feat(node): add Table.countRows()

[gsilvestrin]

No description provided.

[wjones127]

Should this be spawn instead of block_on? so that the promise can return before this task completes?

[gsilvestrin]

I spent some time trying to make spawm work here, but end up with the same "future is not send" error. I tried to refactor the mutex code and explicitly drop the mutex guard, but it did not help here.

error: future cannot be sent between threads safely
   --> rust/ffi/node/src/lib.rs:275:14
    |
275 |       rt.spawn(async move {
    |  ______________^
276 | |         let num_rows_result = table.lock().unwrap().count_rows().await;
277 | |
278 | |         deferred.settle_with(&channel, move |mut cx| {
...   |
281 | |         });
282 | |     });
    | |_____^ future created by async block is not `Send`
    |
    = help: within `[async block@rust/ffi/node/src/lib.rs:275:14: 282:6]`, the trait `std::marker::Send` is not implemented for `std::sync::MutexGuard<'_, Table>`
note: future is not `Send` as this value is used across an await

[wjones127]

I see. You can leave for a future PR then, but I think what we'll want to do is wrap the Mutex in an Arc.

[wjones127]

Unused variable?

[gsilvestrin]

We use it in the deferred.settle_with to send the value back to the caller

[wjones127]

Ah I see 👍