reifydb_core/key/
version_epoch.rs

1// SPDX-License-Identifier: Apache-2.0
2// Copyright (c) 2026 ReifyDB
3
4use std::ops::Bound;
5
6use super::{EncodableKey, KeyKind};
7use crate::{
8	encoded::key::{EncodedKey, EncodedKeyRange},
9	util::encoding::keycode::{deserializer::KeyDeserializer, serializer::KeySerializer},
10};
11
12#[derive(Debug, Clone, Copy, PartialEq, Eq)]
13pub struct VersionEpochKey {
14	pub bucket_nanos: u64,
15}
16
17impl EncodableKey for VersionEpochKey {
18	const KIND: KeyKind = KeyKind::VersionEpoch;
19
20	fn encode(&self) -> EncodedKey {
21		let mut serializer = KeySerializer::with_capacity(9);
22		serializer.extend_u8(Self::KIND as u8).extend_u64(self.bucket_nanos);
23		serializer.to_encoded_key()
24	}
25
26	fn decode(key: &EncodedKey) -> Option<Self> {
27		let mut de = KeyDeserializer::from_bytes(key.as_slice());
28
29		let kind: KeyKind = de.read_u8().ok()?.try_into().ok()?;
30		if kind != Self::KIND {
31			return None;
32		}
33
34		let bucket_nanos = de.read_u64().ok()?;
35
36		Some(Self {
37			bucket_nanos,
38		})
39	}
40}
41
42impl VersionEpochKey {
43	pub fn encoded(bucket_nanos: u64) -> EncodedKey {
44		Self {
45			bucket_nanos,
46		}
47		.encode()
48	}
49
50	pub fn floor_scan(target_nanos: u64) -> EncodedKeyRange {
51		EncodedKeyRange::new(Bound::Included(Self::encoded(target_nanos)), Bound::Included(Self::encoded(0)))
52	}
53
54	pub fn older_than(cutoff_nanos: u64) -> EncodedKeyRange {
55		EncodedKeyRange::new(Bound::Excluded(Self::encoded(cutoff_nanos)), Bound::Included(Self::encoded(0)))
56	}
57}
58
59#[cfg(test)]
60mod tests {
61	use std::ops::Bound;
62
63	use super::{EncodableKey, VersionEpochKey};
64
65	#[test]
66	fn test_encode_decode() {
67		let key = VersionEpochKey {
68			bucket_nanos: 0x0123456789ABCDEF,
69		};
70		let encoded = key.encode();
71		let decoded = VersionEpochKey::decode(&encoded).unwrap();
72		assert_eq!(decoded.bucket_nanos, 0x0123456789ABCDEF);
73	}
74
75	#[test]
76	fn test_descending_order_so_newer_bucket_sorts_first() {
77		let older = VersionEpochKey::encoded(100);
78		let newer = VersionEpochKey::encoded(200);
79		assert!(
80			newer < older,
81			"a newer (larger) bucket must encode to smaller key bytes so floor_scan can take the first entry at-or-after the target"
82		);
83	}
84
85	#[test]
86	fn test_floor_scan_lower_bound_is_target_bucket() {
87		let target = 150u64;
88		let range = VersionEpochKey::floor_scan(target);
89		assert_eq!(range.start, Bound::Included(VersionEpochKey::encoded(target)));
90		assert_eq!(range.end, Bound::Included(VersionEpochKey::encoded(0)));
91		// A bucket exactly at the target is included; a bucket newer than the target is excluded.
92		assert!(VersionEpochKey::encoded(target) >= VersionEpochKey::encoded(target));
93		assert!(VersionEpochKey::encoded(target + 1) < VersionEpochKey::encoded(target));
94	}
95}
reifydb_core/key/version_epoch.rs

reifydb_core/key/
version_epoch.rs
