wasm_dbms_api/dbms/
types.rs

1//! This module exposes the data types used in the DBMS.
2
3use serde::{Deserialize, Serialize};
4
5use crate::dbms::value::Value;
6use crate::memory::Encode;
7
8mod blob;
9mod boolean;
10mod date;
11mod datetime;
12mod decimal;
13mod integers;
14mod json;
15mod nullable;
16mod text;
17mod uuid;
18
19pub use self::blob::Blob;
20pub use self::boolean::Boolean;
21pub use self::date::Date;
22pub use self::datetime::DateTime;
23pub use self::decimal::Decimal;
24pub use self::integers::{Int8, Int16, Int32, Int64, Uint8, Uint16, Uint32, Uint64};
25pub use self::json::Json;
26pub use self::nullable::Nullable;
27pub use self::text::Text;
28pub use self::uuid::Uuid;
29
30/// A trait representing a data type that can be stored in the DBMS.
31///
32/// This is an umbrella trait that combines several other traits to ensure that
33/// any type implementing [`DataType`] can be cloned, compared, hashed, encoded,
34/// and serialized/deserialized using Serde.
35///
36/// Also it is used by the DBMS to compare and sort values of different data types.
37pub trait DataType:
38    Clone
39    + std::fmt::Debug
40    + std::fmt::Display
41    + PartialEq
42    + Eq
43    + Default
44    + PartialOrd
45    + Ord
46    + std::hash::Hash
47    + Encode
48    + Serialize
49    + Into<Value>
50    + for<'de> Deserialize<'de>
51{
52}
53
54/// A trait for user-defined custom data types.
55///
56/// Custom types are stored as type-erased [`CustomValue`](crate::dbms::custom_value::CustomValue)
57/// inside `Value::Custom`. The `TYPE_TAG` constant uniquely identifies the type
58/// and must be stable across versions.
59///
60/// # Ordering contract
61///
62/// For custom types used with range filters (`Gt`, `Lt`, `Ge`, `Le`) or `ORDER BY`,
63/// the [`Encode`](crate::memory::Encode) output must be order-preserving: if `a < b`,
64/// then `a.encode() < b.encode()` lexicographically.
65/// Equality filters (`Eq`, `Ne`, `In`) only require canonical encoding.
66pub trait CustomDataType: DataType {
67    /// Unique string identifier for this type (e.g., `"principal"`, `"role"`).
68    const TYPE_TAG: &'static str;
69}
70
71/// An enumeration of all supported data type kinds in the DBMS.
72#[derive(Debug, Clone, Copy, PartialEq, Eq, Hash)]
73pub enum DataTypeKind {
74    Blob,
75    Boolean,
76    Date,
77    DateTime,
78    Decimal,
79    Int8,
80    Int16,
81    Int32,
82    Int64,
83    Json,
84    Text,
85    Uint8,
86    Uint16,
87    Uint32,
88    Uint64,
89    Uuid,
90    /// A user-defined custom type. Carries the stable [`CustomDataType::TYPE_TAG`]
91    /// and a [`crate::dbms::table::WireSize`] descriptor so the migration codec
92    /// can slice column bytes without invoking the user's `Encode::decode`.
93    Custom {
94        tag: &'static str,
95        wire_size: crate::dbms::table::WireSize,
96    },
97}
98
99#[cfg(test)]
100mod test {
101
102    use std::collections::HashSet;
103
104    use super::*;
105
106    #[test]
107    fn test_should_create_all_data_type_kind_variants() {
108        let kinds = [
109            DataTypeKind::Blob,
110            DataTypeKind::Boolean,
111            DataTypeKind::Date,
112            DataTypeKind::DateTime,
113            DataTypeKind::Decimal,
114            DataTypeKind::Int8,
115            DataTypeKind::Int16,
116            DataTypeKind::Int32,
117            DataTypeKind::Int64,
118            DataTypeKind::Json,
119            DataTypeKind::Text,
120            DataTypeKind::Uint8,
121            DataTypeKind::Uint16,
122            DataTypeKind::Uint32,
123            DataTypeKind::Uint64,
124            DataTypeKind::Uuid,
125        ];
126
127        assert_eq!(kinds.len(), 16);
128    }
129
130    #[test]
131    #[allow(clippy::clone_on_copy)]
132    fn test_should_clone_data_type_kind() {
133        let kind = DataTypeKind::Text;
134        let cloned = kind.clone();
135        assert_eq!(kind, cloned);
136    }
137
138    #[test]
139    fn test_should_copy_data_type_kind() {
140        let kind = DataTypeKind::Uint32;
141        let copied = kind;
142        assert_eq!(kind, copied);
143    }
144
