/rust/registry/src/index.crates.io-1949cf8c6b5b557f/tonic-0.13.0/src/server/grpc.rs

Source
use crate::codec::compression::{
    CompressionEncoding, EnabledCompressionEncodings, SingleMessageCompressionOverride,
};
use crate::codec::EncodeBody;
use crate::metadata::GRPC_CONTENT_TYPE;
use crate::{
    body::Body,
    codec::{Codec, Streaming},
    server::{ClientStreamingService, ServerStreamingService, StreamingService, UnaryService},
    Request, Status,
};
use http_body::Body as HttpBody;
use std::{fmt, pin::pin};
use tokio_stream::{Stream, StreamExt};

macro_rules! t {
    ($result:expr) => {
        match $result {
            Ok(value) => value,
            Err(status) => return status.into_http(),
        }
    };
}

/// A gRPC Server handler.
///
/// This will wrap some inner [`Codec`] and provide utilities to handle
/// inbound unary, client side streaming, server side streaming, and
/// bi-directional streaming.
///
/// Each request handler method accepts some service that implements the
/// corresponding service trait and a http request that contains some body that
/// implements some [`Body`].
pub struct Grpc<T> {
    codec: T,
    /// Which compression encodings does the server accept for requests?
    accept_compression_encodings: EnabledCompressionEncodings,
    /// Which compression encodings might the server use for responses.
    send_compression_encodings: EnabledCompressionEncodings,
    /// Limits the maximum size of a decoded message.
    max_decoding_message_size: Option<usize>,
    /// Limits the maximum size of an encoded message.
    max_encoding_message_size: Option<usize>,
}

impl<T> Grpc<T>
where
    T: Codec,
{
    /// Creates a new gRPC server with the provided [`Codec`].
    pub fn new(codec: T) -> Self {
        Self {
            codec,
            accept_compression_encodings: EnabledCompressionEncodings::default(),
            send_compression_encodings: EnabledCompressionEncodings::default(),
            max_decoding_message_size: None,
            max_encoding_message_size: None,
        }
    }

    /// Enable accepting compressed requests.
    ///
    /// If a request with an unsupported encoding is received the server will respond with
    /// [`Code::UnUnimplemented`](crate::Code).
    ///
    /// # Example
    ///
    /// The most common way of using this is through a server generated by tonic-build:
    ///
    /// ```rust
    /// # enum CompressionEncoding { Gzip }
    /// # struct Svc;
    /// # struct ExampleServer<T>(T);
    /// # impl<T> ExampleServer<T> {
    /// #     fn new(svc: T) -> Self { Self(svc) }
    /// #     fn accept_compressed(self, _: CompressionEncoding) -> Self { self }
    /// # }
    /// # #[tonic::async_trait]
    /// # trait Example {}
    ///
    /// #[tonic::async_trait]
    /// impl Example for Svc {
    ///     // ...
    /// }
    ///
    /// let service = ExampleServer::new(Svc).accept_compressed(CompressionEncoding::Gzip);
    /// ```
    pub fn accept_compressed(mut self, encoding: CompressionEncoding) -> Self {
        self.accept_compression_encodings.enable(encoding);
        self
    }

    /// Enable sending compressed responses.
    ///
    /// Requires the client to also support receiving compressed responses.
    ///
    /// # Example
    ///
    /// The most common way of using this is through a server generated by tonic-build:
    ///
    /// ```rust
    /// # enum CompressionEncoding { Gzip }
    /// # struct Svc;
    /// # struct ExampleServer<T>(T);
    /// # impl<T> ExampleServer<T> {
    /// #     fn new(svc: T) -> Self { Self(svc) }
    /// #     fn send_compressed(self, _: CompressionEncoding) -> Self { self }
    /// # }
    /// # #[tonic::async_trait]
    /// # trait Example {}
    ///
    /// #[tonic::async_trait]
    /// impl Example for Svc {
    ///     // ...
    /// }
    ///
    /// let service = ExampleServer::new(Svc).send_compressed(CompressionEncoding::Gzip);
    /// ```
    pub fn send_compressed(mut self, encoding: CompressionEncoding) -> Self {
        self.send_compression_encodings.enable(encoding);
        self
    }

