reifydb_core/key/
output_frontier.rs

1// SPDX-License-Identifier: Apache-2.0
2// Copyright (c) 2026 ReifyDB
3
4use reifydb_codec::key::{
5	deserializer::KeyDeserializer,
6	encoded::{EncodedKey, EncodedKeyRange},
7	serializer::KeySerializer,
8};
9
10use super::{EncodableKey, KeyKind};
11use crate::{
12	interface::catalog::object::ObjectId,
13	key::catalog::{KeyDeserializerCatalogExt, KeySerializerCatalogExt},
14};
15
16#[derive(Debug, Clone, PartialEq)]
17pub struct OutputFrontierKey {
18	pub object: ObjectId,
19}
20
21impl EncodableKey for OutputFrontierKey {
22	const KIND: KeyKind = KeyKind::OutputFrontier;
23
24	fn encode(&self) -> EncodedKey {
25		let mut serializer = KeySerializer::with_capacity(10);
26		serializer.extend_u8(Self::KIND as u8).extend_object_id(self.object);
27		serializer.to_encoded_key()
28	}
29
30	fn decode(key: &EncodedKey) -> Option<Self> {
31		let mut de = KeyDeserializer::from_bytes(key.as_slice());
32
33		let kind: KeyKind = de.read_u8().ok()?.try_into().ok()?;
34		if kind != Self::KIND {
35			return None;
36		}
37
38		let object = de.read_object_id().ok()?;
39
40		Some(Self {
41			object,
42		})
43	}
44}
45
46impl OutputFrontierKey {
47	pub fn encoded(object: impl Into<ObjectId>) -> EncodedKey {
48		Self {
49			object: object.into(),
50		}
51		.encode()
52	}
53
54	pub fn full_scan() -> EncodedKeyRange {
55		EncodedKeyRange::start_end(Some(Self::frontier_start()), Some(Self::frontier_end()))
56	}
57
58	fn frontier_start() -> EncodedKey {
59		let mut serializer = KeySerializer::with_capacity(1);
60		serializer.extend_u8(Self::KIND as u8);
61		serializer.to_encoded_key()
62	}
63
64	fn frontier_end() -> EncodedKey {
65		let mut serializer = KeySerializer::with_capacity(1);
66		serializer.extend_u8(Self::KIND as u8 - 1);
67		serializer.to_encoded_key()
68	}
69}
70
71#[cfg(test)]
72pub mod tests {
73	use reifydb_codec::key::encoded::EncodedKey;
74
75	use super::{EncodableKey, OutputFrontierKey};
76	use crate::{
77		interface::catalog::{id::ViewId, object::ObjectId},
78		key::KeyKind,
79	};
80
81	#[test]
82	fn test_encode_decode() {
83		let key = OutputFrontierKey {
84			object: ObjectId::View(ViewId(0xABCD)),
85		};
86		let encoded = key.encode();
87		let decoded = OutputFrontierKey::decode(&encoded).unwrap();
88
89		assert_eq!(decoded.object, ObjectId::View(ViewId(0xABCD)));
90		assert_eq!(key, decoded);
91	}
92
93	#[test]
94	fn the_tag_byte_is_the_inverted_kind() {
95		// extend_u8 inverts, so a raw 0x1D here would sort into a neighbouring keyspace.
96		let encoded = OutputFrontierKey::encoded(ObjectId::View(ViewId(1)));
97
98		assert_eq!(encoded.as_slice()[0], !(KeyKind::OutputFrontier as u8));
99	}
100
101	#[test]
102	fn a_key_of_another_kind_never_decodes_as_a_frontier() {
103		// 0x1D previously held FlowNodeInternalState, so a stale row must be rejected, never misread.
104		let mut foreign = OutputFrontierKey::encoded(ObjectId::View(ViewId(1))).as_slice().to_vec();
105		foreign[0] = !(KeyKind::FlowEdgeByFlow as u8);
106
107		assert!(OutputFrontierKey::decode(&EncodedKey::new(foreign)).is_none());
108	}
109
110	#[test]
111	fn every_object_kind_round_trips_under_the_one_frontier_tag() {
112		// A kind landing on another tag escapes the hydration scan, so its consumer pins at the epoch forever.
113		for object in [
114			ObjectId::table(1),
115			ObjectId::View(ViewId(2)),
116			ObjectId::series(3),
117			ObjectId::ringbuffer(4),
118			ObjectId::queue(5),
119		] {
120			let encoded = OutputFrontierKey::encoded(object);
121
122			assert_eq!(
123				encoded.as_slice()[0],
124				!(KeyKind::OutputFrontier as u8),
125				"{:?} encoded under a foreign tag",
126				object
127			);
128			assert_eq!(OutputFrontierKey::decode(&encoded).unwrap().object, object);
129		}
130	}
131}
reifydb_core/key/output_frontier.rs

reifydb_core/key/
output_frontier.rs
