I want to write a server using the current master branch of Hyper that saves a message that is delivered by a POST request and sends this message to every incoming GET request.
I have this, mostly copied from the Hyper examples directory:
extern crate futures;
extern crate hyper;
extern crate pretty_env_logger;
use futures::future::FutureResult;
use hyper::{Get, Post, StatusCode};
use hyper::header::{ContentLength};
use hyper::server::{Http, Service, Request, Response};
use futures::Stream;
struct Echo {
data: Vec<u8>,
}
impl Echo {
fn new() -> Self {
Echo {
data: "text".into(),
}
}
}
impl Service for Echo {
type Request = Request;
type Response = Response;
type Error = hyper::Error;
type Future = FutureResult<Response, hyper::Error>;
fn call(&self, req: Self::Request) -> Self::Future {
let resp = match (req.method(), req.path()) {
(&Get, "/") | (&Get, "/echo") => {
Response::new()
.with_header(ContentLength(self.data.len() as u64))
.with_body(self.data.clone())
},
(&Post, "/") => {
//self.data.clear(); // argh. &self is not mutable :(
// even if it was mutable... how to put the entire body into it?
//req.body().fold(...) ?
let mut res = Response::new();
if let Some(len) = req.headers().get::<ContentLength>() {
res.headers_mut().set(ContentLength(0));
}
res.with_body(req.body())
},
_ => {
Response::new()
.with_status(StatusCode::NotFound)
}
};
futures::future::ok(resp)
}
}
fn main() {
pretty_env_logger::init().unwrap();
let addr = "127.0.0.1:12346".parse().unwrap();
let server = Http::new().bind(&addr, || Ok(Echo::new())).unwrap();
println!("Listening on http://{} with 1 thread.", server.local_addr().unwrap());
server.run().unwrap();
}
How do I turn the req.body() (which seems to be a Stream of Chunks) into a Vec<u8>? I assume I must somehow return a Future that consumes the Stream and turns it into a single Vec<u8>, maybe with fold(). But I have no clue how to do that.
Hyper 0.13 provides a body::to_bytes function for this purpose.
use hyper::body;
use hyper::{Body, Response};
pub async fn read_response_body(res: Response<Body>) -> Result<String, hyper::Error> {
let bytes = body::to_bytes(res.into_body()).await?;
Ok(String::from_utf8(bytes.to_vec()).expect("response was not valid utf-8"))
}
I'm going to simplify the problem to just return the total number of bytes, instead of echoing the entire stream.
Futures 0.3
Hyper 0.13 + TryStreamExt::try_fold
See euclio's answer about hyper::body::to_bytes if you just want all the data as one giant blob.
Accessing the stream allows for more fine-grained control:
use futures::TryStreamExt; // 0.3.7
use hyper::{server::Server, service, Body, Method, Request, Response}; // 0.13.9
use std::convert::Infallible;
use tokio; // 0.2.22
#[tokio::main]
async fn main() {
let addr = "127.0.0.1:12346".parse().expect("Unable to parse address");
let server = Server::bind(&addr).serve(service::make_service_fn(|_conn| async {
Ok::<_, Infallible>(service::service_fn(echo))
}));
println!("Listening on http://{}.", server.local_addr());
if let Err(e) = server.await {
eprintln!("Error: {}", e);
}
}
async fn echo(req: Request<Body>) -> Result<Response<Body>, hyper::Error> {
let (parts, body) = req.into_parts();
match (parts.method, parts.uri.path()) {
(Method::POST, "/") => {
let entire_body = body
.try_fold(Vec::new(), |mut data, chunk| async move {
data.extend_from_slice(&chunk);
Ok(data)
})
.await;
entire_body.map(|body| {
let body = Body::from(format!("Read {} bytes", body.len()));
Response::new(body)
})
}
_ => {
let body = Body::from("Can only POST to /");
Ok(Response::new(body))
}
}
}
Unfortunately, the current implementation of Bytes is no longer compatible with TryStreamExt::try_concat, so we have to switch back to a fold.
Futures 0.1
hyper 0.12 + Stream::concat2
Since futures 0.1.14, you can use Stream::concat2 to stick together all the data into one:
fn concat2(self) -> Concat2<Self>
where
Self: Sized,
Self::Item: Extend<<Self::Item as IntoIterator>::Item> + IntoIterator + Default,
use futures::{
future::{self, Either},
Future, Stream,
}; // 0.1.25
use hyper::{server::Server, service, Body, Method, Request, Response}; // 0.12.20
use tokio; // 0.1.14
fn main() {
let addr = "127.0.0.1:12346".parse().expect("Unable to parse address");
let server = Server::bind(&addr).serve(|| service::service_fn(echo));
println!("Listening on http://{}.", server.local_addr());
let server = server.map_err(|e| eprintln!("Error: {}", e));
tokio::run(server);
}
fn echo(req: Request<Body>) -> impl Future<Item = Response<Body>, Error = hyper::Error> {
let (parts, body) = req.into_parts();
match (parts.method, parts.uri.path()) {
(Method::POST, "/") => {
let entire_body = body.concat2();
let resp = entire_body.map(|body| {
let body = Body::from(format!("Read {} bytes", body.len()));
Response::new(body)
});
Either::A(resp)
}
_ => {
let body = Body::from("Can only POST to /");
let resp = future::ok(Response::new(body));
Either::B(resp)
}
}
}
You could also convert the Bytes into a Vec<u8> via entire_body.to_vec() and then convert that to a String.
