rust/hg-cpython/src/dirstate.rs

dirstate: drop all logic around the "non-normal" sets

The dirstate has a lot of code to compute a set of all "non-normal" and
"from_other_parent" entries.

This is all used in one, unique, location, when `setparent` is called and moved
from a merge to a non merge. At that time, any "merge related" information has
to be dropped. This is mostly useful for command like `graft` or `shelve` that
move to a single-parent state -before- the commit. Otherwise the commit will
already have removed all traces of the merge information in the dirstate (e.g.
for a regular merges).

The bookkeeping for these sets is quite invasive. And it seems simpler to just
drop it and do the full computation in the single location where we actually
use it (since we have to do the computation at least once anyway).

This simplify the code a lot, and clarify why this kind of computation is
needed.

The possible drawback compared to the previous code are:
- if the operation happens in a loop, we will end up doing it multiple time,
- the C code to detect entry of interest have been dropped, for now. It will be
  re-introduced later, with a processing code directly in C for even faster
  operation.

Differential Revision: https://phab.mercurial-scm.org/D11507

// dirstate.rs
//
// Copyright 2019 Raphaël Gomès <[e-mail]>
//
// This software may be used and distributed according to the terms of the
// GNU General Public License version 2 or any later version.

//! Bindings for the `hg::dirstate` module provided by the
//! `hg-core` package.
//!
//! From Python, this will be seen as `mercurial.rustext.dirstate`
mod copymap;
mod dirs_multiset;
mod dirstate_map;
mod item;
mod status;
use self::item::DirstateItem;
use crate::{
    dirstate::{
        dirs_multiset::Dirs, dirstate_map::DirstateMap, status::status_wrapper,
    },
    exceptions,
};
use cpython::{PyBytes, PyDict, PyList, PyModule, PyObject, PyResult, Python};
use hg::dirstate_tree::on_disk::V2_FORMAT_MARKER;

/// Create the module, with `__package__` given from parent
pub fn init_module(py: Python, package: &str) -> PyResult<PyModule> {
    let dotted_name = &format!("{}.dirstate", package);
    let m = PyModule::new(py, dotted_name)?;

    env_logger::init();

    m.add(py, "__package__", package)?;
    m.add(py, "__doc__", "Dirstate - Rust implementation")?;

    m.add(
        py,
        "FallbackError",
        py.get_type::<exceptions::FallbackError>(),
    )?;
    m.add_class::<Dirs>(py)?;
    m.add_class::<DirstateMap>(py)?;
    m.add_class::<DirstateItem>(py)?;
    m.add(py, "V2_FORMAT_MARKER", PyBytes::new(py, V2_FORMAT_MARKER))?;
    m.add(
        py,
        "status",
        py_fn!(
            py,
            status_wrapper(
                dmap: DirstateMap,
                root_dir: PyObject,
                matcher: PyObject,
                ignorefiles: PyList,
                check_exec: bool,
                last_normal_time: i64,
                list_clean: bool,
                list_ignored: bool,
                list_unknown: bool,
                collect_traversed_dirs: bool
            )
        ),
    )?;

    let sys = PyModule::import(py, "sys")?;
    let sys_modules: PyDict = sys.get(py, "modules")?.extract(py)?;
    sys_modules.set_item(py, dotted_name, &m)?;

    Ok(m)
}