Use async-std in multipart example and treat all errors.

multipart/Cargo.toml

@@ -14,3 +14,4 @@ futures = "0.3.1"
 actix-multipart = "0.2.0"
 actix-web = "2.0.0"
 actix-rt = "1.0.0"
+async-std = "1.4.0"

multipart/src/main.rs

@@ -1,25 +1,26 @@
-use std::io::Write;
-
 use actix_multipart::Multipart;
 use actix_web::{middleware, web, App, Error, HttpResponse, HttpServer};
+use async_std;
+use async_std::prelude::*;
 use futures::StreamExt;
 
 async fn save_file(mut payload: Multipart) -> Result<HttpResponse, Error> {
     // iterate over multipart stream
     while let Some(item) = payload.next().await {
         let mut field = item?;
-        let content_type = field.content_disposition().unwrap();
-        let filename = content_type.get_filename().unwrap();
+        let content_type = field
+            .content_disposition()
+            .ok_or_else(|| actix_web::error::ParseError::Incomplete)?;
+        let filename = content_type
+            .get_filename()
+            .ok_or_else(|| actix_web::error::ParseError::Incomplete)?;
         let filepath = format!("./tmp/{}", filename);
-        // File::create is blocking operation, use threadpool
-        let mut f = web::block(|| std::fs::File::create(filepath))
-            .await
-            .unwrap();
+        let mut f = async_std::fs::File::create(filepath).await?;
+
         // Field in turn is stream of *Bytes* object
         while let Some(chunk) = field.next().await {
             let data = chunk.unwrap();
-            // filesystem operations are blocking, we have to use threadpool
-            f = web::block(move || f.write_all(&data).map(|_| f)).await?;
+            f.write_all(&data).await?;
         }
     }
     Ok(HttpResponse::Ok().into())
@@ -42,7 +43,7 @@ fn index() -> HttpResponse {
 #[actix_rt::main]
 async fn main() -> std::io::Result<()> {
     std::env::set_var("RUST_LOG", "actix_server=info,actix_web=info");
-    std::fs::create_dir_all("./tmp").unwrap();
+    async_std::fs::create_dir_all("./tmp").await?;
 
     let ip = "0.0.0.0:3000";