rust/hg-cpython/src/revlog.rs

51245:0b81440e2a73

    PyRevision,
};
use cpython::{
    buffer::{Element, PyBuffer},
    exc::{IndexError, ValueError},
    ObjectProtocol, PyBool, PyBytes, PyClone, PyDict, PyErr, PyInt, PyList,
    PyModule, PyObject, PyResult, PySet, PyString, PyTuple, Python,
    PythonObject, ToPyObject, UnsafePyLeaked,
};
use hg::{
    errors::HgError,
    index::{
        IndexHeader, Phase, RevisionDataParams, SnapshotsCache,

    /// Return Revision if found, raises a bare `error.RevlogError`
    /// in case of ambiguity, same as C version does
    def get_rev(&self, node: PyBytes) -> PyResult<Option<PyRevision>> {
        let opt = self.get_nodetree(py)?.borrow();
        let nt = opt.as_ref().unwrap();
        let idx = &*self.cindex(py).borrow();
        let ridx = &*self.index(py).borrow();
        let node = node_from_py_bytes(py, &node)?;
        let rust_rev =
            nt.find_bin(ridx, node.into()).map_err(|e| nodemap_error(py, e))?;
        let c_rev =
            nt.find_bin(idx, node.into()).map_err(|e| nodemap_error(py, e))?;
        assert_eq!(rust_rev, c_rev);
        Ok(rust_rev.map(Into::into))

    }

    /// same as `get_rev()` but raises a bare `error.RevlogError` if node

        }
        let node_bytes = tup.get_item(py, 7).extract(py)?;
        let node = node_from_py_object(py, &node_bytes)?;

        let rev = self.len(py)? as BaseRevision;
        let mut idx = self.cindex(py).borrow_mut();

        // This is ok since we will just add the revision to the index
        let rev = Revision(rev);
        idx.append(py, tup.clone_ref(py))?;
        self.index(py)
            .borrow_mut()
            .append(py_tuple_to_revision_data_params(py, tup)?)
            .unwrap();
        self.get_nodetree(py)?.borrow_mut().as_mut().unwrap()
            .insert(&*idx, &node, rev)
            .map_err(|e| nodemap_error(py, e))?;
        Ok(py.None())
    }

    def __delitem__(&self, key: PyObject) -> PyResult<()> {
        // __delitem__ is both for `del idx[r]` and `del idx[r1:r2]`
        self.cindex(py).borrow().inner().del_item(py, &key)?;
        let start = key.getattr(py, "start")?;
        let start = UncheckedRevision(start.extract(py)?);
        let start = self.index(py)
            .borrow()
            .check_revision(start)

        self.fill_nodemap(py, nt)?;
        Ok(())
    }

    //
    // Reforwarded C index API
    //

    // index_methods (tp_methods). Same ordering as in revlog.c

    /// return the gca set of the given revs
    def ancestors(&self, *args, **kw) -> PyResult<PyObject> {
        let rust_res = self.inner_ancestors(py, args)?;

        let c_res = self.call_cindex(py, "ancestors", args, kw)?;
        // the algorithm should always provide the results in reverse ordering
        assert_py_eq(py, "ancestors", &rust_res, &c_res)?;

        Ok(rust_res)
    }

    /// return the heads of the common ancestors of the given revs
    def commonancestorsheads(&self, *args, **kw) -> PyResult<PyObject> {
        let rust_res = self.inner_commonancestorsheads(py, args)?;

        let c_res = self.call_cindex(py, "commonancestorsheads", args, kw)?;
        // the algorithm should always provide the results in reverse ordering
        assert_py_eq(py, "commonancestorsheads", &rust_res, &c_res)?;

        Ok(rust_res)
    }

    /// Clear the index caches and inner py_class data.
    /// It is Python's responsibility to call `update_nodemap_data` again.
    def clearcaches(&self, *args, **kw) -> PyResult<PyObject> {
        self.nt(py).borrow_mut().take();
        self.docket(py).borrow_mut().take();
        self.nodemap_mmap(py).borrow_mut().take();
        self.index(py).borrow().clear_caches();
        self.call_cindex(py, "clearcaches", args, kw)
    }

