refactor(client): clarify some code in send_request

This commit is contained in:
Sean McArthur
2018-09-27 20:14:02 -07:00
parent af23dda2e9
commit bddc2d5040

View File

@@ -249,24 +249,23 @@ where C: Connect + Sync + 'static,
let client = self.clone();
let uri = req.uri().clone();
let pool_key = (Arc::new(domain.to_string()), self.ver);
let fut = RetryableSendRequest {
client: client,
future: self.send_request(req, &domain),
domain: domain,
uri: uri,
client,
future: self.send_request(req, pool_key.clone()),
pool_key,
uri,
};
ResponseFuture::new(Box::new(fut))
}
//TODO: replace with `impl Future` when stable
fn send_request(&self, mut req: Request<B>, domain: &str) -> Box<Future<Item=Response<Body>, Error=ClientError<B>> + Send> {
let pool_key = (Arc::new(domain.to_string()), self.ver);
fn send_request(&self, mut req: Request<B>, pool_key: PoolKey) -> Box<Future<Item=Response<Body>, Error=ClientError<B>> + Send> {
let race = self.pool_checkout_or_connect(req.uri().clone(), pool_key);
let ver = self.ver;
let executor = self.executor.clone();
let resp = race.and_then(move |mut pooled| {
let conn_reused = pooled.is_reused();
Box::new(race.and_then(move |mut pooled| {
if ver == Ver::Http1 {
// CONNECT always sends origin-form, so check it first...
if req.method() == &Method::CONNECT {
@@ -283,7 +282,8 @@ where C: Connect + Sync + 'static,
);
}
let fut = pooled.send_request_retryable(req);
let fut = pooled.send_request_retryable(req)
.map_err(ClientError::map_with_reused(pooled.is_reused()));
// As of futures@0.1.21, there is a race condition in the mpsc
// channel, such that sending when the receiver is closing can
@@ -293,83 +293,56 @@ where C: Connect + Sync + 'static,
// To counteract this, we must check if our senders 'want' channel
// has been closed after having tried to send. If so, error out...
if pooled.is_closed() {
drop(pooled);
let fut = fut
.map_err(move |(err, orig_req)| {
if let Some(req) = orig_req {
ClientError::Canceled {
connection_reused: conn_reused,
reason: err,
req,
}
} else {
ClientError::Normal(err)
}
});
Either::A(fut)
} else {
let fut = fut
.map_err(move |(err, orig_req)| {
if let Some(req) = orig_req {
ClientError::Canceled {
connection_reused: conn_reused,
reason: err,
req,
}
} else {
ClientError::Normal(err)
}
})
.and_then(move |mut res| {
// If pooled is HTTP/2, we can toss this reference immediately.
//
// when pooled is dropped, it will try to insert back into the
// pool. To delay that, spawn a future that completes once the
// sender is ready again.
//
// This *should* only be once the related `Connection` has polled
// for a new request to start.
//
// It won't be ready if there is a body to stream.
if ver == Ver::Http2 || !pooled.is_pool_enabled() || pooled.is_ready() {
drop(pooled);
} else if !res.body().is_end_stream() {
let (delayed_tx, delayed_rx) = oneshot::channel();
res.body_mut().delayed_eof(delayed_rx);
let on_idle = future::poll_fn(move || {
pooled.poll_ready()
})
.then(move |_| {
// At this point, `pooled` is dropped, and had a chance
// to insert into the pool (if conn was idle)
drop(delayed_tx);
Ok(())
});
if let Err(err) = executor.execute(on_idle) {
// This task isn't critical, so just log and ignore.
warn!("error spawning task to insert idle connection: {}", err);
}
} else {
// There's no body to delay, but the connection isn't
// ready yet. Only re-insert when it's ready
let on_idle = future::poll_fn(move || {
pooled.poll_ready()
})
.then(|_| Ok(()));
if let Err(err) = executor.execute(on_idle) {
// This task isn't critical, so just log and ignore.
warn!("error spawning task to insert idle connection: {}", err);
}
}
Ok(res)
});
Either::B(fut)
return Either::A(fut);
}
});
Box::new(resp)
Either::B(fut
.and_then(move |mut res| {
// If pooled is HTTP/2, we can toss this reference immediately.
//
// when pooled is dropped, it will try to insert back into the
// pool. To delay that, spawn a future that completes once the
// sender is ready again.
//
// This *should* only be once the related `Connection` has polled
// for a new request to start.
//
// It won't be ready if there is a body to stream.
if ver == Ver::Http2 || !pooled.is_pool_enabled() || pooled.is_ready() {
drop(pooled);
} else if !res.body().is_end_stream() {
let (delayed_tx, delayed_rx) = oneshot::channel();
res.body_mut().delayed_eof(delayed_rx);
let on_idle = future::poll_fn(move || {
pooled.poll_ready()
})
.then(move |_| {
// At this point, `pooled` is dropped, and had a chance
// to insert into the pool (if conn was idle)
drop(delayed_tx);
Ok(())
});
if let Err(err) = executor.execute(on_idle) {
// This task isn't critical, so just log and ignore.
warn!("error spawning task to insert idle connection: {}", err);
}
} else {
// There's no body to delay, but the connection isn't
// ready yet. Only re-insert when it's ready
let on_idle = future::poll_fn(move || {
pooled.poll_ready()
})
.then(|_| Ok(()));
if let Err(err) = executor.execute(on_idle) {
// This task isn't critical, so just log and ignore.
warn!("error spawning task to insert idle connection: {}", err);
}
}
Ok(res)
}))
}))
}
fn pool_checkout_or_connect(&self, uri: Uri, pool_key: PoolKey)
@@ -558,8 +531,8 @@ impl Future for ResponseFuture {
struct RetryableSendRequest<C, B> {
client: Client<C, B>,
domain: String,
future: Box<Future<Item=Response<Body>, Error=ClientError<B>> + Send>,
pool_key: PoolKey,
uri: Uri,
}
@@ -598,7 +571,7 @@ where
trace!("unstarted request canceled, trying again (reason={:?})", reason);
*req.uri_mut() = self.uri.clone();
self.future = self.client.send_request(req, &self.domain);
self.future = self.client.send_request(req, self.pool_key.clone());
}
}
}
@@ -697,6 +670,24 @@ enum ClientError<B> {
}
}
impl<B> ClientError<B> {
fn map_with_reused(conn_reused: bool)
-> impl Fn((::Error, Option<Request<B>>)) -> Self
{
move |(err, orig_req)| {
if let Some(req) = orig_req {
ClientError::Canceled {
connection_reused: conn_reused,
reason: err,
req,
}
} else {
ClientError::Normal(err)
}
}
}
}
/// A marker to identify what version a pooled connection is.
#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)]
enum Ver {