view rust/hg-cpython/src/dirstate/dirs_multiset.rs @ 44203:2a24ead003f0

rust-cpython: add panicking version of borrow_mut() and use it

The original borrow_mut() is renamed to try_borrow_mut().

Since leak_immutable() no longer incref the borrow count, the caller should
know if the underlying value is borrowed or not. No Python world is involved.
That's why we can simply use the panicking borrow_mut().

// dirs_multiset.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::dirs_multiset` file provided by the
//! `hg-core` package.

use std::cell::RefCell;
use std::convert::TryInto;

use cpython::{
    exc, ObjectProtocol, PyBytes, PyClone, PyDict, PyErr, PyObject, PyResult,
    Python,
};

use crate::dirstate::extract_dirstate;
use crate::ref_sharing::{PyLeaked, PySharedRefCell};
use hg::{
    utils::hg_path::{HgPath, HgPathBuf},
    DirsMultiset, DirsMultisetIter, DirstateMapError, DirstateParseError,
    EntryState,
};

py_class!(pub class Dirs |py| {
    data inner: PySharedRefCell<DirsMultiset>;

    // `map` is either a `dict` or a flat iterator (usually a `set`, sometimes
    // a `list`)
    def __new__(
        _cls,
        map: PyObject,
        skip: Option<PyObject> = None
    ) -> PyResult<Self> {
        let mut skip_state: Option<EntryState> = None;
        if let Some(skip) = skip {
            skip_state = Some(
                skip.extract::<PyBytes>(py)?.data(py)[0]
                    .try_into()
                    .map_err(|e: DirstateParseError| {
                        PyErr::new::<exc::ValueError, _>(py, e.to_string())
                    })?,
            );
        }
        let inner = if let Ok(map) = map.cast_as::<PyDict>(py) {
            let dirstate = extract_dirstate(py, &map)?;
            DirsMultiset::from_dirstate(&dirstate, skip_state)
                .map_err(|e| {
                    PyErr::new::<exc::ValueError, _>(py, e.to_string())
                })?
        } else {
            let map: Result<Vec<HgPathBuf>, PyErr> = map
                .iter(py)?
                .map(|o| {
                    Ok(HgPathBuf::from_bytes(
                        o?.extract::<PyBytes>(py)?.data(py),
                    ))
                })
                .collect();
            DirsMultiset::from_manifest(&map?)
                .map_err(|e| {
                    PyErr::new::<exc::ValueError, _>(py, e.to_string())
                })?
        };

        Self::create_instance(
            py,
            PySharedRefCell::new(inner),
        )
    }

    def addpath(&self, path: PyObject) -> PyResult<PyObject> {
        self.inner_shared(py).borrow_mut().add_path(
            HgPath::new(path.extract::<PyBytes>(py)?.data(py)),
        ).and(Ok(py.None())).or_else(|e| {
            match e {
                DirstateMapError::EmptyPath => {
                    Ok(py.None())
                },
                e => {
                    Err(PyErr::new::<exc::ValueError, _>(
                        py,
                        e.to_string(),
                    ))
                }
            }
        })
    }

    def delpath(&self, path: PyObject) -> PyResult<PyObject> {
        self.inner_shared(py).borrow_mut().delete_path(
            HgPath::new(path.extract::<PyBytes>(py)?.data(py)),
        )
            .and(Ok(py.None()))
            .or_else(|e| {
                match e {
                    DirstateMapError::EmptyPath => {
                        Ok(py.None())
                    },
                    e => {
                        Err(PyErr::new::<exc::ValueError, _>(
                            py,
                            e.to_string(),
                        ))
                    }
                }
            })
    }
    def __iter__(&self) -> PyResult<DirsMultisetKeysIterator> {
        let leaked_ref = self.inner_shared(py).leak_immutable();
        DirsMultisetKeysIterator::from_inner(
            py,
            unsafe { leaked_ref.map(py, |o| o.iter()) },
        )
    }

    def __contains__(&self, item: PyObject) -> PyResult<bool> {
        Ok(self.inner_shared(py).borrow().contains(HgPath::new(
            item.extract::<PyBytes>(py)?.data(py).as_ref(),
        )))
    }
});

py_shared_ref!(Dirs, DirsMultiset, inner, inner_shared);

impl Dirs {
    pub fn from_inner(py: Python, d: DirsMultiset) -> PyResult<Self> {
        Self::create_instance(py, PySharedRefCell::new(d))
    }

    fn translate_key(
        py: Python,
        res: &HgPathBuf,
    ) -> PyResult<Option<PyBytes>> {
        Ok(Some(PyBytes::new(py, res.as_ref())))
    }
}

py_shared_iterator!(
    DirsMultisetKeysIterator,
    PyLeaked<DirsMultisetIter<'static>>,
    Dirs::translate_key,
    Option<PyBytes>
);