See also:
How do I convert a Vector of bytes (u8) to a string
hyper 0.11 + Stream::fold
Similar to Iterator::fold, Stream::fold takes an accumulator (called init) and a function that operates on the accumulator and an item from the stream. The result of the function must be another future with the same error type as the original. The total result is itself a future.
fn fold<F, T, Fut>(self, init: T, f: F) -> Fold<Self, F, Fut, T>
where
F: FnMut(T, Self::Item) -> Fut,
Fut: IntoFuture<Item = T>,
Self::Error: From<Fut::Error>,
Self: Sized,
We can use a Vec as the accumulator. Body's Stream implementation returns a Chunk. This implements Deref<[u8]>, so we can use that to append each chunk's data to the Vec.
extern crate futures; // 0.1.23
extern crate hyper; // 0.11.27
use futures::{Future, Stream};
use hyper::{
server::{Http, Request, Response, Service}, Post,
};
fn main() {
let addr = "127.0.0.1:12346".parse().unwrap();
let server = Http::new().bind(&addr, || Ok(Echo)).unwrap();
println!(
"Listening on http://{} with 1 thread.",
server.local_addr().unwrap()
);
server.run().unwrap();
}
struct Echo;
impl Service for Echo {
type Request = Request;
type Response = Response;
type Error = hyper::Error;
type Future = Box<futures::Future<Item = Response, Error = Self::Error>>;
fn call(&self, req: Self::Request) -> Self::Future {
match (req.method(), req.path()) {
(&Post, "/") => {
let f = req.body()
.fold(Vec::new(), |mut acc, chunk| {
acc.extend_from_slice(&*chunk);
futures::future::ok::<_, Self::Error>(acc)
})
.map(|body| Response::new().with_body(format!("Read {} bytes", body.len())));
Box::new(f)
}
_ => panic!("Nope"),
}
}
}
You could also convert the Vec<u8> body to a String.
See also:
How do I convert a Vector of bytes (u8) to a string
Output
When called from the command line, we can see the result:
$ curl -X POST --data hello http://127.0.0.1:12346/
Read 5 bytes
Warning
All of these solutions allow a malicious end user to POST an infinitely sized file, which would cause the machine to run out of memory. Depending on the intended use, you may wish to establish some kind of cap on the number of bytes read, potentially writing to the filesystem at some breakpoint.
See also:
How do I apply a limit to the number of bytes read by futures::Stream::concat2?
Most of the answers on this topic are outdated or overly complicated. The solution is pretty simple:
/*
WARNING for beginners!!! This use statement
is important so we can later use .data() method!!!
*/
use hyper::body::HttpBody;
let my_vector: Vec<u8> = request.into_body().data().await.unwrap().unwrap().to_vec();
let my_string = String::from_utf8(my_vector).unwrap();
You can also use body::to_bytes as #euclio answered. Both approaches are straight-forward! Don't forget to handle unwrap properly.
Related
I have an actix web service and would like to parse the contents of a multipart field while streaming with async-gcode and in addition store the contents e.g. in a database.
However, I have no clue how to feed in the stream to the Parser and at the same time collect the bytes into a Vec<u8> or a String.
The first problem I face is that field is a stream of actix::web::Bytes and not of u8.
#[post("/upload")]
pub async fn upload_job(
mut payload: Multipart,
) -> Result<HttpResponse, Error> {
let mut contents : Vec<u8> = Vec::new();
while let Ok(Some(mut field)) = payload.try_next().await {
let content_disp = field.content_disposition().unwrap();
match content_disp.get_name().unwrap() {
"file" => {
while let Some(chunk) = field.next().await {
contents.append(&mut chunk.unwrap().to_vec());
// already parse the contents
// and additionally store contents somewhere
}
}
_ => (),
}
}
Ok(HttpResponse::Ok().finish())
}
Any hint or suggestion is very much appreciated.
One of the options is to wrap field in a struct and implement Stream trait for it.
use actix_web::{HttpRequest, HttpResponse, Error};
use futures_util::stream::Stream;
use std::pin::Pin;
use actix_multipart::{Multipart, Field};
use futures::stream::{self, StreamExt};
use futures_util::TryStreamExt;
use std::task::{Context, Poll};
use async_gcode::{Parser, Error as PError};
use bytes::BytesMut;
use std::cell::RefCell;
pub struct Wrapper {
field: Field,
buffer: RefCell<BytesMut>,
index: usize,
}
impl Wrapper {
pub fn new(field: Field, buffer: RefCell<BytesMut>) -> Self {
buffer.borrow_mut().truncate(0);
Wrapper {
field,
buffer,
index: 0
}
}
}
impl Stream for Wrapper {
type Item = Result<u8, PError>;
fn poll_next(
mut self: Pin<&mut Self>,
cx: &mut Context<'_>,
) -> Poll<Option<Result<u8, PError>>> {
if self.index == self.buffer.borrow().len() {
match Pin::new(&mut self.field).poll_next(cx) {
Poll::Ready(Some(Ok(chunk))) => self.buffer.get_mut().extend_from_slice(&chunk),
Poll::Pending => return Poll::Pending,
Poll::Ready(None) => return Poll::Ready(None),
Poll::Ready(Some(Err(_))) => return Poll::Ready(Some(Err(PError::BadNumberFormat/* ??? */)))
};
} else {
let b = self.buffer.borrow()[self.index];
self.index += 1;
return Poll::Ready(Some(Ok(b)));
}
Poll::Ready(None)
}
}
#[post("/upload")]
pub async fn upload_job(
mut payload: Multipart,
) -> Result<HttpResponse, Error> {
while let Ok(Some(field)) = payload.try_next().await {
let content_disp = field.content_disposition().unwrap();
match content_disp.get_name().unwrap() {
"file" => {
let mut contents: RefCell<BytesMut> = RefCell::new(BytesMut::new());
let mut w = Wrapper::new(field, contents.clone());
let mut p = Parser::new(w);
while let Some(res) = p.next().await {
// Do something with results
};
// Do something with the buffer
let a = contents.get_mut()[0];
}
_ => (),
}
}
Ok(HttpResponse::Ok().finish())
}
Copying the Bytes from the Field won't be necessary when
Bytes::try_unsplit will be implemented. (https://github.com/tokio-rs/bytes/issues/287)
The answer from dmitryvm (thanks for your effort) showed me that there are actually two problems. At first, flatten the Bytes into u8's and, secondly, to "split" the stream into a buffer for later storage and the async-gcode parser.
