arrow_graph/sql/
window_functions.rs

1use datafusion::error::Result as DataFusionResult;
2
3/// Placeholder for window functions - will implement proper DataFusion window functions
4/// when we have the core SQL functionality working
5pub struct GraphWindowFunctions;
6
7impl GraphWindowFunctions {
8    pub fn new() -> Self {
9        Self
10    }
11    
12    /// Future implementation of PageRank window function
13    /// Will support: SELECT node_id, pagerank() OVER (PARTITION BY component) FROM nodes
14    pub fn pagerank_window(&self, _partition_values: &[f64]) -> DataFusionResult<f64> {
15        // Placeholder - would implement PageRank calculation over window partition
16        Ok(0.25)
17    }
18    
19    /// Future implementation of degree centrality window function
20    /// Will support: SELECT node_id, degree_centrality() OVER (PARTITION BY component) FROM nodes
21    pub fn degree_centrality_window(&self, _partition_values: &[u64]) -> DataFusionResult<f64> {
22        // Placeholder - would implement degree centrality calculation over window partition
23        Ok(0.5)
24    }
25    
26    /// Future implementation of betweenness centrality window function
27    /// Will support: SELECT node_id, betweenness_centrality() OVER (PARTITION BY component) FROM nodes
28    pub fn betweenness_centrality_window(&self, _partition_values: &[f64]) -> DataFusionResult<f64> {
29        // Placeholder - would implement betweenness centrality calculation over window partition
30        Ok(0.3)
31    }
32}
33
34impl Default for GraphWindowFunctions {
35    fn default() -> Self {
36        Self::new()
37    }
38}
39
40/// Register window functions with DataFusion (placeholder for now)
41pub fn register_window_functions(_ctx: &mut datafusion::execution::context::SessionContext) -> DataFusionResult<()> {
42    // TODO: Implement proper DataFusion window function registration
43    // This will require implementing the AggregateUDFImpl trait properly
44    Ok(())
45}
46
47#[cfg(test)]
48mod tests {
49    use super::*;
50    use datafusion::execution::context::SessionContext;
51
52    #[tokio::test]
53    async fn test_window_function_registration() {
54        let mut ctx = SessionContext::new();
55        
56        // Should not panic
57        register_window_functions(&mut ctx).unwrap();
58    }
59
60    #[test]
61    fn test_window_functions_basic() {
62        let window_funcs = GraphWindowFunctions::new();
63        
64        // Test basic functionality
65        let pagerank_result = window_funcs.pagerank_window(&[]).unwrap();
66        assert_eq!(pagerank_result, 0.25);
67        
68        let degree_result = window_funcs.degree_centrality_window(&[]).unwrap();
69        assert_eq!(degree_result, 0.5);
70        
71        let betweenness_result = window_funcs.betweenness_centrality_window(&[]).unwrap();
72        assert_eq!(betweenness_result, 0.3);
73    }
74}
arrow_graph/sql/window_functions.rs

arrow_graph/sql/
window_functions.rs
