From 6f1787e9d1adf96828630bca320de236b6c6801a Mon Sep 17 00:00:00 2001
From: Erick Tryzelaar <etryzelaar@google.com>
Date: Fri, 11 Jan 2019 14:03:37 -0800
Subject: [PATCH] Shrink down the dependency on tokio

it turns out that tokio-rustls only requires a small portion of
the tokio stack. This patch slims down the dependencies since not
all clients need the full tokio stack.
---
 Cargo.toml        | 5 +++--
 src/common/mod.rs | 4 ++--
 src/lib.rs        | 4 +++-
 src/tokio_impl.rs | 5 ++---
 4 files changed, 10 insertions(+), 8 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index b4cd9e1..a0e2017 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -15,7 +15,8 @@ travis-ci = { repository = "quininer/tokio-rustls" }
 appveyor = { repository = "quininer/tokio-rustls" }
 
 [dependencies]
-tokio = { version = "0.1.6", optional = true }
+futures = { version = "0.1", optional = true }
+tokio-io = { version = "0.1.6", optional = true }
 bytes = { version = "0.4", optional = true }
 iovec = { version = "0.1", optional = true }
 rustls = "0.14"
@@ -28,4 +29,4 @@ lazy_static = "1"
 [features]
 default = ["tokio-support"]
 nightly = ["bytes", "iovec"]
-tokio-support = ["tokio"]
+tokio-support = ["futures", "tokio-io"]
diff --git a/src/common/mod.rs b/src/common/mod.rs
index e18aa6e..8e4a5b1 100644
--- a/src/common/mod.rs
+++ b/src/common/mod.rs
@@ -10,7 +10,7 @@ use rustls::Session;
 use rustls::WriteV;
 #[cfg(feature = "nightly")]
 #[cfg(feature = "tokio-support")]
-use tokio::io::AsyncWrite;
+use tokio_io::AsyncWrite;
 
 
 pub struct Stream<'a, S: 'a, IO: 'a> {
@@ -91,7 +91,7 @@ impl<'a, S: Session, IO: Read + Write> WriteTls<'a, S, IO> for Stream<'a, S, IO>
 #[cfg(feature = "tokio-support")]
 impl<'a, S: Session, IO: Read + AsyncWrite> WriteTls<'a, S, IO> for Stream<'a, S, IO> {
     fn write_tls(&mut self) -> io::Result<usize> {
-        use tokio::prelude::Async;
+        use futures::Async;
         use self::vecbuf::VecBuf;
 
         struct V<'a, IO: 'a>(&'a mut IO);
diff --git a/src/lib.rs b/src/lib.rs
index ee1524d..2aaf2e4 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -6,7 +6,9 @@ pub extern crate rustls;
 pub extern crate webpki;
 
 #[cfg(feature = "tokio-support")]
-extern crate tokio;
+extern crate futures;
+#[cfg(feature = "tokio-support")]
+extern crate tokio_io;
 #[cfg(feature = "nightly")]
 #[cfg(feature = "tokio-support")]
 extern crate bytes;
diff --git a/src/tokio_impl.rs b/src/tokio_impl.rs
index 644e4f0..7d9ba57 100644
--- a/src/tokio_impl.rs
+++ b/src/tokio_impl.rs
@@ -1,7 +1,6 @@
 use super::*;
-use tokio::prelude::*;
-use tokio::io::{ AsyncRead, AsyncWrite };
-use tokio::prelude::Poll;
+use tokio_io::{ AsyncRead, AsyncWrite };
+use futures::{Async, Future, Poll};
 use common::Stream;