feat(isolate): expose get/set_data (denoland#911)

Co-authored-by: Bartek Iwańczuk <[email protected]>

src/isolate.rs

@@ -451,22 +451,25 @@ impl Isolate {
 
  /// Associate embedder-specific data with the isolate. `slot` has to be
  /// between 0 and `Isolate::get_number_of_data_slots()`.
+ ///
+ /// 0-indexed slot is used internally by rusty_v8, so users have 3 slots
+ /// left to use.
  #[inline(always)]
- unsafe fn set_data(&mut self, slot: u32, ptr: *mut c_void) {
+ pub unsafe fn set_data(&mut self, slot: u32, ptr: *mut c_void) {
+ assert!(slot < 4);
  v8__Isolate__SetData(self, slot + Self::INTERNAL_SLOT_COUNT, ptr)
  }
 
  /// Retrieve embedder-specific data from the isolate.
  /// Returns NULL if SetData has never been called for the given `slot`.
- #[allow(dead_code)]
- fn get_data(&self, slot: u32) -> *mut c_void {
+ pub fn get_data(&self, slot: u32) -> *mut c_void {
+  assert!(slot < 4);
  unsafe { v8__Isolate__GetData(self, slot + Self::INTERNAL_SLOT_COUNT) }
  }
 
  /// Returns the maximum number of available embedder data slots. Valid slots
  /// are in the range of 0 - `Isolate::get_number_of_data_slots() - 1`.
- #[allow(dead_code)]
- fn get_number_of_data_slots(&self) -> u32 {
+ pub fn get_number_of_data_slots(&self) -> u32 {
  unsafe {
  v8__Isolate__GetNumberOfDataSlots(self) - Self::INTERNAL_SLOT_COUNT
  }

tests/test_api.rs

@@ -7487,6 +7487,60 @@ fn finalizer_on_kept_global() {
  drop(global);
 }
 
+#[test]
+fn isolate_data_fields() {
+ let _setup_guard = setup();
+
+ let mut isolate = v8::Isolate::new(Default::default());
+
+ struct SomeData {
+ foo: &'static str,
+ bar: &'static str,
+ fizz: &'static str,
+ }
+
+ let some_data1 = Box::new(SomeData {
+ foo: "foo",
+ bar: "",
+ fizz: "",
+ });
+ let some_data2 = Box::new(SomeData {
+ foo: "",
+ bar: "bar",
+ fizz: "",
+ });
+ let some_data3 = Box::new(SomeData {
+ foo: "",
+ bar: "",
+ fizz: "fizz",
+ });
+ unsafe {
+ isolate.set_data(1, Box::into_raw(some_data1) as *mut _ as *mut c_void);
+ isolate.set_data(2, Box::into_raw(some_data2) as *mut _ as *mut c_void);
+ isolate.set_data(3, Box::into_raw(some_data3) as *mut _ as *mut c_void);
+ }
+
+ {
+ let data_some_data1 = isolate.get_data(1) as *mut SomeData;
+ let data_some_data1 = unsafe { &mut *data_some_data1 };
+ assert_eq!(data_some_data1.foo, "foo");
+ assert_eq!(data_some_data1.bar, "");
+ assert_eq!(data_some_data1.fizz, "");
+
+ let data_some_data2 = isolate.get_data(2) as *mut SomeData;
+ let data_some_data2 = unsafe { &mut *data_some_data2 };
+ assert_eq!(data_some_data2.foo, "");
+ assert_eq!(data_some_data2.bar, "bar");
+ assert_eq!(data_some_data2.fizz, "");
+
+ let data_some_data3 = isolate.get_data(3) as *mut SomeData;
+ let data_some_data3 = unsafe { &mut *data_some_data3 };
+ assert_eq!(data_some_data3.foo, "");
+ assert_eq!(data_some_data3.bar, "");
+ assert_eq!(data_some_data3.fizz, "fizz");
+ }
+}
+
 #[test]
 fn host_create_shadow_realm_context_callback() {
  let _setup_guard = setup();