view rust/hg-cpython/src/dirstate/dirstate_map.rs @ 47093:787ff5d21bcd

dirstate-tree: Make Rust DirstateMap bindings go through a trait object

This changeset starts a series that adds an experiment to make status faster
by changing the dirstate (first only in memory and later also on disk) to
be shaped as a tree matching the directory structure, instead of the current
flat collection of entries. The status algorithm can then traverse this tree
dirstate at the same time as it traverses the filesystem.

We (Octobus) have made prototypes that show promising results but are prone
to bitrot. We would like to start upstreaming some experimental Rust code that
goes in this direction, but to avoid disrupting users it should only be
enabled by some run-time opt-in while keeping the existing dirstate structure
and status algorithm as-is.

The `DirstateMap` type and `status` function look like the appropriate
boundary. This adds a new trait that abstracts everything Python bindings need
and makes those bindings go through a `dyn` trait object. Later we’ll have two
implementations of this trait, and the same bindings can use either.

Differential Revision: https://phab.mercurial-scm.org/D10362

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

use std::cell::{Ref, RefCell};
use std::convert::TryInto;
use std::time::Duration;

use cpython::{
    exc, ObjectProtocol, PyBool, PyBytes, PyClone, PyDict, PyErr, PyList,
    PyObject, PyResult, PySet, PyString, PyTuple, Python, PythonObject,
    ToPyObject, UnsafePyLeaked,
};

use crate::{
    dirstate::copymap::{CopyMap, CopyMapItemsIterator, CopyMapKeysIterator},
    dirstate::non_normal_entries::{
        NonNormalEntries, NonNormalEntriesIterator,
    },
    dirstate::{dirs_multiset::Dirs, make_dirstate_tuple},
    parsers::dirstate_parents_to_pytuple,
};
use hg::{
    dirstate_tree::dispatch::DirstateMapMethods,
    errors::HgError,
    revlog::Node,
    utils::hg_path::{HgPath, HgPathBuf},
    DirsMultiset, DirstateEntry, DirstateMap as RustDirstateMap,
    DirstateMapError, DirstateParents, EntryState, StateMapIter,
};

// TODO
//     This object needs to share references to multiple members of its Rust
//     inner struct, namely `copy_map`, `dirs` and `all_dirs`.
//     Right now `CopyMap` is done, but it needs to have an explicit reference
//     to `RustDirstateMap` which itself needs to have an encapsulation for
//     every method in `CopyMap` (copymapcopy, etc.).
//     This is ugly and hard to maintain.
//     The same logic applies to `dirs` and `all_dirs`, however the `Dirs`
//     `py_class!` is already implemented and does not mention
//     `RustDirstateMap`, rightfully so.
//     All attributes also have to have a separate refcount data attribute for
//     leaks, with all methods that go along for reference sharing.
py_class!(pub class DirstateMap |py| {
    @shared data inner: Box<dyn DirstateMapMethods + Send>;

    def __new__(_cls, _root: PyObject) -> PyResult<Self> {
        let inner = Box::new(RustDirstateMap::default());
        Self::create_instance(py, inner)
    }

    def clear(&self) -> PyResult<PyObject> {
        self.inner(py).borrow_mut().clear();
        Ok(py.None())
    }

    def get(
        &self,
        key: PyObject,
        default: Option<PyObject> = None
    ) -> PyResult<Option<PyObject>> {
        let key = key.extract::<PyBytes>(py)?;
        match self.inner(py).borrow().get(HgPath::new(key.data(py))) {
            Some(entry) => {
                Ok(Some(make_dirstate_tuple(py, entry)?))
            },
            None => Ok(default)
        }
    }