This shows how I solved it:
#[post("/upload")]
pub async fn upload_job(
mut payload: Multipart,
) -> Result<HttpResponse, Error> {
let mut contents : Vec<u8> = Vec::new();
while let Ok(Some(mut field)) = payload.try_next().await {
let content_disp = field.content_disposition().unwrap();
match content_disp.get_name().unwrap() {
"file" => {
let field_stream = field
.map_err(|_| async_gcode::Error::BadNumberFormat) // Translate error
.map_ok(|y| { // Translate Bytes into stream with Vec<u8>
contents.extend_from_slice(&y); // Copy and store for later usage
stream::iter(y).map(Result::<_, async_gcode::Error>::Ok)
})
.try_flatten(); // Flatten the streams of u8's
let mut parser = Parser::new(field_stream);
while let Some(gcode) = parser.next().await {
// Process result from parser
}
}
_ => (),
}
}
Ok(HttpResponse::Ok().finish())
}
I'd like to write a very simple middleware using actix_web framework but it's so far beating me on every front.
I have a skeleton like this:
let result = actix_web::HttpServer::new(move || {
actix_web::App::new()
.wrap_fn(move |req, srv| {
srv.call(req).map(move|res| {
println!("Got response");
// let s = res.unwrap().response().body();
// ???
res
})
})
})
.bind("0.0.0.0:8080")?
.run()
.await;
and I can access ResponseBody type via res.unwrap().response().body() but I don't know what can I do with this.
Any ideas?
This is an example of how I was able to accomplish this with 4.0.0-beta.14:
use std::cell::RefCell;
use std::pin::Pin;
use std::rc::Rc;
use std::collections::HashMap;
use std::str;
use erp_contrib::{actix_http, actix_web, futures, serde_json};
use actix_web::dev::{Service, ServiceRequest, ServiceResponse, Transform};
use actix_web::{HttpMessage, body, http::StatusCode, error::Error ,HttpResponseBuilder};
use actix_http::{h1::Payload, header};
use actix_web::web::{BytesMut};
use futures::future::{ok, Future, Ready};
use futures::task::{Context, Poll};
use futures::StreamExt;
use crate::response::ErrorResponse;
pub struct UnhandledErrorResponse;
impl<S: 'static> Transform<S, ServiceRequest> for UnhandledErrorResponse
where
S: Service<ServiceRequest, Response = ServiceResponse, Error = Error>,
S::Future: 'static,
{
type Response = ServiceResponse;
type Error = Error;
type Transform = UnhandledErrorResponseMiddleware<S>;
type InitError = ();
type Future = Ready<Result<Self::Transform, Self::InitError>>;
fn new_transform(&self, service: S) -> Self::Future {
ok(UnhandledErrorResponseMiddleware { service: Rc::new(RefCell::new(service)), })
}
}
pub struct UnhandledErrorResponseMiddleware<S> {
service: Rc<RefCell<S>>,
}
impl<S> Service<ServiceRequest> for UnhandledErrorResponseMiddleware<S>
where
S: Service<ServiceRequest, Response = ServiceResponse, Error = Error> + 'static,
S::Future: 'static,
{
type Response = ServiceResponse;
type Error = Error;
type Future = Pin<Box<dyn Future<Output = Result<Self::Response, Self::Error>>>>;
fn poll_ready(&self, cx: &mut Context<'_>) -> Poll<Result<(), Self::Error>> {
self.service.poll_ready(cx)
}
fn call(&self, mut req: ServiceRequest) -> Self::Future {
let svc = self.service.clone();
Box::pin(async move {
/* EXTRACT THE BODY OF REQUEST */
let mut request_body = BytesMut::new();
while let Some(chunk) = req.take_payload().next().await {
request_body.extend_from_slice(&chunk?);
}
let mut orig_payload = Payload::empty();
orig_payload.unread_data(request_body.freeze());
req.set_payload(actix_http::Payload::from(orig_payload));
/* now process the response */
let res: ServiceResponse = svc.call(req).await?;
let content_type = match res.headers().get("content-type") {
None => { "unknown"}
Some(header) => {
match header.to_str() {
Ok(value) => {value}
Err(_) => { "unknown"}
}
}
};
return match res.response().error() {
None => {
Ok(res)
}
Some(error) => {
if content_type.to_uppercase().contains("APPLICATION/JSON") {
Ok(res)
} else {
let error = error.to_string();
let new_request = res.request().clone();
/* EXTRACT THE BODY OF RESPONSE */
let _body_data =
match str::from_utf8(&body::to_bytes(res.into_body()).await?){
Ok(str) => {
str
}
Err(_) => {
"Unknown"
}
};
let mut errors = HashMap::new();
errors.insert("general".to_string(), vec![error]);
let new_response = match ErrorResponse::new(&false, errors) {
Ok(response) => {
HttpResponseBuilder::new(StatusCode::BAD_REQUEST)
.insert_header((header::CONTENT_TYPE, "application/json"))
.body(serde_json::to_string(&response).unwrap())
}
Err(_error) => {
HttpResponseBuilder::new(StatusCode::BAD_REQUEST)
.insert_header((header::CONTENT_TYPE, "application/json"))
.body("An unknown error occurred.")
