comparison rust/hg-core/src/dirstate_tree/dirstate_map.rs @ 47282:ce41ee53263f

dirstate-tree: Extract into a method sorting children of a given node

A later changset will use this in another place.

This is an associated function (that Python would call static method)
instead of a free function so it doesn’t need to be imported separately.
It’s on `Node` rather than `ChildNodes` because the latter is a type alias
to an external type (`HashMap`) so that would require an extension trait
which needs to be imported separately.

Differential Revision: https://phab.mercurial-scm.org/D10721

47281:6763913fa175

}

/// Using a plain `HgPathBuf` of the full path from the repository root as a
/// map key would also work: all paths in a given map have the same parent
/// path, so comparing full paths gives the same result as comparing base
/// names. However `BTreeMap` would waste time always re-comparing the same
/// string prefix.
pub(super) type ChildNodes<'on_disk> =
    FastHashMap<WithBasename<Cow<'on_disk, HgPath>>, Node<'on_disk>>;

/// Represents a file or a directory
#[derive(Default)]
pub(super) struct Node<'on_disk> {
    /// `None` for directories

    /// How many (non-inclusive) descendants of this node are tracked files
    tracked_descendants_count: usize,
}

impl Node<'_> {
    pub(super) fn state(&self) -> Option<EntryState> {
        self.entry.as_ref().map(|entry| entry.state)
    }
}

/// `(full_path, entry, copy_source)`
type NodeDataMut<'tree, 'on_disk> = (

47282:ce41ee53263f

}

/// Using a plain `HgPathBuf` of the full path from the repository root as a
/// map key would also work: all paths in a given map have the same parent
/// path, so comparing full paths gives the same result as comparing base
/// names. However `HashMap` would waste time always re-hashing the same
/// string prefix.
pub(super) type NodeKey<'on_disk> = WithBasename<Cow<'on_disk, HgPath>>;
pub(super) type ChildNodes<'on_disk> =
    FastHashMap<NodeKey<'on_disk>, Node<'on_disk>>;

/// Represents a file or a directory
#[derive(Default)]
pub(super) struct Node<'on_disk> {
    /// `None` for directories

    /// How many (non-inclusive) descendants of this node are tracked files
    tracked_descendants_count: usize,
}

impl<'on_disk> Node<'on_disk> {
    pub(super) fn state(&self) -> Option<EntryState> {
        self.entry.as_ref().map(|entry| entry.state)
    }

    pub(super) fn sorted<'tree>(
        nodes: &'tree mut ChildNodes<'on_disk>,
    ) -> Vec<(&'tree NodeKey<'on_disk>, &'tree mut Self)> {
        let mut vec: Vec<_> = nodes.iter_mut().collect();
        // `sort_unstable_by_key` doesn’t allow keys borrowing from the value:
        // https://github.com/rust-lang/rust/issues/34162
        vec.sort_unstable_by(|(path1, _), (path2, _)| path1.cmp(path2));
        vec
    }
}

/// `(full_path, entry, copy_source)`
type NodeDataMut<'tree, 'on_disk> = (