    /// return the raw binary string representing a revision
    def entry_binary(&self, *args, **kw) -> PyResult<PyObject> {
        let rindex = self.index(py).borrow();
        let rev = UncheckedRevision(args.get_item(py, 0).extract(py)?);
        let rust_bytes = rindex.check_revision(rev).and_then(
            |r| rindex.entry_binary(r))
            .ok_or_else(|| rev_not_in_index(py, rev))?;
        let rust_res = PyBytes::new(py, rust_bytes).into_object();

        let c_res = self.call_cindex(py, "entry_binary", args, kw)?;
        assert_py_eq(py, "entry_binary", &rust_res, &c_res)?;
        Ok(rust_res)
    }

    /// return a binary packed version of the header
    def pack_header(&self, *args, **kw) -> PyResult<PyObject> {
        let rindex = self.index(py).borrow();
        let packed = rindex.pack_header(args.get_item(py, 0).extract(py)?);
        let rust_res = PyBytes::new(py, &packed).into_object();

        let c_res = self.call_cindex(py, "pack_header", args, kw)?;
        assert_py_eq(py, "pack_header", &rust_res, &c_res)?;
        Ok(rust_res)
    }

    /// compute phases
    def computephasesmapsets(&self, *args, **kw) -> PyResult<PyObject> {
        let py_roots = args.get_item(py, 0).extract::<PyDict>(py)?;
        let rust_res = self.inner_computephasesmapsets(py, py_roots)?;

        let c_res = self.call_cindex(py, "computephasesmapsets", args, kw)?;
        assert_py_eq(py, "computephasesmapsets", &rust_res, &c_res)?;
        Ok(rust_res)
    }

    /// reachableroots
    def reachableroots2(&self, *args, **kw) -> PyResult<PyObject> {
        let rust_res = self.inner_reachableroots2(
            py,
            UncheckedRevision(args.get_item(py, 0).extract(py)?),
            args.get_item(py, 1),
            args.get_item(py, 2),
            args.get_item(py, 3).extract(py)?,
        )?;

        let c_res = self.call_cindex(py, "reachableroots2", args, kw)?;
        // ordering of C result depends on how the computation went, and
        // Rust result ordering is arbitrary. Hence we compare after
        // sorting the results (in Python to avoid reconverting everything
        // back to Rust structs).
        assert_py_eq_normalized(py, "reachableroots2", &rust_res, &c_res,
                                |v| format!("sorted({})", v))?;

        Ok(rust_res)
    }

    /// get head revisions
    def headrevs(&self, *args, **kw) -> PyResult<PyObject> {
        let rust_res = self.inner_headrevs(py)?;

        let c_res = self.call_cindex(py, "headrevs", args, kw)?;
        assert_py_eq(py, "headrevs", &rust_res, &c_res)?;
        Ok(rust_res)
    }

    /// get filtered head revisions
    def headrevsfiltered(&self, *args, **kw) -> PyResult<PyObject> {
        let rust_res = self.inner_headrevsfiltered(py, &args.get_item(py, 0))?;
        let c_res = self.call_cindex(py, "headrevsfiltered", args, kw)?;

        assert_py_eq(py, "headrevsfiltered", &rust_res, &c_res)?;
        Ok(rust_res)
    }

    /// True if the object is a snapshot
    def issnapshot(&self, *args, **kw) -> PyResult<bool> {
        let index = self.index(py).borrow();
        let result = index
            .is_snapshot(UncheckedRevision(args.get_item(py, 0).extract(py)?))
            .map_err(|e| {
                PyErr::new::<cpython::exc::ValueError, _>(py, e.to_string())
            })?;
        let cresult = self.call_cindex(py, "issnapshot", args, kw)?;
        assert_eq!(result, cresult.extract(py)?);
        Ok(result)
    }

    /// Gather snapshot data in a cache dict
    def findsnapshots(&self, *args, **kw) -> PyResult<PyObject> {
        let index = self.index(py).borrow();
        let cache: PyDict = args.get_item(py, 0).extract(py)?;
        // this methods operates by setting new values in the cache,
        // hence we will compare results by letting the C implementation
        // operate over a deepcopy of the cache, and finally compare both

        index.find_snapshots(
            start_rev,
            end_rev,
            &mut cache_wrapper,
        ).map_err(|_| revlog_error(py))?;

        let c_args = PyTuple::new(
            py,
            &[
                c_cache.clone_ref(py).into_object(),
                args.get_item(py, 1),
                args.get_item(py, 2)
            ]
        );
        self.call_cindex(py, "findsnapshots", &c_args, kw)?;
        assert_py_eq(py, "findsnapshots cache",
                     &cache_wrapper.into_object(),
                     &c_cache.into_object())?;
        Ok(py.None())
    }

