Struct napi::Env

source · 
pub struct Env(_);
Expand description

Env is used to represent a context that the underlying N-API implementation can use to persist VM-specific state.

Specifically, the same Env that was passed in when the initial native function was called must be passed to any subsequent nested N-API calls.

Caching the Env for the purpose of general reuse, and passing the Env between instances of the same addon running on different Worker threads is not allowed.

The Env becomes invalid when an instance of a native addon is unloaded.

Notification of this event is delivered through the callbacks given to Env::add_env_cleanup_hook and Env::set_instance_data.

Implementations§

Get JsUndefined value

Examples found in repository?
src/call_context.rs (line 72)
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  pub fn try_get<ArgType: NapiValue + TypeName + FromNapiValue>(
    &self,
    index: usize,
  ) -> Result<Either<ArgType, JsUndefined>> {
    if index >= self.arg_len() {
      Err(Error::new(
        Status::GenericFailure,
        "Arguments index out of range".to_owned(),
      ))
    } else if index < self.length {
      unsafe { ArgType::from_raw(self.env.0, self.args[index]) }.map(Either::A)
    } else {
      self.env.get_undefined().map(Either::B)
    }
  }
More examples
Hide additional examples
src/js_values/function.rs (line 49)
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  pub fn call<V>(&self, this: Option<&JsObject>, args: &[V]) -> Result<JsUnknown>
  where
    V: NapiRaw,
  {
    let raw_this = this
      .map(|v| unsafe { v.raw() })
      .or_else(|| {
        unsafe { Env::from_raw(self.0.env) }
          .get_undefined()
          .ok()
          .map(|u| unsafe { u.raw() })
      })
      .ok_or_else(|| Error::new(Status::GenericFailure, "Get raw this failed".to_owned()))?;
    let raw_args = args
      .iter()
      .map(|arg| unsafe { arg.raw() })
      .collect::<Vec<sys::napi_value>>();
    let mut return_value = ptr::null_mut();
    check_pending_exception!(self.0.env, unsafe {
      sys::napi_call_function(
        self.0.env,
        raw_this,
        self.0.value,
        args.len(),
        raw_args.as_ptr(),
        &mut return_value,
      )
    })?;

    unsafe { JsUnknown::from_raw(self.0.env, return_value) }
  }

  /// [napi_call_function](https://nodejs.org/api/n-api.html#n_api_napi_call_function)
  /// The same with `call`, but without arguments
  pub fn call_without_args(&self, this: Option<&JsObject>) -> Result<JsUnknown> {
    let raw_this = this
      .map(|v| unsafe { v.raw() })
      .or_else(|| {
        unsafe { Env::from_raw(self.0.env) }
          .get_undefined()
          .ok()
          .map(|u| unsafe { u.raw() })
      })
      .ok_or_else(|| Error::new(Status::GenericFailure, "Get raw this failed".to_owned()))?;
    let mut return_value = ptr::null_mut();
    check_pending_exception!(self.0.env, unsafe {
      sys::napi_call_function(
        self.0.env,
        raw_this,
        self.0.value,
        0,
        ptr::null_mut(),
        &mut return_value,
      )
    })?;

    unsafe { JsUnknown::from_raw(self.0.env, return_value) }
  }
Examples found in repository?
src/js_values/ser.rs (line 151)
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  fn serialize_unit(self) -> Result<Self::Ok> {
    self.0.get_null().map(|null| null.0)
  }

  fn serialize_none(self) -> Result<Self::Ok> {
    self.0.get_null().map(|null| null.0)
  }

  fn serialize_str(self, v: &str) -> Result<Self::Ok> {
    self.0.create_string(v).map(|string| string.0)
  }

  fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok>
  where
    T: Serialize,
  {
    value.serialize(self)
  }

  fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
    let env = self.0;
    let key = env.create_string("")?;
    let obj = env.create_object()?;
    Ok(MapSerializer { key, obj })
  }

  fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
    let array = self.0.create_array_with_length(len.unwrap_or(0))?;
    Ok(SeqSerializer {
      current_index: 0,
      array,
    })
  }

  fn serialize_tuple_variant(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
    len: usize,
  ) -> Result<Self::SerializeTupleVariant> {
    let env = self.0;
    let array = env.create_array_with_length(len)?;
    let mut object = env.create_object()?;
    object.set_named_property(
      variant,
      JsObject(Value {
        value: array.0.value,
        env: array.0.env,
        value_type: ValueType::Object,
      }),
    )?;
    Ok(SeqSerializer {
      current_index: 0,
      array,
    })
  }

  fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok> {
    self.0.get_null().map(|null| null.0)
  }
Examples found in repository?
src/env.rs (line 1032)
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  pub fn get_napi_version(&self) -> Result<u32> {
    let global = self.get_global()?;
    let process: JsObject = global.get_named_property("process")?;
    let versions: JsObject = process.get_named_property("versions")?;
    let napi_version: JsString = versions.get_named_property("napi")?;
    napi_version
      .into_utf8()?
      .as_str()?
      .parse()
      .map_err(|e| Error::new(Status::InvalidArg, format!("{}", e)))
  }
Examples found in repository?
src/js_values/ser.rs (line 303)
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  fn serialize_element<T: ?Sized>(&mut self, value: &T) -> StdResult<(), Self::Error>
  where
    T: Serialize,
  {
    let env = unsafe { Env::from_raw(self.array.0.env) };
    self.array.set_element(
      self.current_index as _,
      JsUnknown(value.serialize(Ser::new(&env))?),
    )?;
    self.current_index += 1;
    Ok(())
  }

  fn end(self) -> Result<Self::Ok> {
    Ok(self.array.0)
  }
}

#[doc(hidden)]
impl ser::SerializeTuple for SeqSerializer {
  type Ok = Value;
  type Error = Error;

  fn serialize_element<T: ?Sized>(&mut self, value: &T) -> StdResult<(), Self::Error>
  where
    T: Serialize,
  {
    let env = unsafe { Env::from_raw(self.array.0.env) };
    self.array.set_element(
      self.current_index as _,
      JsUnknown(value.serialize(Ser::new(&env))?),
    )?;
    self.current_index += 1;
    Ok(())
  }

  fn end(self) -> StdResult<Self::Ok, Self::Error> {
    Ok(self.array.0)
  }
}

#[doc(hidden)]
impl ser::SerializeTupleStruct for SeqSerializer {
  type Ok = Value;
  type Error = Error;

  fn serialize_field<T: ?Sized>(&mut self, value: &T) -> StdResult<(), Self::Error>
  where
    T: Serialize,
  {
    let env = unsafe { Env::from_raw(self.array.0.env) };
    self.array.set_element(
      self.current_index as _,
      JsUnknown(value.serialize(Ser::new(&env))?),
    )?;
    self.current_index += 1;
    Ok(())
  }

  fn end(self) -> StdResult<Self::Ok, Self::Error> {
    Ok(self.array.0)
  }
}

#[doc(hidden)]
impl ser::SerializeTupleVariant for SeqSerializer {
  type Ok = Value;
  type Error = Error;

  fn serialize_field<T: ?Sized>(&mut self, value: &T) -> StdResult<(), Self::Error>
  where
    T: Serialize,
  {
    let env = unsafe { Env::from_raw(self.array.0.env) };
    self.array.set_element(
      self.current_index as _,
      JsUnknown(value.serialize(Ser::new(&env))?),
    )?;
    self.current_index += 1;
    Ok(())
  }

  fn end(self) -> Result<Self::Ok> {
    Ok(self.array.0)
  }
}

pub struct MapSerializer {
  key: JsString,
  obj: JsObject,
}

#[doc(hidden)]
impl ser::SerializeMap for MapSerializer {
  type Ok = Value;
  type Error = Error;

  fn serialize_key<T: ?Sized>(&mut self, key: &T) -> StdResult<(), Self::Error>
  where
    T: Serialize,
  {
    let env = unsafe { Env::from_raw(self.obj.0.env) };
    self.key = JsString(key.serialize(Ser::new(&env))?);
    Ok(())
  }

  fn serialize_value<T: ?Sized>(&mut self, value: &T) -> StdResult<(), Self::Error>
  where
    T: Serialize,
  {
    let env = unsafe { Env::from_raw(self.obj.0.env) };
    self.obj.set_property(
      JsString(Value {
        env: self.key.0.env,
        value: self.key.0.value,
        value_type: ValueType::String,
      }),
      JsUnknown(value.serialize(Ser::new(&env))?),
    )?;
    Ok(())
  }

