Fix generated code and update example integration

Resolve `Result` ambiguity and lifetime issues in generated services.
Use `file_stem` for proto filenames. Make `StatusBody` public in
`roto-tonic` and update the `hello_world` build process.

examples/hello_world/Cargo.toml

@@ -27,3 +27,4 @@ http-body = "1.0"
 
 [build-dependencies]
 tonic-build = "0.12"
+roto-codegen = { path = "../../codegen" }

examples/hello_world/build.rs

@@ -4,9 +4,9 @@ fn main() {
     let dest_path = std::path::Path::new(&out_dir).join("hello.rs");
 
     // Find the protoc-gen-roto binary
-    // In a real scenario, this should be passed as an environment variable or found in PATH
-    // For this example, we'll try to find it in the target directory
-    let target_dir = std::env::current_dir().unwrap().join("../../target/debug");
+    // Since we added roto-codegen to build-dependencies, it will be built.
+    let manifest_dir = std::env::var("CARGO_MANIFEST_DIR").unwrap();
+    let target_dir = std::path::Path::new(&manifest_dir).join("../../target/debug");
     let plugin_path = target_dir.join("protoc-gen-roto");
 
     if !plugin_path.exists() {

examples/hello_world/proto/hello.rs

@@ -0,0 +1,310 @@
+// @generated by protoc-gen-roto — do not edit
+#[allow(unused_imports)]
+
+use roto_runtime::{ProtoAccessor, ProtoBuilder, Result, RotoError, read_varint, RepeatedFieldIterator};
+use std::str;
+use bytes::{Bytes, BytesMut, Buf, BufMut};
+use tonic::{Request, Response, Status};
+use tokio_stream::Stream;
+use std::pin::Pin;
+use std::sync::Arc;
+use std::task::{Context, Poll};
+use std::future::Future;
+use tonic::body::BoxBody;
+use tower::Service;
+use futures_util::StreamExt;
+use http_body_util::BodyExt;
+use http_body::Body;
+use roto_tonic::{BufferPool, StatusBody};
+
+
+pub struct HelloRequest<'a> {
+    accessor: roto_runtime::ProtoAccessor<'a>,
+    name_offset: Option<usize>,
+}
+
+impl<'a> HelloRequest<'a> {
+    pub fn new(data: &'a [u8]) -> roto_runtime::Result<Self> {
+        let accessor = roto_runtime::ProtoAccessor::new(data)?;
+        let mut name_offset = None;
+        for item in accessor.fields() {
+            let (offset, tag, _) = item?;
+            if tag.field_number == 1 { name_offset = Some(offset); }
+        }
+
+        Ok(Self {
+            accessor,
+name_offset,
+        })
+    }
+
+    pub fn name(&self) -> roto_runtime::Result<&'a str> {
+        let offset = self.name_offset.ok_or(roto_runtime::RotoError::FieldNotFound)?;
+        let (bytes, _) = self.accessor.get_value_at(offset)?;
+        str::from_utf8(bytes).map_err(|_| roto_runtime::RotoError::WireFormatViolation)
+    }
+
+    pub fn name_or_default(&self) -> roto_runtime::Result<&'a str> {
+        self.name().or(Ok(""))
+    }
+
+    pub fn has_name(&self) -> bool { self.name_offset.is_some() }
+
+    pub fn raw_fields(&self) -> roto_runtime::RawFieldIterator<'a> {
+        self.accessor.raw_fields()
+    }
+
+}
+
+pub struct HelloRequestBuilder<'b> {
+    builder: roto_runtime::ProtoBuilder<'b>,
+    name_written: bool,
+}
+
+impl<'b> HelloRequestBuilder<'b> {
+    pub fn builder(buf: &mut [u8]) -> HelloRequestBuilder<'_> {
+        HelloRequestBuilder {
+            builder: roto_runtime::ProtoBuilder::new(buf),
+            name_written: false,
+        }
+    }
+
+    pub fn name(mut self, value: &str) -> roto_runtime::Result<Self> {
+        self.builder.write_string(1, value)?;
+        self.name_written = true;
+        Ok(self)
+    }
+
+    pub fn with(mut self, msg: &HelloRequest<'_>) -> roto_runtime::Result<Self> {
+        for item in msg.raw_fields() {
+            let (field_number, raw_bytes) = item?;
+            let is_written = match field_number {
+                1 => self.name_written,
+                _ => false,
+            };
+            if !is_written {