    def addfile(
        &self,
        f: PyObject,
        oldstate: PyObject,
        state: PyObject,
        mode: PyObject,
        size: PyObject,
        mtime: PyObject
    ) -> PyResult<PyObject> {
        self.inner(py).borrow_mut().add_file(
            HgPath::new(f.extract::<PyBytes>(py)?.data(py)),
            oldstate.extract::<PyBytes>(py)?.data(py)[0]
                .try_into()
                .map_err(|e: HgError| {
                    PyErr::new::<exc::ValueError, _>(py, e.to_string())
                })?,
            DirstateEntry {
                state: state.extract::<PyBytes>(py)?.data(py)[0]
                    .try_into()
                    .map_err(|e: HgError| {
                        PyErr::new::<exc::ValueError, _>(py, e.to_string())
                    })?,
                mode: mode.extract(py)?,
                size: size.extract(py)?,
                mtime: mtime.extract(py)?,
            },
        ).and(Ok(py.None())).or_else(|e: DirstateMapError| {
            Err(PyErr::new::<exc::ValueError, _>(py, e.to_string()))
        })
    }

    def removefile(
        &self,
        f: PyObject,
        oldstate: PyObject,
        size: PyObject
    ) -> PyResult<PyObject> {
        self.inner(py).borrow_mut()
            .remove_file(
                HgPath::new(f.extract::<PyBytes>(py)?.data(py)),
                oldstate.extract::<PyBytes>(py)?.data(py)[0]
                    .try_into()
                    .map_err(|e: HgError| {
                        PyErr::new::<exc::ValueError, _>(py, e.to_string())
                    })?,
                size.extract(py)?,
            )
            .or_else(|_| {
                Err(PyErr::new::<exc::OSError, _>(
                    py,
                    "Dirstate error".to_string(),
                ))
            })?;
        Ok(py.None())
    }

    def dropfile(
        &self,
        f: PyObject,
        oldstate: PyObject
    ) -> PyResult<PyBool> {
        self.inner(py).borrow_mut()
            .drop_file(
                HgPath::new(f.extract::<PyBytes>(py)?.data(py)),
                oldstate.extract::<PyBytes>(py)?.data(py)[0]
                    .try_into()
                    .map_err(|e: HgError| {
                        PyErr::new::<exc::ValueError, _>(py, e.to_string())
                    })?,
            )
            .and_then(|b| Ok(b.to_py_object(py)))
            .or_else(|e| {
                Err(PyErr::new::<exc::OSError, _>(
                    py,
                    format!("Dirstate error: {}", e.to_string()),
                ))
            })
    }

    def clearambiguoustimes(
        &self,
        files: PyObject,
        now: PyObject
    ) -> PyResult<PyObject> {
        let files: PyResult<Vec<HgPathBuf>> = files
            .iter(py)?
            .map(|filename| {
                Ok(HgPathBuf::from_bytes(
                    filename?.extract::<PyBytes>(py)?.data(py),
                ))
            })
            .collect();
        self.inner(py).borrow_mut()
            .clear_ambiguous_times(files?, now.extract(py)?);
        Ok(py.None())
    }

    def other_parent_entries(&self) -> PyResult<PyObject> {
        let mut inner_shared = self.inner(py).borrow_mut();
        let (_, other_parent) =
            inner_shared.get_non_normal_other_parent_entries();

        let set = PySet::empty(py)?;
        for path in other_parent.iter() {
            set.add(py, PyBytes::new(py, path.as_bytes()))?;
        }
        Ok(set.into_object())
    }

    def non_normal_entries(&self) -> PyResult<NonNormalEntries> {
        NonNormalEntries::from_inner(py, self.clone_ref(py))
    }

    def non_normal_entries_contains(&self, key: PyObject) -> PyResult<bool> {
        let key = key.extract::<PyBytes>(py)?;
        Ok(self
            .inner(py)
            .borrow_mut()
            .get_non_normal_other_parent_entries().0
            .contains(HgPath::new(key.data(py))))
    }

    def non_normal_entries_display(&self) -> PyResult<PyString> {
        Ok(
            PyString::new(
                py,
                &format!(
                    "NonNormalEntries: {:?}",
                    self
                        .inner(py)
                        .borrow_mut()
                        .get_non_normal_other_parent_entries().0
                        .iter().map(|o| o))
                )
            )
    }