  fn serialize_entry<K: ?Sized, V: ?Sized>(
    &mut self,
    key: &K,
    value: &V,
  ) -> StdResult<(), Self::Error>
  where
    K: Serialize,
    V: Serialize,
  {
    let env = unsafe { Env::from_raw(self.obj.0.env) };
    self.obj.set_property(
      JsString(key.serialize(Ser::new(&env))?),
      JsUnknown(value.serialize(Ser::new(&env))?),
    )?;
    Ok(())
  }

  fn end(self) -> Result<Self::Ok> {
    Ok(self.obj.0)
  }
}

pub struct StructSerializer {
  obj: JsObject,
}

#[doc(hidden)]
impl ser::SerializeStruct for StructSerializer {
  type Ok = Value;
  type Error = Error;

  fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> StdResult<(), Error>
  where
    T: Serialize,
  {
    let env = unsafe { Env::from_raw(self.obj.0.env) };
    self
      .obj
      .set_named_property(key, JsUnknown(value.serialize(Ser::new(&env))?))?;
    Ok(())
  }

  fn end(self) -> Result<Self::Ok> {
    Ok(self.obj.0)
  }
}

#[doc(hidden)]
impl ser::SerializeStructVariant for StructSerializer {
  type Ok = Value;
  type Error = Error;

  fn serialize_field<T: ?Sized>(&mut self, key: &'static str, value: &T) -> StdResult<(), Error>
  where
    T: Serialize,
  {
    let env = unsafe { Env::from_raw(self.obj.0.env) };
    self
      .obj
      .set_named_property(key, JsUnknown(value.serialize(Ser::new(&env))?))?;
    Ok(())
  }
More examples
Hide additional examples
src/js_values/global.rs (line 18)
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  pub fn set_interval(&self, handler: JsFunction, interval: f64) -> Result<JsTimeout> {
    let func: JsFunction = self.get_named_property_unchecked("setInterval")?;
    func
      .call(
        None,
        &[
          handler.into_unknown(),
          unsafe { Env::from_raw(self.0.env) }
            .create_double(interval)?
            .into_unknown(),
        ],
      )
      .and_then(|ret| ret.try_into())
  }

  pub fn clear_interval(&self, timer: JsTimeout) -> Result<JsUndefined> {
    let func: JsFunction = self.get_named_property_unchecked("clearInterval")?;
    func
      .call(None, &[timer.into_unknown()])
      .and_then(|ret| ret.try_into())
  }

  pub fn set_timeout(&self, handler: JsFunction, interval: f64) -> Result<JsTimeout> {
    let func: JsFunction = self.get_named_property_unchecked("setTimeout")?;
    func
      .call(
        None,
        &[
          handler.into_unknown(),
          unsafe { Env::from_raw(self.0.env) }
            .create_double(interval)?
            .into_unknown(),
        ],
      )
      .and_then(|ret| ret.try_into())
  }
src/js_values/object.rs (line 79)
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unsafe extern "C" fn finalize_callback<T, Hint, F>(
  raw_env: sys::napi_env,
  finalize_data: *mut c_void,
  finalize_hint: *mut c_void,
) where
  T: 'static,
  Hint: 'static,
  F: FnOnce(FinalizeContext<T, Hint>),
{
  let (value, callback, raw_ref) =
    unsafe { *Box::from_raw(finalize_data as *mut (T, F, sys::napi_ref)) };
  let hint = unsafe { *Box::from_raw(finalize_hint as *mut Hint) };
  let env = unsafe { Env::from_raw(raw_env) };
  callback(FinalizeContext { env, value, hint });
  if !raw_ref.is_null() {
    let status = unsafe { sys::napi_delete_reference(raw_env, raw_ref) };
    debug_assert!(
      status == sys::Status::napi_ok,
      "Delete reference in finalize callback failed"
    );
  }
}
src/js_values/function.rs (line 48)
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  pub fn call<V>(&self, this: Option<&JsObject>, args: &[V]) -> Result<JsUnknown>
  where
    V: NapiRaw,
  {
    let raw_this = this
      .map(|v| unsafe { v.raw() })
      .or_else(|| {
        unsafe { Env::from_raw(self.0.env) }
          .get_undefined()
          .ok()
          .map(|u| unsafe { u.raw() })
      })
      .ok_or_else(|| Error::new(Status::GenericFailure, "Get raw this failed".to_owned()))?;
    let raw_args = args
      .iter()
      .map(|arg| unsafe { arg.raw() })
      .collect::<Vec<sys::napi_value>>();
    let mut return_value = ptr::null_mut();
    check_pending_exception!(self.0.env, unsafe {
      sys::napi_call_function(
        self.0.env,
        raw_this,
        self.0.value,
        args.len(),
        raw_args.as_ptr(),
        &mut return_value,
      )
    })?;

    unsafe { JsUnknown::from_raw(self.0.env, return_value) }
  }

  /// [napi_call_function](https://nodejs.org/api/n-api.html#n_api_napi_call_function)
  /// The same with `call`, but without arguments
  pub fn call_without_args(&self, this: Option<&JsObject>) -> Result<JsUnknown> {
    let raw_this = this
      .map(|v| unsafe { v.raw() })
      .or_else(|| {
        unsafe { Env::from_raw(self.0.env) }
          .get_undefined()
          .ok()
          .map(|u| unsafe { u.raw() })
      })
      .ok_or_else(|| Error::new(Status::GenericFailure, "Get raw this failed".to_owned()))?;
    let mut return_value = ptr::null_mut();
    check_pending_exception!(self.0.env, unsafe {
      sys::napi_call_function(
        self.0.env,
        raw_this,
        self.0.value,
        0,
        ptr::null_mut(),
        &mut return_value,
      )
    })?;

    unsafe { JsUnknown::from_raw(self.0.env, return_value) }
  }
src/js_values/deferred.rs (line 112)
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extern "C" fn napi_resolve_deferred<Data: ToNapiValue, Resolver: FnOnce(Env) -> Result<Data>>(
  env: sys::napi_env,
  _js_callback: sys::napi_value,
  context: *mut c_void,
  data: *mut c_void,
) {
  let deferred = context as sys::napi_deferred;
  let resolver = unsafe { Box::from_raw(data as *mut Result<Resolver>) };
  let result = resolver
    .and_then(|resolver| resolver(unsafe { Env::from_raw(env) }))
    .and_then(|res| unsafe { ToNapiValue::to_napi_value(env, res) });

  match result {
    Ok(res) => {
      let status = unsafe { sys::napi_resolve_deferred(env, deferred, res) };
      debug_assert!(status == sys::Status::napi_ok, "Resolve promise failed");
    }
    Err(e) => {
      let status =
        unsafe { sys::napi_reject_deferred(env, deferred, JsError::from(e).into_value(env)) };
      debug_assert!(status == sys::Status::napi_ok, "Reject promise failed");
    }
  }
}
src/bindgen_runtime/js_values/task.rs (line 68)
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  unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> crate::Result<Self> {
    let mut signal = unsafe { JsObject::from_raw_unchecked(env, napi_val) };
    let async_work_inner: Rc<AtomicPtr<sys::napi_async_work__>> =
      Rc::new(AtomicPtr::new(ptr::null_mut()));
    let raw_promise: Rc<AtomicPtr<sys::napi_deferred__>> = Rc::new(AtomicPtr::new(ptr::null_mut()));
    let task_status = Rc::new(AtomicU8::new(0));
    let abort_controller = AbortSignal {
      raw_work: async_work_inner.clone(),
      raw_deferred: raw_promise.clone(),
      status: task_status.clone(),
    };
    let js_env = unsafe { Env::from_raw(env) };
    check_status!(unsafe {
      sys::napi_wrap(
        env,
        signal.0.value,
        Box::into_raw(Box::new(abort_controller)) as *mut _,
        Some(async_task_abort_controller_finalize),
        ptr::null_mut(),
        ptr::null_mut(),
      )
    })?;
    signal.set_named_property("onabort", js_env.create_function("onabort", on_abort)?)?;
    Ok(AbortSignal {
      raw_work: async_work_inner,
      raw_deferred: raw_promise,
      status: task_status,
    })
  }
Additional examples can be found in:
Examples found in repository?
src/js_values/ser.rs (line 31)
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  fn serialize_bool(self, v: bool) -> Result<Self::Ok> {
    self.0.get_boolean(v).map(|js_value| js_value.0)
  }
Examples found in repository?
src/js_values/ser.rs (line 56)
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  fn serialize_i16(self, v: i16) -> Result<Self::Ok> {
    self.0.create_int32(v as _).map(|js_number| js_number.0)
  }

