rusqlite/src/auto_extension.rs
2024-07-17 13:41:16 -04:00

63 lines
2.1 KiB
Rust

//! Automatic extension loading
use super::ffi;
use crate::error::{check, to_sqlite_error};
use crate::{Connection, Error, Result};
use std::os::raw::{c_char, c_int};
use std::panic::catch_unwind;
/// Automatic extension initialization routine
pub type AutoExtension = fn(Connection) -> Result<()>;
/// Raw automatic extension initialization routine
pub type RawAutoExtension = unsafe extern "C" fn(
db: *mut ffi::sqlite3,
pz_err_msg: *mut *mut c_char,
_: *const ffi::sqlite3_api_routines,
) -> c_int;
/// Bridge between `RawAutoExtension` and `AutoExtension`
///
/// # Safety
/// * Opening a database from an auto-extension handler will lead to
/// an endless recursion of the auto-handler triggering itself
/// indirectly for each newly-opened database.
/// * Results are undefined if the given db is closed by an auto-extension.
/// * The list of auto-extensions should not be manipulated from an auto-extension.
pub unsafe fn init_auto_extension(
db: *mut ffi::sqlite3,
pz_err_msg: *mut *mut c_char,
ax: AutoExtension,
) -> c_int {
let r = catch_unwind(|| {
let c = Connection::from_handle(db);
c.and_then(ax)
})
.unwrap_or_else(|_| Err(Error::UnwindingPanic));
match r {
Err(e) => to_sqlite_error(&e, pz_err_msg),
_ => ffi::SQLITE_OK,
}
}
/// Register au auto-extension
///
/// # Safety
/// * Opening a database from an auto-extension handler will lead to
/// an endless recursion of the auto-handler triggering itself
/// indirectly for each newly-opened database.
/// * Results are undefined if the given db is closed by an auto-extension.
/// * The list of auto-extensions should not be manipulated from an auto-extension.
pub unsafe fn register_auto_extension(ax: RawAutoExtension) -> Result<()> {
check(ffi::sqlite3_auto_extension(Some(ax)))
}
/// Unregister the initialization routine
pub fn cancel_auto_extension(ax: RawAutoExtension) -> bool {
unsafe { ffi::sqlite3_cancel_auto_extension(Some(ax)) == 1 }
}
/// Disable all automatic extensions previously registered
pub fn reset_auto_extension() {
unsafe { ffi::sqlite3_reset_auto_extension() }
}