progress` trait for progress bars This will be used in the next few changes to introduce a progress bar for the `hg update` fastpath.

rust-files: separate the listing of files from a revset and a revision We won't need to parse a revset all the time, and an upcoming patch will make use of this new util.

rust-files: add a `Sync` bound to the matcher This enables us to use this code in multithreaded environements, which we very much want to do.

rust-files: also return filenode and flags when listing a revision's files This is going to be useful when implementing parts of `update` and makes it so we don't have to fetch the manifest and each entry twice.

rust-manifest: encode flags as `Option<NonZeroU8>` This makes the compiler use the niche optimization for all flags: since 0 is not a valid representation of any flags, we can use 0 as a replacement for `None`, which reduces memory footprint and could yield a little performance improvement over many iterations.