server: Refactor code around service_fn

Author: leoyvens

core/src/subgraph/registrar.rs

@@ -256,7 +256,7 @@ where
                     let sender = sender.clone();
                     let provider = provider.clone();
                     let logger = logger.clone();
-                    
+
                     // Blocking due to store interactions. Won't be blocking after #905.
                     graph::spawn_blocking(
                         start_subgraph(id, &*provider, logger)

server/http/src/server.rs

@@ -86,21 +86,14 @@ where
         let store = self.store.clone();
         let node_id = self.node_id.clone();
         let new_service = make_service_fn(move |_| {
-            let logger_for_service = logger_for_service.clone();
-            let metrics = metrics.clone();
-            let graphql_runner = graphql_runner.clone();
-            let store = store.clone();
-            let node_id = node_id.clone();
-            async move {
-                Result::<_, Error>::Ok(GraphQLService::new(
-                    logger_for_service.clone(),
-                    metrics.clone(),
-                    graphql_runner.clone(),
-                    store.clone(),
-                    ws_port,
-                    node_id.clone(),
-                ))
-            }
+            futures03::future::ok::<_, Error>(GraphQLService::new(
+                logger_for_service.clone(),
+                metrics.clone(),
+                graphql_runner.clone(),
+                store.clone(),
+                ws_port,
+                node_id.clone(),
+            ))
         });
 
         // Create a task to run the server and handle HTTP requests

server/index-node/src/server.rs

@@ -81,18 +81,12 @@ where
         let store = self.store.clone();
         let node_id = self.node_id.clone();
         let new_service = make_service_fn(move |_| {
-            let logger_for_service = logger_for_service.clone();
-            let graphql_runner = graphql_runner.clone();
-            let store = store.clone();
-            let node_id = node_id.clone();
-            async move {
-                Result::<_, Error>::Ok(IndexNodeService::new(
-                    logger_for_service.clone(),
-                    graphql_runner.clone(),
-                    store.clone(),
-                    node_id.clone(),
-                ))
-            }
+            futures03::future::ok::<_, Error>(IndexNodeService::new(
+                logger_for_service.clone(),
+                graphql_runner.clone(),
+                store.clone(),
+                node_id.clone(),
+            ))
         });
 
         // Create a task to run the server and handle HTTP requests

server/metrics/src/lib.rs

@@ -63,22 +63,20 @@ impl MetricsServerTrait for PrometheusMetricsServer {
         let server = self.clone();
         let new_service = make_service_fn(move |_req| {
             let server = server.clone();
+            let registry = server.registry.clone();
             async move {
                 Ok::<_, Error>(service_fn(move |_| {
-                    let registry = server.registry.clone();
-                    async move {
-                        let metric_families = registry.gather();
-                        let mut buffer = vec![];
-                        let encoder = TextEncoder::new();
-                        encoder.encode(&metric_families, &mut buffer).unwrap();
-                        Ok::<_, Error>(
-                            Response::builder()
-                                .status(200)
-                                .header(hyper::header::CONTENT_TYPE, encoder.format_type())
-                                .body(Body::from(buffer))
-                                .unwrap(),
-                        )
-                    }
+                    let metric_families = registry.gather();
+                    let mut buffer = vec![];
+                    let encoder = TextEncoder::new();
+                    encoder.encode(&metric_families, &mut buffer).unwrap();
+                    futures03::future::ok::<_, Error>(
+                        Response::builder()
+                            .status(200)
+                            .header(hyper::header::CONTENT_TYPE, encoder.format_type())
+                            .body(Body::from(buffer))
+                            .unwrap(),
+                    )
                 }))
             }
         });