rust: Add Repo::dirstate_map and use it in `rhg status` This moves low-level dirstate wrangling out of the status command and into a more reusable location. The open dirstate map is lazily initialized and kept on the Repo object, for reuse by sub-sequent calls. Differential Revision: https://phab.mercurial-scm.org/D11398

rust: Switch to the memmap2-rs crate https://github.com/RazrFalcon/memmap2-rs This is a fork of the original memmap crate which appears to be unmaintained: https://github.com/danburkert/memmap-rs/issues/90 This fork is the most popular according to https://crates.io/keywords/mmap Differential Revision: https://phab.mercurial-scm.org/D11397

rust: Make OwningDirstateMap generic and move it into hg-core This will enable using it in rhg too. The `OwningDirstateMap::new_empty` constructor is generic and accepts a value of any type that gives acces to a bytes buffer. That buffer must stay valid as long as the value hasn’t been dropped, and must keep its memory address even if the value is moved. The `StableDeref` marker trait encodes those constraints. Previously no trait was needed because the value was always of type `PyBytes` which we know satisfies those constraints. The buffer type is ereased in the struct itself through boxing and dynamic dispatch, in order to simplify other signatures that mention `OwningDirstateMap`. Differential Revision: https://phab.mercurial-scm.org/D11396

rust: Move PyBytesWithData out of copy-tracing code So we can use it in other places to. Replace its `.data()` method with the `Deref<Target = [u8]>` trait, allowing this type to be used in generic contexts. Rename the type accordingly. Differential Revision: https://phab.mercurial-scm.org/D11395

rust: Move VFS code to its own module It was previously in the hg::repo module, but both repo code and vfs will likely grow in the future. Differential Revision: https://phab.mercurial-scm.org/D11394

rhg: Switch rhg.ignored-extensions config to Python-compatible list syntax This includes the ability to have an extension name/path that contains a comma, by double-quoting it. Differential Revision: https://phab.mercurial-scm.org/D11390

rhg: Port Python’s `ui.configlist` as `Config::get_list` This new method is not used yet outside of its own unit tests, so this changeset should make no observable change. The Rust parser implementation attempts to exactly replicate the behavior of the Python one, even in edge cases where that behavior is… surprising. New unit tests capture some of these edge cases. This started as a line-by-line port. The main changes are: * Pass around a parser mode enum instead of parser functions * Inline the whole parser into one function * Use `[u8]::get` which returns an `Option`, instead of indexing after explicitly checking the length. Differential Revision: https://phab.mercurial-scm.org/D11389

rust: Generalize the `trim_end_newlines` utility of byte strings … into `trim_end_matches` that takes a callack. Also add `trim_start_matches`. Differential Revision: https://phab.mercurial-scm.org/D11388

dirstate-item: move the C implementation to the same logic Now that we know were we are going, we can update the C implementation. Differential Revision: https://phab.mercurial-scm.org/D11387

dirstate-item: introduce low level C function Since a lot of logic is about to change, we need to isolate it into bits that are easy reusable in the rest of the C code. Especially we need to split the part that do the pure logic from the part that do the Python wrapping. Differential Revision: https://phab.mercurial-scm.org/D11386