dfir_pipes/pull/half_join_state/
mod.rs

1//! State management for symmetric hash joins.
2//!
3//! This module provides the [`HalfJoinState`] trait and implementations for
4//! managing the state of each half of a symmetric hash join operation.
5
6use std::borrow::Cow;
7
8use smallvec::SmallVec;
9
10mod multiset;
11pub use multiset::HalfMultisetJoinState;
12
13mod set;
14pub use set::HalfSetJoinState;
15
16/// State semantics for each half of a join.
17///
18/// This trait defines the interface for storing and probing join state.
19/// Different implementations provide different semantics (set vs multiset).
20pub trait HalfJoinState<Key, ValBuild, ValProbe>
21where
22    ValBuild: Clone,
23{
24    /// Insert a key-value pair into the join state.
25    ///
26    /// Returns `true` if the pair was inserted (implementation-defined for duplicates).
27    fn build(&mut self, k: Key, v: Cow<'_, ValBuild>) -> bool;
28
29    /// Probe the join state for matches with the given key and value.
30    ///
31    /// Returns the first match directly. Additional matches are stored internally
32    /// and can be retrieved with [`pop_match`](Self::pop_match).
33    fn probe(&mut self, k: &Key, v: &ValProbe) -> Option<(Key, ValProbe, ValBuild)>;
34
35    /// Pop a stored match from previous [`probe`](Self::probe) calls.
36    fn pop_match(&mut self) -> Option<(Key, ValProbe, ValBuild)>;
37
38    /// Returns the number of keys in the join state.
39    fn len(&self) -> usize;
40
41    /// Returns `true` if the state is empty.
42    fn is_empty(&self) -> bool {
43        0 == self.len()
44    }
45
46    /// Returns an iterator over all entries in the state.
47    fn iter(&self) -> std::collections::hash_map::Iter<'_, Key, SmallVec<[ValBuild; 1]>>;
48
49    /// Returns an iterator over all values for a given key.
50    fn full_probe(&self, k: &Key) -> std::slice::Iter<'_, ValBuild>;
51
52    /// Clear the state without de-allocating.
53    fn clear(&mut self);
54}
dfir_pipes/pull/half_join_state/mod.rs

dfir_pipes/pull/half_join_state/
mod.rs
