rusqlite/src/limits.rs
2022-10-08 18:45:51 +02:00

164 lines
6.2 KiB
Rust

//! Run-Time Limits
use crate::{ffi, Connection};
use std::os::raw::c_int;
/// Run-Time limit categories, for use with [`Connection::limit`] and
/// [`Connection::set_limit`].
///
/// See the official documentation for more information:
/// - <https://www.sqlite.org/c3ref/c_limit_attached.html>
/// - <https://www.sqlite.org/limits.html>
#[repr(i32)]
#[non_exhaustive]
#[allow(clippy::upper_case_acronyms, non_camel_case_types)]
#[cfg_attr(docsrs, doc(cfg(feature = "limits")))]
pub enum Limit {
/// The maximum size of any string or BLOB or table row, in bytes.
SQLITE_LIMIT_LENGTH = ffi::SQLITE_LIMIT_LENGTH,
/// The maximum length of an SQL statement, in bytes.
SQLITE_LIMIT_SQL_LENGTH = ffi::SQLITE_LIMIT_SQL_LENGTH,
/// The maximum number of columns in a table definition or in the result set
/// of a SELECT or the maximum number of columns in an index or in an
/// ORDER BY or GROUP BY clause.
SQLITE_LIMIT_COLUMN = ffi::SQLITE_LIMIT_COLUMN,
/// The maximum depth of the parse tree on any expression.
SQLITE_LIMIT_EXPR_DEPTH = ffi::SQLITE_LIMIT_EXPR_DEPTH,
/// The maximum number of terms in a compound SELECT statement.
SQLITE_LIMIT_COMPOUND_SELECT = ffi::SQLITE_LIMIT_COMPOUND_SELECT,
/// The maximum number of instructions in a virtual machine program used to
/// implement an SQL statement.
SQLITE_LIMIT_VDBE_OP = ffi::SQLITE_LIMIT_VDBE_OP,
/// The maximum number of arguments on a function.
SQLITE_LIMIT_FUNCTION_ARG = ffi::SQLITE_LIMIT_FUNCTION_ARG,
/// The maximum number of attached databases.
SQLITE_LIMIT_ATTACHED = ffi::SQLITE_LIMIT_ATTACHED,
/// The maximum length of the pattern argument to the LIKE or GLOB
/// operators.
SQLITE_LIMIT_LIKE_PATTERN_LENGTH = ffi::SQLITE_LIMIT_LIKE_PATTERN_LENGTH,
/// The maximum index number of any parameter in an SQL statement.
SQLITE_LIMIT_VARIABLE_NUMBER = ffi::SQLITE_LIMIT_VARIABLE_NUMBER,
/// The maximum depth of recursion for triggers.
SQLITE_LIMIT_TRIGGER_DEPTH = ffi::SQLITE_LIMIT_TRIGGER_DEPTH,
/// The maximum number of auxiliary worker threads that a single prepared
/// statement may start.
SQLITE_LIMIT_WORKER_THREADS = ffi::SQLITE_LIMIT_WORKER_THREADS,
}
impl Connection {
/// Returns the current value of a [`Limit`].
#[inline]
#[cfg_attr(docsrs, doc(cfg(feature = "limits")))]
pub fn limit(&self, limit: Limit) -> i32 {
let c = self.db.borrow();
unsafe { ffi::sqlite3_limit(c.db(), limit as c_int, -1) }
}
/// Changes the [`Limit`] to `new_val`, returning the prior
/// value of the limit.