145    #[test]
146    fn test_should_compare_data_type_kinds() {
147        assert_eq!(DataTypeKind::Blob, DataTypeKind::Blob);
148        assert_eq!(DataTypeKind::Boolean, DataTypeKind::Boolean);
149        assert_ne!(DataTypeKind::Blob, DataTypeKind::Boolean);
150        assert_ne!(DataTypeKind::Int32, DataTypeKind::Int64);
151        assert_ne!(DataTypeKind::Uint32, DataTypeKind::Uint64);
152    }
153
154    #[test]
155    fn test_should_hash_data_type_kind() {
156        let mut set = HashSet::new();
157        set.insert(DataTypeKind::Text);
158        set.insert(DataTypeKind::Uint32);
159        set.insert(DataTypeKind::Boolean);
160
161        assert!(set.contains(&DataTypeKind::Text));
162        assert!(set.contains(&DataTypeKind::Uint32));
163        assert!(set.contains(&DataTypeKind::Boolean));
164        assert!(!set.contains(&DataTypeKind::Blob));
165    }
166
167    #[test]
168    fn test_should_debug_data_type_kind() {
169        assert_eq!(format!("{:?}", DataTypeKind::Blob), "Blob");
170        assert_eq!(format!("{:?}", DataTypeKind::Boolean), "Boolean");
171        assert_eq!(format!("{:?}", DataTypeKind::Date), "Date");
172        assert_eq!(format!("{:?}", DataTypeKind::DateTime), "DateTime");
173        assert_eq!(format!("{:?}", DataTypeKind::Decimal), "Decimal");
174        assert_eq!(format!("{:?}", DataTypeKind::Int8), "Int8");
175        assert_eq!(format!("{:?}", DataTypeKind::Int16), "Int16");
176        assert_eq!(format!("{:?}", DataTypeKind::Int32), "Int32");
177        assert_eq!(format!("{:?}", DataTypeKind::Int64), "Int64");
178        assert_eq!(format!("{:?}", DataTypeKind::Json), "Json");
179        assert_eq!(format!("{:?}", DataTypeKind::Text), "Text");
180        assert_eq!(format!("{:?}", DataTypeKind::Uint8), "Uint8");
181        assert_eq!(format!("{:?}", DataTypeKind::Uint16), "Uint16");
182        assert_eq!(format!("{:?}", DataTypeKind::Uint32), "Uint32");
183        assert_eq!(format!("{:?}", DataTypeKind::Uint64), "Uint64");
184        assert_eq!(format!("{:?}", DataTypeKind::Uuid), "Uuid");
185    }
186
187    #[test]
188    fn test_should_use_data_type_kind_as_hashmap_key() {
189        use std::collections::HashMap;
190
191        let mut map = HashMap::new();
192        map.insert(DataTypeKind::Text, "String type");
193        map.insert(DataTypeKind::Uint32, "32-bit unsigned integer");
194
195        assert_eq!(map.get(&DataTypeKind::Text), Some(&"String type"));
196        assert_eq!(
197            map.get(&DataTypeKind::Uint32),
198            Some(&"32-bit unsigned integer")
199        );
200        assert_eq!(map.get(&DataTypeKind::Blob), None);
201    }
202
203    #[test]
204    fn test_should_create_custom_data_type_kind() {
205        use crate::dbms::table::WireSize;
206        let kind = DataTypeKind::Custom {
207            tag: "role",
208            wire_size: WireSize::Fixed(1),
209        };
210        assert_eq!(
211            kind,
212            DataTypeKind::Custom {
213                tag: "role",
214                wire_size: WireSize::Fixed(1)
215            }
216        );
217        assert_ne!(
218            kind,
219            DataTypeKind::Custom {
220                tag: "status",
221                wire_size: WireSize::Fixed(1)
222            }
223        );
224        assert_ne!(kind, DataTypeKind::Text);
225    }
226
227    #[test]
228    fn test_should_copy_custom_data_type_kind() {
229        use crate::dbms::table::WireSize;
230        let kind = DataTypeKind::Custom {
231            tag: "role",
232            wire_size: WireSize::LengthPrefixed,
233        };
234        let copied = kind;
235        assert_eq!(kind, copied);
236    }
237
238    #[test]
239    fn test_should_debug_custom_data_type_kind() {
240        use crate::dbms::table::WireSize;
241        let kind = DataTypeKind::Custom {
242            tag: "role",
243            wire_size: WireSize::Fixed(1),
244        };
245        let debug = format!("{kind:?}");
246        assert!(debug.contains("Custom"));
247        assert!(debug.contains("role"));
248    }
249}
wasm_dbms_api/dbms/types.rs

wasm_dbms_api/dbms/
types.rs
