arrow_graph/sql/
graph_functions.rs

1use datafusion::error::Result as DataFusionResult;
2
3/// Basic graph functions for SQL integration
4/// These are simplified implementations to establish the foundation
5/// Full DataFusion UDF integration will be implemented in a future iteration
6pub struct GraphFunctions;
7
8impl GraphFunctions {
9    pub fn new() -> Self {
10        Self
11    }
12
13    /// Calculate graph density: edges / (nodes * (nodes - 1))
14    pub fn graph_density(&self, _edges_table: &str) -> DataFusionResult<f64> {
15        // Placeholder - would analyze the provided table and compute actual density
16        Ok(0.5)
17    }
18
19    /// Calculate clustering coefficient for a specific node
20    pub fn clustering_coefficient(&self, _node_id: &str, _edges_table: &str) -> DataFusionResult<f64> {
21        // Placeholder - would compute actual clustering coefficient
22        Ok(0.3)
23    }
24
25    /// Calculate PageRank score for a specific node
26    pub fn pagerank(&self, _node_id: &str, _edges_table: &str, _damping_factor: Option<f64>) -> DataFusionResult<f64> {
27        // Placeholder - would compute actual PageRank
28        Ok(0.25)
29    }
30
31    /// Calculate degree centrality for a specific node
32    pub fn degree_centrality(&self, _node_id: &str, _edges_table: &str) -> DataFusionResult<f64> {
33        // Placeholder - would compute actual degree centrality
34        Ok(0.4)
35    }
36
37    /// Calculate betweenness centrality for a specific node
38    pub fn betweenness_centrality(&self, _node_id: &str, _edges_table: &str) -> DataFusionResult<f64> {
39        // Placeholder - would compute actual betweenness centrality
40        Ok(0.2)
41    }
42
43    /// Basic graph pattern matching
44    pub fn graph_match(&self, _pattern: &str, _nodes_table: &str, _edges_table: &str) -> DataFusionResult<bool> {
45        // Placeholder - would implement actual GQL pattern matching
46        Ok(true)
47    }
48
49    /// Count connected components
50    pub fn connected_components(&self, _edges_table: &str, _algorithm: Option<&str>) -> DataFusionResult<u64> {
51        // Placeholder - would compute actual connected components
52        Ok(3)
53    }
54
55    /// Batch shortest path calculation (simplified)
56    pub fn shortest_path_batch(&self, _sources: &[String], _targets: &[String], _edges_table: &str) -> DataFusionResult<Vec<f64>> {
57        // Placeholder - would implement vectorized shortest path computation
58        Ok(vec![1.0, 2.0, 3.0])
59    }
60}
61
62impl Default for GraphFunctions {
63    fn default() -> Self {
64        Self::new()
65    }
66}
67
68/// Register graph functions with DataFusion (simplified for now)
69pub fn register_all_graph_functions(_ctx: &mut datafusion::execution::context::SessionContext) -> DataFusionResult<()> {
70    // TODO: Implement proper DataFusion UDF registration
71    // This will require implementing the ScalarUDFImpl trait properly for DataFusion 48.0
72    // For now, we'll establish the foundation and implement full integration later
73    Ok(())
74}
75
76#[cfg(test)]
77mod tests {
78    use super::*;
79    use datafusion::execution::context::SessionContext;
80
81    #[tokio::test]
82    async fn test_graph_function_registration() {
83        let mut ctx = SessionContext::new();
84        
85        // Should not panic
86        register_all_graph_functions(&mut ctx).unwrap();
87    }
88
89    #[test]
90    fn test_graph_functions_basic() {
91        let graph_funcs = GraphFunctions::new();
92        
93        // Test basic functionality
94        assert_eq!(graph_funcs.graph_density("edges").unwrap(), 0.5);
95        assert_eq!(graph_funcs.clustering_coefficient("node1", "edges").unwrap(), 0.3);
96        assert_eq!(graph_funcs.pagerank("node1", "edges", Some(0.85)).unwrap(), 0.25);
97        assert_eq!(graph_funcs.degree_centrality("node1", "edges").unwrap(), 0.4);
98        assert_eq!(graph_funcs.betweenness_centrality("node1", "edges").unwrap(), 0.2);
99        assert_eq!(graph_funcs.graph_match("(a)-[r]->(b)", "nodes", "edges").unwrap(), true);
100        assert_eq!(graph_funcs.connected_components("edges", None).unwrap(), 3);
101        
102        let paths = graph_funcs.shortest_path_batch(&vec!["A".to_string()], &vec!["B".to_string()], "edges").unwrap();
103        assert_eq!(paths.len(), 3);
104    }
105
106    #[test]
107    fn test_graph_functions_with_parameters() {
108        let graph_funcs = GraphFunctions::new();
109        
110        // Test with different parameters
111        assert_eq!(graph_funcs.pagerank("node1", "edges", None).unwrap(), 0.25);
112        assert_eq!(graph_funcs.connected_components("edges", Some("union_find")).unwrap(), 3);
113    }
114}
arrow_graph/sql/graph_functions.rs

arrow_graph/sql/
graph_functions.rs
