Implementation of sqlite3_update_hook #260

First draft (no tested and a memory leak)

.travis.yml

@@ -30,13 +30,14 @@ script:
   - cargo test --features backup
   - cargo test --features blob
   - cargo test --features functions
+  - cargo test --features hooks
   - cargo test --features limits
   - cargo test --features load_extension
   - cargo test --features trace
   - cargo test --features chrono
   - cargo test --features serde_json
   - cargo test --features bundled
-  - cargo test --features "backup blob chrono functions limits load_extension serde_json trace"
+  - cargo test --features "backup blob chrono functions hooks limits load_extension serde_json trace"
-  - cargo test --features "backup blob chrono functions limits load_extension serde_json trace buildtime_bindgen"
+  - cargo test --features "backup blob chrono functions hooks limits load_extension serde_json trace buildtime_bindgen"
-  - cargo test --features "backup blob chrono functions limits load_extension serde_json trace bundled"
+  - cargo test --features "backup blob chrono functions hooks limits load_extension serde_json trace bundled"
-  - cargo test --features "backup blob chrono functions limits load_extension serde_json trace bundled buildtime_bindgen"
+  - cargo test --features "backup blob chrono functions hooks limits load_extension serde_json trace bundled buildtime_bindgen"

Cargo.toml

@@ -26,6 +26,7 @@ trace = ["libsqlite3-sys/min_sqlite_version_3_6_23"]
 bundled = ["libsqlite3-sys/bundled"]
 buildtime_bindgen = ["libsqlite3-sys/buildtime_bindgen"]
 limits = []
+hooks = []
 
 [dependencies]
 time = "0.1.0"

appveyor.yml

@@ -20,10 +20,10 @@ build: false
 test_script:
   - cargo test --lib --verbose
   - cargo test --lib --verbose --features bundled
-  - cargo test --lib --features "backup blob chrono functions limits load_extension serde_json trace"
+  - cargo test --lib --features "backup blob chrono functions hooks limits load_extension serde_json trace"
-  - cargo test --lib --features "backup blob chrono functions limits load_extension serde_json trace buildtime_bindgen"
+  - cargo test --lib --features "backup blob chrono functions hooks limits load_extension serde_json trace buildtime_bindgen"
-  - cargo test --lib --features "backup blob chrono functions limits load_extension serde_json trace bundled"
+  - cargo test --lib --features "backup blob chrono functions hooks limits load_extension serde_json trace bundled"
-  - cargo test --lib --features "backup blob chrono functions limits load_extension serde_json trace bundled buildtime_bindgen"
+  - cargo test --lib --features "backup blob chrono functions hooks limits load_extension serde_json trace bundled buildtime_bindgen"
 
