util: make `mmapread()` work on Windows again
522b4d729e89 started referencing `mmap.MAP_PRIVATE`, but that's not available on
Windows, so `hg version` worked, but `make local` did not. That commit also
started calling the constructor with the fine-grained `flags` and `prot` args,
but those aren't available on Windows either[1] (though the backing C code
doesn't seem conditionalized to disallow usage of them).
I assume the change away from from the `access` arg was to provide the same
options, plus `MAP_POPULATE`. Looking at the source code[2], they're not quite
the same- `ACCESS_READ` is equivalent to `flags = MAP_SHARED` and `prot = PROT_READ`.
`MAP_PRIVATE` is only used with `ACCESS_COPY`, which allows read and write.
Therefore, we can't quite get the same baseline flags on Windows, but this was
the status quo ante and `MAP_POPULATE` is a Linux thing, so presumably it works.
I realize that typically the OS differences are abstracted into the platform
modules, but I'm leaving it here so that it is obvious what the differences are
between the platforms.
[1] https://docs.python.org/3/library/mmap.html#mmap.mmap
[2] https://github.com/python/cpython/blob/
5e0abb47886bc665eefdcc19fde985f803e49d4c/Modules/mmapmodule.c#L1539
typing: add type annotations to the dirstate classes
The basic procedure here was to use `merge-pyi` to merge the `git/dirstate.pyi`
file in (after renaming the interface class to match), cleaning up the import
statement mess, and then repeating the procedure for `mercurial/dirstate.pyi`.
Surprisingly, git's dirstate had more hints inferred in its *.pyi file.
After that, it was a manual examination of each method in the interface, and how
they were implemented in the core and git classes to verify what was inferred by
pytype, and fill in the missing gaps. Since this involved jumping around
between three different files, I applied the same type info to all three at the
same time. Complex types I rolled up into type aliases in the interface module,
and used that as needed. That way if it changes, there's one place to edit.
There are some hints still missing, and some documentation that doesn't match
the signatures. They should all be marked with TODOs. There are also a bunch
of methods on the core class that aren't on the Protocol class that seem like
maybe they should be (like `set_tracked()`). There are even more methods
missing from the git class. But that's a project for another time.