rust/hg-cpython/src/dirstate/copymap.rs

rust: Use `&HgPath` instead of `&HgPathBuf` in may APIs

Getting the former (through `Deref`) is almost the only useful thing one can
do with the latter anyway. With this changes, API become more flexible for the
"provider" of these paths which may store something else that Deref’s to HgPath,
such as `std::borrow::Cow<HgPath>`. Using `Cow` can help reduce memory alloactions
and copying.

Differential Revision: https://phab.mercurial-scm.org/D10558

// copymap.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 `hg::dirstate::dirstate_map::CopyMap` provided by the
//! `hg-core` package.

use cpython::{
    PyBytes, PyClone, PyDict, PyObject, PyResult, Python, UnsafePyLeaked,
};
use std::cell::RefCell;

use crate::dirstate::dirstate_map::DirstateMap;
use hg::utils::hg_path::HgPath;
use hg::CopyMapIter;

py_class!(pub class CopyMap |py| {
    data dirstate_map: DirstateMap;

    def __getitem__(&self, key: PyObject) -> PyResult<PyBytes> {
        (*self.dirstate_map(py)).copymapgetitem(py, key)
    }

    def __len__(&self) -> PyResult<usize> {
        self.dirstate_map(py).copymaplen(py)
    }

    def __contains__(&self, key: PyObject) -> PyResult<bool> {
        self.dirstate_map(py).copymapcontains(py, key)
    }

    def get(
        &self,
        key: PyObject,
        default: Option<PyObject> = None
    ) -> PyResult<Option<PyObject>> {
        self.dirstate_map(py).copymapget(py, key, default)
    }

    def pop(
        &self,
        key: PyObject,
        default: Option<PyObject> = None
    ) -> PyResult<Option<PyObject>> {
        self.dirstate_map(py).copymappop(py, key, default)
    }

    def __iter__(&self) -> PyResult<CopyMapKeysIterator> {
        self.dirstate_map(py).copymapiter(py)
    }

    // Python's `dict()` builtin works with either a subclass of dict
    // or an abstract mapping. Said mapping needs to implement `__getitem__`
    // and `keys`.
    def keys(&self) -> PyResult<CopyMapKeysIterator> {
        self.dirstate_map(py).copymapiter(py)
    }

    def items(&self) -> PyResult<CopyMapItemsIterator> {
        self.dirstate_map(py).copymapitemsiter(py)
    }

    def iteritems(&self) -> PyResult<CopyMapItemsIterator> {
        self.dirstate_map(py).copymapitemsiter(py)
    }

    def __setitem__(
        &self,
        key: PyObject,
        item: PyObject
    ) -> PyResult<()> {
        self.dirstate_map(py).copymapsetitem(py, key, item)?;
        Ok(())
    }

    def copy(&self) -> PyResult<PyDict> {
        self.dirstate_map(py).copymapcopy(py)
    }

});

impl CopyMap {
    pub fn from_inner(py: Python, dm: DirstateMap) -> PyResult<Self> {
        Self::create_instance(py, dm)
    }
    fn translate_key(
        py: Python,
        res: (&HgPath, &HgPath),
    ) -> PyResult<Option<PyBytes>> {
        Ok(Some(PyBytes::new(py, res.0.as_bytes())))
    }
    fn translate_key_value(
        py: Python,
        res: (&HgPath, &HgPath),
    ) -> PyResult<Option<(PyBytes, PyBytes)>> {
        let (k, v) = res;
        Ok(Some((
            PyBytes::new(py, k.as_bytes()),
            PyBytes::new(py, v.as_bytes()),
        )))
    }
}

py_shared_iterator!(
    CopyMapKeysIterator,
    UnsafePyLeaked<CopyMapIter<'static>>,
    CopyMap::translate_key,
    Option<PyBytes>
);

py_shared_iterator!(
    CopyMapItemsIterator,
    UnsafePyLeaked<CopyMapIter<'static>>,
    CopyMap::translate_key_value,
    Option<(PyBytes, PyBytes)>
);