    /// Limits the maximum size of a decoded message.
    ///
    /// # Example
    ///
    /// The most common way of using this is through a server generated by tonic-build:
    ///
    /// ```rust
    /// # struct Svc;
    /// # struct ExampleServer<T>(T);
    /// # impl<T> ExampleServer<T> {
    /// #     fn new(svc: T) -> Self { Self(svc) }
    /// #     fn max_decoding_message_size(self, _: usize) -> Self { self }
    /// # }
    /// # #[tonic::async_trait]
    /// # trait Example {}
    ///
    /// #[tonic::async_trait]
    /// impl Example for Svc {
    ///     // ...
    /// }
    ///
    /// // Set the limit to 2MB, Defaults to 4MB.
    /// let limit = 2 * 1024 * 1024;
    /// let service = ExampleServer::new(Svc).max_decoding_message_size(limit);
    /// ```
    pub fn max_decoding_message_size(mut self, limit: usize) -> Self {
        self.max_decoding_message_size = Some(limit);
        self
    }

    /// Limits the maximum size of a encoded message.
    ///
    /// # Example
    ///
    /// The most common way of using this is through a server generated by tonic-build:
    ///
    /// ```rust
    /// # struct Svc;
    /// # struct ExampleServer<T>(T);
    /// # impl<T> ExampleServer<T> {
    /// #     fn new(svc: T) -> Self { Self(svc) }
    /// #     fn max_encoding_message_size(self, _: usize) -> Self { self }
    /// # }
    /// # #[tonic::async_trait]
    /// # trait Example {}
    ///
    /// #[tonic::async_trait]
    /// impl Example for Svc {
    ///     // ...
    /// }
    ///
    /// // Set the limit to 2MB, Defaults to 4MB.
    /// let limit = 2 * 1024 * 1024;
    /// let service = ExampleServer::new(Svc).max_encoding_message_size(limit);
    /// ```
    pub fn max_encoding_message_size(mut self, limit: usize) -> Self {
        self.max_encoding_message_size = Some(limit);
        self
    }

    #[doc(hidden)]
    pub fn apply_compression_config(
        mut self,
        accept_encodings: EnabledCompressionEncodings,
        send_encodings: EnabledCompressionEncodings,
    ) -> Self {
        for &encoding in CompressionEncoding::ENCODINGS {
            if accept_encodings.is_enabled(encoding) {
                self = self.accept_compressed(encoding);
            }
            if send_encodings.is_enabled(encoding) {
                self = self.send_compressed(encoding);
            }
        }

        self
    }

    #[doc(hidden)]
    pub fn apply_max_message_size_config(
        mut self,
        max_decoding_message_size: Option<usize>,
        max_encoding_message_size: Option<usize>,
    ) -> Self {
        if let Some(limit) = max_decoding_message_size {
            self = self.max_decoding_message_size(limit);
        }
        if let Some(limit) = max_encoding_message_size {
            self = self.max_encoding_message_size(limit);
        }

        self
    }

    /// Handle a single unary gRPC request.
    pub async fn unary<S, B>(
        &mut self,
        mut service: S,
        req: http::Request<B>,
    ) -> http::Response<Body>
    where
        S: UnaryService<T::Decode, Response = T::Encode>,
        B: HttpBody + Send + 'static,
        B::Error: Into<crate::BoxError> + Send,
    {
        let accept_encoding = CompressionEncoding::from_accept_encoding_header(
            req.headers(),
            self.send_compression_encodings,
        );

        let request = match self.map_request_unary(req).await {
            Ok(r) => r,
            Err(status) => {
                return self.map_response::<tokio_stream::Once<Result<T::Encode, Status>>>(
                    Err(status),
                    accept_encoding,
                    SingleMessageCompressionOverride::default(),
                    self.max_encoding_message_size,
                );
            }
        };

        let response = service
            .call(request)
            .await
            .map(|r| r.map(|m| tokio_stream::once(Ok(m))));

        let compression_override = compression_override_from_response(&response);

        self.map_response(
            response,
            accept_encoding,
            compression_override,
            self.max_encoding_message_size,
        )
    }