    /// determine revisions with deltas to reconstruct fulltext
    def deltachain(&self, *args, **kw) -> PyResult<PyObject> {
        let index = self.index(py).borrow();
        let rev = args.get_item(py, 0).extract::<BaseRevision>(py)?.into();
        let stop_rev =
            args.get_item(py, 1).extract::<Option<BaseRevision>>(py)?;
        let rev = index.check_revision(rev).ok_or_else(|| {

            rev, stop_rev, using_general_delta
        ).map_err(|e| {
            PyErr::new::<cpython::exc::ValueError, _>(py, e.to_string())
        })?;

        let cresult = self.call_cindex(py, "deltachain", args, kw)?;
        let cchain: Vec<BaseRevision> =
            cresult.get_item(py, 0)?.extract::<Vec<BaseRevision>>(py)?;
        let chain: Vec<_> = chain.into_iter().map(|r| r.0).collect();
        assert_eq!(chain, cchain);
        assert_eq!(stopped, cresult.get_item(py, 1)?.extract(py)?);

        Ok(
            PyTuple::new(
                py,
                &[
                    chain.into_py_object(py).into_object(),

        )

    }

    /// slice planned chunk read to reach a density threshold
    def slicechunktodensity(&self, *args, **kw) -> PyResult<PyObject> {
        let rust_res = self.inner_slicechunktodensity(
            py,
            args.get_item(py, 0),
            args.get_item(py, 1).extract(py)?,
            args.get_item(py, 2).extract(py)?
        )?;

        let c_res = self.call_cindex(py, "slicechunktodensity", args, kw)?;
        assert_py_eq(py, "slicechunktodensity", &rust_res, &c_res)?;
        Ok(rust_res)
    }

    // index_sequence_methods and index_mapping_methods.
    //

        self.len(py)
    }

    def __getitem__(&self, key: PyObject) -> PyResult<PyObject> {
        let rust_res = self.inner_getitem(py, key.clone_ref(py))?;

        // this conversion seems needless, but that's actually because
        // `index_getitem` does not handle conversion from PyLong,
        // which expressions such as [e for e in index] internally use.
        // Note that we don't seem to have a direct way to call
        // PySequence_GetItem (does the job), which would possibly be better
        // for performance
        // gracinet 2023: the above comment can be removed when we use
        // the pure Rust impl only. Note also that `key` can be a binary
        // node id.
        let c_key = match key.extract::<BaseRevision>(py) {
            Ok(rev) => rev.to_py_object(py).into_object(),
            Err(_) => key,
        };
        let c_res = self.cindex(py).borrow().inner().get_item(py, c_key)?;

        assert_py_eq(py, "__getitem__", &rust_res, &c_res)?;
        Ok(rust_res)
    }

    def __contains__(&self, item: PyObject) -> PyResult<bool> {
        // ObjectProtocol does not seem to provide contains(), so
        // this is an equivalent implementation of the index_contains()
        // defined in revlog.c
        let cindex = self.cindex(py).borrow();
        match item.extract::<i32>(py) {
            Ok(rev) => {
                Ok(rev >= -1 && rev < self.len(py)? as BaseRevision)
            }
            Err(_) => {
                let item_bytes: PyBytes = item.extract(py)?;
                let rust_res = self.has_node(py, item_bytes)?;

                let c_res = cindex.inner().call_method(
                    py,
                    "has_node",
                    PyTuple::new(py, &[item.clone_ref(py)]),
                    None)?
                .extract(py)?;

                assert_eq!(rust_res, c_res);
                Ok(rust_res)
            }
        }
    }

    }

    @property
    def entry_size(&self) -> PyResult<PyInt> {
        let rust_res: PyInt = INDEX_ENTRY_SIZE.to_py_object(py);

        let c_res = self.cindex(py).borrow().inner()
            .getattr(py, "entry_size")?;
        assert_py_eq(py, "entry_size", rust_res.as_object(), &c_res)?;

        Ok(rust_res)
    }

    @property
    def rust_ext_compat(&self) -> PyResult<PyInt> {
        // will be entirely removed when the Rust index yet useful to
        // implement in Rust to detangle things when removing `self.cindex`
        let rust_res: PyInt = 1.to_py_object(py);

        let c_res = self.cindex(py).borrow().inner()
            .getattr(py, "rust_ext_compat")?;
        assert_py_eq(py, "rust_ext_compat", rust_res.as_object(), &c_res)?;