  fn serialize_i32(self, v: i32) -> Result<Self::Ok> {
    self.0.create_int32(v).map(|js_number| js_number.0)
  }

  fn serialize_i64(self, v: i64) -> Result<Self::Ok> {
    self.0.create_int64(v).map(|js_number| js_number.0)
  }

  fn serialize_i8(self, v: i8) -> Result<Self::Ok> {
    self.0.create_int32(v as _).map(|js_number| js_number.0)
  }
Examples found in repository?
src/js_values/ser.rs (line 64)
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  fn serialize_i64(self, v: i64) -> Result<Self::Ok> {
    self.0.create_int64(v).map(|js_number| js_number.0)
  }
Examples found in repository?
src/js_values/ser.rs (line 72)
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  fn serialize_u8(self, v: u8) -> Result<Self::Ok> {
    self.0.create_uint32(v as _).map(|js_number| js_number.0)
  }

  fn serialize_u16(self, v: u16) -> Result<Self::Ok> {
    self.0.create_uint32(v as _).map(|js_number| js_number.0)
  }

  fn serialize_u32(self, v: u32) -> Result<Self::Ok> {
    self.0.create_uint32(v).map(|js_number| js_number.0)
  }
Examples found in repository?
src/js_values/ser.rs (line 48)
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  fn serialize_f32(self, v: f32) -> Result<Self::Ok> {
    self.0.create_double(v as _).map(|js_number| js_number.0)
  }

  fn serialize_f64(self, v: f64) -> Result<Self::Ok> {
    self.0.create_double(v).map(|js_number| js_number.0)
  }
More examples
Hide additional examples
src/js_values/global.rs (line 19)
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  pub fn set_interval(&self, handler: JsFunction, interval: f64) -> Result<JsTimeout> {
    let func: JsFunction = self.get_named_property_unchecked("setInterval")?;
    func
      .call(
        None,
        &[
          handler.into_unknown(),
          unsafe { Env::from_raw(self.0.env) }
            .create_double(interval)?
            .into_unknown(),
        ],
      )
      .and_then(|ret| ret.try_into())
  }

  pub fn clear_interval(&self, timer: JsTimeout) -> Result<JsUndefined> {
    let func: JsFunction = self.get_named_property_unchecked("clearInterval")?;
    func
      .call(None, &[timer.into_unknown()])
      .and_then(|ret| ret.try_into())
  }

  pub fn set_timeout(&self, handler: JsFunction, interval: f64) -> Result<JsTimeout> {
    let func: JsFunction = self.get_named_property_unchecked("setTimeout")?;
    func
      .call(
        None,
        &[
          handler.into_unknown(),
          unsafe { Env::from_raw(self.0.env) }
            .create_double(interval)?
            .into_unknown(),
        ],
      )
      .and_then(|ret| ret.try_into())
  }

n_api_napi_create_bigint_int64

Examples found in repository?
src/js_values/ser.rs (line 100)
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  fn serialize_u64(self, v: u64) -> Result<Self::Ok> {
    self
      .0
      .create_bigint_from_u64(v)
      .map(|js_number| js_number.raw)
  }

n_api_napi_create_bigint_words

The resulting BigInt will be negative when sign_bit is true.

Examples found in repository?
src/js_values/ser.rs (line 123)
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  fn serialize_u128(self, v: u128) -> Result<Self::Ok> {
    let words_ref = &v as *const _;
    let words = unsafe { slice::from_raw_parts(words_ref as *const u64, 2) };
    self
      .0
      .create_bigint_from_words(false, words.to_vec())
      .map(|v| v.raw)
  }

  #[cfg(all(
    any(
      feature = "napi2",
      feature = "napi3",
      feature = "napi4",
      feature = "napi5"
    ),
    not(feature = "napi6")
  ))]
  fn serialize_i128(self, v: i128) -> Result<Self::Ok> {
    self.0.create_string(v.to_string().as_str()).map(|v| v.0)
  }

  #[cfg(feature = "napi6")]
  fn serialize_i128(self, v: i128) -> Result<Self::Ok> {
    let words_ref = &(v as u128) as *const _;
    let words = unsafe { slice::from_raw_parts(words_ref as *const u64, 2) };
    self
      .0
      .create_bigint_from_words(v < 0, words.to_vec())
      .map(|v| v.raw)
  }
Examples found in repository?
src/js_values/ser.rs (line 44)
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  fn serialize_char(self, v: char) -> Result<Self::Ok> {
    let mut b = [0; 4];
    let result = v.encode_utf8(&mut b);
    self.0.create_string(result).map(|js_string| js_string.0)
  }

  fn serialize_f32(self, v: f32) -> Result<Self::Ok> {
    self.0.create_double(v as _).map(|js_number| js_number.0)
  }

  fn serialize_f64(self, v: f64) -> Result<Self::Ok> {
    self.0.create_double(v).map(|js_number| js_number.0)
  }

  fn serialize_i16(self, v: i16) -> Result<Self::Ok> {
    self.0.create_int32(v as _).map(|js_number| js_number.0)
  }

  fn serialize_i32(self, v: i32) -> Result<Self::Ok> {
    self.0.create_int32(v).map(|js_number| js_number.0)
  }

  fn serialize_i64(self, v: i64) -> Result<Self::Ok> {
    self.0.create_int64(v).map(|js_number| js_number.0)
  }

  fn serialize_i8(self, v: i8) -> Result<Self::Ok> {
    self.0.create_int32(v as _).map(|js_number| js_number.0)
  }

  fn serialize_u8(self, v: u8) -> Result<Self::Ok> {
    self.0.create_uint32(v as _).map(|js_number| js_number.0)
  }

  fn serialize_u16(self, v: u16) -> Result<Self::Ok> {
    self.0.create_uint32(v as _).map(|js_number| js_number.0)
  }

  fn serialize_u32(self, v: u32) -> Result<Self::Ok> {
    self.0.create_uint32(v).map(|js_number| js_number.0)
  }

  #[cfg(all(
    any(
      feature = "napi2",
      feature = "napi3",
      feature = "napi4",
      feature = "napi5"
    ),
    not(feature = "napi6")
  ))]
  fn serialize_u64(self, v: u64) -> Result<Self::Ok> {
    self.0.create_int64(v as _).map(|js_number| js_number.0)
  }

  #[cfg(feature = "napi6")]
  fn serialize_u64(self, v: u64) -> Result<Self::Ok> {
    self
      .0
      .create_bigint_from_u64(v)
      .map(|js_number| js_number.raw)
  }

  #[cfg(all(
    any(
      feature = "napi2",
      feature = "napi3",
      feature = "napi4",
      feature = "napi5"
    ),
    not(feature = "napi6")
  ))]
  fn serialize_u128(self, v: u128) -> Result<Self::Ok> {
    self.0.create_string(v.to_string().as_str()).map(|v| v.0)
  }

  #[cfg(feature = "napi6")]
  fn serialize_u128(self, v: u128) -> Result<Self::Ok> {
    let words_ref = &v as *const _;
    let words = unsafe { slice::from_raw_parts(words_ref as *const u64, 2) };
    self
      .0
      .create_bigint_from_words(false, words.to_vec())
      .map(|v| v.raw)
  }

  #[cfg(all(
    any(
      feature = "napi2",
      feature = "napi3",
      feature = "napi4",
      feature = "napi5"
    ),
    not(feature = "napi6")
  ))]
  fn serialize_i128(self, v: i128) -> Result<Self::Ok> {
    self.0.create_string(v.to_string().as_str()).map(|v| v.0)
  }

