Support gRPC packages in generated code

Include package names in the `NamedService` identifier and request
paths. Change generated imports to use `crate` and add `tokio` and
`tokio-stream` dependencies to `roto-tonic`.

Cargo.lock

@@ -1201,6 +1201,8 @@ dependencies = [
  "http-body-util",
  "prost",
  "roto-runtime",
+ "tokio",
+ "tokio-stream",
  "tonic",
  "tower 0.4.13",
 ]

codegen/src/generator.rs

@@ -562,7 +562,7 @@ pub fn generate_rust_code(
         output.push_str("use futures_util::StreamExt;\n");
         output.push_str("use http_body_util::BodyExt;\n");
         output.push_str("use http_body::Body;\n");
-        output.push_str("use roto_tonic::{BufferPool, StatusBody};\n\n");
+        output.push_str("use crate::{BufferPool, StatusBody};\n\n");
 
         for dep_res in file_proto.dependency() {
             let (dep_data, _) = dep_res.expect("Failed to iterate dependency");
@@ -595,6 +595,7 @@ pub fn generate_rust_code(
             let (svc_data, _) = svc_res.expect("Failed to iterate service");
             write_service(
                 &ServiceDescriptorProto::new(svc_data).expect("Failed to parse ServiceDescriptorProto"),
+                file_proto.package().unwrap_or(""),
                 &mut output,
             );
         }
@@ -654,7 +655,7 @@ pub fn generate_rust_code(
     generated_files
 }
 
-fn write_service(svc_proto: &ServiceDescriptorProto, output: &mut String) {
+fn write_service(svc_proto: &ServiceDescriptorProto, package: &str, output: &mut String) {
     let svc_name = to_pascal_case(svc_proto.name().unwrap());
     output.push_str(&format!("#[tonic::async_trait]\npub trait {}: Send + Sync + 'static {{\n", svc_name));
 
@@ -707,7 +708,12 @@ fn write_service(svc_proto: &ServiceDescriptorProto, output: &mut String) {
     output.push_str("}\n\n");
 
     output.push_str(&format!("impl tonic::server::NamedService for {} {{\n", server_name));
-    output.push_str(&format!("    const NAME: &'static str = \"{}\";\n", svc_proto.name().unwrap()));
+    let full_svc_name = if package.is_empty() {
+        svc_proto.name().unwrap().to_string()
+    } else {
+        format!("{}.{}", package, svc_proto.name().unwrap())
+    };
+    output.push_str(&format!("    const NAME: &'static str = \"{}\";\n", full_svc_name));
     output.push_str("}\n\n");
 
     output.push_str(&format!("impl Service<http::Request<BoxBody>> for {} {{\n", server_name));
@@ -756,7 +762,12 @@ fn write_service(svc_proto: &ServiceDescriptorProto, output: &mut String) {
     }
 
     for (method_name, input_owned) in methods {
-        output.push_str(&format!("            if path == \"/{}/{}\" {{\n", svc_proto.name().unwrap(), method_name));
+        let full_path = if package.is_empty() {
+            format!("/{}/{}", svc_proto.name().unwrap(), method_name)
+        } else {
+            format!("/{}.{}/{}", package, svc_proto.name().unwrap(), method_name)
+        };
+        output.push_str(&format!("            if path == \"{}\" {{\n", full_path));
         output.push_str(&format!("                let request_msg = match {}::decode(payload) {{\n", input_owned));
         output.push_str("                    Ok(msg) => msg,\n");
         output.push_str("                    Err(e) => {\n");

roto-tonic/Cargo.toml

@@ -12,4 +12,6 @@ http-body = "1.0"
 http-body-util = "0.1"
 tower = "0.4"
 futures-util = "0.3"
+tokio-stream = { version = "0.1", features = ["net"] }
+tokio = { version = "1.38", features = ["full"] }
 http = "1.1"

roto-tonic/src/lib.rs

@@ -8,6 +8,10 @@ use std::future::Future;
 use std::task::{Context, Poll};
 use http_body::Body;
 
+pub mod generated {
+    pub mod helloworld;
+}
+
 pub struct RotoCodec<T, U> {
     _phantom: PhantomData<(T, U)>,
 }