+                self.builder.write_raw(raw_bytes)?;
+            }
+        }
+        Ok(self)
+    }
+
+    pub fn finish(self) -> roto_runtime::Result<&'b mut [u8]> {
+        self.builder.finish()
+    }
+}
+
+pub struct OwnedHelloRequest {
+    pub data: bytes::Bytes,
+}
+
+impl roto_runtime::RotoOwned for OwnedHelloRequest {
+    type Reader<'a> = HelloRequest<'a>;
+    fn reader(&self) -> HelloRequest<'_> {
+        HelloRequest::new(&self.data).expect("failed to create reader")
+    }
+}
+
+impl roto_runtime::RotoMessage for OwnedHelloRequest {
+    fn decode(buf: bytes::Bytes) -> roto_runtime::Result<Self> {
+        Ok(OwnedHelloRequest { data: buf })
+    }
+
+    fn bytes(&self) -> bytes::Bytes {
+        self.data.clone()
+    }
+}
+
+pub struct HelloResponse<'a> {
+    accessor: roto_runtime::ProtoAccessor<'a>,
+    message_offset: Option<usize>,
+}
+
+impl<'a> HelloResponse<'a> {
+    pub fn new(data: &'a [u8]) -> roto_runtime::Result<Self> {
+        let accessor = roto_runtime::ProtoAccessor::new(data)?;
+        let mut message_offset = None;
+        for item in accessor.fields() {
+            let (offset, tag, _) = item?;
+            if tag.field_number == 1 { message_offset = Some(offset); }
+        }
+
+        Ok(Self {
+            accessor,
+message_offset,
+        })
+    }
+
+    pub fn message(&self) -> roto_runtime::Result<&'a str> {
+        let offset = self.message_offset.ok_or(roto_runtime::RotoError::FieldNotFound)?;
+        let (bytes, _) = self.accessor.get_value_at(offset)?;
+        str::from_utf8(bytes).map_err(|_| roto_runtime::RotoError::WireFormatViolation)
+    }
+
+    pub fn message_or_default(&self) -> roto_runtime::Result<&'a str> {
+        self.message().or(Ok(""))
+    }
+
+    pub fn has_message(&self) -> bool { self.message_offset.is_some() }
+
+    pub fn raw_fields(&self) -> roto_runtime::RawFieldIterator<'a> {
+        self.accessor.raw_fields()
+    }
+
+}
+
+pub struct HelloResponseBuilder<'b> {
+    builder: roto_runtime::ProtoBuilder<'b>,
+    message_written: bool,
+}
+
+impl<'b> HelloResponseBuilder<'b> {
+    pub fn builder(buf: &mut [u8]) -> HelloResponseBuilder<'_> {
+        HelloResponseBuilder {
+            builder: roto_runtime::ProtoBuilder::new(buf),
+            message_written: false,
+        }
+    }
+
+    pub fn message(mut self, value: &str) -> roto_runtime::Result<Self> {
+        self.builder.write_string(1, value)?;
+        self.message_written = true;
+        Ok(self)
+    }
+
+    pub fn with(mut self, msg: &HelloResponse<'_>) -> roto_runtime::Result<Self> {
+        for item in msg.raw_fields() {
+            let (field_number, raw_bytes) = item?;
+            let is_written = match field_number {
+                1 => self.message_written,
+                _ => false,
+            };
+            if !is_written {
+                self.builder.write_raw(raw_bytes)?;
+            }
+        }
+        Ok(self)
+    }
+
+    pub fn finish(self) -> roto_runtime::Result<&'b mut [u8]> {
+        self.builder.finish()
+    }
+}
+
+pub struct OwnedHelloResponse {
+    pub data: bytes::Bytes,
+}
+
+impl roto_runtime::RotoOwned for OwnedHelloResponse {
+    type Reader<'a> = HelloResponse<'a>;
+    fn reader(&self) -> HelloResponse<'_> {
+        HelloResponse::new(&self.data).expect("failed to create reader")
+    }
+}
+
+impl roto_runtime::RotoMessage for OwnedHelloResponse {
+    fn decode(buf: bytes::Bytes) -> roto_runtime::Result<Self> {
+        Ok(OwnedHelloResponse { data: buf })
+    }
+
+    fn bytes(&self) -> bytes::Bytes {
+        self.data.clone()
+    }
+}
+
+#[tonic::async_trait]
+pub trait HelloWorldService: Send + Sync + 'static {
+    async fn hello_world(&self, request: Request<OwnedHelloRequest>) -> std::result::Result<Response<OwnedHelloResponse>, Status>;
+}
+
+pub struct HelloWorldServiceServer {