  #[cfg(feature = "napi6")]
  fn serialize_i128(self, v: i128) -> Result<Self::Ok> {
    let words_ref = &(v as u128) as *const _;
    let words = unsafe { slice::from_raw_parts(words_ref as *const u64, 2) };
    self
      .0
      .create_bigint_from_words(v < 0, words.to_vec())
      .map(|v| v.raw)
  }

  fn serialize_unit(self) -> Result<Self::Ok> {
    self.0.get_null().map(|null| null.0)
  }

  fn serialize_none(self) -> Result<Self::Ok> {
    self.0.get_null().map(|null| null.0)
  }

  fn serialize_str(self, v: &str) -> Result<Self::Ok> {
    self.0.create_string(v).map(|string| string.0)
  }

  fn serialize_some<T: ?Sized>(self, value: &T) -> Result<Self::Ok>
  where
    T: Serialize,
  {
    value.serialize(self)
  }

  fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
    let env = self.0;
    let key = env.create_string("")?;
    let obj = env.create_object()?;
    Ok(MapSerializer { key, obj })
  }

  fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
    let array = self.0.create_array_with_length(len.unwrap_or(0))?;
    Ok(SeqSerializer {
      current_index: 0,
      array,
    })
  }

  fn serialize_tuple_variant(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
    len: usize,
  ) -> Result<Self::SerializeTupleVariant> {
    let env = self.0;
    let array = env.create_array_with_length(len)?;
    let mut object = env.create_object()?;
    object.set_named_property(
      variant,
      JsObject(Value {
        value: array.0.value,
        env: array.0.env,
        value_type: ValueType::Object,
      }),
    )?;
    Ok(SeqSerializer {
      current_index: 0,
      array,
    })
  }

  fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok> {
    self.0.get_null().map(|null| null.0)
  }

  fn serialize_unit_variant(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
  ) -> Result<Self::Ok> {
    self.0.create_string(variant).map(|string| string.0)
  }
More examples
Hide additional examples
src/env.rs (line 213)
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  pub fn create_symbol(&self, description: Option<&str>) -> Result<JsSymbol> {
    let mut result = ptr::null_mut();
    check_status!(unsafe {
      sys::napi_create_symbol(
        self.0,
        description
          .and_then(|desc| self.create_string(desc).ok())
          .map(|string| string.0.value)
          .unwrap_or(ptr::null_mut()),
        &mut result,
      )
    })?;
    Ok(unsafe { JsSymbol::from_raw_unchecked(self.0, result) })
  }

  pub fn create_object(&self) -> Result<JsObject> {
    let mut raw_value = ptr::null_mut();
    check_status!(unsafe { sys::napi_create_object(self.0, &mut raw_value) })?;
    Ok(unsafe { JsObject::from_raw_unchecked(self.0, raw_value) })
  }

  pub fn create_empty_array(&self) -> Result<JsObject> {
    let mut raw_value = ptr::null_mut();
    check_status!(unsafe { sys::napi_create_array(self.0, &mut raw_value) })?;
    Ok(unsafe { JsObject::from_raw_unchecked(self.0, raw_value) })
  }

  pub fn create_array_with_length(&self, length: usize) -> Result<JsObject> {
    let mut raw_value = ptr::null_mut();
    check_status!(unsafe { sys::napi_create_array_with_length(self.0, length, &mut raw_value) })?;
    Ok(unsafe { JsObject::from_raw_unchecked(self.0, raw_value) })
  }

  /// This API allocates a node::Buffer object. While this is still a fully-supported data structure, in most cases using a TypedArray will suffice.
  pub fn create_buffer(&self, length: usize) -> Result<JsBufferValue> {
    let mut raw_value = ptr::null_mut();
    let mut data_ptr = ptr::null_mut();
    check_status!(unsafe {
      sys::napi_create_buffer(self.0, length, &mut data_ptr, &mut raw_value)
    })?;

    Ok(JsBufferValue::new(
      JsBuffer(Value {
        env: self.0,
        value: raw_value,
        value_type: ValueType::Object,
      }),
      mem::ManuallyDrop::new(unsafe { Vec::from_raw_parts(data_ptr as *mut _, length, length) }),
    ))
  }

  /// This API allocates a node::Buffer object and initializes it with data backed by the passed in buffer.
  ///
  /// While this is still a fully-supported data structure, in most cases using a TypedArray will suffice.
  pub fn create_buffer_with_data(&self, mut data: Vec<u8>) -> Result<JsBufferValue> {
    let length = data.len();
    let mut raw_value = ptr::null_mut();
    let data_ptr = data.as_mut_ptr();
    check_status!(unsafe {
      if length == 0 {
        // Rust uses 0x1 as the data pointer for empty buffers,
        // but NAPI/V8 only allows multiple buffers to have
        // the same data pointer if it's 0x0.
        sys::napi_create_buffer(self.0, length, ptr::null_mut(), &mut raw_value)
      } else {
        sys::napi_create_external_buffer(
          self.0,
          length,
          data_ptr as *mut c_void,
          Some(drop_buffer),
          Box::into_raw(Box::new((length, data.capacity()))) as *mut c_void,
          &mut raw_value,
        )
      }
    })?;
    Ok(JsBufferValue::new(
      JsBuffer(Value {
        env: self.0,
        value: raw_value,
        value_type: ValueType::Object,
      }),
      mem::ManuallyDrop::new(data),
    ))
  }

  /// # Safety
  /// Mostly the same with `create_buffer_with_data`
  ///
  /// Provided `finalize_callback` will be called when `Buffer` got dropped.
  ///
  /// You can pass in `noop_finalize` if you have nothing to do in finalize phase.
  pub unsafe fn create_buffer_with_borrowed_data<Hint, Finalize>(
    &self,
    data: *const u8,
    length: usize,
    hint: Hint,
    finalize_callback: Finalize,
  ) -> Result<JsBufferValue>
  where
    Finalize: FnOnce(Hint, Env),
  {
    let mut raw_value = ptr::null_mut();
    if data.is_null() || data == EMPTY_VEC.as_ptr() {
      return Err(Error::new(
        Status::InvalidArg,
        "Borrowed data should not be null".to_owned(),
      ));
    }
    check_status!(unsafe {
      sys::napi_create_external_buffer(
        self.0,
        length,
        data as *mut c_void,
        Some(
          raw_finalize_with_custom_callback::<Hint, Finalize>
            as unsafe extern "C" fn(
              env: sys::napi_env,
              finalize_data: *mut c_void,
              finalize_hint: *mut c_void,
            ),
        ),
        Box::into_raw(Box::new((hint, finalize_callback))) as *mut c_void,
        &mut raw_value,
      )
    })?;
    Ok(JsBufferValue::new(
      JsBuffer(Value {
        env: self.0,
        value: raw_value,
        value_type: ValueType::Object,
      }),
      mem::ManuallyDrop::new(unsafe { Vec::from_raw_parts(data as *mut u8, length, length) }),
    ))
  }

  /// This function gives V8 an indication of the amount of externally allocated memory that is kept alive by JavaScript objects (i.e. a JavaScript object that points to its own memory allocated by a native module).
  ///
  /// Registering externally allocated memory will trigger global garbage collections more often than it would otherwise.
  ///
  /// ***ATTENTION ⚠️***, do not use this with `create_buffer_with_data/create_arraybuffer_with_data`, since these two functions already called the `adjust_external_memory` internal.
  pub fn adjust_external_memory(&mut self, size: i64) -> Result<i64> {
    let mut changed = 0i64;
    check_status!(unsafe { sys::napi_adjust_external_memory(self.0, size, &mut changed) })?;
    Ok(changed)
  }

  /// This API allocates a node::Buffer object and initializes it with data copied from the passed-in buffer.
  ///
  /// While this is still a fully-supported data structure, in most cases using a TypedArray will suffice.
  pub fn create_buffer_copy<D>(&self, data_to_copy: D) -> Result<JsBufferValue>
  where
    D: AsRef<[u8]>,
  {
    let length = data_to_copy.as_ref().len();
    let data_ptr = data_to_copy.as_ref().as_ptr();
    let mut copy_data = ptr::null_mut();
    let mut raw_value = ptr::null_mut();
    check_status!(unsafe {
      sys::napi_create_buffer_copy(
        self.0,
        length,
        data_ptr as *mut c_void,
        &mut copy_data,
        &mut raw_value,
      )
    })?;
    Ok(JsBufferValue::new(
      JsBuffer(Value {
        env: self.0,
        value: raw_value,
        value_type: ValueType::Object,
      }),
      mem::ManuallyDrop::new(unsafe { Vec::from_raw_parts(copy_data as *mut u8, length, length) }),
    ))
  }

  pub fn create_arraybuffer(&self, length: usize) -> Result<JsArrayBufferValue> {
    let mut raw_value = ptr::null_mut();
    let mut data_ptr = ptr::null_mut();
    check_status!(unsafe {
      sys::napi_create_arraybuffer(self.0, length, &mut data_ptr, &mut raw_value)
    })?;