#[inline]
#[cfg_attr(docsrs, doc(cfg(feature = "limits")))]
pub fn set_limit(&self, limit: Limit, new_val: i32) -> i32 {
let c = self.db.borrow_mut();
unsafe { ffi::sqlite3_limit(c.db(), limit as c_int, new_val) }
}
}
#[cfg(test)]
mod test {
use super::*;
use crate::{Connection, Result};
#[test]
fn test_limit_values() {
assert_eq!(Limit::SQLITE_LIMIT_LENGTH as i32, ffi::SQLITE_LIMIT_LENGTH,);
assert_eq!(
Limit::SQLITE_LIMIT_SQL_LENGTH as i32,
ffi::SQLITE_LIMIT_SQL_LENGTH,
);
assert_eq!(Limit::SQLITE_LIMIT_COLUMN as i32, ffi::SQLITE_LIMIT_COLUMN,);
assert_eq!(
Limit::SQLITE_LIMIT_EXPR_DEPTH as i32,
ffi::SQLITE_LIMIT_EXPR_DEPTH,
);
assert_eq!(
Limit::SQLITE_LIMIT_COMPOUND_SELECT as i32,
ffi::SQLITE_LIMIT_COMPOUND_SELECT,
);
assert_eq!(
Limit::SQLITE_LIMIT_VDBE_OP as i32,
ffi::SQLITE_LIMIT_VDBE_OP,
);
assert_eq!(
Limit::SQLITE_LIMIT_FUNCTION_ARG as i32,
ffi::SQLITE_LIMIT_FUNCTION_ARG,
);
assert_eq!(
Limit::SQLITE_LIMIT_ATTACHED as i32,
ffi::SQLITE_LIMIT_ATTACHED,
);
assert_eq!(
Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH as i32,
ffi::SQLITE_LIMIT_LIKE_PATTERN_LENGTH,
);
assert_eq!(
Limit::SQLITE_LIMIT_VARIABLE_NUMBER as i32,
ffi::SQLITE_LIMIT_VARIABLE_NUMBER,
);
#[cfg(feature = "bundled")]
assert_eq!(
Limit::SQLITE_LIMIT_TRIGGER_DEPTH as i32,
ffi::SQLITE_LIMIT_TRIGGER_DEPTH,
);
#[cfg(feature = "bundled")]
assert_eq!(
Limit::SQLITE_LIMIT_WORKER_THREADS as i32,
ffi::SQLITE_LIMIT_WORKER_THREADS,
);
}
#[test]
fn test_limit() -> Result<()> {
let db = Connection::open_in_memory()?;
db.set_limit(Limit::SQLITE_LIMIT_LENGTH, 1024);
assert_eq!(1024, db.limit(Limit::SQLITE_LIMIT_LENGTH));
db.set_limit(Limit::SQLITE_LIMIT_SQL_LENGTH, 1024);
assert_eq!(1024, db.limit(Limit::SQLITE_LIMIT_SQL_LENGTH));
db.set_limit(Limit::SQLITE_LIMIT_COLUMN, 64);
assert_eq!(64, db.limit(Limit::SQLITE_LIMIT_COLUMN));
db.set_limit(Limit::SQLITE_LIMIT_EXPR_DEPTH, 256);
assert_eq!(256, db.limit(Limit::SQLITE_LIMIT_EXPR_DEPTH));
db.set_limit(Limit::SQLITE_LIMIT_COMPOUND_SELECT, 32);
assert_eq!(32, db.limit(Limit::SQLITE_LIMIT_COMPOUND_SELECT));
db.set_limit(Limit::SQLITE_LIMIT_FUNCTION_ARG, 32);
assert_eq!(32, db.limit(Limit::SQLITE_LIMIT_FUNCTION_ARG));
db.set_limit(Limit::SQLITE_LIMIT_ATTACHED, 2);
assert_eq!(2, db.limit(Limit::SQLITE_LIMIT_ATTACHED));
db.set_limit(Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH, 128);
assert_eq!(128, db.limit(Limit::SQLITE_LIMIT_LIKE_PATTERN_LENGTH));
db.set_limit(Limit::SQLITE_LIMIT_VARIABLE_NUMBER, 99);
assert_eq!(99, db.limit(Limit::SQLITE_LIMIT_VARIABLE_NUMBER));
// SQLITE_LIMIT_TRIGGER_DEPTH was added in SQLite 3.6.18.
if crate::version_number() >= 3_006_018 {
db.set_limit(Limit::SQLITE_LIMIT_TRIGGER_DEPTH, 32);
assert_eq!(32, db.limit(Limit::SQLITE_LIMIT_TRIGGER_DEPTH));
}
// SQLITE_LIMIT_WORKER_THREADS was added in SQLite 3.8.7.
if crate::version_number() >= 3_008_007 {
db.set_limit(Limit::SQLITE_LIMIT_WORKER_THREADS, 2);
assert_eq!(2, db.limit(Limit::SQLITE_LIMIT_WORKER_THREADS));
}
Ok(())
}
}