+    inner: Arc<dyn HelloWorldService>,
+    pool: Arc<BufferPool>,
+}
+
+impl HelloWorldServiceServer {
+    pub fn new(inner: Arc<dyn HelloWorldService>, pool: Arc<BufferPool>) -> Self {
+        Self { inner, pool }
+    }
+}
+
+impl tonic::server::NamedService for HelloWorldServiceServer {
+    const NAME: &'static str = "HelloWorldService";
+}
+
+impl Service<http::Request<BoxBody>> for HelloWorldServiceServer {
+    type Response = http::Response<BoxBody>;
+    type Error = std::convert::Infallible;
+    type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>> + Send>>;
+
+    fn poll_ready(&mut self, _: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
+        Poll::Ready(Ok(()))
+    }
+
+    fn call(&mut self, req: http::Request<BoxBody>) -> Self::Future {
+        let inner = self.inner.clone();
+        let pool = self.pool.clone();
+        Box::pin(async move {
+            let body = req.into_body();
+            let mut buf = pool.get();
+            let mut stream = body;
+            while let Some(frame_result) = stream.frame().await {
+                let frame = frame_result.map_err(|e| {
+                    panic!("Body frame error: {}", e);
+                })?;
+                if let Some(data) = frame.data_ref() {
+                    buf.put(data.clone());
+                }
+            }
+
+            let total_len = buf.len();
+            let bytes_vec = buf.split_to(total_len).freeze();
+            pool.put(buf);
+            if bytes_vec.len() < 5 {
+                let res_body = BoxBody::new(StatusBody(Some(Bytes::from_static(&[0, 0, 0, 0, 0]))));
+                return Ok(http::Response::builder().status(200).body(res_body).unwrap());
+            }
+
+            let payload = bytes_vec.slice(5..);
+            let path = req.uri().path();
+            let mut routed = false;
+
+            if path == "/HelloWorldService/hello_world" {
+                let request_msg = match OwnedHelloRequest::decode(payload) {
+                    Ok(msg) => msg,
+                    Err(e) => {
+                        let res_body = BoxBody::new(StatusBody(Some(Bytes::from_static(&[0, 0, 0, 0, 0]))));
+                        return Ok(http::Response::builder().status(200).body(res_body).unwrap());
+                    }
+                }};
+
+                let response = match inner.hello_world(Request::new(request_msg)).await {
+                    Ok(res) => res,
+                    Err(e) => {
+                        let res_body = BoxBody::new(StatusBody(Some(Bytes::from_static(&[0, 0, 0, 0, 0]))));
+                        return Ok(http::Response::builder().status(200).body(res_body).unwrap());
+                    }
+                }};
+
+                let response_msg = response.into_inner();
+                let response_bytes = response_msg.bytes();
+                let mut res_buf = pool.get();
+                res_buf.put_u8(0);
+                let len = response_bytes.len() as u32;
+                res_buf.put_slice(&len.to_be_bytes());
+                res_buf.put_slice(&response_bytes);
+                let frame_len = res_buf.len();
+                let frame = res_buf.split_to(frame_len).freeze();
+                pool.put(res_buf);
+                let res_body = BoxBody::new(StatusBody(Some(frame)));
+                routed = true;
+                return Ok(http::Response::builder().status(200).header("content-type", "application/grpc").body(res_body).unwrap());
+            }
+            if !routed {
+                let res_body = BoxBody::new(StatusBody(Some(Bytes::from_static(&[0, 0, 0, 0, 0]))));
+                return Ok(http::Response::builder().status(200).body(res_body).unwrap());
+            }
+            Ok(http::Response::builder().status(200).body(BoxBody::new(StatusBody(None))).unwrap())
+        })
+    }
+}