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
25impl From<u128> for Partition {
26	fn from(value: u128) -> Self {
27		Partition(value)
28	}
29}
30
31#[cfg(test)]
32mod tests {
33	use super::*;
34
35	#[test]
36	fn test_deterministic() {
37		let a = Partition::of(&[Value::Utf8("us".to_string())]);
38		let b = Partition::of(&[Value::Utf8("us".to_string())]);
39		assert_eq!(a, b, "same values must hash to the same partition");
40	}
41
42	#[test]
43	fn test_distinct_values_distinct_partition() {
44		let us = Partition::of(&[Value::Utf8("us".to_string())]);
45		let eu = Partition::of(&[Value::Utf8("eu".to_string())]);
46		assert_ne!(us, eu, "different values should (overwhelmingly) hash differently");
47	}
48
49	#[test]
50	fn test_multi_column() {
51		let a = Partition::of(&[Value::Utf8("us".to_string()), Value::Uint8(1)]);
52		let b = Partition::of(&[Value::Utf8("us".to_string()), Value::Uint8(2)]);
53		assert_ne!(a, b);
54	}
55}
reifydb_value/value/partition/mod.rs

reifydb_value/value/partition/
mod.rs