        Ok(rust_res)
    }

});

struct PySnapshotsCache<'p> {
    py: Python<'p>,
    dict: PyDict,
}

impl<'p> PySnapshotsCache<'p> {
    fn into_object(self) -> PyObject {
        self.dict.into_object()
    }
}

impl<'p> SnapshotsCache for PySnapshotsCache<'p> {
    fn insert_for(
        &mut self,
        rev: BaseRevision,
        value: BaseRevision,

        )
    }

    fn len(&self, py: Python) -> PyResult<usize> {
        let rust_index_len = self.index(py).borrow().len();
        let cindex_len = self.cindex(py).borrow().inner().len(py)?;
        assert_eq!(rust_index_len, cindex_len);
        Ok(rust_index_len)
    }

    /// This is scaffolding at this point, but it could also become
    /// a way to start a persistent nodemap or perform a

            let mut nt = NodeTree::load_bytes(readonly, 0);
            self.fill_nodemap(py, &mut nt)?;
            self.nt(py).borrow_mut().replace(nt);
        }
        Ok(self.nt(py))
    }

    /// forward a method call to the underlying C index
    fn call_cindex(
        &self,
        py: Python,
        name: &str,
        args: &PyTuple,
        kwargs: Option<&PyDict>,
    ) -> PyResult<PyObject> {
        self.cindex(py)
            .borrow()
            .inner()
            .call_method(py, name, args, kwargs)
    }

    pub fn clone_cindex(&self, py: Python) -> cindex::Index {
        self.cindex(py).borrow().clone_ref(py)
    }

        NodeMapError::MultipleResults => revlog_error(py),
        NodeMapError::RevisionNotInIndex(r) => nodemap_rev_not_in_index(py, r),
    }
}

/// assert two Python objects to be equal from a Python point of view
///
/// `method` is a label for the assertion error message, intended to be the
/// name of the caller.
/// `normalizer` is a function that takes a Python variable name and returns
/// an expression that the conparison will actually use.
/// Foe example: `|v| format!("sorted({})", v)`
fn assert_py_eq_normalized(
    py: Python,
    method: &str,
    rust: &PyObject,
    c: &PyObject,
    normalizer: impl FnOnce(&str) -> String + Copy,
) -> PyResult<()> {
    let locals = PyDict::new(py);
    locals.set_item(py, "rust".into_py_object(py).into_object(), rust)?;
    locals.set_item(py, "c".into_py_object(py).into_object(), c)?;
    //    let lhs = format!(normalizer_fmt, "rust");
    //    let rhs = format!(normalizer_fmt, "c");
    let is_eq: PyBool = py
        .eval(
            &format!("{} == {}", &normalizer("rust"), &normalizer("c")),
            None,
            Some(&locals),
        )?
        .extract(py)?;
    assert!(
        is_eq.is_true(),
        "{} results differ. Rust: {:?} C: {:?} (before any normalization)",
        method,
        rust,
        c
    );
    Ok(())
}

fn assert_py_eq(
    py: Python,
    method: &str,
    rust: &PyObject,
    c: &PyObject,
) -> PyResult<()> {
    assert_py_eq_normalized(py, method, rust, c, |v| v.to_owned())
}

/// Create the module, with __package__ given from parent
pub fn init_module(py: Python, package: &str) -> PyResult<PyModule> {
    let dotted_name = &format!("{}.revlog", package);
    let m = PyModule::new(py, dotted_name)?;
    m.add(py, "__package__", package)?;

51246:41e19e8a6133

    PyRevision,
};
use cpython::{
    buffer::{Element, PyBuffer},
    exc::{IndexError, ValueError},
    ObjectProtocol, PyBytes, PyClone, PyDict, PyErr, PyInt, PyList, PyModule,
    PyObject, PyResult, PySet, PyString, PyTuple, Python, PythonObject,
    ToPyObject, UnsafePyLeaked,
};
use hg::{
    errors::HgError,
    index::{
        IndexHeader, Phase, RevisionDataParams, SnapshotsCache,

    /// Return Revision if found, raises a bare `error.RevlogError`
    /// in case of ambiguity, same as C version does
    def get_rev(&self, node: PyBytes) -> PyResult<Option<PyRevision>> {
        let opt = self.get_nodetree(py)?.borrow();
        let nt = opt.as_ref().unwrap();
        let ridx = &*self.index(py).borrow();
        let node = node_from_py_bytes(py, &node)?;
        let rust_rev =
            nt.find_bin(ridx, node.into()).map_err(|e| nodemap_error(py, e))?;
        Ok(rust_rev.map(Into::into))