    /// Handle a server side streaming request.
    pub async fn server_streaming<S, B>(
        &mut self,
        mut service: S,
        req: http::Request<B>,
    ) -> http::Response<Body>
    where
        S: ServerStreamingService<T::Decode, Response = T::Encode>,
        S::ResponseStream: Send + 'static,
        B: HttpBody + Send + 'static,
        B::Error: Into<crate::BoxError> + Send,
    {
        let accept_encoding = CompressionEncoding::from_accept_encoding_header(
            req.headers(),
            self.send_compression_encodings,
        );

        let request = match self.map_request_unary(req).await {
            Ok(r) => r,
            Err(status) => {
                return self.map_response::<S::ResponseStream>(
                    Err(status),
                    accept_encoding,
                    SingleMessageCompressionOverride::default(),
                    self.max_encoding_message_size,
                );
            }
        };

        let response = service.call(request).await;

        self.map_response(
            response,
            accept_encoding,
            // disabling compression of individual stream items must be done on
            // the items themselves
            SingleMessageCompressionOverride::default(),
            self.max_encoding_message_size,
        )
    }

    /// Handle a client side streaming gRPC request.
    pub async fn client_streaming<S, B>(
        &mut self,
        mut service: S,
        req: http::Request<B>,
    ) -> http::Response<Body>
    where
        S: ClientStreamingService<T::Decode, Response = T::Encode>,
        B: HttpBody + Send + 'static,
        B::Error: Into<crate::BoxError> + Send + 'static,
    {
        let accept_encoding = CompressionEncoding::from_accept_encoding_header(
            req.headers(),
            self.send_compression_encodings,
        );

        let request = t!(self.map_request_streaming(req));

        let response = service
            .call(request)
            .await
            .map(|r| r.map(|m| tokio_stream::once(Ok(m))));

        let compression_override = compression_override_from_response(&response);

        self.map_response(
            response,
            accept_encoding,
            compression_override,
            self.max_encoding_message_size,
        )
    }

    /// Handle a bi-directional streaming gRPC request.
    pub async fn streaming<S, B>(
        &mut self,
        mut service: S,
        req: http::Request<B>,
    ) -> http::Response<Body>
    where
        S: StreamingService<T::Decode, Response = T::Encode> + Send,
        S::ResponseStream: Send + 'static,
        B: HttpBody + Send + 'static,
        B::Error: Into<crate::BoxError> + Send,
    {
        let accept_encoding = CompressionEncoding::from_accept_encoding_header(
            req.headers(),
            self.send_compression_encodings,
        );

        let request = t!(self.map_request_streaming(req));

        let response = service.call(request).await;

        self.map_response(
            response,
            accept_encoding,
            SingleMessageCompressionOverride::default(),
            self.max_encoding_message_size,
        )
    }

    async fn map_request_unary<B>(
        &mut self,
        request: http::Request<B>,
    ) -> Result<Request<T::Decode>, Status>
    where
        B: HttpBody + Send + 'static,
        B::Error: Into<crate::BoxError> + Send,
    {
        let request_compression_encoding = self.request_encoding_if_supported(&request)?;

        let (parts, body) = request.into_parts();

        let mut stream = pin!(Streaming::new_request(
            self.codec.decoder(),
            body,
            request_compression_encoding,
            self.max_decoding_message_size,
        ));

        let message = stream
            .try_next()
            .await?
            .ok_or_else(|| Status::internal("Missing request message."))?;

        let mut req = Request::from_http_parts(parts, message);

        if let Some(trailers) = stream.trailers().await? {
            req.metadata_mut().merge(trailers);
        }