    Ok(JsArrayBufferValue::new(
      unsafe { JsArrayBuffer::from_raw_unchecked(self.0, raw_value) },
      data_ptr as *mut c_void,
      length,
    ))
  }

  pub fn create_arraybuffer_with_data(&self, mut data: Vec<u8>) -> Result<JsArrayBufferValue> {
    let length = data.len();
    let mut raw_value = ptr::null_mut();
    let data_ptr = data.as_mut_ptr();
    check_status!(unsafe {
      if length == 0 {
        // Rust uses 0x1 as the data pointer for empty buffers,
        // but NAPI/V8 only allows multiple buffers to have
        // the same data pointer if it's 0x0.
        sys::napi_create_arraybuffer(self.0, length, ptr::null_mut(), &mut raw_value)
      } else {
        sys::napi_create_external_arraybuffer(
          self.0,
          data_ptr as *mut c_void,
          length,
          Some(drop_buffer),
          Box::into_raw(Box::new((length, data.capacity()))) as *mut c_void,
          &mut raw_value,
        )
      }
    })?;

    mem::forget(data);
    Ok(JsArrayBufferValue::new(
      JsArrayBuffer(Value {
        env: self.0,
        value: raw_value,
        value_type: ValueType::Object,
      }),
      data_ptr as *mut c_void,
      length,
    ))
  }

  /// # Safety
  /// Mostly the same with `create_arraybuffer_with_data`
  ///
  /// Provided `finalize_callback` will be called when `Buffer` got dropped.
  ///
  /// You can pass in `noop_finalize` if you have nothing to do in finalize phase.
  pub unsafe fn create_arraybuffer_with_borrowed_data<Hint, Finalize>(
    &self,
    data: *const u8,
    length: usize,
    hint: Hint,
    finalize_callback: Finalize,
  ) -> Result<JsArrayBufferValue>
  where
    Finalize: FnOnce(Hint, Env),
  {
    let mut raw_value = ptr::null_mut();
    check_status!(unsafe {
      sys::napi_create_external_arraybuffer(
        self.0,
        if length == 0 {
          // Rust uses 0x1 as the data pointer for empty buffers,
          // but NAPI/V8 only allows multiple buffers to have
          // the same data pointer if it's 0x0.
          ptr::null_mut()
        } else {
          data as *mut c_void
        },
        length,
        Some(
          raw_finalize_with_custom_callback::<Hint, Finalize>
            as unsafe extern "C" fn(
              env: sys::napi_env,
              finalize_data: *mut c_void,
              finalize_hint: *mut c_void,
            ),
        ),
        Box::into_raw(Box::new((hint, finalize_callback))) as *mut c_void,
        &mut raw_value,
      )
    })?;
    Ok(JsArrayBufferValue::new(
      JsArrayBuffer(Value {
        env: self.0,
        value: raw_value,
        value_type: ValueType::Object,
      }),
      data as *mut c_void,
      length,
    ))
  }

  /// This API allows an add-on author to create a function object in native code.
  ///
  /// This is the primary mechanism to allow calling into the add-on's native code from JavaScript.
  ///
  /// The newly created function is not automatically visible from script after this call.
  ///
  /// Instead, a property must be explicitly set on any object that is visible to JavaScript, in order for the function to be accessible from script.
  pub fn create_function(&self, name: &str, callback: Callback) -> Result<JsFunction> {
    let mut raw_result = ptr::null_mut();
    let len = name.len();
    let name = CString::new(name)?;
    check_status!(unsafe {
      sys::napi_create_function(
        self.0,
        name.as_ptr(),
        len,
        Some(callback),
        ptr::null_mut(),
        &mut raw_result,
      )
    })?;

    Ok(unsafe { JsFunction::from_raw_unchecked(self.0, raw_result) })
  }

  #[cfg(feature = "napi5")]
  pub fn create_function_from_closure<R, F>(&self, name: &str, callback: F) -> Result<JsFunction>
  where
    F: 'static + Fn(crate::CallContext<'_>) -> Result<R>,
    R: NapiRaw,
  {
    use crate::CallContext;
    let boxed_callback = Box::new(callback);
    let closure_data_ptr: *mut F = Box::into_raw(boxed_callback);

    let mut raw_result = ptr::null_mut();
    let len = name.len();
    let name = CString::new(name)?;
    check_status!(unsafe {
      sys::napi_create_function(
        self.0,
        name.as_ptr(),
        len,
        Some({
          unsafe extern "C" fn trampoline<R: NapiRaw, F: Fn(CallContext<'_>) -> Result<R>>(
            raw_env: sys::napi_env,
            cb_info: sys::napi_callback_info,
          ) -> sys::napi_value {
            use ::std::panic::{self, AssertUnwindSafe};
            panic::catch_unwind(AssertUnwindSafe(|| {
              let (raw_this, ref raw_args, closure_data_ptr) = {
                let argc = {
                  let mut argc = 0;
                  let status = unsafe {
                    sys::napi_get_cb_info(
                      raw_env,
                      cb_info,
                      &mut argc,
                      ptr::null_mut(),
                      ptr::null_mut(),
                      ptr::null_mut(),
                    )
                  };
                  debug_assert!(
                    Status::from(status) == Status::Ok,
                    "napi_get_cb_info failed"
                  );
                  argc
                };
                let mut raw_args = vec![ptr::null_mut(); argc];
                let mut raw_this = ptr::null_mut();
                let mut closure_data_ptr = ptr::null_mut();

                let status = unsafe {
                  sys::napi_get_cb_info(
                    raw_env,
                    cb_info,
                    &mut { argc },
                    raw_args.as_mut_ptr(),
                    &mut raw_this,
                    &mut closure_data_ptr,
                  )
                };
                debug_assert!(
                  Status::from(status) == Status::Ok,
                  "napi_get_cb_info failed"
                );
                (raw_this, raw_args, closure_data_ptr)
              };

              let closure: &F = unsafe {
                closure_data_ptr
                  .cast::<F>()
                  .as_ref()
                  .expect("`napi_get_cb_info` should have yielded non-`NULL` assoc data")
              };
              let env = &mut unsafe { Env::from_raw(raw_env) };
              let ctx = CallContext::new(env, cb_info, raw_this, raw_args, raw_args.len());
              closure(ctx).map(|ret: R| unsafe { ret.raw() })
            }))
            .map_err(|e| {
              Error::from_reason(format!(
                "panic from Rust code: {}",
                if let Some(s) = e.downcast_ref::<String>() {
                  s
                } else if let Some(s) = e.downcast_ref::<&str>() {
                  s
                } else {
                  "<no error message>"
                },
              ))
            })
            .and_then(|v| v)
            .unwrap_or_else(|e| {
              unsafe { JsError::from(e).throw_into(raw_env) };
              ptr::null_mut()
            })
          }

          trampoline::<R, F>
        }),
        closure_data_ptr.cast(), // We let it borrow the data here
        &mut raw_result,
      )
    })?;

    // Note: based on N-API docs, at this point, we have created an effective
    // `&'static dyn Fn…` in Rust parlance, in that thanks to `Box::into_raw()`
    // we are sure the context won't be freed, and thus the callback may use
    // it to call the actual method thanks to the trampoline…
    // But we thus have a data leak: there is nothing yet responsible for
    // running the `drop(Box::from_raw(…))` cleanup code.
    //
    // To solve that, according to the docs, we need to attach a finalizer:
    check_status!(unsafe {
      sys::napi_add_finalizer(
        self.0,
        raw_result,
        closure_data_ptr.cast(),
        Some({
          unsafe extern "C" fn finalize_box_trampoline<F>(
            _raw_env: sys::napi_env,
            closure_data_ptr: *mut c_void,
            _finalize_hint: *mut c_void,
          ) {
            drop(unsafe { Box::<F>::from_raw(closure_data_ptr.cast()) })
          }

          finalize_box_trampoline::<F>
        }),
        ptr::null_mut(),
        ptr::null_mut(),
      )
    })?;

    Ok(unsafe { JsFunction::from_raw_unchecked(self.0, raw_result) })
  }

  /// This API retrieves a napi_extended_error_info structure with information about the last error that occurred.
  ///
  /// The content of the napi_extended_error_info returned is only valid up until an n-api function is called on the same env.
  ///
  /// Do not rely on the content or format of any of the extended information as it is not subject to SemVer and may change at any time. It is intended only for logging purposes.
  ///
  /// This API can be called even if there is a pending JavaScript exception.
  pub fn get_last_error_info(&self) -> Result<ExtendedErrorInfo> {
    let mut raw_extended_error = ptr::null();
    check_status!(unsafe { sys::napi_get_last_error_info(self.0, &mut raw_extended_error) })?;
    unsafe { ptr::read(raw_extended_error) }.try_into()
  }

  /// Throw any JavaScript value
  pub fn throw<T: NapiRaw>(&self, value: T) -> Result<()> {
    check_status!(unsafe { sys::napi_throw(self.0, value.raw()) })
  }

