From 1e6603353e0d9445e9a6be61b0742f37aa365be9 Mon Sep 17 00:00:00 2001
From: Sean McArthur <sean@seanmonstar.com>
Date: Mon, 25 Feb 2019 17:27:51 -0800
Subject: [PATCH] perf(http2): don't register callback with main h2 client task

---
 src/client/dispatch.rs | 11 +++++++++--
 src/proto/h2/client.rs |  8 ++++----
 2 files changed, 13 insertions(+), 6 deletions(-)

diff --git a/src/client/dispatch.rs b/src/client/dispatch.rs
index 6973df79..b49c6d3f 100644
--- a/src/client/dispatch.rs
+++ b/src/client/dispatch.rs
@@ -178,14 +178,21 @@ pub enum Callback<T, U> {
 }
 
 impl<T, U> Callback<T, U> {
-    pub fn poll_cancel(&mut self) -> Poll<(), ()> {
+    pub(crate) fn is_canceled(&self) -> bool {
+        match *self {
+            Callback::Retry(ref tx) => tx.is_canceled(),
+            Callback::NoRetry(ref tx) => tx.is_canceled(),
+        }
+    }
+
+    pub(crate) fn poll_cancel(&mut self) -> Poll<(), ()> {
         match *self {
             Callback::Retry(ref mut tx) => tx.poll_cancel(),
             Callback::NoRetry(ref mut tx) => tx.poll_cancel(),
         }
     }
 
-    pub fn send(self, val: Result<U, (::Error, Option<T>)>) {
+    pub(crate) fn send(self, val: Result<U, (::Error, Option<T>)>) {
         match self {
             Callback::Retry(tx) => {
                 let _ = tx.send(val);
diff --git a/src/proto/h2/client.rs b/src/proto/h2/client.rs
index 7ccceac0..c48561c8 100644
--- a/src/proto/h2/client.rs
+++ b/src/proto/h2/client.rs
@@ -102,7 +102,7 @@ where
                     match self.rx.poll() {
                         Ok(Async::Ready(Some((req, mut cb)))) => {
                             // check that future hasn't been canceled already
-                            if let Async::Ready(()) = cb.poll_cancel().expect("poll_cancel cannot error") {
+                            if cb.is_canceled() {
                                 trace!("request canceled");
                                 continue;
                             }
@@ -117,7 +117,7 @@ where
                                 Ok(ok) => ok,
                                 Err(err) => {
                                     debug!("client send request error: {}", err);
-                                    let _ = cb.send(Err((::Error::new_h2(err), None)));
+                                    cb.send(Err((::Error::new_h2(err), None)));
                                     continue;
                                 }
                             };
@@ -147,11 +147,11 @@ where
                                             let content_length = content_length_parse_all(res.headers());
                                             let res = res.map(|stream|
                                                 ::Body::h2(stream, content_length));
-                                            let _ = cb.send(Ok(res));
+                                            cb.send(Ok(res));
                                         },
                                         Err(err) => {
                                             debug!("client response error: {}", err);
-                                            let _ = cb.send(Err((::Error::new_h2(err), None)));
+                                            cb.send(Err((::Error::new_h2(err), None)));
                                         }
                                     }
                                     Ok(())