dirstate-v2: Remove the `.d` suffix in data file names It could cause confusion since `.d` is already used for revlogs. This suffix is not necessary since there is already a `dirstate.` prefix. Differential Revision: https://phab.mercurial-scm.org/D11413

rhg: Don’t compare ambiguous files one byte at a time Even though the use of `BufReader` reduces the number of syscalls to read the file from disk, `.bytes()` yields a separate `Result` for every byte. Creating those results and dispatching on them is most likely costly. Instead, this commit opts for simplicity by reading the entire file into memory and comparing a single pair of byte strings. Note that memory already needs to contain the entire previous contents of the file, as read from the filelog. So with an extremely large file this doubles memory use but does not make it grow by orders of magnitude. At first I wrote code that still avoids reading the entire file into memory and compares one buffer at a time with `BufReader`. Find this code below for posterity. However its correctness is subtle. I ended up preferring the simplicity of the obviously-correct single comparison. ```rust let mut reader = BufReader::new(fobj); let mut expected = &contents_in_p1[..]; loop { let buf = reader.fill_buf().when_reading_file(&fs_path)?; if buf.is_empty() { // Found EOF return Ok(expected.is_empty()); } else if let Some(rest) = expected.drop_prefix(buf) { // What we read so far matches the expected content, continue reading let buf_len = buf.len(); reader.consume(buf_len); expected = rest } else { // Found different content return Ok(false); } } ``` Differential Revision: https://phab.mercurial-scm.org/D11412

rhg: Reuse manifest when checking status of multiple ambiguous files When `rhg status` cannot determine whether a file is clean based on mtime and size alone, it needs to compare its contents with those found in the parent commit. Previously, rhg would find the (same) manifest of that commit again for every such file. This is lifted out of the loop and reused. Differential Revision: https://phab.mercurial-scm.org/D11411

rust: Return HgError instead of RevlogError in revlog constructors This leaves fewer cases for callers to handle, as RevlogError is more general Differential Revision: https://phab.mercurial-scm.org/D11410

rhg: Align with Python on some revset parsing corner cases In particular: * A string of ASCII digits can be either an integer on a hex prefix * The NULL node ID should convert to the NULL revision number Differential Revision: https://phab.mercurial-scm.org/D11409

rust: Add a Filelog struct that wraps Revlog Some filelog-specific logic is moved from code `rhg cat` into this struct where it can better be reused. Additionally, a missing end delimiter for metadata causes an error to be returned instead of being silently ignored. Differential Revision: https://phab.mercurial-scm.org/D11408

rust: Add Repo::manifest(revision) This deduplicates some common code. Differential Revision: https://phab.mercurial-scm.org/D11407

rust: Keep lazily-initialized Changelog and Manifest log on the Repo object That way if one of them is accessed multiple times it won’t be reopened from the filesystem. Differential Revision: https://phab.mercurial-scm.org/D11406

rust: Move lazy initialization of `Repo::dirstate_map` into a generic struct More components of `Repo` will be added following the same pattern. Differential Revision: https://phab.mercurial-scm.org/D11405

rust: Rename Manifest to Manifestlog, ManifestEntry to Manifest This appears to match the terminology used in Python code and on https://www.mercurial-scm.org/wiki/Manifest Differential Revision: https://phab.mercurial-scm.org/D11404

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

dirstate-item: factor some code in the C implementation We have both `dirstate_item_from_v1_meth`, a class method, and `dirstate_item_from_v1_data`, a function taking low level C argument. Lets implement the former with the later. Differential Revision: https://phab.mercurial-scm.org/D11385

dirstate-item: `dirstate_item_from_v1_data` replaces make_dirstate_item For different format, we will need multiple capsule anyways. Differential Revision: https://phab.mercurial-scm.org/D11384

pathutil: replace the `skip` argument of `dirs` with a boolean It is ever only used for `r` file. So we make it a boolean this will give use more versatility later as we will stop storing the state explicitly. Differential Revision: https://phab.mercurial-scm.org/D11383

dirstate: clarify the message in nonnormal checking The previous message was quite verbose and hard to understand. The new one should be friendlier. Differential Revision: https://phab.mercurial-scm.org/D11382