  /// This API throws a JavaScript Error with the text provided.
  pub fn throw_error(&self, msg: &str, code: Option<&str>) -> Result<()> {
    let code = code.and_then(|s| CString::new(s).ok());
    let msg = CString::new(msg)?;
    check_status!(unsafe {
      sys::napi_throw_error(
        self.0,
        code.map(|s| s.as_ptr()).unwrap_or(ptr::null_mut()),
        msg.as_ptr(),
      )
    })
  }

  /// This API throws a JavaScript RangeError with the text provided.
  pub fn throw_range_error(&self, msg: &str, code: Option<&str>) -> Result<()> {
    let code = code.and_then(|s| CString::new(s).ok());
    let msg = CString::new(msg)?;
    check_status!(unsafe {
      sys::napi_throw_range_error(
        self.0,
        code.map(|s| s.as_ptr()).unwrap_or(ptr::null_mut()),
        msg.as_ptr(),
      )
    })
  }

  /// This API throws a JavaScript TypeError with the text provided.
  pub fn throw_type_error(&self, msg: &str, code: Option<&str>) -> Result<()> {
    let code = code.and_then(|s| CString::new(s).ok());
    let msg = CString::new(msg)?;
    check_status!(unsafe {
      sys::napi_throw_type_error(
        self.0,
        code.map(|s| s.as_ptr()).unwrap_or(ptr::null_mut()),
        msg.as_ptr(),
      )
    })
  }

  /// This API throws a JavaScript SyntaxError with the text provided.
  #[cfg(feature = "experimental")]
  pub fn throw_syntax_error(&self, msg: &str, code: Option<&str>) -> Result<()> {
    let code = code.and_then(|s| CString::new(s).ok());
    let msg = CString::new(msg)?;
    check_status!(unsafe {
      sys::node_api_throw_syntax_error(
        self.0,
        code.map(|s| s.as_ptr()).unwrap_or(ptr::null_mut()),
        msg.as_ptr(),
      )
    })
  }

  #[allow(clippy::expect_fun_call)]
  /// In the event of an unrecoverable error in a native module
  ///
  /// A fatal error can be thrown to immediately terminate the process.
  pub fn fatal_error(self, location: &str, message: &str) {
    let location_len = location.len();
    let message_len = message.len();
    let location =
      CString::new(location).expect(format!("Convert [{}] to CString failed", location).as_str());
    let message =
      CString::new(message).expect(format!("Convert [{}] to CString failed", message).as_str());

    unsafe {
      sys::napi_fatal_error(
        location.as_ptr(),
        location_len,
        message.as_ptr(),
        message_len,
      )
    }
  }

  #[cfg(feature = "napi3")]
  /// Trigger an 'uncaughtException' in JavaScript.
  ///
  /// Useful if an async callback throws an exception with no way to recover.
  pub fn fatal_exception(&self, err: Error) {
    unsafe {
      let js_error = JsError::from(err).into_value(self.0);
      debug_assert!(sys::napi_fatal_exception(self.0, js_error) == sys::Status::napi_ok);
    };
  }

  /// Create JavaScript class
  pub fn define_class(
    &self,
    name: &str,
    constructor_cb: Callback,
    properties: &[Property],
  ) -> Result<JsFunction> {
    let mut raw_result = ptr::null_mut();
    let raw_properties = properties
      .iter()
      .map(|prop| prop.raw())
      .collect::<Vec<sys::napi_property_descriptor>>();
    let c_name = CString::new(name)?;
    check_status!(unsafe {
      sys::napi_define_class(
        self.0,
        c_name.as_ptr() as *const c_char,
        name.len(),
        Some(constructor_cb),
        ptr::null_mut(),
        raw_properties.len(),
        raw_properties.as_ptr(),
        &mut raw_result,
      )
    })?;

    Ok(unsafe { JsFunction::from_raw_unchecked(self.0, raw_result) })
  }

  pub fn wrap<T: 'static>(&self, js_object: &mut JsObject, native_object: T) -> Result<()> {
    check_status!(unsafe {
      sys::napi_wrap(
        self.0,
        js_object.0.value,
        Box::into_raw(Box::new(TaggedObject::new(native_object))) as *mut c_void,
        Some(raw_finalize::<T>),
        ptr::null_mut(),
        ptr::null_mut(),
      )
    })
  }

  pub fn unwrap<T: 'static>(&self, js_object: &JsObject) -> Result<&mut T> {
    unsafe {
      let mut unknown_tagged_object: *mut c_void = ptr::null_mut();
      check_status!(sys::napi_unwrap(
        self.0,
        js_object.0.value,
        &mut unknown_tagged_object,
      ))?;

      let type_id = unknown_tagged_object as *const TypeId;
      if *type_id == TypeId::of::<T>() {
        let tagged_object = unknown_tagged_object as *mut TaggedObject<T>;
        (*tagged_object).object.as_mut().ok_or_else(|| {
          Error::new(
            Status::InvalidArg,
            "Invalid argument, nothing attach to js_object".to_owned(),
          )
        })
      } else {
        Err(Error::new(
          Status::InvalidArg,
          format!(
            "Invalid argument, {} on unwrap is not the type of wrapped object",
            type_name::<T>()
          ),
        ))
      }
    }
  }

  pub fn unwrap_from_ref<T: 'static>(&self, js_ref: &Ref<()>) -> Result<&'static mut T> {
    unsafe {
      let mut unknown_tagged_object: *mut c_void = ptr::null_mut();
      check_status!(sys::napi_unwrap(
        self.0,
        js_ref.raw_value,
        &mut unknown_tagged_object,
      ))?;

      let type_id = unknown_tagged_object as *const TypeId;
      if *type_id == TypeId::of::<T>() {
        let tagged_object = unknown_tagged_object as *mut TaggedObject<T>;
        (*tagged_object).object.as_mut().ok_or_else(|| {
          Error::new(
            Status::InvalidArg,
            "Invalid argument, nothing attach to js_object".to_owned(),
          )
        })
      } else {
        Err(Error::new(
          Status::InvalidArg,
          format!(
            "Invalid argument, {} on unwrap is not the type of wrapped object",
            type_name::<T>()
          ),
        ))
      }
    }
  }

  pub fn drop_wrapped<T: 'static>(&self, js_object: &mut JsObject) -> Result<()> {
    unsafe {
      let mut unknown_tagged_object = ptr::null_mut();
      check_status!(sys::napi_remove_wrap(
        self.0,
        js_object.0.value,
        &mut unknown_tagged_object,
      ))?;
      let type_id = unknown_tagged_object as *const TypeId;
      if *type_id == TypeId::of::<T>() {
        drop(Box::from_raw(unknown_tagged_object as *mut TaggedObject<T>));
        Ok(())
      } else {
        Err(Error::new(
          Status::InvalidArg,
          format!(
            "Invalid argument, {} on unwrap is not the type of wrapped object",
            type_name::<T>()
          ),
        ))
      }
    }
  }

  /// This API create a new reference with the initial 1 ref count to the Object passed in.
  pub fn create_reference<T>(&self, value: T) -> Result<Ref<()>>
  where
    T: NapiRaw,
  {
    let mut raw_ref = ptr::null_mut();
    let initial_ref_count = 1;
    let raw_value = unsafe { value.raw() };
    check_status!(unsafe {
      sys::napi_create_reference(self.0, raw_value, initial_ref_count, &mut raw_ref)
    })?;
    Ok(Ref {
      raw_ref,
      count: 1,
      inner: (),
      raw_value,
    })
  }

  /// This API create a new reference with the specified reference count to the Object passed in.
  pub fn create_reference_with_refcount<T>(&self, value: T, ref_count: u32) -> Result<Ref<()>>
  where
    T: NapiRaw,
  {
    let mut raw_ref = ptr::null_mut();
    let raw_value = unsafe { value.raw() };
    check_status!(unsafe {
      sys::napi_create_reference(self.0, raw_value, ref_count, &mut raw_ref)
    })?;
    Ok(Ref {
      raw_ref,
      count: ref_count,
      inner: (),
      raw_value,
    })
  }

