reifydb_value/value/partition/
mod.rs

1// SPDX-License-Identifier: Apache-2.0
2// Copyright (c) 2026 ReifyDB
3
4use postcard::to_extend;
5use serde::{Deserialize, Serialize};
6
7use super::Value;
8use crate::util::hash::xxh3_128;
9
10#[repr(transparent)]
11#[derive(Default, Debug, Copy, Clone, PartialEq, Eq, PartialOrd, Ord, Hash, Serialize, Deserialize)]
12#[serde(transparent)]
13pub struct Partition(pub u128);
14
15impl Partition {
16	pub fn of(values: &[Value]) -> Self {
17		let mut buf: Vec<u8> = Vec::new();
18		for value in values {
19			buf = to_extend(value, buf).expect("postcard serialization of a Value is total");
20		}
21		Partition(xxh3_128(&buf).0)
22	}
23}
24
25#[derive(Debug, Clone, PartialEq, Eq)]
26pub enum ScanPartitions {
27	All,
28	One(Partition),
29	Many(Vec<Partition>),
30}
31
32impl From<u128> for Partition {
33	fn from(value: u128) -> Self {
34		Partition(value)
35	}
36}
37
38#[cfg(test)]
39#[allow(clippy::disallowed_methods)]
40mod tests {
41	use super::*;
42
43	#[test]
44	fn test_deterministic() {
45		let a = Partition::of(&[Value::Utf8("us".to_string())]);
46		let b = Partition::of(&[Value::Utf8("us".to_string())]);
47		assert_eq!(a, b, "same values must hash to the same partition");
48	}
49
50	#[test]
51	fn test_distinct_values_distinct_partition() {
52		let us = Partition::of(&[Value::Utf8("us".to_string())]);
53		let eu = Partition::of(&[Value::Utf8("eu".to_string())]);
54		assert_ne!(us, eu, "different values should (overwhelmingly) hash differently");
55	}
56
57	#[test]
58	fn test_multi_column() {
59		let a = Partition::of(&[Value::Utf8("us".to_string()), Value::Uint8(1)]);
60		let b = Partition::of(&[Value::Utf8("us".to_string()), Value::Uint8(2)]);
61		assert_ne!(a, b);
62	}
63}
reifydb_value/value/partition/mod.rs

reifydb_value/value/partition/
mod.rs