        Ok(req)
    }

    fn map_request_streaming<B>(
        &mut self,
        request: http::Request<B>,
    ) -> Result<Request<Streaming<T::Decode>>, Status>
    where
        B: HttpBody + Send + 'static,
        B::Error: Into<crate::BoxError> + Send,
    {
        let encoding = self.request_encoding_if_supported(&request)?;

        let request = request.map(|body| {
            Streaming::new_request(
                self.codec.decoder(),
                body,
                encoding,
                self.max_decoding_message_size,
            )
        });

        Ok(Request::from_http(request))
    }

    fn map_response<B>(
        &mut self,
        response: Result<crate::Response<B>, Status>,
        accept_encoding: Option<CompressionEncoding>,
        compression_override: SingleMessageCompressionOverride,
        max_message_size: Option<usize>,
    ) -> http::Response<Body>
    where
        B: Stream<Item = Result<T::Encode, Status>> + Send + 'static,
    {
        let response = t!(response);

        let (mut parts, body) = response.into_http().into_parts();

        // Set the content type
        parts
            .headers
            .insert(http::header::CONTENT_TYPE, GRPC_CONTENT_TYPE);

        #[cfg(any(feature = "gzip", feature = "deflate", feature = "zstd"))]
        if let Some(encoding) = accept_encoding {
            // Set the content encoding
            parts.headers.insert(
                crate::codec::compression::ENCODING_HEADER,
                encoding.into_header_value(),
            );
        }

        let body = EncodeBody::new_server(
            self.codec.encoder(),
            body,
            accept_encoding,
            compression_override,
            max_message_size,
        );

        http::Response::from_parts(parts, Body::new(body))
    }

    fn request_encoding_if_supported<B>(
        &self,
        request: &http::Request<B>,
    ) -> Result<Option<CompressionEncoding>, Status> {
        CompressionEncoding::from_encoding_header(
            request.headers(),
            self.accept_compression_encodings,
        )
    }
}

impl<T: fmt::Debug> fmt::Debug for Grpc<T> {
    fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
        f.debug_struct("Grpc")
            .field("codec", &self.codec)
            .field(
                "accept_compression_encodings",
                &self.accept_compression_encodings,
            )
            .field(
                "send_compression_encodings",
                &self.send_compression_encodings,
            )
            .finish()
    }
}

fn compression_override_from_response<B, E>(
    res: &Result<crate::Response<B>, E>,
) -> SingleMessageCompressionOverride {
    res.as_ref()
        .ok()
        .and_then(|response| {
            response
                .extensions()
                .get::<SingleMessageCompressionOverride>()
                .copied()
        })
        .unwrap_or_default()
}

