core_query/
view.rs

1use core_storage::v8::seam::{ColumnsView, EdgePropsView, TopologyView, ValueRef};
2use core_storage::{IdMap, Interner};
3use std::collections::HashSet;
4
5/// Read-only twin of `GraphMut`. Holds only borrowed graph state.
6pub struct GraphView<'a> {
7    pub ids: &'a IdMap,
8    pub syms: &'a Interner,
9    pub labels: &'a [u32],
10    /// Overlay-over-base column store view.  For V5–V7 snapshots and fresh
11    /// databases, `base` is `None` and all column reads go to the overlay.
12    /// For V8 snapshots, `base` holds the archived columns from the mmap.
13    pub props: ColumnsView<'a>,
14    /// Overlay-over-base topology view. For V5–V7 snapshots and fresh
15    /// databases, `base` is `None` and all topology reads go to the owned
16    /// overlay. For V8 snapshots, `base` holds the archived CSR from the
17    /// mmap, and WAL-replayed edges accumulate in the overlay.
18    pub topo: TopologyView<'a>,
19    /// Overlay-over-base edge-property view.  For V8 snapshots the base
20    /// section is consulted zero-copy; the overlay holds only post-snapshot
21    /// changes.  Tombstones in the overlay mask deleted-from-base entries.
22    pub edge_props: EdgePropsView<'a>,
23    /// Optional query-scoped node visibility set. `None` = all nodes visible.
24    /// When `Some(set)`, only dense ids present in `set` are accessible.
25    pub mask: Option<&'a HashSet<u32>>,
26}
27
28impl<'a> GraphView<'a> {
29    /// Returns `true` if `id` is visible under the current mask.
30    /// Always `true` when no mask is set.
31    #[inline]
32    pub fn visible(&self, id: u32) -> bool {
33        self.mask.is_none_or(|m| m.contains(&id))
34    }
35
36    pub fn node_id(&self, key: &str) -> Option<u32> {
37        self.ids.get(key)
38    }
39
40    pub fn key_of(&self, id: u32) -> &str {
41        self.ids.key_of(id).expect("dense ids")
42    }
43
44    pub fn label_of(&self, id: u32) -> Option<&str> {
45        let sym = *self.labels.get(id as usize)?;
46        if sym == u32::MAX {
47            return None;
48        }
49        self.syms.resolve(sym)
50    }
51
52    pub fn nodes_with_label(&self, label: &str) -> Vec<u32> {
53        let Some(sym) = self.syms.get(label) else {
54            return Vec::new();
55        };
56        self.labels
57            .iter()
58            .enumerate()
59            .filter_map(|(i, &s)| if s == sym { Some(i as u32) } else { None })
60            .collect()
61    }
62
63    /// Look up the property `field` for node `id`.
64    ///
65    /// Returns `ValueRef::Borrowed` for overlay hits (zero allocation) and
66    /// `ValueRef::Owned` for base-section hits (value materialised from
67    /// archived data).  Returns `None` when neither overlay nor base has a
68    /// value for `(id, field)`.
69    pub fn prop(&self, id: u32, field: &str) -> Option<ValueRef<'_>> {
70        self.props.get(id, field)
71    }
72}
73
74#[cfg(test)]
75mod tests {
76    use super::GraphView;
77    use core_storage::v8::seam::{ColumnsView, EdgePropsView, TopologyView};
78    use core_storage::{ColumnStore, EdgeProps, IdMap, Interner, Topology, Value};
79
80    struct Fx {
81        ids: IdMap,
82        syms: Interner,
83        labels: Vec<u32>,
84        props: ColumnStore,
85        topo: Topology,
86        eprops: EdgeProps,
87    }
88
89    impl Fx {
90        fn new() -> Self {
91            Fx {
92                ids: IdMap::new(),
93                syms: Interner::new(),
94                labels: vec![],
95                props: ColumnStore::new(),
96                topo: Topology::new(),
97                eprops: EdgeProps::new(),
98            }
99        }
100
101        fn add(&mut self, label: &str, key: &str, props: Vec<(&str, Value)>) -> u32 {
102            let id = self.ids.get_or_insert(key);
103            let sym = self.syms.intern(label);
104            self.labels.resize(id as usize + 1, u32::MAX);
105            self.labels[id as usize] = sym;
106            for (f, v) in props {
107                self.props.set(id, f, v);
108            }
109            id
110        }
111
112        fn view(&self) -> GraphView<'_> {
113            GraphView {
114                ids: &self.ids,
115                syms: &self.syms,
116                labels: &self.labels,
117                props: ColumnsView::owned(&self.props),
118                topo: TopologyView::owned(&self.topo),
119                edge_props: EdgePropsView::owned(&self.eprops),
120                mask: None,
121            }
122        }
123    }
124
125    #[test]
126    fn prop_returns_none_for_missing() {
127        let mut fx = Fx::new();
128        let id = fx.add("N", "alice", vec![("age", Value::Int(36))]);
129        let v = fx.view();
130        assert_eq!(
131            v.prop(id, "age").map(|vr| vr.into_value()),
132            Some(Value::Int(36))
133        );
134        assert!(v.prop(id, "missing").is_none());
135    }
136
137    #[test]
138    fn graph_view_lookups() {
139        let mut fx = Fx::new();
140        let id = fx.add("Person", "ada", vec![("age", Value::Int(36))]);
141        let v = fx.view();
142        assert_eq!(v.node_id("ada"), Some(id));
143        assert_eq!(v.node_id("zzz"), None);
144        assert_eq!(v.key_of(id), "ada");
145        assert_eq!(v.label_of(id), Some("Person"));
146        assert_eq!(v.label_of(99), None);
147        assert_eq!(
148            v.prop(id, "age").map(|vr| vr.into_value()),
149            Some(Value::Int(36))
150        );
151        assert_eq!(v.prop(id, "missing"), None);
152    }
153
154    #[test]
155    fn gap_sentinel_is_not_a_label() {
156        let mut fx = Fx::new();
157        let kept = fx.add("Person", "ada", vec![]);
158        fx.ids.get_or_insert("ghost");
159        fx.labels.resize(2, u32::MAX);
160        let later = fx.add("Person", "bob", vec![]);
161        let v = fx.view();
162        assert_eq!(v.label_of(1), None);
163        assert_eq!(v.nodes_with_label("Person"), vec![kept, later]);
164    }
165
166    #[test]
167    fn nodes_with_label_skips_tombstoned_id() {
168        let mut fx = Fx::new();
169        let ada = fx.add("Person", "ada", vec![]);
170        let bob = fx.add("Person", "bob", vec![]);
171        fx.ids.delete("ada");
172        fx.labels[ada as usize] = u32::MAX;
173        let v = fx.view();
174        assert_eq!(v.node_id("ada"), None);
175        assert_eq!(v.label_of(ada), None);
176        assert_eq!(v.nodes_with_label("Person"), vec![bob]);
177    }
178
179    #[test]
180    fn nodes_with_label_dense_id_order_and_unknown_empty() {
181        let mut fx = Fx::new();
182        let bob = fx.add("Person", "bob", vec![]);
183        let ada = fx.add("Person", "ada", vec![]);
184        let _acme = fx.add("Company", "acme", vec![]);
185        let v = fx.view();
186        assert_eq!(v.nodes_with_label("Person"), vec![bob, ada]);
187        assert_eq!(v.nodes_with_label("Person"), vec![0, 1]);
188        assert!(v.nodes_with_label("Nope").is_empty());
189    }
190}
core_query/view.rs

core_query/
view.rs
