rust/hg-core/src/revlog/index.rs

51395:3f37d80d3ab4

    /// Python-specific shortcut to save on PyList creation
    pub fn head_revs_shortcut(
        &self,
    ) -> Result<Option<Vec<Revision>>, GraphError> {
        self.head_revs_filtered(&HashSet::new(), true)
    }

    /// Return the head revisions of this index
    pub fn head_revs_filtered(
        &self,

51396:b01e7d97e167

    /// Python-specific shortcut to save on PyList creation
    pub fn head_revs_shortcut(
        &self,
    ) -> Result<Option<Vec<Revision>>, GraphError> {
        self.head_revs_filtered(&HashSet::new(), true)
    }

    /// Return the heads removed and added by advancing from `begin` to `end`.
    /// In revset language, we compute:
    /// - `heads(:begin)-heads(:end)`
    /// - `heads(:end)-heads(:begin)`
    pub fn head_revs_diff(
        &self,
        begin: Revision,
        end: Revision,
    ) -> Result<(Vec<Revision>, Vec<Revision>), GraphError> {
        let mut heads_added = vec![];
        let mut heads_removed = vec![];

        let mut acc = HashSet::new();
        let Revision(begin) = begin;
        let Revision(end) = end;
        let mut i = end;

        while i > begin {
            // acc invariant:
            // `j` is in the set iff `j <= i` and it has children
            // among `i+1..end` (inclusive)
            if !acc.remove(&i) {
                heads_added.push(Revision(i));
            }
            for Revision(parent) in self.parents(Revision(i))? {
                acc.insert(parent);
            }
            i -= 1;
        }

        // At this point `acc` contains old revisions that gained new children.
        // We need to check if they had any children before. If not, those
        // revisions are the removed heads.
        while !acc.is_empty() {
            // acc invariant:
            // `j` is in the set iff `j <= i` and it has children
            // among `begin+1..end`, but not among `i+1..begin` (inclusive)

            assert!(i >= -1); // yes, `-1` can also be a head if the repo is empty
            if acc.remove(&i) {
                heads_removed.push(Revision(i));
            }
            for Revision(parent) in self.parents(Revision(i))? {
                acc.remove(&parent);
            }
            i -= 1;
        }

        Ok((heads_removed, heads_added))
    }

    /// Return the head revisions of this index
    pub fn head_revs_filtered(
        &self,