remove redundant recursion in p2p::io

p2p/src/io/handshake.rs

@@ -58,7 +58,6 @@ enum HandshakeState<A> {
 		version: Option<Version>,
 		future: ReadMessage<Verack, A>,
 	},
-	Finished,
 }
 
 enum AcceptHandshakeState<A> {
@@ -74,7 +73,6 @@ enum AcceptHandshakeState<A> {
 		version: Option<Version>,
 		future: WriteMessage<Verack, A>,
 	},
-	Finished,
 }
 
 pub struct Handshake<A> {
@@ -98,10 +96,11 @@ impl<A> Future for Handshake<A> where A: AsyncRead + AsyncWrite {
 	type Error = io::Error;
 
 	fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-		let (next, result) = match self.state {
+		loop {
+			let next_state = match self.state {
 				HandshakeState::SendVersion(ref mut future) => {
 					let (stream, _) = try_ready!(future.poll());
-				(HandshakeState::ReceiveVersion(read_message(stream, self.magic, 0)), Async::NotReady)
+					HandshakeState::ReceiveVersion(read_message(stream, self.magic, 0))
 				},
 				HandshakeState::ReceiveVersion(ref mut future) => {
 					let (stream, version) = try_ready!(future.poll());
@@ -119,24 +118,20 @@ impl<A> Future for Handshake<A> where A: AsyncRead + AsyncWrite {
 						}
 					}
 
-				let next = HandshakeState::SendVerack {
+					HandshakeState::SendVerack {
 						version: Some(version),
 						future: write_message(stream, verack_message(self.magic)),
-				};
-
-				(next, Async::NotReady)
+					}
 				},
 				HandshakeState::SendVerack { ref mut version, ref mut future } => {
 					let (stream, _) = try_ready!(future.poll());
 
 					let version = version.take().expect("verack must be preceded by version");
 
-				let next = HandshakeState::ReceiveVerack {
+					HandshakeState::ReceiveVerack {
 						version: Some(version),
 						future: read_message(stream, self.magic, 0),
-				};
-
-				(next, Async::NotReady)
+					}
 				},
 				HandshakeState::ReceiveVerack { ref mut version, ref mut future } => {
 					let (stream, _verack) = try_ready!(future.poll());
@@ -147,16 +142,10 @@ impl<A> Future for Handshake<A> where A: AsyncRead + AsyncWrite {
 						version: version,
 					};
 
-				(HandshakeState::Finished, Async::Ready((stream, Ok(result))))
+					return Ok(Async::Ready((stream, Ok(result))));
 				},
-			HandshakeState::Finished => panic!("poll Handshake after it's done"),
 			};
-
-		self.state = next;
-		match result {
-			// by polling again, we register new future
-			Async::NotReady => self.poll(),
-			result => Ok(result)
+			self.state = next_state;
 		}
 	}
 }
@@ -166,7 +155,8 @@ impl<A> Future for AcceptHandshake<A> where A: AsyncRead + AsyncWrite {
 	type Error = io::Error;
 
 	fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-		let (next, result) = match self.state {
+		loop {
+			let next_state = match self.state {
 				AcceptHandshakeState::ReceiveVersion { ref mut local_version, ref mut future } => {
 					let (stream, version) = try_ready!(future.poll());
 					let version = match version {
@@ -184,21 +174,17 @@ impl<A> Future for AcceptHandshake<A> where A: AsyncRead + AsyncWrite {
 					}
 
 					let local_version = local_version.take().expect("local version must be set");
-				let next = AcceptHandshakeState::SendVersion {
+					AcceptHandshakeState::SendVersion {
 						version: Some(version),
 						future: write_message(stream, version_message(self.magic, local_version)),
-				};
-
-				(next, Async::NotReady)
+					}
 				},
 				AcceptHandshakeState::SendVersion { ref mut version, ref mut future } => {
 					let (stream, _) = try_ready!(future.poll());
-				let next = AcceptHandshakeState::SendVerack {
+					AcceptHandshakeState::SendVerack {
 						version: version.take(),
 						future: write_message(stream, verack_message(self.magic)),
-				};
-
-				(next, Async::NotReady)
+					}
 				},
 				AcceptHandshakeState::SendVerack { ref mut version, ref mut future } => {
 					let (stream, _) = try_ready!(future.poll());
@@ -210,16 +196,10 @@ impl<A> Future for AcceptHandshake<A> where A: AsyncRead + AsyncWrite {
 						version: version,
 					};
 