    def non_normal_entries_remove(&self, key: PyObject) -> PyResult<PyObject> {
        let key = key.extract::<PyBytes>(py)?;
        self
            .inner(py)
            .borrow_mut()
            .non_normal_entries_remove(HgPath::new(key.data(py)));
        Ok(py.None())
    }

    def non_normal_entries_union(&self, other: PyObject) -> PyResult<PyList> {
        let other: PyResult<_> = other.iter(py)?
                    .map(|f| {
                        Ok(HgPathBuf::from_bytes(
                            f?.extract::<PyBytes>(py)?.data(py),
                        ))
                    })
                    .collect();

        let res = self
            .inner(py)
            .borrow_mut()
            .non_normal_entries_union(other?);

        let ret = PyList::new(py, &[]);
        for filename in res.iter() {
            let as_pystring = PyBytes::new(py, filename.as_bytes());
            ret.append(py, as_pystring.into_object());
        }
        Ok(ret)
    }

    def non_normal_entries_iter(&self) -> PyResult<NonNormalEntriesIterator> {
        // Make sure the sets are defined before we no longer have a mutable
        // reference to the dmap.
        self.inner(py)
            .borrow_mut()
            .set_non_normal_other_parent_entries(false);

        let leaked_ref = self.inner(py).leak_immutable();

        NonNormalEntriesIterator::from_inner(py, unsafe {
            leaked_ref.map(py, |o| {
                o.get_non_normal_other_parent_entries_panic().0.iter()
            })
        })
    }

    def hastrackeddir(&self, d: PyObject) -> PyResult<PyBool> {
        let d = d.extract::<PyBytes>(py)?;
        Ok(self.inner(py).borrow_mut()
            .has_tracked_dir(HgPath::new(d.data(py)))
            .map_err(|e| {
                PyErr::new::<exc::ValueError, _>(py, e.to_string())
            })?
            .to_py_object(py))
    }

    def hasdir(&self, d: PyObject) -> PyResult<PyBool> {
        let d = d.extract::<PyBytes>(py)?;
        Ok(self.inner(py).borrow_mut()
            .has_dir(HgPath::new(d.data(py)))
            .map_err(|e| {
                PyErr::new::<exc::ValueError, _>(py, e.to_string())
            })?
            .to_py_object(py))
    }

    def parents(&self, st: PyObject) -> PyResult<PyTuple> {
        self.inner(py).borrow_mut()
            .parents(st.extract::<PyBytes>(py)?.data(py))
            .map(|parents| dirstate_parents_to_pytuple(py, parents))
            .or_else(|_| {
                Err(PyErr::new::<exc::OSError, _>(
                    py,
                    "Dirstate error".to_string(),
                ))
            })
    }

    def setparents(&self, p1: PyObject, p2: PyObject) -> PyResult<PyObject> {
        let p1 = extract_node_id(py, &p1)?;
        let p2 = extract_node_id(py, &p2)?;

        self.inner(py).borrow_mut()
            .set_parents(&DirstateParents { p1, p2 });
        Ok(py.None())
    }

    def read(&self, st: PyObject) -> PyResult<Option<PyObject>> {
        match self.inner(py).borrow_mut()
            .read(st.extract::<PyBytes>(py)?.data(py))
        {
            Ok(Some(parents)) => Ok(Some(
                dirstate_parents_to_pytuple(py, parents)
                    .into_object()
            )),
            Ok(None) => Ok(Some(py.None())),
            Err(_) => Err(PyErr::new::<exc::OSError, _>(
                py,
                "Dirstate error".to_string(),
            )),
        }
    }
    def write(
        &self,
        p1: PyObject,
        p2: PyObject,
        now: PyObject
    ) -> PyResult<PyBytes> {
        let now = Duration::new(now.extract(py)?, 0);
        let parents = DirstateParents {
            p1: extract_node_id(py, &p1)?,
            p2: extract_node_id(py, &p2)?,
        };

        match self.inner(py).borrow_mut().pack(parents, now) {
            Ok(packed) => Ok(PyBytes::new(py, &packed)),
            Err(_) => Err(PyErr::new::<exc::OSError, _>(
                py,
                "Dirstate error".to_string(),
            )),
        }
    }