    }

    /// same as `get_rev()` but raises a bare `error.RevlogError` if node

        }
        let node_bytes = tup.get_item(py, 7).extract(py)?;
        let node = node_from_py_object(py, &node_bytes)?;

        let rev = self.len(py)? as BaseRevision;

        // This is ok since we will just add the revision to the index
        let rev = Revision(rev);
        self.index(py)
            .borrow_mut()
            .append(py_tuple_to_revision_data_params(py, tup)?)
            .unwrap();
        let idx = &*self.index(py).borrow();
        self.get_nodetree(py)?.borrow_mut().as_mut().unwrap()
            .insert(idx, &node, rev)
            .map_err(|e| nodemap_error(py, e))?;
        Ok(py.None())
    }

    def __delitem__(&self, key: PyObject) -> PyResult<()> {
        // __delitem__ is both for `del idx[r]` and `del idx[r1:r2]`
        let start = key.getattr(py, "start")?;
        let start = UncheckedRevision(start.extract(py)?);
        let start = self.index(py)
            .borrow()
            .check_revision(start)

        self.fill_nodemap(py, nt)?;
        Ok(())
    }

    //
    // Index methods previously reforwarded to C index (tp_methods)
    // Same ordering as in revlog.c
    //

    /// return the gca set of the given revs
    def ancestors(&self, *args, **_kw) -> PyResult<PyObject> {
        let rust_res = self.inner_ancestors(py, args)?;
        Ok(rust_res)
    }

    /// return the heads of the common ancestors of the given revs
    def commonancestorsheads(&self, *args, **_kw) -> PyResult<PyObject> {
        let rust_res = self.inner_commonancestorsheads(py, args)?;
        Ok(rust_res)
    }

    /// Clear the index caches and inner py_class data.
    /// It is Python's responsibility to call `update_nodemap_data` again.
    def clearcaches(&self) -> PyResult<PyObject> {
        self.nt(py).borrow_mut().take();
        self.docket(py).borrow_mut().take();
        self.nodemap_mmap(py).borrow_mut().take();
        self.index(py).borrow().clear_caches();
        Ok(py.None())
    }

    /// return the raw binary string representing a revision
    def entry_binary(&self, *args, **_kw) -> PyResult<PyObject> {
        let rindex = self.index(py).borrow();
        let rev = UncheckedRevision(args.get_item(py, 0).extract(py)?);
        let rust_bytes = rindex.check_revision(rev).and_then(
            |r| rindex.entry_binary(r))
            .ok_or_else(|| rev_not_in_index(py, rev))?;
        let rust_res = PyBytes::new(py, rust_bytes).into_object();
        Ok(rust_res)
    }

    /// return a binary packed version of the header
    def pack_header(&self, *args, **_kw) -> PyResult<PyObject> {
        let rindex = self.index(py).borrow();
        let packed = rindex.pack_header(args.get_item(py, 0).extract(py)?);
        let rust_res = PyBytes::new(py, &packed).into_object();
        Ok(rust_res)
    }

    /// compute phases
    def computephasesmapsets(&self, *args, **_kw) -> PyResult<PyObject> {
        let py_roots = args.get_item(py, 0).extract::<PyDict>(py)?;
        let rust_res = self.inner_computephasesmapsets(py, py_roots)?;
        Ok(rust_res)
    }

    /// reachableroots
    def reachableroots2(&self, *args, **_kw) -> PyResult<PyObject> {
        let rust_res = self.inner_reachableroots2(
            py,
            UncheckedRevision(args.get_item(py, 0).extract(py)?),
            args.get_item(py, 1),
            args.get_item(py, 2),
            args.get_item(py, 3).extract(py)?,
        )?;
        Ok(rust_res)
    }

    /// get head revisions
    def headrevs(&self) -> PyResult<PyObject> {
        let rust_res = self.inner_headrevs(py)?;
        Ok(rust_res)
    }

    /// get filtered head revisions
    def headrevsfiltered(&self, *args, **_kw) -> PyResult<PyObject> {
        let rust_res = self.inner_headrevsfiltered(py, &args.get_item(py, 0))?;
        Ok(rust_res)
    }

    /// True if the object is a snapshot
    def issnapshot(&self, *args, **_kw) -> PyResult<bool> {
        let index = self.index(py).borrow();
        let result = index
            .is_snapshot(UncheckedRevision(args.get_item(py, 0).extract(py)?))
            .map_err(|e| {
                PyErr::new::<cpython::exc::ValueError, _>(py, e.to_string())
            })?;
        Ok(result)
    }

