rust/hg-cpython/src/dirstate.rs

dirstate-map: move most of `dirstate.update_file` logic in the dsmap

A new `reset_state` method is introduced to deal with most of that logic. This
move things one layer lower, but the ultimate goal is to deal with most of this
at the DirstateItem level.

This reveal various imperfection with the data passed to update_file by
`mergestate.recordupdates`, however this is orthogonal to this patch and should
be dealt with at a higher level.

Differential Revision: https://phab.mercurial-scm.org/D11134

// 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 dispatch;
mod non_normal_entries;
mod owning;
mod status;
use crate::{
    dirstate::{
        dirs_multiset::Dirs, dirstate_map::DirstateMap, status::status_wrapper,
    },
    exceptions,
};
use cpython::{
    exc, PyBytes, PyDict, PyErr, PyList, PyModule, PyObject, PyResult,
    PySequence, Python,
};
use hg::dirstate_tree::on_disk::V2_FORMAT_MARKER;
use hg::{utils::hg_path::HgPathBuf, DirstateEntry, EntryState, StateMap};
use libc::{c_char, c_int};
use std::convert::TryFrom;

// C code uses a custom `dirstate_tuple` type, checks in multiple instances
// for this type, and raises a Python `Exception` if the check does not pass.
// Because this type differs only in name from the regular Python tuple, it
// would be a good idea in the near future to remove it entirely to allow
// for a pure Python tuple of the same effective structure to be used,
// rendering this type and the capsule below useless.
py_capsule_fn!(
    from mercurial.cext.parsers import make_dirstate_item_CAPI
        as make_dirstate_item_capi
        signature (
            state: c_char,
            mode: c_int,
            size: c_int,
            mtime: c_int,
        ) -> *mut RawPyObject
);

pub fn make_dirstate_item(
    py: Python,
    entry: &DirstateEntry,
) -> PyResult<PyObject> {
    let &DirstateEntry {
        state,
        mode,
        size,
        mtime,
    } = entry;
    // Explicitly go through u8 first, then cast to platform-specific `c_char`
    // because Into<u8> has a specific implementation while `as c_char` would
    // just do a naive enum cast.
    let state_code: u8 = state.into();
    make_dirstate_item_raw(py, state_code, mode, size, mtime)
}

pub fn make_dirstate_item_raw(
    py: Python,
    state: u8,
    mode: i32,
    size: i32,
    mtime: i32,
) -> PyResult<PyObject> {
    let make = make_dirstate_item_capi::retrieve(py)?;
    let maybe_obj = unsafe {
        let ptr = make(state as c_char, mode, size, mtime);
        PyObject::from_owned_ptr_opt(py, ptr)
    };
    maybe_obj.ok_or_else(|| PyErr::fetch(py))
}

pub fn extract_dirstate(py: Python, dmap: &PyDict) -> Result<StateMap, PyErr> {
    dmap.items(py)
        .iter()
        .map(|(filename, stats)| {
            let stats = stats.extract::<PySequence>(py)?;
            let state = stats.get_item(py, 0)?.extract::<PyBytes>(py)?;
            let state =
                EntryState::try_from(state.data(py)[0]).map_err(|e| {
                    PyErr::new::<exc::ValueError, _>(py, e.to_string())
                })?;
            let mode = stats.get_item(py, 1)?.extract(py)?;
            let size = stats.get_item(py, 2)?.extract(py)?;
            let mtime = stats.get_item(py, 3)?.extract(py)?;
            let filename = filename.extract::<PyBytes>(py)?;
            let filename = filename.data(py);
            Ok((
                HgPathBuf::from(filename.to_owned()),
                DirstateEntry {
                    state,
                    mode,
                    size,
                    mtime,
                },
            ))
        })
        .collect()
}

/// 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(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)
}