Struct napi::CallContext

source ·

pub struct CallContext<'env> {
    pub env: &'env mut Env,
    pub length: usize,
    /* private fields */
}

Expand description

Function call context

Fields§

§env: &'env mut Env§length: usize

arguments.length

Implementations§

source §

impl<'env> CallContext<'env>

source

pub fn new(
    env: &'env mut Env,
    callback_info: napi_callback_info,
    raw_this: napi_value,
    args: &'env [napi_value],
    length: usize
) -> Self

Examples found in repository ?

src/env.rs (line 580)

          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()
            })
          }