Coverage Report

Created: 2025-10-29 07:05

Line	Count	Source
1		use crate::codec::compression::{
2		CompressionEncoding, EnabledCompressionEncodings, SingleMessageCompressionOverride,
3		};
4		use crate::codec::EncodeBody;
5		use crate::metadata::GRPC_CONTENT_TYPE;
6		use crate::{
7		body::Body,
8		codec::{Codec, Streaming},
9		server::{ClientStreamingService, ServerStreamingService, StreamingService, UnaryService},
10		Request, Status,
11		};
12		use http_body::Body as HttpBody;
13		use std::{fmt, pin::pin};
14		use tokio_stream::{Stream, StreamExt};
15
16		macro_rules! t {
17		($result:expr) => {
18		match $result {
19		Ok(value) => value,
20		Err(status) => return status.into_http(),
21		}
22		};
23		}
24
25		/// A gRPC Server handler.
26		///
27		/// This will wrap some inner [`Codec`] and provide utilities to handle
28		/// inbound unary, client side streaming, server side streaming, and
29		/// bi-directional streaming.
30		///
31		/// Each request handler method accepts some service that implements the
32		/// corresponding service trait and a http request that contains some body that
33		/// implements some [`Body`].
34		pub struct Grpc<T> {
35		codec: T,
36		/// Which compression encodings does the server accept for requests?
37		accept_compression_encodings: EnabledCompressionEncodings,
38		/// Which compression encodings might the server use for responses.
39		send_compression_encodings: EnabledCompressionEncodings,
40		/// Limits the maximum size of a decoded message.
41		max_decoding_message_size: Option<usize>,
42		/// Limits the maximum size of an encoded message.
43		max_encoding_message_size: Option<usize>,
44		}
45
46		impl<T> Grpc<T>
47		where
48		T: Codec,
49		{
50		/// Creates a new gRPC server with the provided [`Codec`].
51	0	pub fn new(codec: T) -> Self {
52	0	Self {
53	0	codec,
54	0	accept_compression_encodings: EnabledCompressionEncodings::default(),
55	0	send_compression_encodings: EnabledCompressionEncodings::default(),
56	0	max_decoding_message_size: None,
57	0	max_encoding_message_size: None,
58	0	}
59	0	}
60
61		/// Enable accepting compressed requests.
62		///
63		/// If a request with an unsupported encoding is received the server will respond with
64		/// [`Code::UnUnimplemented`](crate::Code).
65		///
66		/// # Example
67		///
68		/// The most common way of using this is through a server generated by tonic-build:
69		///
70		/// ```rust
71		/// # enum CompressionEncoding { Gzip }
72		/// # struct Svc;
73		/// # struct ExampleServer<T>(T);
74		/// # impl<T> ExampleServer<T> {
75		/// # fn new(svc: T) -> Self { Self(svc) }
76		/// # fn accept_compressed(self, _: CompressionEncoding) -> Self { self }
77		/// # }
78		/// # #[tonic::async_trait]
79		/// # trait Example {}
80		///
81		/// #[tonic::async_trait]
82		/// impl Example for Svc {
83		/// // ...
84		/// }
85		///
86		/// let service = ExampleServer::new(Svc).accept_compressed(CompressionEncoding::Gzip);
87		/// ```
88	0	pub fn accept_compressed(mut self, encoding: CompressionEncoding) -> Self {
89	0	self.accept_compression_encodings.enable(encoding);
90	0	self
91	0	}
92
93		/// Enable sending compressed responses.
94		///
95		/// Requires the client to also support receiving compressed responses.
96		///
97		/// # Example
98		///
99		/// The most common way of using this is through a server generated by tonic-build:
100		///
101		/// ```rust
102		/// # enum CompressionEncoding { Gzip }
103		/// # struct Svc;
104		/// # struct ExampleServer<T>(T);
105		/// # impl<T> ExampleServer<T> {
106		/// # fn new(svc: T) -> Self { Self(svc) }
107		/// # fn send_compressed(self, _: CompressionEncoding) -> Self { self }
108		/// # }
