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reifydb_core/key/
variant_handler.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};
9use reifydb_value::value::sumtype::SumTypeId;
10
11use crate::{
12	interface::catalog::id::{HandlerId, NamespaceId},
13	key::{EncodableKey, KeyKind},
14};
15
16#[derive(Debug, Clone, PartialEq)]
17pub struct VariantHandlerKey {
18	pub namespace: NamespaceId,
19	pub sumtype: SumTypeId,
20	pub variant_tag: u8,
21	pub handler: HandlerId,
22}
23
24impl VariantHandlerKey {
25	pub fn new(namespace: NamespaceId, sumtype: SumTypeId, variant_tag: u8, handler: HandlerId) -> Self {
26		Self {
27			namespace,
28			sumtype,
29			variant_tag,
30			handler,
31		}
32	}
33
34	pub fn encoded(
35		namespace: impl Into<NamespaceId>,
36		sumtype: impl Into<SumTypeId>,
37		variant_tag: u8,
38		handler: impl Into<HandlerId>,
39	) -> EncodedKey {
40		Self::new(namespace.into(), sumtype.into(), variant_tag, handler.into()).encode()
41	}
42
43	pub fn variant_scan(namespace: NamespaceId, sumtype: SumTypeId, variant_tag: u8) -> EncodedKeyRange {
44		EncodedKeyRange::start_end(
45			Some(Self::variant_start(namespace, sumtype, variant_tag)),
46			Some(Self::variant_end(namespace, sumtype, variant_tag)),
47		)
48	}
49
50	fn variant_start(namespace: NamespaceId, sumtype: SumTypeId, variant_tag: u8) -> EncodedKey {
51		let mut serializer = KeySerializer::with_capacity(18);
52		serializer.extend_u8(Self::KIND as u8).extend_u64(namespace).extend_u64(sumtype).extend_u8(variant_tag);
53		serializer.to_encoded_key()
54	}
55
56	fn variant_end(namespace: NamespaceId, sumtype: SumTypeId, variant_tag: u8) -> EncodedKey {
57		let mut serializer = KeySerializer::with_capacity(18);
58		serializer
59			.extend_u8(Self::KIND as u8)
60			.extend_u64(namespace)
61			.extend_u64(sumtype)
62			.extend_u8(variant_tag.wrapping_sub(1));
63		serializer.to_encoded_key()
64	}
65}
66
67impl EncodableKey for VariantHandlerKey {
68	const KIND: KeyKind = KeyKind::VariantHandler;
69
70	fn encode(&self) -> EncodedKey {
71		let mut serializer = KeySerializer::with_capacity(26);
72		serializer
73			.extend_u8(Self::KIND as u8)
74			.extend_u64(self.namespace)
75			.extend_u64(self.sumtype)
76			.extend_u8(self.variant_tag)
77			.extend_u64(self.handler);
78		serializer.to_encoded_key()
79	}
80
81	fn decode(key: &EncodedKey) -> Option<Self> {
82		let mut de = KeyDeserializer::from_bytes(key.as_slice());
83
84		let kind: KeyKind = de.read_u8().ok()?.try_into().ok()?;
85		if kind != Self::KIND {
86			return None;
87		}
88
89		let namespace = de.read_u64().ok()?;
90		let sumtype = de.read_u64().ok()?;
91		let variant_tag = de.read_u8().ok()?;
92		let handler = de.read_u64().ok()?;
93
94		Some(Self {
95			namespace: NamespaceId(namespace),
96			sumtype: SumTypeId(sumtype),
97			variant_tag,
98			handler: HandlerId(handler),
99		})
100	}
101}
102
103#[cfg(test)]
104pub mod tests {
105	use std::ops::Bound;
106
107	use reifydb_value::value::sumtype::SumTypeId;
108
109	use super::{EncodableKey, VariantHandlerKey};
110	use crate::interface::catalog::id::{HandlerId, NamespaceId};
111
112	#[test]
113	fn test_encode_decode() {
114		let key = VariantHandlerKey {
115			namespace: NamespaceId(0xABCD),
116			sumtype: SumTypeId(0x1234),
117			variant_tag: 5,
118			handler: HandlerId(0x6789),
119		};
120		let encoded = key.encode();
121		let expected: Vec<u8> = vec![
122			0xD2, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x54, 0x32, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xED,
123			0xCB, 0xFA, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0xFF, 0x98, 0x76,
124		];
125		assert_eq!(encoded.as_slice(), expected);
126
127		let decoded = VariantHandlerKey::decode(&encoded).unwrap();
128		assert_eq!(decoded.namespace, NamespaceId(0xABCD));
129		assert_eq!(decoded.sumtype, SumTypeId(0x1234));
130		assert_eq!(decoded.variant_tag, 5);
131		assert_eq!(decoded.handler, HandlerId(0x6789));
132	}
133
134	#[test]
135	fn test_order_preserving() {
136		let key1 = VariantHandlerKey {
137			namespace: NamespaceId::SYSTEM,
138			sumtype: SumTypeId(5),
139			variant_tag: 3,
140			handler: HandlerId(100),
141		};
142		let key2 = VariantHandlerKey {
143			namespace: NamespaceId::SYSTEM,
144			sumtype: SumTypeId(5),
145			variant_tag: 3,
146			handler: HandlerId(200),
147		};
148		let key3 = VariantHandlerKey {
149			namespace: NamespaceId::SYSTEM,
150			sumtype: SumTypeId(5),
151			variant_tag: 4,
152			handler: HandlerId(1),
153		};
154		let key4 = VariantHandlerKey {
155			namespace: NamespaceId::DEFAULT,
156			sumtype: SumTypeId(1),
157			variant_tag: 0,
158			handler: HandlerId(1),
159		};
160
161		let encoded1 = key1.encode();
162		let encoded2 = key2.encode();
163		let encoded3 = key3.encode();
164		let encoded4 = key4.encode();
165
166		assert!(encoded4 < encoded3, "ordering not preserved");
167		assert!(encoded3 < encoded2, "ordering not preserved");
168		assert!(encoded2 < encoded1, "ordering not preserved");
169	}
170
171	#[test]
172	fn test_variant_scan() {
173		let ns = NamespaceId::SYSTEM;
174		let st = SumTypeId(10);
175		let tag = 5u8;
176
177		let range = VariantHandlerKey::variant_scan(ns, st, tag);
178		let start = match &range.start {
179			Bound::Included(k) | Bound::Excluded(k) => k,
180			Bound::Unbounded => panic!("expected bounded start"),
181		};
182		let end = match &range.end {
183			Bound::Included(k) | Bound::Excluded(k) => k,
184			Bound::Unbounded => panic!("expected bounded end"),
185		};
186
187		let key = VariantHandlerKey {
188			namespace: ns,
189			sumtype: st,
190			variant_tag: tag,
191			handler: HandlerId(42),
192		};
193		let encoded = key.encode();
194		assert!(encoded.as_slice() >= start.as_slice());
195		assert!(encoded.as_slice() <= end.as_slice());
196
197		let other = VariantHandlerKey {
198			namespace: ns,
199			sumtype: st,
200			variant_tag: tag + 1,
201			handler: HandlerId(42),
202		};
203		let other_encoded = other.encode();
204		assert!(other_encoded.as_slice() < start.as_slice());
205	}
206}