    def filefoldmapasdict(&self) -> PyResult<PyDict> {
        let dict = PyDict::new(py);
        for (key, value) in
            self.inner(py).borrow_mut().build_file_fold_map().iter()
        {
            dict.set_item(
                py,
                PyBytes::new(py, key.as_bytes()).into_object(),
                PyBytes::new(py, value.as_bytes()).into_object(),
            )?;
        }
        Ok(dict)
    }

    def __len__(&self) -> PyResult<usize> {
        Ok(self.inner(py).borrow().len())
    }

    def __contains__(&self, key: PyObject) -> PyResult<bool> {
        let key = key.extract::<PyBytes>(py)?;
        Ok(self.inner(py).borrow().contains_key(HgPath::new(key.data(py))))
    }

    def __getitem__(&self, key: PyObject) -> PyResult<PyObject> {
        let key = key.extract::<PyBytes>(py)?;
        let key = HgPath::new(key.data(py));
        match self.inner(py).borrow().get(key) {
            Some(entry) => {
                Ok(make_dirstate_tuple(py, entry)?)
            },
            None => Err(PyErr::new::<exc::KeyError, _>(
                py,
                String::from_utf8_lossy(key.as_bytes()),
            )),
        }
    }

    def keys(&self) -> PyResult<DirstateMapKeysIterator> {
        let leaked_ref = self.inner(py).leak_immutable();
        DirstateMapKeysIterator::from_inner(
            py,
            unsafe { leaked_ref.map(py, |o| o.iter()) },
        )
    }

    def items(&self) -> PyResult<DirstateMapItemsIterator> {
        let leaked_ref = self.inner(py).leak_immutable();
        DirstateMapItemsIterator::from_inner(
            py,
            unsafe { leaked_ref.map(py, |o| o.iter()) },
        )
    }

    def __iter__(&self) -> PyResult<DirstateMapKeysIterator> {
        let leaked_ref = self.inner(py).leak_immutable();
        DirstateMapKeysIterator::from_inner(
            py,
            unsafe { leaked_ref.map(py, |o| o.iter()) },
        )
    }

    def getdirs(&self) -> PyResult<Dirs> {
        // TODO don't copy, share the reference
        self.inner(py).borrow_mut().set_dirs()
            .map_err(|e| {
                PyErr::new::<exc::ValueError, _>(py, e.to_string())
            })?;
        Dirs::from_inner(
            py,
            DirsMultiset::from_dirstate(
                self.inner(py).borrow().iter(),
                Some(EntryState::Removed),
            )
            .map_err(|e| {
                PyErr::new::<exc::ValueError, _>(py, e.to_string())
            })?,
        )
    }
    def getalldirs(&self) -> PyResult<Dirs> {
        // TODO don't copy, share the reference
        self.inner(py).borrow_mut().set_all_dirs()
            .map_err(|e| {
                PyErr::new::<exc::ValueError, _>(py, e.to_string())
            })?;
        Dirs::from_inner(
            py,
            DirsMultiset::from_dirstate(
                self.inner(py).borrow().iter(),
                None,
            ).map_err(|e| {
                PyErr::new::<exc::ValueError, _>(py, e.to_string())
            })?,
        )
    }

    // TODO all copymap* methods, see docstring above
    def copymapcopy(&self) -> PyResult<PyDict> {
        let dict = PyDict::new(py);
        for (key, value) in self.inner(py).borrow().copy_map_iter() {
            dict.set_item(
                py,
                PyBytes::new(py, key.as_bytes()),
                PyBytes::new(py, value.as_bytes()),
            )?;
        }
        Ok(dict)
    }

    def copymapgetitem(&self, key: PyObject) -> PyResult<PyBytes> {
        let key = key.extract::<PyBytes>(py)?;
        match self.inner(py).borrow().copy_map_get(HgPath::new(key.data(py))) {
            Some(copy) => Ok(PyBytes::new(py, copy.as_bytes())),
            None => Err(PyErr::new::<exc::KeyError, _>(
                py,
                String::from_utf8_lossy(key.data(py)),
            )),
        }
    }
    def copymap(&self) -> PyResult<CopyMap> {
        CopyMap::from_inner(py, self.clone_ref(py))
    }