109		/// # #[tonic::async_trait]
110		/// # trait Example {}
111		///
112		/// #[tonic::async_trait]
113		/// impl Example for Svc {
114		/// // ...
115		/// }
116		///
117		/// let service = ExampleServer::new(Svc).send_compressed(CompressionEncoding::Gzip);
118		/// ```
119	0	pub fn send_compressed(mut self, encoding: CompressionEncoding) -> Self {
120	0	self.send_compression_encodings.enable(encoding);
121	0	self
122	0	}
123
124		/// Limits the maximum size of a decoded message.
125		///
126		/// # Example
127		///
128		/// The most common way of using this is through a server generated by tonic-build:
129		///
130		/// ```rust
131		/// # struct Svc;
132		/// # struct ExampleServer<T>(T);
133		/// # impl<T> ExampleServer<T> {
134		/// # fn new(svc: T) -> Self { Self(svc) }
135		/// # fn max_decoding_message_size(self, _: usize) -> Self { self }
136		/// # }
137		/// # #[tonic::async_trait]
138		/// # trait Example {}
139		///
140		/// #[tonic::async_trait]
141		/// impl Example for Svc {
142		/// // ...
143		/// }
144		///
145		/// // Set the limit to 2MB, Defaults to 4MB.
146		/// let limit = 2 * 1024 * 1024;
147		/// let service = ExampleServer::new(Svc).max_decoding_message_size(limit);
148		/// ```
149	0	pub fn max_decoding_message_size(mut self, limit: usize) -> Self {
150	0	self.max_decoding_message_size = Some(limit);
151	0	self
152	0	}
153
154		/// Limits the maximum size of a encoded message.
155		///
156		/// # Example
157		///
158		/// The most common way of using this is through a server generated by tonic-build:
159		///
160		/// ```rust
161		/// # struct Svc;
162		/// # struct ExampleServer<T>(T);
163		/// # impl<T> ExampleServer<T> {
164		/// # fn new(svc: T) -> Self { Self(svc) }
165		/// # fn max_encoding_message_size(self, _: usize) -> Self { self }
166		/// # }
167		/// # #[tonic::async_trait]
168		/// # trait Example {}
169		///
170		/// #[tonic::async_trait]
171		/// impl Example for Svc {
172		/// // ...
173		/// }
174		///
175		/// // Set the limit to 2MB, Defaults to 4MB.
176		/// let limit = 2 * 1024 * 1024;
177		/// let service = ExampleServer::new(Svc).max_encoding_message_size(limit);
178		/// ```
179	0	pub fn max_encoding_message_size(mut self, limit: usize) -> Self {
180	0	self.max_encoding_message_size = Some(limit);
181	0	self
182	0	}
183
184		#[doc(hidden)]
185	0	pub fn apply_compression_config(
186	0	mut self,
187	0	accept_encodings: EnabledCompressionEncodings,
188	0	send_encodings: EnabledCompressionEncodings,
189	0	) -> Self {
190	0	for &encoding in CompressionEncoding::ENCODINGS {
191	0	if accept_encodings.is_enabled(encoding) {
192	0	self = self.accept_compressed(encoding);
193	0	}
194	0	if send_encodings.is_enabled(encoding) {
195	0	self = self.send_compressed(encoding);
196	0	}
197		}
198
199	0	self
200	0	}
201
202		#[doc(hidden)]
203	0	pub fn apply_max_message_size_config(
204	0	mut self,
205	0	max_decoding_message_size: Option<usize>,
206	0	max_encoding_message_size: Option<usize>,
207	0	) -> Self {
208	0	if let Some(limit) = max_decoding_message_size {
209	0	self = self.max_decoding_message_size(limit);
210	0	}
211	0	if let Some(limit) = max_encoding_message_size {
212	0	self = self.max_encoding_message_size(limit);
213	0	}
214
215	0	self
216	0	}
217
218		/// Handle a single unary gRPC request.
219	0	pub async fn unary<S, B>(
220	0	&mut self,
221	0	mut service: S,
222	0	req: http::Request<B>,
223	0	) -> http::Response<Body>
224	0	where
225	0	S: UnaryService<T::Decode, Response = T::Encode>,
226	0	B: HttpBody + Send + 'static,
227	0	B::Error: Into<crate::BoxError> + Send,
228	0	{
229	0	let accept_encoding = CompressionEncoding::from_accept_encoding_header(