 cache:
   - C:\Users\appveyor\.cargo

src/hooks.rs

@@ -0,0 +1,158 @@
+//! Data Change Notification Callbacks
+#![allow(non_camel_case_types)]
+
+use std::mem;
+use std::ptr;
+use std::os::raw::{c_int, c_char, c_void};
+
+use ffi;
+
+use {Connection, InnerConnection};
+
+// Commit And Rollback Notification Callbacks
+// http://sqlite.org/c3ref/commit_hook.html
+/*
+void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
+void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
+*/
+
+/// Authorizer Action Codes
+pub enum Action {
+    UNKNOWN = -1,
+    SQLITE_CREATE_INDEX = ffi::SQLITE_CREATE_INDEX as isize,
+    SQLITE_CREATE_TABLE = ffi::SQLITE_CREATE_TABLE as isize,
+    SQLITE_CREATE_TEMP_INDEX = ffi::SQLITE_CREATE_TEMP_INDEX as isize,
+    SQLITE_CREATE_TEMP_TABLE = ffi::SQLITE_CREATE_TEMP_TABLE as isize,
+    SQLITE_CREATE_TEMP_TRIGGER = ffi::SQLITE_CREATE_TEMP_TRIGGER as isize,
+    SQLITE_CREATE_TEMP_VIEW = ffi::SQLITE_CREATE_TEMP_VIEW as isize,
+    SQLITE_CREATE_TRIGGER = ffi::SQLITE_CREATE_TRIGGER as isize,
+    SQLITE_CREATE_VIEW = ffi::SQLITE_CREATE_VIEW as isize,
+    SQLITE_DELETE = ffi::SQLITE_DELETE as isize,
+    SQLITE_DROP_INDEX = ffi::SQLITE_DROP_INDEX as isize,
+    SQLITE_DROP_TABLE = ffi::SQLITE_DROP_TABLE as isize,
+    SQLITE_DROP_TEMP_INDEX = ffi::SQLITE_DROP_TEMP_INDEX as isize,
+    SQLITE_DROP_TEMP_TABLE = ffi::SQLITE_DROP_TEMP_TABLE as isize,
+    SQLITE_DROP_TEMP_TRIGGER = ffi::SQLITE_DROP_TEMP_TRIGGER as isize,
+    SQLITE_DROP_TEMP_VIEW = ffi::SQLITE_DROP_TEMP_VIEW as isize,
+    SQLITE_DROP_TRIGGER = ffi::SQLITE_DROP_TRIGGER as isize,
+    SQLITE_DROP_VIEW = ffi::SQLITE_DROP_VIEW as isize,
+    SQLITE_INSERT = ffi::SQLITE_INSERT as isize,
+    SQLITE_PRAGMA = ffi::SQLITE_PRAGMA as isize,
+    SQLITE_READ = ffi::SQLITE_READ as isize,
+    SQLITE_SELECT = ffi::SQLITE_SELECT as isize,
+    SQLITE_TRANSACTION = ffi::SQLITE_TRANSACTION as isize,
+    SQLITE_UPDATE = ffi::SQLITE_UPDATE as isize,
+    SQLITE_ATTACH = ffi::SQLITE_ATTACH as isize,
+    SQLITE_DETACH = ffi::SQLITE_DETACH as isize,
+    SQLITE_ALTER_TABLE = ffi::SQLITE_ALTER_TABLE as isize,
+    SQLITE_REINDEX = ffi::SQLITE_REINDEX as isize,
+    SQLITE_ANALYZE = ffi::SQLITE_ANALYZE as isize,
+    SQLITE_CREATE_VTABLE = ffi::SQLITE_CREATE_VTABLE as isize,
+    SQLITE_DROP_VTABLE = ffi::SQLITE_DROP_VTABLE as isize,
+    SQLITE_FUNCTION = ffi::SQLITE_FUNCTION as isize,
+    SQLITE_SAVEPOINT = ffi::SQLITE_SAVEPOINT as isize,
+    SQLITE_COPY = ffi::SQLITE_COPY as isize,
+    SQLITE_RECURSIVE = ffi::SQLITE_RECURSIVE as isize,
+}
+
+impl From<i32> for Action {
+    fn from(code: i32) -> Action {
+        match code {
+            ffi::SQLITE_CREATE_INDEX => Action::SQLITE_CREATE_INDEX,
+            ffi::SQLITE_CREATE_TABLE => Action::SQLITE_CREATE_TABLE,
+            ffi::SQLITE_CREATE_TEMP_INDEX => Action::SQLITE_CREATE_TEMP_INDEX,
+            ffi::SQLITE_CREATE_TEMP_TABLE => Action::SQLITE_CREATE_TEMP_TABLE,
+            ffi::SQLITE_CREATE_TEMP_TRIGGER => Action::SQLITE_CREATE_TEMP_TRIGGER,
+            ffi::SQLITE_CREATE_TEMP_VIEW => Action::SQLITE_CREATE_TEMP_VIEW,
+            ffi::SQLITE_CREATE_TRIGGER => Action::SQLITE_CREATE_TRIGGER,
+            ffi::SQLITE_CREATE_VIEW => Action::SQLITE_CREATE_VIEW,
+            ffi::SQLITE_DELETE => Action::SQLITE_DELETE,
+            ffi::SQLITE_DROP_INDEX => Action::SQLITE_DROP_INDEX,
+            ffi::SQLITE_DROP_TABLE => Action::SQLITE_DROP_TABLE,
+            ffi::SQLITE_DROP_TEMP_INDEX => Action::SQLITE_DROP_TEMP_INDEX,
+            ffi::SQLITE_DROP_TEMP_TABLE => Action::SQLITE_DROP_TEMP_TABLE,
+            ffi::SQLITE_DROP_TEMP_TRIGGER => Action::SQLITE_DROP_TEMP_TRIGGER,
