rusqlite/
limits.rs

1//! Run-Time Limits
2
3use crate::{ffi, Connection, Result};
4use std::ffi::c_int;
5
6/// Run-Time limit categories, for use with [`Connection::limit`] and
7/// [`Connection::set_limit`].
8///
9/// See the official documentation for more information:
10/// - <https://www.sqlite.org/c3ref/c_limit_attached.html>
11/// - <https://www.sqlite.org/limits.html>
12#[derive(Copy, Clone, Debug)]
13#[repr(i32)]
14#[non_exhaustive]
15#[expect(non_camel_case_types)]
16pub enum Limit {
17    /// The maximum size of any string or BLOB or table row, in bytes.
18    SQLITE_LIMIT_LENGTH = ffi::SQLITE_LIMIT_LENGTH,
19    /// The maximum length of an SQL statement, in bytes.
20    SQLITE_LIMIT_SQL_LENGTH = ffi::SQLITE_LIMIT_SQL_LENGTH,
21    /// The maximum number of columns in a table definition or in the result set
22    /// of a SELECT or the maximum number of columns in an index or in an
23    /// ORDER BY or GROUP BY clause.
24    SQLITE_LIMIT_COLUMN = ffi::SQLITE_LIMIT_COLUMN,
25    /// The maximum depth of the parse tree on any expression.
26    SQLITE_LIMIT_EXPR_DEPTH = ffi::SQLITE_LIMIT_EXPR_DEPTH,
27    /// The maximum number of terms in a compound SELECT statement.
28    SQLITE_LIMIT_COMPOUND_SELECT = ffi::SQLITE_LIMIT_COMPOUND_SELECT,
29    /// The maximum number of instructions in a virtual machine program used to
30    /// implement an SQL statement.
31    SQLITE_LIMIT_VDBE_OP = ffi::SQLITE_LIMIT_VDBE_OP,
32    /// The maximum number of arguments on a function.
33    SQLITE_LIMIT_FUNCTION_ARG = ffi::SQLITE_LIMIT_FUNCTION_ARG,
34    /// The maximum number of attached databases.
35    SQLITE_LIMIT_ATTACHED = ffi::SQLITE_LIMIT_ATTACHED,
36    /// The maximum length of the pattern argument to the LIKE or GLOB
37    /// operators.
38    SQLITE_LIMIT_LIKE_PATTERN_LENGTH = ffi::SQLITE_LIMIT_LIKE_PATTERN_LENGTH,
39    /// The maximum index number of any parameter in an SQL statement.
40    SQLITE_LIMIT_VARIABLE_NUMBER = ffi::SQLITE_LIMIT_VARIABLE_NUMBER,
41    /// The maximum depth of recursion for triggers.
42    SQLITE_LIMIT_TRIGGER_DEPTH = ffi::SQLITE_LIMIT_TRIGGER_DEPTH,
43    /// The maximum number of auxiliary worker threads that a single prepared
44    /// statement may start.
45    SQLITE_LIMIT_WORKER_THREADS = ffi::SQLITE_LIMIT_WORKER_THREADS,
46    /// The maximum depth of the parse tree on any expression.
47    SQLITE_LIMIT_PARSER_DEPTH = 12, // 3.53.0
48    /// Only used for testing
49    #[cfg(test)]
50    INVALID = -1,
51}
52
53impl Connection {
54    /// Returns the current value of a [`Limit`].
55    #[inline]
56    pub fn limit(&self, limit: Limit) -> Result<i32> {
57        let c = self.db.borrow();
58        let rc = unsafe { ffi::sqlite3_limit(c.db(), limit as c_int, -1) };
59        if rc < 0 {
60            return Err(err!(ffi::SQLITE_RANGE, "{limit:?} is invalid"));
61        }
62        Ok(rc)
63    }
64
65    /// Changes the [`Limit`] to `new_val`, returning the prior
66    /// value of the limit.
