How do I access an Actix Web session store from a resolver?

[forty1thousand]

I have a project going where I need to store state inside of a session object and need to access it from inside of both a query and mutation resolver.

Here is a simple version of my current code.

_graphql.rs

use actix_session::Session;
use juniper::graphql_object;

pub struct MyCtx {
    ses: Session,
}

#[graphql_object(context = MyCtx)]
impl Query {
    // ...
}
// ...

_endpoints.rs

use crate::graphql::{Schema, MyCtx};
use actix_session::Session;
use actix_web::{HttpResponse, Error, HttpRequest, web::{Payload, Data}};

pub async fn graphql(
    req: HttpRequest,
    payload: Payload,
    schema: Data<Schema>,
    ses: Session
) -> Result<HttpResponse, Error> {
    let ctx = MyCtx { ses };
    graphql_handler(&schema, &ctx, req, payload).await
}
// ...

This code gives me a thread safety error when I run it.

`Rc<RefCell<actix_session::session::SessionInner>>` cannot be shared between threads safely
within `MyCtx`, the trait `Sync` is not implemented for `Rc<RefCell<actix_session::session::SessionInner>>`

I know the session store can also be accessed from a HttpRequest object but that also returns the same error.

Is there a workaround or an example of this being done?

[ilslv]

@forty1thousand actix uses a bunch of single-threaded tokio runtimes instead of a single multi-threaded to avoid overhead of work stealing, so many types are !Send. Due to limitations in Rust type system we can't be transparent over Send and Sync, but here it actually should be ok to use SendWrapper, which moves Send check into a runtime.

See

• https://github.com/actix/actix-extras/issues/251
• https://github.com/async-graphql/async-graphql/issues/426

[tyranron]

@forty1thousand I'm closing this as @ilslv gave the working solution, which we do use in our production without problem. Feel free to re-open if there are further questions.

[forty1thousand]

Is there an example of this being done somewhere