Fix memory leak and add test

This commit is contained in:
gwenn 2017-04-26 20:12:48 +02:00
parent 6eb98afd67
commit 63a444a95f
2 changed files with 67 additions and 20 deletions

View File

@ -16,7 +16,9 @@ void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*); void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
*/ */
/// Authorizer Action Codes /// Authorizer Action Codes
#[derive(Debug, PartialEq)]
pub enum Action { pub enum Action {
UNKNOWN = -1, UNKNOWN = -1,
SQLITE_CREATE_INDEX = ffi::SQLITE_CREATE_INDEX as isize, SQLITE_CREATE_INDEX = ffi::SQLITE_CREATE_INDEX as isize,
@ -91,23 +93,31 @@ impl From<i32> for Action {
ffi::SQLITE_FUNCTION => Action::SQLITE_FUNCTION, ffi::SQLITE_FUNCTION => Action::SQLITE_FUNCTION,
ffi::SQLITE_SAVEPOINT => Action::SQLITE_SAVEPOINT, ffi::SQLITE_SAVEPOINT => Action::SQLITE_SAVEPOINT,
ffi::SQLITE_COPY => Action::SQLITE_COPY, ffi::SQLITE_COPY => Action::SQLITE_COPY,
ffi::SQLITE_RECURSIVE => Action::SQLITE_RECURSIVE, 33 => Action::SQLITE_RECURSIVE,
_ => Action::UNKNOWN, _ => Action::UNKNOWN,
} }
} }
} }
impl Connection { impl Connection {
pub fn update_hook<F>(&self, hook: Option<F>) /// Register a callback function to be invoked whenever a row is updated, inserted or deleted in a rowid table.
pub fn update_hook<F>(&self, hook: F)
where F: FnMut(Action, &str, &str, i64) where F: FnMut(Action, &str, &str, i64)
{ {
self.db.borrow_mut().update_hook(hook); self.db.borrow_mut().update_hook(hook);
} }
pub fn remove_update_hook(&self) {
self.db.borrow_mut().remove_update_hook();
}
} }
impl InnerConnection { impl InnerConnection {
// TODO self.update_hook(None) must be called in InnerConnection#close to free any hook pub fn remove_hooks(&mut self) {
fn update_hook<F>(&mut self, hook: Option<F>) self.remove_update_hook();
}
fn update_hook<F>(&mut self, hook: F)
where F: FnMut(Action, &str, &str, i64) where F: FnMut(Action, &str, &str, i64)
{ {
unsafe extern "C" fn call_boxed_closure<F>(p_arg: *mut c_void, unsafe extern "C" fn call_boxed_closure<F>(p_arg: *mut c_void,
@ -120,9 +130,7 @@ impl InnerConnection {
use std::ffi::CStr; use std::ffi::CStr;
use std::str; use std::str;
let boxed_hook: *mut F = mem::transmute(p_arg); let boxed_hook: &mut Box<F> = mem::transmute(p_arg);
assert!(!boxed_hook.is_null(),
"Internal error - null function pointer");
let action = Action::from(action_code); let action = Action::from(action_code);
let db_name = { let db_name = {
@ -134,25 +142,59 @@ impl InnerConnection {
str::from_utf8_unchecked(c_slice) str::from_utf8_unchecked(c_slice)
}; };
(*boxed_hook)(action, db_name, tbl_name, row_id); boxed_hook(action, db_name, tbl_name, row_id);
} }
let previous_hook = if let Some(hook) = hook { let previous_hook = {
let boxed_hook: *mut F = Box::into_raw(Box::new(hook)); let boxed_hook: Box<Box<FnMut(Action, &str, &str, i64)>> = Box::new(Box::new(hook));
unsafe { unsafe {
ffi::sqlite3_update_hook(self.db(), ffi::sqlite3_update_hook(self.db(),
Some(call_boxed_closure::<F>), Some(call_boxed_closure::<F>),
mem::transmute(boxed_hook)) Box::into_raw(boxed_hook) as *mut _)
} }
} else {
unsafe { ffi::sqlite3_update_hook(self.db(), None, ptr::null_mut()) }
}; };
// TODO Validate: what happens if the previous hook has been set from C ? free_boxed_update_hook(previous_hook);
if !previous_hook.is_null() { }
// free_boxed_value
unsafe { fn remove_update_hook(&mut self) {
let _: Box<F> = Box::from_raw(mem::transmute(previous_hook)); let previous_hook = unsafe { ffi::sqlite3_update_hook(self.db(), None, ptr::null_mut()) };
} free_boxed_update_hook(previous_hook);
} }
}
fn free_boxed_update_hook(hook: *mut c_void) {
/*
http://stackoverflow.com/questions/32270030/how-do-i-convert-a-rust-closure-to-a-c-style-callback
Double indirection (i.e. Box<Box<...>>) is necessary
because Box<Fn(..) -> ..> is a trait object and therefore a fat pointer,
incompatible with *mut c_void because of different size.
*/
if !hook.is_null() {
let _: Box<Box<FnMut(Action, &str, &str, i64)>> = unsafe { Box::from_raw(hook as *mut _) };
}
}
#[cfg(test)]
mod test {
use super::Action;
use Connection;
#[test]
fn test_update_hook() {
let db = Connection::open_in_memory().unwrap();
let mut called = false;
db.update_hook(|action, db, tbl, row_id| {
assert_eq!(Action::SQLITE_INSERT, action);
assert_eq!("main", db);
assert_eq!("foo", tbl);
assert_eq!(1, row_id);
called = true;
});
db.execute_batch("CREATE TABLE foo (t TEXT)").unwrap();
db.execute_batch("INSERT INTO foo VALUES ('lisa')")
.unwrap();
assert!(called);
} }
} }

View File

@ -781,6 +781,7 @@ impl InnerConnection {
} }
fn close(&mut self) -> Result<()> { fn close(&mut self) -> Result<()> {
self.remove_hooks();
unsafe { unsafe {
let r = ffi::sqlite3_close(self.db()); let r = ffi::sqlite3_close(self.db());
let r = self.decode_result(r); let r = self.decode_result(r);
@ -857,6 +858,10 @@ impl InnerConnection {
fn changes(&mut self) -> c_int { fn changes(&mut self) -> c_int {
unsafe { ffi::sqlite3_changes(self.db()) } unsafe { ffi::sqlite3_changes(self.db()) }
} }
#[cfg(not(feature = "hooks"))]
fn remove_hooks(&mut self) {
}
} }
impl Drop for InnerConnection { impl Drop for InnerConnection {