}
};
Ok(ServiceResponse::new(
new_request,
new_response
))
}
}
}
})
}
}
The extraction of the Request Body is straightforward and similar to how Actix example's illustrate. However, with the update to version Beta 14, pulling the bytes directly from AnyBody has changed with the introduction of BoxedBody. Fortunately, I found a utility function body::to_bytes (use actix_web::body::to_bytes) which does a good job. It's current implementation looks like this:
pub async fn to_bytes<B: MessageBody>(body: B) -> Result<Bytes, B::Error> {
let cap = match body.size() {
BodySize::None | BodySize::Sized(0) => return Ok(Bytes::new()),
BodySize::Sized(size) => size as usize,
// good enough first guess for chunk size
BodySize::Stream => 32_768,
};
let mut buf = BytesMut::with_capacity(cap);
pin!(body);
poll_fn(|cx| loop {
let body = body.as_mut();
match ready!(body.poll_next(cx)) {
Some(Ok(bytes)) => buf.extend_from_slice(&*bytes),
None => return Poll::Ready(Ok(())),
Some(Err(err)) => return Poll::Ready(Err(err)),
}
})
.await?;
Ok(buf.freeze())
}
which I believe should be fine to extract the body in this way, as the body is extracted from the body stream by to_bytes().
If someone has a better way, let me know, but it was a little bit of pain, and I only had recently determined how to do it in Beta 13 when it switched to Beta 14.
This particular example intercepts errors and rewrites them to JSON format if they're not already json format. This would be the case, as an example, if an error occurs outside of a handler, such as parsing JSON in the handler function itself _data: web::Json<Request<'a, LoginRequest>> and not in the handler body. Extracting the Request Body and Response Body is not necessary to accomplish the goal, and is just here for illustration.
I want to write a server using the current master branch of Hyper that saves a message that is delivered by a POST request and sends this message to every incoming GET request.
I have this, mostly copied from the Hyper examples directory:
extern crate futures;
extern crate hyper;
extern crate pretty_env_logger;
use futures::future::FutureResult;
use hyper::{Get, Post, StatusCode};
use hyper::header::{ContentLength};
use hyper::server::{Http, Service, Request, Response};
use futures::Stream;
struct Echo {
data: Vec<u8>,
}
impl Echo {
fn new() -> Self {
Echo {
data: "text".into(),
}
}
}
impl Service for Echo {
type Request = Request;
type Response = Response;
type Error = hyper::Error;
type Future = FutureResult<Response, hyper::Error>;
fn call(&self, req: Self::Request) -> Self::Future {
let resp = match (req.method(), req.path()) {
(&Get, "/") | (&Get, "/echo") => {
Response::new()
.with_header(ContentLength(self.data.len() as u64))
.with_body(self.data.clone())
},
(&Post, "/") => {
//self.data.clear(); // argh. &self is not mutable :(
// even if it was mutable... how to put the entire body into it?
//req.body().fold(...) ?
let mut res = Response::new();
if let Some(len) = req.headers().get::<ContentLength>() {
res.headers_mut().set(ContentLength(0));
}
res.with_body(req.body())
},
_ => {
Response::new()
.with_status(StatusCode::NotFound)
}
};
futures::future::ok(resp)
}
}
fn main() {
pretty_env_logger::init().unwrap();
let addr = "127.0.0.1:12346".parse().unwrap();
let server = Http::new().bind(&addr, || Ok(Echo::new())).unwrap();
println!("Listening on http://{} with 1 thread.", server.local_addr().unwrap());
server.run().unwrap();
}
How do I turn the req.body() (which seems to be a Stream of Chunks) into a Vec<u8>? I assume I must somehow return a Future that consumes the Stream and turns it into a single Vec<u8>, maybe with fold(). But I have no clue how to do that.
Hyper 0.13 provides a body::to_bytes function for this purpose.
use hyper::body;
use hyper::{Body, Response};
pub async fn read_response_body(res: Response<Body>) -> Result<String, hyper::Error> {
let bytes = body::to_bytes(res.into_body()).await?;
Ok(String::from_utf8(bytes.to_vec()).expect("response was not valid utf-8"))
}
I'm going to simplify the problem to just return the total number of bytes, instead of echoing the entire stream.
Futures 0.3
Hyper 0.13 + TryStreamExt::try_fold
See euclio's answer about hyper::body::to_bytes if you just want all the data as one giant blob.
Accessing the stream allows for more fine-grained control:
use futures::TryStreamExt; // 0.3.7
use hyper::{server::Server, service, Body, Method, Request, Response}; // 0.13.9
use std::convert::Infallible;
use tokio; // 0.2.22
#[tokio::main]
async fn main() {
let addr = "127.0.0.1:12346".parse().expect("Unable to parse address");
let server = Server::bind(&addr).serve(service::make_service_fn(|_conn| async {
Ok::<_, Infallible>(service::service_fn(echo))
}));
println!("Listening on http://{}.", server.local_addr());
if let Err(e) = server.await {
eprintln!("Error: {}", e);
}
}
async fn echo(req: Request<Body>) -> Result<Response<Body>, hyper::Error> {
let (parts, body) = req.into_parts();
match (parts.method, parts.uri.path()) {
(Method::POST, "/") => {
let entire_body = body
.try_fold(Vec::new(), |mut data, chunk| async move {
data.extend_from_slice(&chunk);
Ok(data)
})
.await;
entire_body.map(|body| {
let body = Body::from(format!("Read {} bytes", body.len()));
Response::new(body)
})
}
_ => {
let body = Body::from("Can only POST to /");
Ok(Response::new(body))
}
}
}
Unfortunately, the current implementation of Bytes is no longer compatible with TryStreamExt::try_concat, so we have to switch back to a fold.
