Currently I'm checking out Actix, a Rust based actor framework. I'm also using Actix web to build a REST API. Now, I'm familiar with actor based architecture from working with Akka, however, I'm not being able to start a simple async task inside of my handler.
It's simplified, but I have the following code:
#[post("/upload")]
pub async fn upload_images(
app_config: web::Data<AppConfig>,
mut payload: Multipart,
) -> Result<HttpResponse> {
... transforms the multipart form into images...
for img in img_vec {
app_config.image_processor_addr.do_send(ResizeImage{
img_id: img._id,
img_format: img.format,
image_buffer: img.image.bytes,
});
};
Ok(HttpResponse::Ok().content_type(ContentType::plaintext()).body(format!("Inserted {} images.", vec_len)))
}
As you can see, I receive a multipart upload which consists of images, which I then send to an image processing actor to perform a resize on the images.
And this is the simplified code for the handling of the message ResizeImage for the ImageProcessor actor:
impl Handler<ResizeImage> for ImageProcessor {
type Result = ();
fn handle(&mut self, msg: ResizeImage, _: &mut Self::Context) -> Self::Result {
let thumbnail_col = self.thumbnail_col.clone();
let img_col = self.img_col.clone();
let img_format: ImageFormat = msg.img_format.clone().into();
log::info!("Parsing image {} with actor {}.", msg.img_id, self.id);
let actor_task_fut = Box::pin(async move {
... parses the image here...
});
match Arbiter::current().spawn(actor_task_fut) {
true => log::info!("Sent task to arbiter."),
false => log::error!("Failed to send task to arbiter!"),
}
}
}
The idea is that I would resolve the web handler, and the resize task would be done async on the actor thread. However, this works on the first call, but when I call the same endpoint before all the images from the previous call are parsed, it doesn't resolve immediately, it waits till the actor has resized the previous batch.
I was under the impression that the messages would be sent to the actor mailbox and then the handler code would not need to wait for anything, since I'm using do_sent, which the documentation states that it doesn't await for the answer. Using Akka I can easily do something similar, and it seems to work. Am I missing something here? Is the way I'm handling async inside the actor thread wrong?
