Merge pull request #368 from napi-rs/reference

feat(napi): implement create_reference/get_reference_value

napi/src/env.rs

@@ -637,6 +637,53 @@ impl Env {
     }
   }
 
+  #[inline]
+  /// This API create a new reference with the specified reference count to the Object passed in.
+  pub fn create_reference<T>(&self, value: T) -> Result<Ref<()>>
+  where
+    T: NapiValue,
+  {
+    let mut raw_ref = ptr::null_mut();
+    let initial_ref_count = 1;
+    check_status!(unsafe {
+      sys::napi_create_reference(self.0, value.raw(), initial_ref_count, &mut raw_ref)
+    })?;
+    Ok(Ref {
+      raw_ref,
+      count: 1,
+      inner: (),
+    })
+  }
+
+  #[inline]
+  /// Get reference value from `Ref` with type check
+  /// Return error if the type of `reference` provided is mismatched with `T`
+  pub fn get_reference_value<T>(&self, reference: &Ref<()>) -> Result<T>
+  where
+    T: NapiValue,
+  {
+    let mut js_value = ptr::null_mut();
+    check_status!(unsafe {
+      sys::napi_get_reference_value(self.0, reference.raw_ref, &mut js_value)
+    })?;
+    unsafe { T::from_raw(self.0, js_value) }
+  }
+
+  #[inline]
+  /// Get reference value from `Ref` without type check
+  /// Using this API if you are sure the type of `T` is matched with provided `Ref<()>`.
+  /// If type mismatched, calling `T::method` would return `Err`.
+  pub fn get_reference_value_unchecked<T>(&self, reference: &Ref<()>) -> Result<T>
+  where
+    T: NapiValue,
+  {
+    let mut js_value = ptr::null_mut();
+    check_status!(unsafe {
+      sys::napi_get_reference_value(self.0, reference.raw_ref, &mut js_value)
+    })?;
+    Ok(unsafe { T::from_raw_unchecked(self.0, js_value) })
+  }
+
   #[inline]
   pub fn create_external<T: 'static>(&self, native_object: T) -> Result<JsExternal> {
     let mut object_value = ptr::null_mut();

napi/src/js_values/mod.rs

@@ -55,7 +55,7 @@ pub use string::*;
 pub(crate) use tagged_object::TaggedObject;
 pub use undefined::JsUndefined;
 pub(crate) use value::Value;
-pub use value_ref::Ref;
+pub use value_ref::*;
 pub use value_type::ValueType;
 
 // Value types

napi/src/js_values/value_ref.rs

@@ -6,8 +6,8 @@ use crate::{sys, Env, Result};
 
 pub struct Ref<T> {
   pub(crate) raw_ref: sys::napi_ref,
-  count: u32,
+  pub(crate) count: u32,
-  inner: T,
+  pub(crate) inner: T,
 }
 
 unsafe impl<T> Send for Ref<T> {}

test_module/__test__/napi4/threadsafe_function.spec.ts

@@ -12,7 +12,7 @@ test('should get js function called from a thread', async (t) => {
     return
   }
 
-  await new Promise((resolve, reject) => {
+  await new Promise<void>((resolve, reject) => {
     bindings.testThreadsafeFunction((...args: any[]) => {
       called += 1
       try {
@@ -55,3 +55,20 @@ test('should return Closing while calling aborted tsfn', (t) => {
   }
   t.notThrows(() => bindings.testCallAbortedThreadsafeFunction(() => {}))
 })
+
+test('should work with napi ref', (t) => {
+  if (napiVersion < 4) {
+    t.is(bindings.testTsfnWithRef, undefined)
+  } else {
+    const obj = {
+      foo: Symbol(),
+    }
+    return new Promise<void>((resolve) => {
+      bindings.testTsfnWithRef((err: Error | null, returnObj: any) => {
+        t.is(err, null)
+        t.is(obj, returnObj)
+        resolve()
+      }, obj)
+    })
+  }
+})

test_module/src/napi4/mod.rs

@@ -20,5 +20,6 @@ pub fn register_js(exports: &mut JsObject) -> Result<()> {
     "testCallAbortedThreadsafeFunction",
     test_call_aborted_threadsafe_function,
   )?;
+  exports.create_named_method("testTsfnWithRef", test_tsfn_with_ref)?;
   Ok(())
 }

test_module/src/napi4/tsfn.rs

@@ -3,7 +3,8 @@ use std::thread;
 
 use napi::{
   threadsafe_function::{ThreadSafeCallContext, ThreadsafeFunctionCallMode},
-  CallContext, Error, JsBoolean, JsFunction, JsNumber, JsString, JsUndefined, Result, Status,
+  CallContext, Error, JsBoolean, JsFunction, JsNumber, JsObject, JsString, JsUndefined, Ref,
+  Result, Status,
 };
 use tokio;
 
@@ -148,3 +149,25 @@ pub fn test_tokio_readfile(ctx: CallContext) -> Result<JsUndefined> {
 
   ctx.env.get_undefined()
 }
+
+#[js_function(2)]
+pub fn test_tsfn_with_ref(ctx: CallContext) -> Result<JsUndefined> {
+  let callback = ctx.get::<JsFunction>(0)?;
+  let options = ctx.get::<JsObject>(1)?;
+  let options_ref = ctx.env.create_reference(options)?;
+  let tsfn =
+    ctx
+      .env
+      .create_threadsafe_function(&callback, 0, |ctx: ThreadSafeCallContext<Ref<()>>| {
+        ctx
+          .env
+          .get_reference_value_unchecked::<JsObject>(&ctx.value)
+          .and_then(|obj| ctx.value.unref(ctx.env).map(|_| vec![obj]))
+      })?;
+
+  thread::spawn(move || {
+    tsfn.call(Ok(options_ref), ThreadsafeFunctionCallMode::Blocking);
+  });
+
+  ctx.env.get_undefined()
+}