Futures 0.1
hyper 0.12 + Stream::concat2
Since futures 0.1.14, you can use Stream::concat2 to stick together all the data into one:
fn concat2(self) -> Concat2<Self>
where
Self: Sized,
Self::Item: Extend<<Self::Item as IntoIterator>::Item> + IntoIterator + Default,
use futures::{
future::{self, Either},
Future, Stream,
}; // 0.1.25
use hyper::{server::Server, service, Body, Method, Request, Response}; // 0.12.20
use tokio; // 0.1.14
fn main() {
let addr = "127.0.0.1:12346".parse().expect("Unable to parse address");
let server = Server::bind(&addr).serve(|| service::service_fn(echo));
println!("Listening on http://{}.", server.local_addr());
let server = server.map_err(|e| eprintln!("Error: {}", e));
tokio::run(server);
}
fn echo(req: Request<Body>) -> impl Future<Item = Response<Body>, Error = hyper::Error> {
let (parts, body) = req.into_parts();
match (parts.method, parts.uri.path()) {
(Method::POST, "/") => {
let entire_body = body.concat2();
let resp = entire_body.map(|body| {
let body = Body::from(format!("Read {} bytes", body.len()));
Response::new(body)
});
Either::A(resp)
}
_ => {
let body = Body::from("Can only POST to /");
let resp = future::ok(Response::new(body));
Either::B(resp)
}
}
}
You could also convert the Bytes into a Vec<u8> via entire_body.to_vec() and then convert that to a String.
See also:
How do I convert a Vector of bytes (u8) to a string
hyper 0.11 + Stream::fold
Similar to Iterator::fold, Stream::fold takes an accumulator (called init) and a function that operates on the accumulator and an item from the stream. The result of the function must be another future with the same error type as the original. The total result is itself a future.
fn fold<F, T, Fut>(self, init: T, f: F) -> Fold<Self, F, Fut, T>
where
F: FnMut(T, Self::Item) -> Fut,
Fut: IntoFuture<Item = T>,
Self::Error: From<Fut::Error>,
Self: Sized,
We can use a Vec as the accumulator. Body's Stream implementation returns a Chunk. This implements Deref<[u8]>, so we can use that to append each chunk's data to the Vec.
extern crate futures; // 0.1.23
extern crate hyper; // 0.11.27
use futures::{Future, Stream};
use hyper::{
server::{Http, Request, Response, Service}, Post,
};
fn main() {
let addr = "127.0.0.1:12346".parse().unwrap();
let server = Http::new().bind(&addr, || Ok(Echo)).unwrap();
println!(
"Listening on http://{} with 1 thread.",
server.local_addr().unwrap()
);
server.run().unwrap();
}
struct Echo;
impl Service for Echo {
type Request = Request;
type Response = Response;
type Error = hyper::Error;
type Future = Box<futures::Future<Item = Response, Error = Self::Error>>;
fn call(&self, req: Self::Request) -> Self::Future {
match (req.method(), req.path()) {
(&Post, "/") => {
let f = req.body()
.fold(Vec::new(), |mut acc, chunk| {
acc.extend_from_slice(&*chunk);
futures::future::ok::<_, Self::Error>(acc)
})
.map(|body| Response::new().with_body(format!("Read {} bytes", body.len())));
Box::new(f)
}
_ => panic!("Nope"),
}
}
}
You could also convert the Vec<u8> body to a String.
See also:
How do I convert a Vector of bytes (u8) to a string
Output
When called from the command line, we can see the result:
$ curl -X POST --data hello http://127.0.0.1:12346/
Read 5 bytes
Warning
All of these solutions allow a malicious end user to POST an infinitely sized file, which would cause the machine to run out of memory. Depending on the intended use, you may wish to establish some kind of cap on the number of bytes read, potentially writing to the filesystem at some breakpoint.
See also:
How do I apply a limit to the number of bytes read by futures::Stream::concat2?
Most of the answers on this topic are outdated or overly complicated. The solution is pretty simple:
/*
WARNING for beginners!!! This use statement
is important so we can later use .data() method!!!
*/
use hyper::body::HttpBody;
let my_vector: Vec<u8> = request.into_body().data().await.unwrap().unwrap().to_vec();
let my_string = String::from_utf8(my_vector).unwrap();
You can also use body::to_bytes as #euclio answered. Both approaches are straight-forward! Don't forget to handle unwrap properly.
I am experiencing a bug where my Hyper HTTP response is being truncated to a specific size (7829 bytes). Making the same request with cURL works fine.
The request queries a JSON endpoint for data. The response struct is then shuffled around a lot, because a relatively complex rate-limiting procedure is used to make a number of these requests at once. However, if only one request is made, the response is still truncated.
Before implementing rate-limiting and doing some heavy refactoring, the program made these responses properly.
I made the minimal example below, but it fails to reproduce the problem. At this point I'm not sure where to look. The codebase is moderately complicated and iteratively expanding the reproduction example is difficult, especially when I don't know what might possibly cause this.
What are some ways that Hyper's Response body might get truncated? The response body is acquired as in the handle function below.
