Method find_provenance_for_change

atomic-repository/src/repository/changes.rs:713–767

Find all provenance graphs that explain a specific change. Uses REV_DEPS to find nodes that depend on the given change, then filters by `node_type::PROVENANCE`. # Arguments `change_hash` - The hash of the change to find provenance for # Returns A vector of `(Hash, ProvenanceGraph)` pairs explaining this change.

(
        &self,
        change_hash: &Hash,
    )

    ///
    /// A vector of `(Hash, ProvenanceGraph)` pairs explaining this change.
    pub fn find_provenance_for_change(
        &self,
        change_hash: &Hash,
    ) -> Result<Vec<(Hash, atomic_core::change::ProvenanceGraph)>, RepositoryError> {
        use atomic_core::pristine::{node_type, GraphTxnT};

        let txn = self
            .pristine
            .read_txn()
            .map_err(|e| RepositoryError::Database(e.to_string()))?;

        // Get the internal ID for this change
        let change_id = match txn
            .get_internal(change_hash)
            .map_err(|e| RepositoryError::Database(e.to_string()))?
        {
            Some(id) => id,
            None => return Ok(Vec::new()),
        };

        // Look up REV_DEPS: who depends on this change?
        let rev_deps = txn
            .get_rev_deps(change_id)
            .map_err(|e| RepositoryError::Database(e.to_string()))?;

        let mut graphs = Vec::new();

        for dep_id in rev_deps {
            // Check if this dependent is a provenance graph
            let node_type_val = txn
                .get_node_type(dep_id)
                .map_err(|e| RepositoryError::Database(e.to_string()))?;

            if node_type_val != Some(node_type::PROVENANCE) {
                continue;
            }

            // Get the external hash
            let dep_hash = match txn
                .get_external(dep_id)
                .map_err(|e| RepositoryError::Database(e.to_string()))?
            {
                Some(h) => h,
                None => continue,
            };

            // Load the provenance graph from disk
            match self.load_provenance_graph(&dep_hash) {
                Ok(graph) => graphs.push((dep_hash, graph)),
                Err(_) => continue, // File missing or corrupt — skip
            }
        }

        Ok(graphs)
    }

    /// Find all provenance graphs that explain a change by scanning disk.
    ///