Mercurial > hg
view rust/hg-cpython/src/dirstate/dirs_multiset.rs @ 43285:ffc1fbd7d1f5
rust-cpython: make PyLeakedRef operations relatively safe
This patch encapsulates the access to the leaked reference to make most
leaked-ref operations safe. The only exception is leaked_ref.map(). I
couldn't figure out how to allow arbitrary map operation safely over an
unsafe static reference. See the docstring and inline comment for details.
Now leak_immutable() can be safely implemented as the PyLeakedRef owns
its inner data.
author | Yuya Nishihara <yuya@tcha.org> |
---|---|
date | Sun, 15 Sep 2019 22:19:10 +0900 |
parents | ce6dd1cee4c8 |
children | f8c114f20d2d |
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// dirs_multiset.rs // // Copyright 2019 Raphaël Gomès <rgomes@octobus.net> // // 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::{PyLeakedRef, 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) } 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?) }; 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)), ); Ok(py.None()) } 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::PathNotFound(_p) => { Err(PyErr::new::<exc::ValueError, _>( py, "expected a value, found none".to_string(), )) } DirstateMapError::EmptyPath => { Ok(py.None()) } } }) } 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(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, PyLeakedRef<DirsMultisetIter<'static>>, Dirs::translate_key, Option<PyBytes> );