#![feature(use_nested_groups)]
extern crate futures;
extern crate hyper;
extern crate hyper_tls;
extern crate tokio_core;
use futures::{Future, Stream};
use hyper::{Body, Chunk, Client, Method, Request, Response};
use hyper_tls::HttpsConnector;
use tokio_core::reactor::Core;
use std::env;
fn main() {
let mut core = Core::new().unwrap();
let client = Client::configure()
.connector(HttpsConnector::new(4, &core.handle()).unwrap())
.build(&core.handle());
fn handle(response: Response<Body>) -> Box<Future<Item = usize, Error = hyper::Error>> {
Box::new(
response
.body()
.concat2()
.map(move |body: Chunk| -> usize { body.len() }),
)
}
let args: Vec<String> = env::args().collect();
let uri = &args[1];
let req = Request::new(Method::Get, uri.parse().unwrap());
let response_body_length = {
let future = Box::new(client.request(req).map(handle).flatten());
core.run(future).unwrap()
};
println!("response body length: {}", response_body_length);
}
Offending code:
extern crate serde;
extern crate serde_json;
use futures::{future, stream, Future, Stream};
use hyper;
use hyper::{client, Body, Chunk, Client, Headers, Method, Request, Response, header::Accept,
header::Date as DateHeader, header::RetryAfter};
use hyper_tls::HttpsConnector;
use tokio_core::reactor::Core;
use models::Bucket;
use std::thread;
use std::time::{Duration, UNIX_EPOCH};
use std::str;
header! { (XRateLimitRemaining, "x-ratelimit-remaining") => [String] }
#[derive(Debug)]
struct Uri(pub String);
const MAX_REQ_SIZE: u32 = 500;
fn make_uri(symbol: &str, page_ix: u32) -> Uri {
Uri(format!(
"https://www.bitmex.com/api/v1/trade/bucketed?\
symbol={symbol}&\
columns={columns}&\
partial=false&\
reverse=true&\
binSize={bin_size}&\
count={count}&\
start={start}",
symbol = symbol,
columns = "close,timestamp",
bin_size = "5m",
count = MAX_REQ_SIZE,
start = 0 + MAX_REQ_SIZE * page_ix
))
}
#[derive(Debug)]
struct RateLimitInfo {
remaining_reqs: u32,
retry_after: Option<Duration>,
}
impl RateLimitInfo {
fn default() -> RateLimitInfo {
RateLimitInfo {
remaining_reqs: 1,
retry_after: None,
}
}
fn from<T>(resp: &Response<T>) -> RateLimitInfo {
let headers = resp.headers();
let remaining_reqs = headers
.get::<XRateLimitRemaining>()
.unwrap_or_else(|| panic!("x-ratelimit-remaining not on request."))
.parse()
.unwrap();
let retry_after = match headers.get::<RetryAfter>() {
Some(RetryAfter::Delay(duration)) => Some(*duration),
_ => None,
};
RateLimitInfo {
remaining_reqs,
retry_after,
}
}
}
fn resp_dated_later<'a>(a: &'a Response<Body>, b: &'a Response<Body>) -> &'a Response<Body> {
let get_date = |resp: &Response<Body>| {
let headers: &Headers = resp.headers();
**headers.get::<DateHeader>().unwrap()
};
if get_date(&a) > get_date(&b) {
a
} else {
b
}
}
#[derive(Debug)]
struct Query {
uri: Uri,
response: Option<Response<Body>>,
}
impl Query {
fn from_uri(uri: Uri) -> Query {
Query {
uri: uri,
response: None,
}
}
}
fn query_good(q: &Query) -> bool {
match &q.response {
Some(response) => response.status().is_success(),
_ => false,
}
}
type HttpsClient = hyper::Client<HttpsConnector<client::HttpConnector>>;
type FutureQuery = Box<Future<Item = Query, Error = hyper::Error>>;
fn to_future(x: Query) -> FutureQuery {
Box::new(future::ok(x))
}
fn exec_if_needed(client: &HttpsClient, query: Query) -> FutureQuery {
fn exec(client: &HttpsClient, q: Query) -> FutureQuery {
println!("exec: {:?}", q);
let uri = q.uri;
let req = {
let mut req = Request::new(Method::Get, uri.0.parse().unwrap());
req.headers_mut().set(Accept::json());
req
};
Box::new(
client
.request(req)
.inspect(|resp| println!("HTTP {}", resp.status()))
.map(|resp| Query {
uri: uri,
response: Some(resp),
}),
)
}
if query_good(&query) {
to_future(query)
} else {
exec(client, query)
}
}
type BoxedFuture<T> = Box<Future<Item = T, Error = hyper::Error>>;
fn do_batch(client: &HttpsClient, queries: Vec<Query>) -> BoxedFuture<Vec<Query>> {
println!("do_batch() {} queries", queries.len());
let exec_if_needed = |q| exec_if_needed(client, q);
let futures = queries.into_iter().map(exec_if_needed);
println!("do_batch() futures {:?}", futures);
Box::new(
stream::futures_ordered(futures).collect(), //future::join_all(futures)
)
}
fn take<T>(right: &mut Vec<T>, suggested_n: usize) -> Vec<T> {
let n: usize = if right.len() < suggested_n {
right.len()
} else {
suggested_n
};
let left = right.drain(0..n);
return left.collect();
}
type BoxedResponses = Box<Vec<Response<Body>>>;
fn batched_throttle(uris: Vec<Uri>) -> BoxedResponses {
println!("batched_throttle({} uris)", uris.len());
let mut core = Core::new().unwrap();
let client = Client::configure()
.connector(HttpsConnector::new(4, &core.handle()).unwrap())
.build(&core.handle());
let mut rate_limit_info = RateLimitInfo::default();
let mut queries_right: Vec<Query> = uris.into_iter().map(Query::from_uri).collect();
loop {
let mut queries_left: Vec<Query> = Vec::with_capacity(queries_right.len());
println!("batched_throttle: starting inner loop");
loop {
// throttle program during testing
thread::sleep(Duration::from_millis(800));
println!("batched_throttle: {:?}", rate_limit_info);
if let Some(retry_after) = rate_limit_info.retry_after {
println!("batched_throttle: retrying after {:?}", retry_after);
thread::sleep(retry_after)
}