  /// 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) }
  }

  /// 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) })
  }

  /// If `size_hint` provided, `Env::adjust_external_memory` will be called under the hood.
  ///
  /// If no `size_hint` provided, global garbage collections will be triggered less times than expected.
  ///
  /// If getting the exact `native_object` size is difficult, you can provide an approximate value, it's only effect to the GC.
  pub fn create_external<T: 'static>(
    &self,
    native_object: T,
    size_hint: Option<i64>,
  ) -> Result<JsExternal> {
    let mut object_value = ptr::null_mut();
    check_status!(unsafe {
      sys::napi_create_external(
        self.0,
        Box::into_raw(Box::new(TaggedObject::new(native_object))) as *mut c_void,
        Some(raw_finalize::<T>),
        Box::into_raw(Box::new(size_hint)) as *mut c_void,
        &mut object_value,
      )
    })?;
    if let Some(changed) = size_hint {
      if changed != 0 {
        let mut adjusted_value = 0i64;
        check_status!(unsafe {
          sys::napi_adjust_external_memory(self.0, changed, &mut adjusted_value)
        })?;
      }
    };
    Ok(unsafe { JsExternal::from_raw_unchecked(self.0, object_value) })
  }

  pub fn get_value_external<T: 'static>(&self, js_external: &JsExternal) -> Result<&mut T> {
    unsafe {
      let mut unknown_tagged_object = ptr::null_mut();
      check_status!(sys::napi_get_value_external(
        self.0,
        js_external.0.value,
        &mut unknown_tagged_object,
      ))?;

      let type_id = unknown_tagged_object as *const TypeId;
      if *type_id == TypeId::of::<T>() {
        let tagged_object = unknown_tagged_object as *mut TaggedObject<T>;
        (*tagged_object).object.as_mut().ok_or_else(|| {
          Error::new(
            Status::InvalidArg,
            "nothing attach to js_external".to_owned(),
          )
        })
      } else {
        Err(Error::new(
          Status::InvalidArg,
          "T on get_value_external is not the type of wrapped object".to_owned(),
        ))
      }
    }
  }

  pub fn create_error(&self, e: Error) -> Result<JsObject> {
    let reason = &e.reason;
    let reason_string = self.create_string(reason.as_str())?;
    let mut result = ptr::null_mut();
    check_status!(unsafe {
      sys::napi_create_error(self.0, ptr::null_mut(), reason_string.0.value, &mut result)
    })?;
    Ok(unsafe { JsObject::from_raw_unchecked(self.0, result) })
  }

  /// Run [Task](./trait.Task.html) in libuv thread pool, return [AsyncWorkPromise](./struct.AsyncWorkPromise.html)
  pub fn spawn<T: 'static + Task>(&self, task: T) -> Result<AsyncWorkPromise> {
    async_work::run(self.0, task, None)
  }

  pub fn run_in_scope<T, F>(&self, executor: F) -> Result<T>
  where
    F: FnOnce() -> Result<T>,
  {
    let mut handle_scope = ptr::null_mut();
    check_status!(unsafe { sys::napi_open_handle_scope(self.0, &mut handle_scope) })?;

    let result = executor();

    check_status!(unsafe { sys::napi_close_handle_scope(self.0, handle_scope) })?;
    result
  }

  pub fn run_script<S: AsRef<str>>(&self, script: S) -> Result<JsObject> {
    let s = self.create_string(script.as_ref())?;
    let mut raw_value = ptr::null_mut();
    check_status!(unsafe { sys::napi_run_script(self.0, s.raw(), &mut raw_value) })?;
    Ok(unsafe { JsObject::from_raw_unchecked(self.0, raw_value) })
  }

This API is used for C ffi scenario. Convert raw *const c_char into JsString

Safety

Create JsString from known valid utf-8 string

Examples found in repository?
src/env.rs (line 157)
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  pub fn create_string(&self, s: &str) -> Result<JsString> {
    unsafe { self.create_string_from_c_char(s.as_ptr() as *const c_char, s.len()) }
  }

  pub fn create_string_from_std(&self, s: String) -> Result<JsString> {
    unsafe { self.create_string_from_c_char(s.as_ptr() as *const c_char, s.len()) }
  }
Examples found in repository?
src/js_values/ser.rs (line 172)
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  fn serialize_map(self, _len: Option<usize>) -> Result<Self::SerializeMap> {
    let env = self.0;
    let key = env.create_string("")?;
    let obj = env.create_object()?;
    Ok(MapSerializer { key, obj })
  }

  fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
    let array = self.0.create_array_with_length(len.unwrap_or(0))?;
    Ok(SeqSerializer {
      current_index: 0,
      array,
    })
  }

  fn serialize_tuple_variant(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
    len: usize,
  ) -> Result<Self::SerializeTupleVariant> {
    let env = self.0;
    let array = env.create_array_with_length(len)?;
    let mut object = env.create_object()?;
    object.set_named_property(
      variant,
      JsObject(Value {
        value: array.0.value,
        env: array.0.env,
        value_type: ValueType::Object,
      }),
    )?;
    Ok(SeqSerializer {
      current_index: 0,
      array,
    })
  }

  fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok> {
    self.0.get_null().map(|null| null.0)
  }

  fn serialize_unit_variant(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
  ) -> Result<Self::Ok> {
    self.0.create_string(variant).map(|string| string.0)
  }

  fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> Result<Self::Ok>
  where
    T: Serialize,
  {
    value.serialize(self)
  }

  fn serialize_newtype_variant<T: ?Sized>(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
    value: &T,
  ) -> Result<Self::Ok>
  where
    T: Serialize,
  {
    let mut obj = self.0.create_object()?;
    obj.set_named_property(variant, JsUnknown(value.serialize(self)?))?;
    Ok(obj.0)
  }

  fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple> {
    Ok(SeqSerializer {
      array: self.0.create_array_with_length(len)?,
      current_index: 0,
    })
  }

  fn serialize_tuple_struct(
    self,
    _name: &'static str,
    len: usize,
  ) -> Result<Self::SerializeTupleStruct> {
    Ok(SeqSerializer {
      array: self.0.create_array_with_length(len)?,
      current_index: 0,
    })
  }

  fn serialize_struct(self, _name: &'static str, _len: usize) -> Result<Self::SerializeStruct> {
    Ok(StructSerializer {
      obj: self.0.create_object()?,
    })
  }

  fn serialize_struct_variant(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
    _len: usize,
  ) -> Result<Self::SerializeStructVariant> {
    let mut outer = self.0.create_object()?;
    let inner = self.0.create_object()?;
    outer.set_named_property(
      variant,
      JsObject(Value {
        env: inner.0.env,
        value: inner.0.value,
        value_type: ValueType::Object,
      }),
    )?;
    Ok(StructSerializer {
      obj: self.0.create_object()?,
    })
  }
More examples
Hide additional examples
src/bindgen_runtime/js_values/map.rs (line 25)
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  unsafe fn to_napi_value(raw_env: sys::napi_env, val: Self) -> Result<sys::napi_value> {
    let env = Env::from(raw_env);
    let mut obj = env.create_object()?;
    for (k, v) in val.into_iter() {
      obj.set(k.as_ref(), v)?;
    }

    unsafe { Object::to_napi_value(raw_env, obj) }
  }
Examples found in repository?
src/js_values/ser.rs (line 177)
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  fn serialize_seq(self, len: Option<usize>) -> Result<Self::SerializeSeq> {
    let array = self.0.create_array_with_length(len.unwrap_or(0))?;
    Ok(SeqSerializer {
      current_index: 0,
      array,
    })
  }

  fn serialize_tuple_variant(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
    len: usize,
  ) -> Result<Self::SerializeTupleVariant> {
    let env = self.0;
    let array = env.create_array_with_length(len)?;
    let mut object = env.create_object()?;
    object.set_named_property(
      variant,
      JsObject(Value {
        value: array.0.value,
        env: array.0.env,
        value_type: ValueType::Object,
      }),
    )?;
    Ok(SeqSerializer {
      current_index: 0,
      array,
    })
  }

  fn serialize_unit_struct(self, _name: &'static str) -> Result<Self::Ok> {
    self.0.get_null().map(|null| null.0)
  }

  fn serialize_unit_variant(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
  ) -> Result<Self::Ok> {
    self.0.create_string(variant).map(|string| string.0)
  }

  fn serialize_newtype_struct<T: ?Sized>(self, _name: &'static str, value: &T) -> Result<Self::Ok>
  where
    T: Serialize,
  {
    value.serialize(self)
  }

  fn serialize_newtype_variant<T: ?Sized>(
    self,
    _name: &'static str,
    _variant_index: u32,
    variant: &'static str,
    value: &T,
  ) -> Result<Self::Ok>
  where
    T: Serialize,
  {
    let mut obj = self.0.create_object()?;
    obj.set_named_property(variant, JsUnknown(value.serialize(self)?))?;
    Ok(obj.0)
  }

  fn serialize_tuple(self, len: usize) -> Result<Self::SerializeTuple> {
    Ok(SeqSerializer {
      array: self.0.create_array_with_length(len)?,
      current_index: 0,
    })
  }

  fn serialize_tuple_struct(
    self,
    _name: &'static str,
    len: usize,
  ) -> Result<Self::SerializeTupleStruct> {
    Ok(SeqSerializer {
      array: self.0.create_array_with_length(len)?,
      current_index: 0,
    })
  }

This API allocates a node::Buffer object. While this is still a fully-supported data structure, in most cases using a TypedArray will suffice.