+            ffi::SQLITE_DROP_TEMP_VIEW => Action::SQLITE_DROP_TEMP_VIEW,
+            ffi::SQLITE_DROP_TRIGGER => Action::SQLITE_DROP_TRIGGER,
+            ffi::SQLITE_DROP_VIEW => Action::SQLITE_DROP_VIEW,
+            ffi::SQLITE_INSERT => Action::SQLITE_INSERT,
+            ffi::SQLITE_PRAGMA => Action::SQLITE_PRAGMA,
+            ffi::SQLITE_READ => Action::SQLITE_READ,
+            ffi::SQLITE_SELECT => Action::SQLITE_SELECT,
+            ffi::SQLITE_TRANSACTION => Action::SQLITE_TRANSACTION,
+            ffi::SQLITE_UPDATE => Action::SQLITE_UPDATE,
+            ffi::SQLITE_ATTACH => Action::SQLITE_ATTACH,
+            ffi::SQLITE_DETACH => Action::SQLITE_DETACH,
+            ffi::SQLITE_ALTER_TABLE => Action::SQLITE_ALTER_TABLE,
+            ffi::SQLITE_REINDEX => Action::SQLITE_REINDEX,
+            ffi::SQLITE_ANALYZE => Action::SQLITE_ANALYZE,
+            ffi::SQLITE_CREATE_VTABLE => Action::SQLITE_CREATE_VTABLE,
+            ffi::SQLITE_DROP_VTABLE => Action::SQLITE_DROP_VTABLE,
+            ffi::SQLITE_FUNCTION => Action::SQLITE_FUNCTION,
+            ffi::SQLITE_SAVEPOINT => Action::SQLITE_SAVEPOINT,
+            ffi::SQLITE_COPY => Action::SQLITE_COPY,
+            ffi::SQLITE_RECURSIVE => Action::SQLITE_RECURSIVE,
+            _ => Action::UNKNOWN,
+        }
+    }
+}
+
+impl Connection {
+    pub fn update_hook<F>(&self, hook: Option<F>)
+        where F: FnMut(Action, &str, &str, i64)
+    {
+        self.db.borrow_mut().update_hook(hook);
+    }
+}
+
+impl InnerConnection {
+    // TODO self.update_hook(None) must be called in InnerConnection#close to free any hook
+    fn update_hook<F>(&mut self, hook: Option<F>)
+        where F: FnMut(Action, &str, &str, i64)
+    {
+        unsafe extern "C" fn call_boxed_closure<F>(p_arg: *mut c_void,
+                                                   action_code: c_int,
+                                                   db_str: *const c_char,
+                                                   tbl_str: *const c_char,
+                                                   row_id: i64)
+            where F: FnMut(Action, &str, &str, i64)
+        {
+            use std::ffi::CStr;
+            use std::str;
+
+            let boxed_hook: *mut F = mem::transmute(p_arg);
+            assert!(!boxed_hook.is_null(),
+                    "Internal error - null function pointer");
+
+            let action = Action::from(action_code);
+            let db_name = {
+                let c_slice = CStr::from_ptr(db_str).to_bytes();
+                str::from_utf8_unchecked(c_slice)
+            };
+            let tbl_name = {
+                let c_slice = CStr::from_ptr(tbl_str).to_bytes();
+                str::from_utf8_unchecked(c_slice)
+            };
+
+            (*boxed_hook)(action, db_name, tbl_name, row_id);
+        }
+
+        let previous_hook = if let Some(hook) = hook {
+            let boxed_hook: *mut F = Box::into_raw(Box::new(hook));
+            unsafe {
+                ffi::sqlite3_update_hook(self.db(),
+                                         Some(call_boxed_closure::<F>),
+                                         mem::transmute(boxed_hook))
+            }
+        } 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 ?
+        if !previous_hook.is_null() {
+            // free_boxed_value
+            unsafe {
+                let _: Box<F> = Box::from_raw(mem::transmute(previous_hook));
+            }
+        }
+    }
+}

src/lib.rs

@@ -121,6 +121,8 @@ pub mod functions;
 pub mod blob;
 #[cfg(feature = "limits")]
 pub mod limits;
+#[cfg(feature = "hooks")]
+pub mod hooks;
 
 // Number of cached prepared statements we'll hold on to.
 const STATEMENT_CACHE_DEFAULT_CAPACITY: usize = 16;