if queries_right.is_empty() {
break;
}
let mut queries_mid = {
let ri_count = rate_limit_info.remaining_reqs;
let iter_req_count = if ri_count == 0 { 1 } else { ri_count };
println!("batched_throttle: iter_req_count {}", iter_req_count);
take(&mut queries_right, iter_req_count as usize)
};
println!(
"batched_throttle: \
queries_right.len() {}, \
queries_left.len() {}, \
queries_mid.len() {})",
queries_right.len(),
queries_left.len(),
queries_mid.len()
);
if queries_mid.iter().all(query_good) {
println!("batched_throttle: queries_mid.iter().all(query_good)");
continue;
}
queries_mid = { core.run(do_batch(&client, queries_mid)).unwrap() };
rate_limit_info = {
let create_very_old_response =
|| Response::new().with_header(DateHeader(UNIX_EPOCH.into()));
let very_old_response = create_very_old_response();
let last_resp = queries_mid
.iter()
.map(|q| match &q.response {
Some(r) => r,
_ => panic!("Impossible"),
})
.fold(&very_old_response, resp_dated_later);
RateLimitInfo::from(&last_resp)
};
&queries_left.append(&mut queries_mid);
}
queries_right = queries_left;
if queries_right.iter().all(query_good) {
break;
}
}
println!(
"batched_throttle: finishing. queries_right.len() {}",
queries_right.len()
);
Box::new(
queries_right
.into_iter()
.map(|q| q.response.unwrap())
.collect(),
)
}
fn bucket_count_to_req_count(bucket_count: u32) -> u32 {
let needed_req_count = (bucket_count as f32 / MAX_REQ_SIZE as f32).ceil() as u32;
return needed_req_count;
}
type BoxedBuckets = Box<Vec<Bucket>>;
fn response_to_buckets(response: Response<Body>) -> BoxedFuture<Vec<Bucket>> {
Box::new(response.body().concat2().map(|body: Chunk| -> Vec<Bucket> {
println!("body.len(): {}", body.len());
println!("JSON: {}", str::from_utf8(&body).unwrap());
serde_json::from_slice(&body).unwrap()
}))
}
pub fn get_n_last(symbol: &str, bucket_count: u32) -> BoxedBuckets {
let req_count = bucket_count_to_req_count(bucket_count);
let uris = (0..req_count)
.map(|page_ix| make_uri(symbol, page_ix))
.collect();
let responses = batched_throttle(uris);
let mut core = Core::new().unwrap();
let boxed_buckets = {
let futures = responses.into_iter().map(response_to_buckets);
let future = stream::futures_ordered(futures).collect();
let groups_of_buckets = core.run(future).unwrap();
Box::new(
groups_of_buckets
.into_iter()
.flat_map(|bs| bs.into_iter())
.rev()
.collect(),
)
};
return boxed_buckets;
}
You first create a Core and start lots of requests and gather the Response "results".
After you got all the Responses you start a new Core and try to start reading the data from those Responses - but the server probably closed them long ago due to write timeouts, and you only get partial data.
You shouldn't keep the server waiting; start reading the Responses as soon as possible.
I want to write a server using the current master branch of Hyper that saves a message that is delivered by a POST request and sends this message to every incoming GET request.
I have this, mostly copied from the Hyper examples directory:
extern crate futures;
extern crate hyper;
extern crate pretty_env_logger;
use futures::future::FutureResult;
use hyper::{Get, Post, StatusCode};
use hyper::header::{ContentLength};
use hyper::server::{Http, Service, Request, Response};
use futures::Stream;
struct Echo {
data: Vec<u8>,
}
impl Echo {
fn new() -> Self {
Echo {
data: "text".into(),
}
}
}
impl Service for Echo {
type Request = Request;
type Response = Response;
type Error = hyper::Error;
type Future = FutureResult<Response, hyper::Error>;
fn call(&self, req: Self::Request) -> Self::Future {
let resp = match (req.method(), req.path()) {
(&Get, "/") | (&Get, "/echo") => {
Response::new()
.with_header(ContentLength(self.data.len() as u64))
.with_body(self.data.clone())
},
(&Post, "/") => {
//self.data.clear(); // argh. &self is not mutable :(
// even if it was mutable... how to put the entire body into it?
//req.body().fold(...) ?
let mut res = Response::new();
if let Some(len) = req.headers().get::<ContentLength>() {
res.headers_mut().set(ContentLength(0));
}
res.with_body(req.body())
},
_ => {
Response::new()
.with_status(StatusCode::NotFound)
}
};
futures::future::ok(resp)
}
}
fn main() {
pretty_env_logger::init().unwrap();
let addr = "127.0.0.1:12346".parse().unwrap();
let server = Http::new().bind(&addr, || Ok(Echo::new())).unwrap();
println!("Listening on http://{} with 1 thread.", server.local_addr().unwrap());
server.run().unwrap();
}
How do I turn the req.body() (which seems to be a Stream of Chunks) into a Vec<u8>? I assume I must somehow return a Future that consumes the Stream and turns it into a single Vec<u8>, maybe with fold(). But I have no clue how to do that.
Hyper 0.13 provides a body::to_bytes function for this purpose.
use hyper::body;
use hyper::{Body, Response};
pub async fn read_response_body(res: Response<Body>) -> Result<String, hyper::Error> {
let bytes = body::to_bytes(res.into_body()).await?;
Ok(String::from_utf8(bytes.to_vec()).expect("response was not valid utf-8"))
}
I'm going to simplify the problem to just return the total number of bytes, instead of echoing the entire stream.
Futures 0.3
Hyper 0.13 + TryStreamExt::try_fold
See euclio's answer about hyper::body::to_bytes if you just want all the data as one giant blob.
