feat(tonic-web): implement grpc <-> grpc-web protocol translation (#455)

tonic-web enables tonic servers to handle requests from grpc-web clients directly, without the need of an external proxy. Co-authored-by: John Hernandez <[email protected]> Co-authored-by: zancas <[email protected]>
2021-05-13 12:20:33 -05:00
parent 352b0f584b
commit c309063254
24 changed files with 2445 additions and 2 deletions
@@ -0,0 +1,69 @@
+use std::pin::Pin;
+
+use tokio_stream::{self as stream, StreamExt, Stream};
+use tonic::{Request, Response, Status, Streaming};
+
+use pb::{test_server::Test, Input, Output};
+
+pub mod pb {
+    tonic::include_proto!("test");
+}
+
+type BoxStream<T> = Pin<Box<dyn Stream<Item = Result<T, Status>> + Send + Sync + 'static>>;
+
+pub struct Svc;
+
+#[tonic::async_trait]
+impl Test for Svc {
+    async fn unary_call(&self, req: Request<Input>) -> Result<Response<Output>, Status> {
+        let req = req.into_inner();
+
+        if &req.desc == "boom" {
+            Err(Status::invalid_argument("invalid boom"))
+        } else {
+            Ok(Response::new(Output {
+                id: req.id,
+                desc: req.desc,
+            }))
+        }
+    }
+
+    type ServerStreamStream = BoxStream<Output>;
+
+    async fn server_stream(
+        &self,
+        req: Request<Input>,
+    ) -> Result<Response<Self::ServerStreamStream>, Status> {
+        let req = req.into_inner();
+
+        Ok(Response::new(Box::pin(stream::iter(vec![1, 2]).map(
+            move |n| {
+                Ok(Output {
+                    id: req.id,
+                    desc: format!("{}-{}", n, req.desc),
+                })
+            },
+        ))))
+    }
+
+    async fn client_stream(
+        &self,
+        req: Request<Streaming<Input>>,
+    ) -> Result<Response<Output>, Status> {
+        let out = Output {
+            id: 0,
+            desc: "".into(),
+        };
+
+        Ok(Response::new(
+            req.into_inner()
+                .fold(out, |mut acc, input| {
+                    let input = input.unwrap();
+                    acc.id += input.id;
+                    acc.desc += &input.desc;
+                    acc
+                })
+                .await,
+        ))
+    }
+}