Method union_graphs

graphlite/src/storage/multi_graph.rs:120–162

Perform a graph union operation

(
        &self,
        graphs_to_union: Vec<GraphCache>,
    )

    /// Perform a graph union operation
    pub fn union_graphs(
        &self,
        graphs_to_union: Vec<GraphCache>,
    ) -> Result<GraphCache, StorageError> {
        debug!("Performing graph union on {} graphs", graphs_to_union.len());

        if graphs_to_union.is_empty() {
            return Err(StorageError::InvalidOperation(
                "Cannot union empty graph list".to_string(),
            ));
        }

        // Start with the first graph
        let mut result_graph = graphs_to_union[0].clone();

        // Union with remaining graphs
        for graph in graphs_to_union.iter().skip(1) {
            // Manually union graphs by adding all nodes and edges
            for node in graph.get_all_nodes() {
                let has_node = result_graph
                    .has_node(&node.id)
                    .map_err(StorageError::Graph)?;
                if !has_node {
                    result_graph
                        .add_node(node.clone())
                        .map_err(StorageError::Graph)?;
                }
            }
            for edge in graph.get_all_edges() {
                let has_edge = result_graph
                    .has_edge(&edge.id)
                    .map_err(StorageError::Graph)?;
                if !has_edge {
                    result_graph
                        .add_edge(edge.clone())
                        .map_err(StorageError::Graph)?;
                }
            }
        }

        debug!("Successfully created union graph");
        Ok(result_graph)
    }

    /// Clear all graphs
    pub fn clear(&self) -> Result<(), StorageError> {