Accessing the stream allows for more fine-grained control:
use futures::TryStreamExt; // 0.3.7
use hyper::{server::Server, service, Body, Method, Request, Response}; // 0.13.9
use std::convert::Infallible;
use tokio; // 0.2.22
#[tokio::main]
async fn main() {
let addr = "127.0.0.1:12346".parse().expect("Unable to parse address");
let server = Server::bind(&addr).serve(service::make_service_fn(|_conn| async {
Ok::<_, Infallible>(service::service_fn(echo))
}));
println!("Listening on http://{}.", server.local_addr());
if let Err(e) = server.await {
eprintln!("Error: {}", e);
}
}
async fn echo(req: Request<Body>) -> Result<Response<Body>, hyper::Error> {
let (parts, body) = req.into_parts();
match (parts.method, parts.uri.path()) {
(Method::POST, "/") => {
let entire_body = body
.try_fold(Vec::new(), |mut data, chunk| async move {
data.extend_from_slice(&chunk);
Ok(data)
})
.await;
entire_body.map(|body| {
let body = Body::from(format!("Read {} bytes", body.len()));
Response::new(body)
})
}
_ => {
let body = Body::from("Can only POST to /");
Ok(Response::new(body))
}
}
}
Unfortunately, the current implementation of Bytes is no longer compatible with TryStreamExt::try_concat, so we have to switch back to a fold.
Futures 0.1
hyper 0.12 + Stream::concat2
Since futures 0.1.14, you can use Stream::concat2 to stick together all the data into one:
fn concat2(self) -> Concat2<Self>
where
Self: Sized,
Self::Item: Extend<<Self::Item as IntoIterator>::Item> + IntoIterator + Default,
use futures::{
future::{self, Either},
Future, Stream,
}; // 0.1.25
use hyper::{server::Server, service, Body, Method, Request, Response}; // 0.12.20
use tokio; // 0.1.14
fn main() {
let addr = "127.0.0.1:12346".parse().expect("Unable to parse address");
let server = Server::bind(&addr).serve(|| service::service_fn(echo));
println!("Listening on http://{}.", server.local_addr());
let server = server.map_err(|e| eprintln!("Error: {}", e));
tokio::run(server);
}
fn echo(req: Request<Body>) -> impl Future<Item = Response<Body>, Error = hyper::Error> {
let (parts, body) = req.into_parts();
match (parts.method, parts.uri.path()) {
(Method::POST, "/") => {
let entire_body = body.concat2();
let resp = entire_body.map(|body| {
let body = Body::from(format!("Read {} bytes", body.len()));
Response::new(body)
});
Either::A(resp)
}
_ => {
let body = Body::from("Can only POST to /");
let resp = future::ok(Response::new(body));
Either::B(resp)
}
}
}
You could also convert the Bytes into a Vec<u8> via entire_body.to_vec() and then convert that to a String.
See also:
How do I convert a Vector of bytes (u8) to a string
hyper 0.11 + Stream::fold
Similar to Iterator::fold, Stream::fold takes an accumulator (called init) and a function that operates on the accumulator and an item from the stream. The result of the function must be another future with the same error type as the original. The total result is itself a future.
fn fold<F, T, Fut>(self, init: T, f: F) -> Fold<Self, F, Fut, T>
where
F: FnMut(T, Self::Item) -> Fut,
Fut: IntoFuture<Item = T>,
Self::Error: From<Fut::Error>,
Self: Sized,
We can use a Vec as the accumulator. Body's Stream implementation returns a Chunk. This implements Deref<[u8]>, so we can use that to append each chunk's data to the Vec.
extern crate futures; // 0.1.23
extern crate hyper; // 0.11.27
use futures::{Future, Stream};
use hyper::{
server::{Http, Request, Response, Service}, Post,
};
fn main() {
let addr = "127.0.0.1:12346".parse().unwrap();
let server = Http::new().bind(&addr, || Ok(Echo)).unwrap();
println!(
"Listening on http://{} with 1 thread.",
server.local_addr().unwrap()
);
server.run().unwrap();
}
struct Echo;
impl Service for Echo {
type Request = Request;
type Response = Response;
type Error = hyper::Error;
type Future = Box<futures::Future<Item = Response, Error = Self::Error>>;
fn call(&self, req: Self::Request) -> Self::Future {
match (req.method(), req.path()) {
(&Post, "/") => {
let f = req.body()
.fold(Vec::new(), |mut acc, chunk| {
acc.extend_from_slice(&*chunk);
futures::future::ok::<_, Self::Error>(acc)
})
.map(|body| Response::new().with_body(format!("Read {} bytes", body.len())));
Box::new(f)
}
_ => panic!("Nope"),
}
}
}
You could also convert the Vec<u8> body to a String.
See also:
How do I convert a Vector of bytes (u8) to a string
Output
When called from the command line, we can see the result:
$ curl -X POST --data hello http://127.0.0.1:12346/
Read 5 bytes
Warning
All of these solutions allow a malicious end user to POST an infinitely sized file, which would cause the machine to run out of memory. Depending on the intended use, you may wish to establish some kind of cap on the number of bytes read, potentially writing to the filesystem at some breakpoint.
See also:
How do I apply a limit to the number of bytes read by futures::Stream::concat2?
Most of the answers on this topic are outdated or overly complicated. The solution is pretty simple:
/*
WARNING for beginners!!! This use statement
is important so we can later use .data() method!!!
*/
use hyper::body::HttpBody;
let my_vector: Vec<u8> = request.into_body().data().await.unwrap().unwrap().to_vec();
let my_string = String::from_utf8(my_vector).unwrap();
You can also use body::to_bytes as #euclio answered. Both approaches are straight-forward! Don't forget to handle unwrap properly.