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

52176:72bc29f01570

        if let Some(nodemap) = &self.nodemap {
            nodemap
                .find_bin(self.index(), node)?
                .ok_or(RevlogError::InvalidRevision(format!("{:x}", node)))
        } else {
            self.rev_from_node_no_persistent_nodemap(node)
        }
    }

    /// Same as `rev_from_node`, without using a persistent nodemap
    ///
    /// This is used as fallback when a persistent nodemap is not present.
    /// This happens when the persistent-nodemap experimental feature is not
    /// enabled, or for small revlogs.
    fn rev_from_node_no_persistent_nodemap(
        &self,
        node: NodePrefix,
    ) -> Result<Revision, RevlogError> {
        // Linear scan of the revlog
        // TODO: consider building a non-persistent nodemap in memory to
        // optimize these cases.
        let mut found_by_prefix = None;
        for rev in (-1..self.len() as BaseRevision).rev() {
            let rev = Revision(rev as BaseRevision);
            let candidate_node = if rev == Revision(-1) {
                NULL_NODE
            } else {
                let index_entry =
                    self.index().get_entry(rev).ok_or_else(|| {
                        HgError::corrupted(
                            "revlog references a revision not in the index",
                        )
                    })?;
                *index_entry.hash()
            };
            if node == candidate_node {
                return Ok(rev);
            }
            if node.is_prefix_of(&candidate_node) {
                if found_by_prefix.is_some() {
                    return Err(RevlogError::AmbiguousPrefix);
                }
                found_by_prefix = Some(rev)
            }
        }
        found_by_prefix
            .ok_or(RevlogError::InvalidRevision(format!("{:x}", node)))
    }

    /// Returns whether the given revision exists in this revlog.
    pub fn has_rev(&self, rev: UncheckedRevision) -> bool {
        self.index().check_revision(rev).is_some()

52177:1da6995835b4

        if let Some(nodemap) = &self.nodemap {
            nodemap
                .find_bin(self.index(), node)?
                .ok_or(RevlogError::InvalidRevision(format!("{:x}", node)))
        } else {
            self.index().rev_from_node_no_persistent_nodemap(node)
        }
    }

    /// Returns whether the given revision exists in this revlog.
    pub fn has_rev(&self, rev: UncheckedRevision) -> bool {
        self.index().check_revision(rev).is_some()