grafeo_core/index/vector/
accessor.rs

1//! Vector accessor trait for reading vectors by node ID.
2//!
3//! This module provides the [`VectorAccessor`] trait, which decouples vector
4//! storage from vector indexing. The HNSW index is topology-only (neighbor
5//! lists only, no stored vectors) and reads vectors through this trait from
6//! [`PropertyStorage`], the single source of truth, halving memory usage
7//! for vector workloads.
8//!
9//! # Example
10//!
11//! ```
12//! use grafeo_core::index::vector::VectorAccessor;
13//! use grafeo_common::types::NodeId;
14//! use std::sync::Arc;
15//!
16//! // Closure-based accessor for tests
17//! let accessor = |id: NodeId| -> Option<Arc<[f32]>> {
18//!     Some(vec![1.0, 2.0, 3.0].into())
19//! };
20//! assert!(accessor.get_vector(NodeId::new(1)).is_some());
21//! ```
22
23use std::sync::Arc;
24
25use grafeo_common::types::{NodeId, PropertyKey, Value};
26
27use crate::graph::GraphStore;
28
29/// Trait for reading vectors by node ID.
30///
31/// HNSW is topology-only: vectors live in property storage, not in
32/// HNSW nodes. This trait provides the bridge for reading them.
33pub trait VectorAccessor: Send + Sync {
34    /// Returns the vector associated with the given node ID, if it exists.
35    fn get_vector(&self, id: NodeId) -> Option<Arc<[f32]>>;
36}
37
38/// Reads vectors from a graph store's property storage for a given property key.
39///
40/// This is the primary accessor used by the engine when performing vector
41/// operations. It reads directly from the property store, avoiding any
42/// duplication.
43pub struct PropertyVectorAccessor<'a> {
44    store: &'a dyn GraphStore,
45    property: PropertyKey,
46}
47
48impl<'a> PropertyVectorAccessor<'a> {
49    /// Creates a new accessor for the given store and property key.
50    #[must_use]
51    pub fn new(store: &'a dyn GraphStore, property: impl Into<PropertyKey>) -> Self {
52        Self {
53            store,
54            property: property.into(),
55        }
56    }
57}
58
59impl VectorAccessor for PropertyVectorAccessor<'_> {
60    fn get_vector(&self, id: NodeId) -> Option<Arc<[f32]>> {
61        match self.store.get_node_property(id, &self.property) {
62            Some(Value::Vector(v)) => Some(v),
63            _ => None,
64        }
65    }
66}
67
68/// Blanket implementation for closures, useful in tests.
69impl<F> VectorAccessor for F
70where
71    F: Fn(NodeId) -> Option<Arc<[f32]>> + Send + Sync,
72{
73    fn get_vector(&self, id: NodeId) -> Option<Arc<[f32]>> {
74        self(id)
75    }
76}
77
78#[cfg(test)]
79mod tests {
80    use super::*;
81    use crate::graph::lpg::LpgStore;
82
83    #[test]
84    fn test_closure_accessor() {
85        let vectors: std::collections::HashMap<NodeId, Arc<[f32]>> = [
86            (NodeId::new(1), Arc::from(vec![1.0_f32, 0.0, 0.0])),
87            (NodeId::new(2), Arc::from(vec![0.0_f32, 1.0, 0.0])),
88        ]
89        .into_iter()
90        .collect();
91
92        let accessor = move |id: NodeId| -> Option<Arc<[f32]>> { vectors.get(&id).cloned() };
93
94        assert!(accessor.get_vector(NodeId::new(1)).is_some());
95        assert_eq!(accessor.get_vector(NodeId::new(1)).unwrap().len(), 3);
96        assert!(accessor.get_vector(NodeId::new(3)).is_none());
97    }
98
99    #[test]
100    fn test_property_vector_accessor() {
101        let store = LpgStore::new().unwrap();
102        let id = store.create_node(&["Test"]);
103        let vec_data: Arc<[f32]> = vec![1.0, 2.0, 3.0].into();
104        store.set_node_property(id, "embedding", Value::Vector(vec_data.clone()));
105
106        let accessor = PropertyVectorAccessor::new(&store, "embedding");
107        let result = accessor.get_vector(id);
108        assert!(result.is_some());
109        assert_eq!(result.unwrap().as_ref(), vec_data.as_ref());
110
111        // Non-existent node
112        assert!(accessor.get_vector(NodeId::new(999)).is_none());
113
114        // Wrong property type
115        store.set_node_property(id, "name", Value::from("hello"));
116        let name_accessor = PropertyVectorAccessor::new(&store, "name");
117        assert!(name_accessor.get_vector(id).is_none());
118    }
119}
grafeo_core/index/vector/accessor.rs

grafeo_core/index/vector/
accessor.rs
