我正在使用Actix_web在Rust中构建API服务。我有一个API处理函数register_business，负责向数据库添加新业务。
my API处理程序函数

#[post("/businesses/")]
async fn add_business(payload: web::Json<BusinessPayload>,pool: Connection) ->Result<HttpResponse,Error>{
     //error thrown here web::block
    let reg_business = web::block(move || {
        let conn = pool.get().unwrap();
        register_business(payload.into_inner(), &conn)
    })
    .await
    .unwrap()
    .await
    .map_err(|_| actix_web::error::ErrorInternalServerError("Internal Server Error"))?;

    Ok(HttpResponse::Ok().json(reg_business))
}

字符串
register_business函数

pub async fn register_business(payload: BusinessPayload, conn: &PgConnection) -> Result<Business, DbError> {
    let images_paths = upload_images(payload.images).await.unwrap();

            let reg_business = NewBusiness {
                uuid: nanoid!(),
                images: images_paths,

               //assigning other payload values here
            };

            let res_registration = diesel::insert_into(businesses)
                .values(&reg_business)
                .get_result(conn)?;

            Ok(res_registration)
}

型
最后我的upload_image，它接受一个base64编码字符串数组，向cloudinary API发出请求并存储图像路径。

pub async fn upload_images(payload: Vec<String>) -> Result<Vec<String>, Error> {
    let client = Client::default();
    let mut uploaded_images = Vec::new();
     //TODO: move key to env var
    let api_key = String::from("api-key-here");
    let authorization_header = format!("Bearer {}", api_key);

    for image_data in payload {
        let response = client
            .post("https://api.cloudinary.com/v1_1/deye3gicq/image/upload")
            .insert_header(("Authorization", authorization_header.clone()))
            .send_body(image_data)
            .await
            .unwrap()
            .json::<Value>()
            .await
            .unwrap();

        if let Some(image_url) = response.get("imageUrl").and_then(Value::as_str) {
            uploaded_images.push(image_url.to_string());
            println!("{:?}", image_url);
        }
    }

    Ok(uploaded_images)
}

型
我正在使用这个项目来学习Rust，无法确定这里可能有什么问题。如有任何帮助，我们将不胜感激。
我试过检查Rust手册，但无法修复此错误。对于上下文，这是完整的编译器诊断错误。

error: future cannot be sent between threads safely
   --> src/routes/handlers.rs:32:24
    |
32  |     let reg_business = web::block(move || {
    |                        ^^^^^^^^^^ future returned by `register_business` is not `Send`
    |
    = help: within `diesel::PgConnection`, the trait `Sync` is not implemented for `NonNull<pq_sys::pg_conn>`
note: future is not `Send` as this value is used across an await
   --> src/utils/helpers.rs:19:53
    |
18  | pub async fn register_business(payload: BusinessPayload, conn: &PgConnection) -> Result<Business, DbError> {
    |                                                          ---- has type `&diesel::PgConnection` which is not `Send`
19  |     let images_paths = upload_images(payload.images).await.unwrap();
    |                                                     ^^^^^^ await occurs here, with `conn` maybe used later
...
44  | }
    | - `conn` is later dropped here
note: required by a bound in `block`
   --> /Users/cooper/.cargo/registry/src/github.com-1ecc6299db9ec823/actix-web-4.3.1/src/web.rs:215:8
    |
215 |     R: Send + 'static,
    |        ^^^^ required by this bound in `block`

型