    def copymaplen(&self) -> PyResult<usize> {
        Ok(self.inner(py).borrow().copy_map_len())
    }
    def copymapcontains(&self, key: PyObject) -> PyResult<bool> {
        let key = key.extract::<PyBytes>(py)?;
        Ok(self
            .inner(py)
            .borrow()
            .copy_map_contains_key(HgPath::new(key.data(py))))
    }
    def copymapget(
        &self,
        key: PyObject,
        default: Option<PyObject>
    ) -> PyResult<Option<PyObject>> {
        let key = key.extract::<PyBytes>(py)?;
        match self
            .inner(py)
            .borrow()
            .copy_map_get(HgPath::new(key.data(py)))
        {
            Some(copy) => Ok(Some(
                PyBytes::new(py, copy.as_bytes()).into_object(),
            )),
            None => Ok(default),
        }
    }
    def copymapsetitem(
        &self,
        key: PyObject,
        value: PyObject
    ) -> PyResult<PyObject> {
        let key = key.extract::<PyBytes>(py)?;
        let value = value.extract::<PyBytes>(py)?;
        self.inner(py).borrow_mut().copy_map_insert(
            HgPathBuf::from_bytes(key.data(py)),
            HgPathBuf::from_bytes(value.data(py)),
        );
        Ok(py.None())
    }
    def copymappop(
        &self,
        key: PyObject,
        default: Option<PyObject>
    ) -> PyResult<Option<PyObject>> {
        let key = key.extract::<PyBytes>(py)?;
        match self
            .inner(py)
            .borrow_mut()
            .copy_map_remove(HgPath::new(key.data(py)))
        {
            Some(_) => Ok(None),
            None => Ok(default),
        }
    }

    def copymapiter(&self) -> PyResult<CopyMapKeysIterator> {
        let leaked_ref = self.inner(py).leak_immutable();
        CopyMapKeysIterator::from_inner(
            py,
            unsafe { leaked_ref.map(py, |o| o.copy_map_iter()) },
        )
    }

    def copymapitemsiter(&self) -> PyResult<CopyMapItemsIterator> {
        let leaked_ref = self.inner(py).leak_immutable();
        CopyMapItemsIterator::from_inner(
            py,
            unsafe { leaked_ref.map(py, |o| o.copy_map_iter()) },
        )
    }

});

impl DirstateMap {
    pub fn get_inner<'a>(
        &'a self,
        py: Python<'a>,
    ) -> Ref<'a, Box<dyn DirstateMapMethods + Send>> {
        self.inner(py).borrow()
    }
    fn translate_key(
        py: Python,
        res: (&HgPathBuf, &DirstateEntry),
    ) -> PyResult<Option<PyBytes>> {
        Ok(Some(PyBytes::new(py, res.0.as_bytes())))
    }
    fn translate_key_value(
        py: Python,
        res: (&HgPathBuf, &DirstateEntry),
    ) -> PyResult<Option<(PyBytes, PyObject)>> {
        let (f, entry) = res;
        Ok(Some((
            PyBytes::new(py, f.as_bytes()),
            make_dirstate_tuple(py, &entry)?,
        )))
    }
}

py_shared_iterator!(
    DirstateMapKeysIterator,
    UnsafePyLeaked<StateMapIter<'static>>,
    DirstateMap::translate_key,
    Option<PyBytes>
);

py_shared_iterator!(
    DirstateMapItemsIterator,
    UnsafePyLeaked<StateMapIter<'static>>,
    DirstateMap::translate_key_value,
    Option<(PyBytes, PyObject)>
);

fn extract_node_id(py: Python, obj: &PyObject) -> PyResult<Node> {
    let bytes = obj.extract::<PyBytes>(py)?;
    match bytes.data(py).try_into() {
        Ok(s) => Ok(s),
        Err(e) => Err(PyErr::new::<exc::ValueError, _>(py, e.to_string())),
    }
}