67    #[inline]
68    pub fn set_limit(&self, limit: Limit, new_val: i32) -> Result<i32> {
69        if new_val < 0 {
70            return Err(err!(ffi::SQLITE_RANGE, "{new_val} is invalid"));
71        }
72        let c = self.db.borrow_mut();
73        let rc = unsafe { ffi::sqlite3_limit(c.db(), limit as c_int, new_val) };
74        if rc < 0 {
75            return Err(err!(ffi::SQLITE_RANGE, "{limit:?} is invalid"));
76        }
77        Ok(rc)
78    }
79}
80
81#[cfg(test)]
82mod test {
83    #[cfg(all(target_family = "wasm", target_os = "unknown"))]
84    use wasm_bindgen_test::wasm_bindgen_test as test;
85
86    use super::*;
87    use crate::Result;
88
89    #[test]
90    fn test_limit_values() {
91        assert_eq!(Limit::SQLITE_LIMIT_LENGTH as i32, ffi::SQLITE_LIMIT_LENGTH,);
92        assert_eq!(
93            Limit::SQLITE_LIMIT_SQL_LENGTH as i32,
94            ffi::SQLITE_LIMIT_SQL_LENGTH,
95        );
96        assert_eq!(Limit::SQLITE_LIMIT_COLUMN as i32, ffi::SQLITE_LIMIT_COLUMN,);
97        assert_eq!(
98            Limit::SQLITE_LIMIT_EXPR_DEPTH as i32,
99            ffi::SQLITE_LIMIT_EXPR_DEPTH,
100        );
101        assert_eq!(
102            Limit::SQLITE_LIMIT_COMPOUND_SELECT as i32,
103            ffi::SQLITE_LIMIT_COMPOUND_SELECT,
104        );
105        assert_eq!(
106            Limit::SQLITE_LIMIT_VDBE_OP as i32,
107            ffi::SQLITE_LIMIT_VDBE_OP,
108        );
109        assert_eq!(
110            Limit::SQLITE_LIMIT_FUNCTION_ARG as i32,
111            ffi::SQLITE_LIMIT_FUNCTION_ARG,
112        );
113        assert_eq!(
114            Limit::SQLITE_LIMIT_ATTACHED as i32,
115            ffi::SQLITE_LIMIT_ATTACHED,
116        );
117        assert_eq!(
118            Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH as i32,
119            ffi::SQLITE_LIMIT_LIKE_PATTERN_LENGTH,
120        );
121        assert_eq!(
122            Limit::SQLITE_LIMIT_VARIABLE_NUMBER as i32,
123            ffi::SQLITE_LIMIT_VARIABLE_NUMBER,
124        );
125        assert_eq!(
126            Limit::SQLITE_LIMIT_TRIGGER_DEPTH as i32,
127            ffi::SQLITE_LIMIT_TRIGGER_DEPTH,
128        );
129        assert_eq!(
130            Limit::SQLITE_LIMIT_WORKER_THREADS as i32,
131            ffi::SQLITE_LIMIT_WORKER_THREADS,
132        );
133    }
134
135    #[test]
136    #[cfg_attr(miri, ignore)]
137    fn test_limit() -> Result<()> {
138        let db = Connection::open_in_memory()?;
139        db.set_limit(Limit::SQLITE_LIMIT_LENGTH, 1024)?;
140        assert_eq!(1024, db.limit(Limit::SQLITE_LIMIT_LENGTH)?);
141
142        db.set_limit(Limit::SQLITE_LIMIT_SQL_LENGTH, 1024)?;
143        assert_eq!(1024, db.limit(Limit::SQLITE_LIMIT_SQL_LENGTH)?);
144
145        db.set_limit(Limit::SQLITE_LIMIT_COLUMN, 64)?;
146        assert_eq!(64, db.limit(Limit::SQLITE_LIMIT_COLUMN)?);
147
148        db.set_limit(Limit::SQLITE_LIMIT_EXPR_DEPTH, 256)?;
149        assert_eq!(256, db.limit(Limit::SQLITE_LIMIT_EXPR_DEPTH)?);
150
151        db.set_limit(Limit::SQLITE_LIMIT_COMPOUND_SELECT, 32)?;
152        assert_eq!(32, db.limit(Limit::SQLITE_LIMIT_COMPOUND_SELECT)?);
153
154        db.set_limit(Limit::SQLITE_LIMIT_FUNCTION_ARG, 32)?;
155        assert_eq!(32, db.limit(Limit::SQLITE_LIMIT_FUNCTION_ARG)?);
156
157        db.set_limit(Limit::SQLITE_LIMIT_ATTACHED, 2)?;
158        assert_eq!(2, db.limit(Limit::SQLITE_LIMIT_ATTACHED)?);
159
160        db.set_limit(Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH, 128)?;
161        assert_eq!(128, db.limit(Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH)?);
162
163        db.set_limit(Limit::SQLITE_LIMIT_VARIABLE_NUMBER, 99)?;
164        assert_eq!(99, db.limit(Limit::SQLITE_LIMIT_VARIABLE_NUMBER)?);
165
166        db.set_limit(Limit::SQLITE_LIMIT_TRIGGER_DEPTH, 32)?;
167        assert_eq!(32, db.limit(Limit::SQLITE_LIMIT_TRIGGER_DEPTH)?);
168
169        db.set_limit(Limit::SQLITE_LIMIT_WORKER_THREADS, 2)?;
170        #[cfg(not(all(target_family = "wasm", target_os = "unknown")))]
171        assert_eq!(2, db.limit(Limit::SQLITE_LIMIT_WORKER_THREADS)?);
172
173        // wasm build with DSQLITE_THREADSAFE=0, so limit not working
174        // see <https://sqlite.org/threadsafe.html>
175        #[cfg(all(target_family = "wasm", target_os = "unknown"))]
176        assert_eq!(0, db.limit(Limit::SQLITE_LIMIT_WORKER_THREADS)?);
177
178        assert!(db
179            .set_limit(Limit::SQLITE_LIMIT_WORKER_THREADS, -1)
180            .is_err());
181        assert!(db.set_limit(Limit::INVALID, 0).is_err());
182        assert!(db.limit(Limit::INVALID).is_err());
183        Ok(())
184    }
185}
rusqlite/limits.rs

rusqlite/
limits.rs