This API allocates a node::Buffer object and initializes it with data backed by the passed in buffer.

While this is still a fully-supported data structure, in most cases using a TypedArray will suffice.

Examples found in repository?
src/js_values/ser.rs (line 37)
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  fn serialize_bytes(self, v: &[u8]) -> Result<Self::Ok> {
    self
      .0
      .create_buffer_with_data(v.to_owned())
      .map(|js_value| js_value.value.0)
  }
Safety

Mostly the same with create_buffer_with_data

Provided finalize_callback will be called when Buffer got dropped.

You can pass in noop_finalize if you have nothing to do in finalize phase.

This function gives V8 an indication of the amount of externally allocated memory that is kept alive by JavaScript objects (i.e. a JavaScript object that points to its own memory allocated by a native module).

Registering externally allocated memory will trigger global garbage collections more often than it would otherwise.

ATTENTION ⚠️, do not use this with create_buffer_with_data/create_arraybuffer_with_data, since these two functions already called the adjust_external_memory internal.

This API allocates a node::Buffer object and initializes it with data copied from the passed-in buffer.

While this is still a fully-supported data structure, in most cases using a TypedArray will suffice.

Safety

Mostly the same with create_arraybuffer_with_data

Provided finalize_callback will be called when Buffer got dropped.

You can pass in noop_finalize if you have nothing to do in finalize phase.

This API allows an add-on author to create a function object in native code.

This is the primary mechanism to allow calling into the add-on’s native code from JavaScript.

The newly created function is not automatically visible from script after this call.

Instead, a property must be explicitly set on any object that is visible to JavaScript, in order for the function to be accessible from script.

Examples found in repository?
src/bindgen_runtime/js_values/task.rs (line 79)
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  unsafe fn from_napi_value(env: sys::napi_env, napi_val: sys::napi_value) -> crate::Result<Self> {
    let mut signal = unsafe { JsObject::from_raw_unchecked(env, napi_val) };
    let async_work_inner: Rc<AtomicPtr<sys::napi_async_work__>> =
      Rc::new(AtomicPtr::new(ptr::null_mut()));
    let raw_promise: Rc<AtomicPtr<sys::napi_deferred__>> = Rc::new(AtomicPtr::new(ptr::null_mut()));
    let task_status = Rc::new(AtomicU8::new(0));
    let abort_controller = AbortSignal {
      raw_work: async_work_inner.clone(),
      raw_deferred: raw_promise.clone(),
      status: task_status.clone(),
    };
    let js_env = unsafe { Env::from_raw(env) };
    check_status!(unsafe {
      sys::napi_wrap(
        env,
        signal.0.value,
        Box::into_raw(Box::new(abort_controller)) as *mut _,
        Some(async_task_abort_controller_finalize),
        ptr::null_mut(),
        ptr::null_mut(),
      )
    })?;
    signal.set_named_property("onabort", js_env.create_function("onabort", on_abort)?)?;
    Ok(AbortSignal {
      raw_work: async_work_inner,
      raw_deferred: raw_promise,
      status: task_status,
    })
  }

This API retrieves a napi_extended_error_info structure with information about the last error that occurred.

The content of the napi_extended_error_info returned is only valid up until an n-api function is called on the same env.

Do not rely on the content or format of any of the extended information as it is not subject to SemVer and may change at any time. It is intended only for logging purposes.

This API can be called even if there is a pending JavaScript exception.

Throw any JavaScript value

This API throws a JavaScript Error with the text provided.

This API throws a JavaScript RangeError with the text provided.

This API throws a JavaScript TypeError with the text provided.

This API throws a JavaScript SyntaxError with the text provided.

In the event of an unrecoverable error in a native module

A fatal error can be thrown to immediately terminate the process.

Trigger an ‘uncaughtException’ in JavaScript.

Useful if an async callback throws an exception with no way to recover.

Create JavaScript class

This API create a new reference with the initial 1 ref count to the Object passed in.

This API create a new reference with the specified reference count to the Object passed in.

Get reference value from Ref with type check

Return error if the type of reference provided is mismatched with T

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.

If size_hint provided, Env::adjust_external_memory will be called under the hood.

If no size_hint provided, global garbage collections will be triggered less times than expected.

If getting the exact native_object size is difficult, you can provide an approximate value, it’s only effect to the GC.

Run Task in libuv thread pool, return AsyncWorkPromise

Creates a deferred promise, which can be resolved or rejected from a background thread.

This API does not observe leap seconds; they are ignored, as ECMAScript aligns with POSIX time specification.

This API allocates a JavaScript Date object.

JavaScript Date objects are described in Section 20.3 of the ECMAScript Language Specification.

This API associates data with the currently running Agent. data can later be retrieved using Env::get_instance_data().

Any existing data associated with the currently running Agent which was set by means of a previous call to Env::set_instance_data() will be overwritten.

If a finalize_cb was provided by the previous call, it will not be called.

This API retrieves data that was previously associated with the currently running Agent via Env::set_instance_data().

If no data is set, the call will succeed and data will be set to NULL.

Registers hook, which is a function of type FnOnce(Arg), as a function to be run with the arg parameter once the current Node.js environment exits.

Unlike add_env_cleanup_hook, the hook is allowed to be asynchronous.

Otherwise, behavior generally matches that of add_env_cleanup_hook.

This API is very similar to add_removable_async_cleanup_hook

Use this one if you don’t want remove the cleanup hook anymore.

Serialize Rust Struct into JavaScript Value
#[derive(Serialize, Debug, Deserialize)]
struct AnObject {
    a: u32,
    b: Vec<f64>,
    c: String,
}

#[js_function]
fn serialize(ctx: CallContext) -> Result<JsUnknown> {
    let value = AnyObject { a: 1, b: vec![0.1, 2.22], c: "hello" };
    ctx.env.to_js_value(&value)
}
Deserialize data from JsValue
#[derive(Serialize, Debug, Deserialize)]
struct AnObject {
    a: u32,
    b: Vec<f64>,
    c: String,
}

#[js_function(1)]
fn deserialize_from_js(ctx: CallContext) -> Result<JsUndefined> {
    let arg0 = ctx.get::<JsUnknown>(0)?;
    let de_serialized: AnObject = ctx.env.from_js_value(arg0)?;
    ...
}

This API represents the invocation of the Strict Equality algorithm as defined in Section 7.2.14 of the ECMAScript Language Specification.

get raw env ptr

Examples found in repository?
src/bindgen_runtime/js_values/class.rs (line 25)
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  pub fn as_object(&self, env: Env) -> Object {
    unsafe { Object::from_raw_unchecked(env.raw(), self.value) }
  }
More examples
Hide additional examples
src/env.rs (line 1124)
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  pub fn create_deferred<Data: ToNapiValue, Resolver: FnOnce(Env) -> Result<Data>>(
    &self,
  ) -> Result<(JsDeferred<Data, Resolver>, JsObject)> {
    JsDeferred::new(self.raw())
  }
src/tokio_runtime.rs (line 86)
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pub fn execute_tokio_future<
  Data: 'static + Send,
  Fut: 'static + Send + Future<Output = Result<Data>>,
  Resolver: 'static + Send + Sync + FnOnce(sys::napi_env, Data) -> Result<sys::napi_value>,
>(
  env: sys::napi_env,
  fut: Fut,
  resolver: Resolver,
) -> Result<sys::napi_value> {
  let mut promise = ptr::null_mut();
  let mut deferred = ptr::null_mut();

  check_status!(unsafe { sys::napi_create_promise(env, &mut deferred, &mut promise) })?;

  let (deferred, promise) = JsDeferred::new(env)?;

  spawn(async move {
    match fut.await {
      Ok(v) => deferred.resolve(|env| {
        resolver(env.raw(), v).map(|v| unsafe { JsUnknown::from_raw_unchecked(env.raw(), v) })
      }),
      Err(e) => deferred.reject(e),
    }
  });

  Ok(promise.0.value)
}

Trait Implementations§

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
source§

impl From<*mut napi_env__> for Env

Converts to this type from the input type.

Auto Trait Implementations§

Blanket Implementations§

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Calls U::from(self).

That is, this conversion is whatever the implementation of From<T> for U chooses to do.

The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.