From 4fe518de86ecb0805421cca6e291db168c10eac1 Mon Sep 17 00:00:00 2001
From: Max Inden <mail@max-inden.de>
Date: Fri, 9 Dec 2022 18:56:30 +0100
Subject: [PATCH] feat!: Remove simple::SimpleProtocol (#3191)

Due to lack of usage, remove the `simple::SimpleProtocol`. Users may look at `libp2p::core::upgrade`
for alternatives.
---
 CHANGELOG.md  |  4 +++
 src/lib.rs    |  2 --
 src/simple.rs | 96 ---------------------------------------------------
 3 files changed, 4 insertions(+), 98 deletions(-)
 delete mode 100644 src/simple.rs

diff --git a/CHANGELOG.md b/CHANGELOG.md
index c9db1151f7cc..6ed797773194 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -47,9 +47,13 @@
 
 # 0.51.0 [unreleased]
 
+- Remove `SimpleProtocol` due to being unused. See [`libp2p::core::upgrade`](https://docs.rs/libp2p/0.50.0/libp2p/core/upgrade/index.html) for alternatives. See [PR 3191].
+
 - Update individual crates.
   - Update to [`libp2p-swarm` `v0.42.0`](swarm/CHANGELOG.md#0420).
 
+[PR 3191]: https://github.com/libp2p/rust-libp2p/pull/3191
+
 # 0.50.0
 
 This is a large release. After > 4 years, rust-libp2p ships with an [(alpha) QUIC
diff --git a/src/lib.rs b/src/lib.rs
index 1d80de1bd892..e87a5f746daf 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -140,7 +140,6 @@ pub use libp2p_yamux as yamux;
 mod transport_ext;
 
 pub mod bandwidth;
-pub mod simple;
 
 #[cfg(doc)]
 pub mod tutorials;
@@ -152,7 +151,6 @@ pub use self::core::{
     PeerId, Transport,
 };
 pub use self::multiaddr::{multiaddr as build_multiaddr, Multiaddr};
-pub use self::simple::SimpleProtocol;
 pub use self::swarm::Swarm;
 pub use self::transport_ext::TransportExt;
 
diff --git a/src/simple.rs b/src/simple.rs
deleted file mode 100644
index fb4d3b735d25..000000000000
--- a/src/simple.rs
+++ /dev/null
@@ -1,96 +0,0 @@
-// Copyright 2017 Parity Technologies (UK) Ltd.
-//
-// Permission is hereby granted, free of charge, to any person obtaining a
-// copy of this software and associated documentation files (the "Software"),
-// to deal in the Software without restriction, including without limitation
-// the rights to use, copy, modify, merge, publish, distribute, sublicense,
-// and/or sell copies of the Software, and to permit persons to whom the
-// Software is furnished to do so, subject to the following conditions:
-//
-// The above copyright notice and this permission notice shall be included in
-// all copies or substantial portions of the Software.
-//
-// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
-// OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
-// FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
-// AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
-// LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
-// FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
-// DEALINGS IN THE SOFTWARE.
-
-use crate::core::upgrade::{InboundUpgrade, OutboundUpgrade, UpgradeInfo};
-use bytes::Bytes;
-use futures::prelude::*;
-use std::{iter, sync::Arc};
-
-/// Implementation of `ConnectionUpgrade`. Convenient to use with small protocols.
-#[derive(Debug)]
-pub struct SimpleProtocol<F> {
-    info: Bytes,
-    // Note: we put the closure `F` in an `Arc` because Rust closures aren't automatically clonable
-    // yet.
-    upgrade: Arc<F>,
-}
-
-impl<F> SimpleProtocol<F> {
-    /// Builds a `SimpleProtocol`.
-    pub fn new<N>(info: N, upgrade: F) -> SimpleProtocol<F>
-    where
-        N: Into<Bytes>,
-    {
-        SimpleProtocol {
-            info: info.into(),
-            upgrade: Arc::new(upgrade),
-        }
-    }
-}
-
-impl<F> Clone for SimpleProtocol<F> {
-    fn clone(&self) -> Self {
-        SimpleProtocol {
-            info: self.info.clone(),
-            upgrade: self.upgrade.clone(),
-        }
-    }
-}
-
-impl<F> UpgradeInfo for SimpleProtocol<F> {
-    type Info = Bytes;
-    type InfoIter = iter::Once<Self::Info>;
-
-    fn protocol_info(&self) -> Self::InfoIter {
-        iter::once(self.info.clone())
-    }
-}
-
-impl<C, F, O, A, E> InboundUpgrade<C> for SimpleProtocol<F>
-where
-    C: AsyncRead + AsyncWrite,
-    F: Fn(C) -> O,
-    O: Future<Output = Result<A, E>>,
-{
-    type Output = A;
-    type Error = E;
-    type Future = O;
-
-    fn upgrade_inbound(self, socket: C, _: Self::Info) -> Self::Future {
-        let upgrade = &self.upgrade;
-        upgrade(socket)
-    }
-}
-
-impl<C, F, O, A, E> OutboundUpgrade<C> for SimpleProtocol<F>
-where
-    C: AsyncRead + AsyncWrite,
-    F: Fn(C) -> O,
-    O: Future<Output = Result<A, E>>,
-{
-    type Output = A;
-    type Error = E;
-    type Future = O;
-
-    fn upgrade_outbound(self, socket: C, _: Self::Info) -> Self::Future {
-        let upgrade = &self.upgrade;
-        upgrade(socket)
-    }
-}