rusqlite/
limits.rs

1//! Run-Time Limits
2
3use crate::{ffi, Connection};
4use std::os::raw::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#[repr(i32)]
13#[non_exhaustive]
14#[allow(clippy::upper_case_acronyms, non_camel_case_types)]
15#[cfg_attr(docsrs, doc(cfg(feature = "limits")))]
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 = 10,
43    /// The maximum number of auxiliary worker threads that a single prepared
44    /// statement may start.
45    SQLITE_LIMIT_WORKER_THREADS = 11,
46}
47
48impl Connection {
49    /// Returns the current value of a [`Limit`].
50    #[inline]
51    #[cfg_attr(docsrs, doc(cfg(feature = "limits")))]
52    pub fn limit(&self, limit: Limit) -> i32 {
53        let c = self.db.borrow();
54        unsafe { ffi::sqlite3_limit(c.db(), limit as c_int, -1) }
55    }
56
57    /// Changes the [`Limit`] to `new_val`, returning the prior
58    /// value of the limit.
59    #[inline]
60    #[cfg_attr(docsrs, doc(cfg(feature = "limits")))]
61    pub fn set_limit(&self, limit: Limit, new_val: i32) -> i32 {
62        let c = self.db.borrow_mut();
63        unsafe { ffi::sqlite3_limit(c.db(), limit as c_int, new_val) }
64    }
65}
66
67#[cfg(test)]
68mod test {
69    use super::*;
70    use crate::{Connection, Result};
71
72    #[test]
73    fn test_limit_values() {
74        assert_eq!(
75            Limit::SQLITE_LIMIT_LENGTH as i32,
76            ffi::SQLITE_LIMIT_LENGTH as i32,
77        );
78        assert_eq!(
79            Limit::SQLITE_LIMIT_SQL_LENGTH as i32,
80            ffi::SQLITE_LIMIT_SQL_LENGTH as i32,
81        );
82        assert_eq!(
83            Limit::SQLITE_LIMIT_COLUMN as i32,
84            ffi::SQLITE_LIMIT_COLUMN as i32,
85        );
86        assert_eq!(
87            Limit::SQLITE_LIMIT_EXPR_DEPTH as i32,
88            ffi::SQLITE_LIMIT_EXPR_DEPTH as i32,
89        );
90        assert_eq!(
91            Limit::SQLITE_LIMIT_COMPOUND_SELECT as i32,
92            ffi::SQLITE_LIMIT_COMPOUND_SELECT as i32,
93        );
94        assert_eq!(
95            Limit::SQLITE_LIMIT_VDBE_OP as i32,
96            ffi::SQLITE_LIMIT_VDBE_OP as i32,
97        );
98        assert_eq!(
99            Limit::SQLITE_LIMIT_FUNCTION_ARG as i32,
100            ffi::SQLITE_LIMIT_FUNCTION_ARG as i32,
101        );
102        assert_eq!(
103            Limit::SQLITE_LIMIT_ATTACHED as i32,
104            ffi::SQLITE_LIMIT_ATTACHED as i32,
105        );
106        assert_eq!(
107            Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH as i32,
108            ffi::SQLITE_LIMIT_LIKE_PATTERN_LENGTH as i32,
109        );
110        assert_eq!(
111            Limit::SQLITE_LIMIT_VARIABLE_NUMBER as i32,
112            ffi::SQLITE_LIMIT_VARIABLE_NUMBER as i32,
113        );
114        #[cfg(feature = "bundled")]
115        assert_eq!(
116            Limit::SQLITE_LIMIT_TRIGGER_DEPTH as i32,
117            ffi::SQLITE_LIMIT_TRIGGER_DEPTH as i32,
118        );
119        #[cfg(feature = "bundled")]
120        assert_eq!(
121            Limit::SQLITE_LIMIT_WORKER_THREADS as i32,
122            ffi::SQLITE_LIMIT_WORKER_THREADS as i32,
123        );
124    }
125
126    #[test]
127    fn test_limit() -> Result<()> {
128        let db = Connection::open_in_memory()?;
129        db.set_limit(Limit::SQLITE_LIMIT_LENGTH, 1024);
130        assert_eq!(1024, db.limit(Limit::SQLITE_LIMIT_LENGTH));
131
132        db.set_limit(Limit::SQLITE_LIMIT_SQL_LENGTH, 1024);
133        assert_eq!(1024, db.limit(Limit::SQLITE_LIMIT_SQL_LENGTH));
134
135        db.set_limit(Limit::SQLITE_LIMIT_COLUMN, 64);
136        assert_eq!(64, db.limit(Limit::SQLITE_LIMIT_COLUMN));
137
138        db.set_limit(Limit::SQLITE_LIMIT_EXPR_DEPTH, 256);
139        assert_eq!(256, db.limit(Limit::SQLITE_LIMIT_EXPR_DEPTH));
140
141        db.set_limit(Limit::SQLITE_LIMIT_COMPOUND_SELECT, 32);
142        assert_eq!(32, db.limit(Limit::SQLITE_LIMIT_COMPOUND_SELECT));
143
144        db.set_limit(Limit::SQLITE_LIMIT_FUNCTION_ARG, 32);
145        assert_eq!(32, db.limit(Limit::SQLITE_LIMIT_FUNCTION_ARG));
146
147        db.set_limit(Limit::SQLITE_LIMIT_ATTACHED, 2);
148        assert_eq!(2, db.limit(Limit::SQLITE_LIMIT_ATTACHED));
149
150        db.set_limit(Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH, 128);
151        assert_eq!(128, db.limit(Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH));
152
153        db.set_limit(Limit::SQLITE_LIMIT_VARIABLE_NUMBER, 99);
154        assert_eq!(99, db.limit(Limit::SQLITE_LIMIT_VARIABLE_NUMBER));
155
156        // SQLITE_LIMIT_TRIGGER_DEPTH was added in SQLite 3.6.18.
157        if crate::version_number() >= 3_006_018 {
158            db.set_limit(Limit::SQLITE_LIMIT_TRIGGER_DEPTH, 32);
159            assert_eq!(32, db.limit(Limit::SQLITE_LIMIT_TRIGGER_DEPTH));
160        }
161
162        // SQLITE_LIMIT_WORKER_THREADS was added in SQLite 3.8.7.
163        if crate::version_number() >= 3_008_007 {
164            db.set_limit(Limit::SQLITE_LIMIT_WORKER_THREADS, 2);
165            assert_eq!(2, db.limit(Limit::SQLITE_LIMIT_WORKER_THREADS));
166        }
167        Ok(())
168    }
169}
rusqlite/limits.rs

rusqlite/
limits.rs