230	0	req.headers(),
231	0	self.send_compression_encodings,
232		);
233
234	0	let request = match self.map_request_unary(req).await {
235	0	Ok(r) => r,
236	0	Err(status) => {
237	0	return self.map_response::<tokio_stream::Once<Result<T::Encode, Status>>>(
238	0	Err(status),
239	0	accept_encoding,
240	0	SingleMessageCompressionOverride::default(),
241	0	self.max_encoding_message_size,
242		);
243		}
244		};
245
246	0	let response = service
247	0	.call(request)
248	0	.await
249	0	.map(\|r\| r.map(\|m\| tokio_stream::once(Ok(m))));
250
251	0	let compression_override = compression_override_from_response(&response);
252
253	0	self.map_response(
254	0	response,
255	0	accept_encoding,
256	0	compression_override,
257	0	self.max_encoding_message_size,
258		)
259	0	}
260
261		/// Handle a server side streaming request.
262	0	pub async fn server_streaming<S, B>(
263	0	&mut self,
264	0	mut service: S,
265	0	req: http::Request<B>,
266	0	) -> http::Response<Body>
267	0	where
268	0	S: ServerStreamingService<T::Decode, Response = T::Encode>,
269	0	S::ResponseStream: Send + 'static,
270	0	B: HttpBody + Send + 'static,
271	0	B::Error: Into<crate::BoxError> + Send,
272	0	{
273	0	let accept_encoding = CompressionEncoding::from_accept_encoding_header(
274	0	req.headers(),
275	0	self.send_compression_encodings,
276		);
277
278	0	let request = match self.map_request_unary(req).await {
279	0	Ok(r) => r,
280	0	Err(status) => {
281	0	return self.map_response::<S::ResponseStream>(
282	0	Err(status),
283	0	accept_encoding,
284	0	SingleMessageCompressionOverride::default(),
285	0	self.max_encoding_message_size,
286		);
287		}
288		};
289
290	0	let response = service.call(request).await;
291
292	0	self.map_response(
293	0	response,
294	0	accept_encoding,
295		// disabling compression of individual stream items must be done on
296		// the items themselves
297	0	SingleMessageCompressionOverride::default(),
298	0	self.max_encoding_message_size,
299		)
300	0	}
301
302		/// Handle a client side streaming gRPC request.
303	0	pub async fn client_streaming<S, B>(
304	0	&mut self,
305	0	mut service: S,
306	0	req: http::Request<B>,
307	0	) -> http::Response<Body>
308	0	where
309	0	S: ClientStreamingService<T::Decode, Response = T::Encode>,
310	0	B: HttpBody + Send + 'static,
311	0	B::Error: Into<crate::BoxError> + Send + 'static,
312	0	{
313	0	let accept_encoding = CompressionEncoding::from_accept_encoding_header(
314	0	req.headers(),
315	0	self.send_compression_encodings,
316		);
317
318	0	let request = t!(self.map_request_streaming(req));
319
320	0	let response = service
321	0	.call(request)
322	0	.await
323	0	.map(\|r\| r.map(\|m\| tokio_stream::once(Ok(m))));
324
325	0	let compression_override = compression_override_from_response(&response);
326
327	0	self.map_response(
328	0	response,
329	0	accept_encoding,
330	0	compression_override,
331	0	self.max_encoding_message_size,
332		)
333	0	}
334
335		/// Handle a bi-directional streaming gRPC request.
336	0	pub async fn streaming<S, B>(
337	0	&mut self,
338	0	mut service: S,
339	0	req: http::Request<B>,
340	0	) -> http::Response<Body>
341	0	where
342	0	S: StreamingService<T::Decode, Response = T::Encode> + Send,
343	0	S::ResponseStream: Send + 'static,
344	0	B: HttpBody + Send + 'static,
345	0	B::Error: Into<crate::BoxError> + Send,
346	0	{
347	0	let accept_encoding = CompressionEncoding::from_accept_encoding_header(
348	0	req.headers(),
349	0	self.send_compression_encodings,
350		);
351
352	0	let request = t!(self.map_request_streaming(req));
353
354	0	let response = service.call(request).await;
355
356	0	self.map_response(
357	0	response,
358	0	accept_encoding,
359	0	SingleMessageCompressionOverride::default(),