    /// Gather snapshot data in a cache dict
    def findsnapshots(&self, *args, **_kw) -> PyResult<PyObject> {
        let index = self.index(py).borrow();
        let cache: PyDict = args.get_item(py, 0).extract(py)?;
        // this methods operates by setting new values in the cache,
        // hence we will compare results by letting the C implementation
        // operate over a deepcopy of the cache, and finally compare both

        index.find_snapshots(
            start_rev,
            end_rev,
            &mut cache_wrapper,
        ).map_err(|_| revlog_error(py))?;
        Ok(py.None())
    }

    /// determine revisions with deltas to reconstruct fulltext
    def deltachain(&self, *args, **_kw) -> PyResult<PyObject> {
        let index = self.index(py).borrow();
        let rev = args.get_item(py, 0).extract::<BaseRevision>(py)?.into();
        let stop_rev =
            args.get_item(py, 1).extract::<Option<BaseRevision>>(py)?;
        let rev = index.check_revision(rev).ok_or_else(|| {

            rev, stop_rev, using_general_delta
        ).map_err(|e| {
            PyErr::new::<cpython::exc::ValueError, _>(py, e.to_string())
        })?;

        let chain: Vec<_> = chain.into_iter().map(|r| r.0).collect();
        Ok(
            PyTuple::new(
                py,
                &[
                    chain.into_py_object(py).into_object(),

        )

    }

    /// slice planned chunk read to reach a density threshold
    def slicechunktodensity(&self, *args, **_kw) -> PyResult<PyObject> {
        let rust_res = self.inner_slicechunktodensity(
            py,
            args.get_item(py, 0),
            args.get_item(py, 1).extract(py)?,
            args.get_item(py, 2).extract(py)?
        )?;
        Ok(rust_res)
    }

    // index_sequence_methods and index_mapping_methods.
    //

        self.len(py)
    }

    def __getitem__(&self, key: PyObject) -> PyResult<PyObject> {
        let rust_res = self.inner_getitem(py, key.clone_ref(py))?;
        Ok(rust_res)
    }

    def __contains__(&self, item: PyObject) -> PyResult<bool> {
        // ObjectProtocol does not seem to provide contains(), so
        // this is an equivalent implementation of the index_contains()
        // defined in revlog.c
        match item.extract::<i32>(py) {
            Ok(rev) => {
                Ok(rev >= -1 && rev < self.len(py)? as BaseRevision)
            }
            Err(_) => {
                let item_bytes: PyBytes = item.extract(py)?;
                let rust_res = self.has_node(py, item_bytes)?;
                Ok(rust_res)
            }
        }
    }

    }

    @property
    def entry_size(&self) -> PyResult<PyInt> {
        let rust_res: PyInt = INDEX_ENTRY_SIZE.to_py_object(py);
        Ok(rust_res)
    }

    @property
    def rust_ext_compat(&self) -> PyResult<PyInt> {
        // will be entirely removed when the Rust index yet useful to
        // implement in Rust to detangle things when removing `self.cindex`
        let rust_res: PyInt = 1.to_py_object(py);
        Ok(rust_res)
    }

});

struct PySnapshotsCache<'p> {
    py: Python<'p>,
    dict: PyDict,
}

impl<'p> SnapshotsCache for PySnapshotsCache<'p> {
    fn insert_for(
        &mut self,
        rev: BaseRevision,
        value: BaseRevision,

        )
    }

    fn len(&self, py: Python) -> PyResult<usize> {
        let rust_index_len = self.index(py).borrow().len();
        Ok(rust_index_len)
    }

    /// This is scaffolding at this point, but it could also become
    /// a way to start a persistent nodemap or perform a

            let mut nt = NodeTree::load_bytes(readonly, 0);
            self.fill_nodemap(py, &mut nt)?;
            self.nt(py).borrow_mut().replace(nt);
        }
        Ok(self.nt(py))
    }

    pub fn clone_cindex(&self, py: Python) -> cindex::Index {
        self.cindex(py).borrow().clone_ref(py)
    }

        NodeMapError::MultipleResults => revlog_error(py),
        NodeMapError::RevisionNotInIndex(r) => nodemap_rev_not_in_index(py, r),
    }
}

/// Create the module, with __package__ given from parent
pub fn init_module(py: Python, package: &str) -> PyResult<PyModule> {
    let dotted_name = &format!("{}.revlog", package);
    let m = PyModule::new(py, dotted_name)?;
    m.add(py, "__package__", package)?;