-				(AcceptHandshakeState::Finished, Async::Ready((stream, Ok(result))))
+					return Ok(Async::Ready((stream, Ok(result))));
 				},
-			AcceptHandshakeState::Finished => panic!("poll AcceptHandshake after it's done"),
 			};
-
-		self.state = next;
-		match result {
-			// by polling again, we register new future
-			Async::NotReady => self.poll(),
-			result => Ok(result)
+			self.state = next_state;
 		}
 	}
 }

p2p/src/io/read_any_message.rs

@@ -20,7 +20,6 @@ pub enum ReadAnyMessageState<A> {
 		header: MessageHeader,
 		future: ReadExact<A, Bytes>
 	},
-	Finished,
 }
 
 pub struct ReadAnyMessage<A> {
@@ -32,36 +31,30 @@ impl<A> Future for ReadAnyMessage<A> where A: AsyncRead {
 	type Error = io::Error;
 
 	fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-		let (next, result) = match self.state {
+		loop {
+			let next_state = match self.state {
 				ReadAnyMessageState::ReadHeader(ref mut header) => {
 					let (stream, header) = try_ready!(header.poll());
 					let header = match header {
 						Ok(header) => header,
 						Err(err) => return Ok(Err(err).into()),
 					};
-				let future = read_exact(stream, Bytes::new_with_len(header.len as usize));
-				let next = ReadAnyMessageState::ReadPayload {
+					ReadAnyMessageState::ReadPayload {
+						future: read_exact(stream, Bytes::new_with_len(header.len as usize)),
 						header: header,
-					future: future,
-				};
-				(next, Async::NotReady)
+					}
 				},
 				ReadAnyMessageState::ReadPayload { ref mut header, ref mut future } => {
 					let (_stream, bytes) = try_ready!(future.poll());
 					if checksum(&bytes) != header.checksum {
 						return Ok(Err(Error::InvalidChecksum).into());
 					}
-				let next = ReadAnyMessageState::Finished;
-				(next, Ok((header.command.clone(), bytes)).into())
+
+					return Ok(Async::Ready(Ok((header.command.clone(), bytes))));
 				},
-			ReadAnyMessageState::Finished => panic!("poll ReadAnyMessage after it's done"),
 			};
 
-		self.state = next;
-		match result {
-			// by polling again, we register new future
-			Async::NotReady => self.poll(),
-			result => Ok(result)
+			self.state = next_state;
 		}
 	}
 }

p2p/src/io/read_message.rs

@@ -25,7 +25,6 @@ enum ReadMessageState<M, A> {
 	ReadPayload {
 		future: ReadPayload<M, A>,
 	},
-	Finished,
 }
 
 pub struct ReadMessage<M, A> {
@@ -38,7 +37,8 @@ impl<M, A> Future for ReadMessage<M, A> where A: AsyncRead, M: Payload {
 	type Error = io::Error;
 
 	fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
-		let (next, result) = match self.state {
+		loop {
+			let next_state = match self.state {
 				ReadMessageState::ReadHeader { version, ref mut future } => {
 					let (read, header) = try_ready!(future.poll());
 					let header = match header {
@@ -51,23 +51,16 @@ impl<M, A> Future for ReadMessage<M, A> where A: AsyncRead, M: Payload {
 					let future = read_payload(
 						read, version, header.len as usize, header.checksum,
 					);
-				let next = ReadMessageState::ReadPayload {
+					ReadMessageState::ReadPayload {
 						future: future,
-				};
-				(next, Async::NotReady)
+					}
 				},
 				ReadMessageState::ReadPayload { ref mut future } => {
 					let (read, payload) = try_ready!(future.poll());
-				(ReadMessageState::Finished, Async::Ready((read, payload)))
+					return Ok(Async::Ready((read, payload)));
 				},
-			ReadMessageState::Finished => panic!("poll ReadMessage after it's done"),
 			};
-
-		self.state = next;
-		match result {
-			// by polling again, we register new future
-			Async::NotReady => self.poll(),
-			result => Ok(result)
+			self.state = next_state;
 		}
 	}
 }