360	0	self.max_encoding_message_size,
361		)
362	0	}
363
364	0	async fn map_request_unary<B>(
365	0	&mut self,
366	0	request: http::Request<B>,
367	0	) -> Result<Request<T::Decode>, Status>
368	0	where
369	0	B: HttpBody + Send + 'static,
370	0	B::Error: Into<crate::BoxError> + Send,
371	0	{
372	0	let request_compression_encoding = self.request_encoding_if_supported(&request)?;
373
374	0	let (parts, body) = request.into_parts();
375
376	0	let mut stream = pin!(Streaming::new_request(
377	0	self.codec.decoder(),
378	0	body,
379	0	request_compression_encoding,
380	0	self.max_decoding_message_size,
381		));
382
383	0	let message = stream
384	0	.try_next()
385	0	.await?
386	0	.ok_or_else(\|\| Status::internal("Missing request message."))?;
387
388	0	let mut req = Request::from_http_parts(parts, message);
389
390	0	if let Some(trailers) = stream.trailers().await? {
391	0	req.metadata_mut().merge(trailers);
392	0	}
393
394	0	Ok(req)
395	0	}
396
397	0	fn map_request_streaming<B>(
398	0	&mut self,
399	0	request: http::Request<B>,
400	0	) -> Result<Request<Streaming<T::Decode>>, Status>
401	0	where
402	0	B: HttpBody + Send + 'static,
403	0	B::Error: Into<crate::BoxError> + Send,
404		{
405	0	let encoding = self.request_encoding_if_supported(&request)?;
406
407	0	let request = request.map(\|body\| {
408	0	Streaming::new_request(
409	0	self.codec.decoder(),
410	0	body,
411	0	encoding,
412	0	self.max_decoding_message_size,
413		)
414	0	});
415
416	0	Ok(Request::from_http(request))
417	0	}
418
419	0	fn map_response<B>(
420	0	&mut self,
421	0	response: Result<crate::Response<B>, Status>,
422	0	accept_encoding: Option<CompressionEncoding>,
423	0	compression_override: SingleMessageCompressionOverride,
424	0	max_message_size: Option<usize>,
425	0	) -> http::Response<Body>
426	0	where
427	0	B: Stream<Item = Result<T::Encode, Status>> + Send + 'static,
428		{
429	0	let response = t!(response);
430
431	0	let (mut parts, body) = response.into_http().into_parts();
432
433		// Set the content type
434	0	parts
435	0	.headers
436	0	.insert(http::header::CONTENT_TYPE, GRPC_CONTENT_TYPE);
437
438		#[cfg(any(feature = "gzip", feature = "deflate", feature = "zstd"))]
439		if let Some(encoding) = accept_encoding {
440		// Set the content encoding
441		parts.headers.insert(
442		crate::codec::compression::ENCODING_HEADER,
443		encoding.into_header_value(),
444		);
445		}
446
447	0	let body = EncodeBody::new_server(
448	0	self.codec.encoder(),
449	0	body,
450	0	accept_encoding,
451	0	compression_override,
452	0	max_message_size,
453		);
454
455	0	http::Response::from_parts(parts, Body::new(body))
456	0	}
457
458	0	fn request_encoding_if_supported<B>(
459	0	&self,
460	0	request: &http::Request<B>,
461	0	) -> Result<Option<CompressionEncoding>, Status> {
462	0	CompressionEncoding::from_encoding_header(
463	0	request.headers(),
464	0	self.accept_compression_encodings,
465		)
466	0	}
467		}
468
469		impl<T: fmt::Debug> fmt::Debug for Grpc<T> {
470	0	fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
471	0	f.debug_struct("Grpc")
472	0	.field("codec", &self.codec)
473	0	.field(
474	0	"accept_compression_encodings",
475	0	&self.accept_compression_encodings,
476	0	)
477	0	.field(
478	0	"send_compression_encodings",
479	0	&self.send_compression_encodings,
480	0	)
481	0	.finish()
482	0	}
483		}
484
485	0	fn compression_override_from_response<B, E>(
486	0	res: &Result<crate::Response<B>, E>,
487	0	) -> SingleMessageCompressionOverride {
488	0	res.as_ref()
489	0	.ok()
490	0	.and_then(\|response\| {
491	0	response
492	0	.extensions()
493	0	.get::<SingleMessageCompressionOverride>()
494	0	.copied()
495	0	})
496	0	.unwrap_or_default()
497	0	}