Merge pull request #78 from tomaka/multistream-select-ls

Implement the ls command for multistream-select

multistream-select/Cargo.toml

@@ -8,6 +8,7 @@ bytes = "0.4"
 futures = { version = "0.1" }
 smallvec = "0.5"
 tokio-io = "0.1"
+varint = { path = "../varint-rs" }
 
 [dev-dependencies]
 tokio-core = "0.1"

multistream-select/src/lib.rs

@@ -122,6 +122,7 @@ extern crate bytes;
 extern crate futures;
 extern crate smallvec;
 extern crate tokio_io;
+extern crate varint;
 
 mod dialer_select;
 mod error;

multistream-select/src/protocol/dialer.rs

@@ -25,12 +25,13 @@ use futures::{Async, AsyncSink, Future, Poll, Sink, StartSend, Stream};
 use length_delimited::LengthDelimitedFramedRead;
 use protocol::DialerToListenerMessage;
 use protocol::ListenerToDialerMessage;
-
 use protocol::MULTISTREAM_PROTOCOL_WITH_LF;
 use protocol::MultistreamSelectError;
+use std::io::{Cursor, Read, BufRead};
 use tokio_io::{AsyncRead, AsyncWrite};
 use tokio_io::codec::length_delimited::Builder as LengthDelimitedBuilder;
 use tokio_io::codec::length_delimited::FramedWrite as LengthDelimitedFramedWrite;
+use varint;
 
 /// Wraps around a `AsyncRead+AsyncWrite`. Assumes that we're on the dialer's side. Produces and
 /// accepts messages.
@@ -149,7 +150,32 @@ impl<R> Stream for Dialer<R>
 
 			} else {
 				// A varint number of protocols
-				unimplemented!()
+				let mut reader = Cursor::new(frame);
+				let num_protocols: usize = varint::decode(reader.by_ref())?;
+
+				let mut iter = BufRead::split(reader, b'\r');
+				if !iter.next().ok_or(MultistreamSelectError::UnknownMessage)??.is_empty() {
+					return Err(MultistreamSelectError::UnknownMessage);
+				}
+
+				let mut out = Vec::with_capacity(num_protocols);
+				for proto in iter.by_ref().take(num_protocols) {
+					let mut proto = proto?;
+					let poped = proto.pop();		// Pop the `\n`
+					if poped != Some(b'\n') {
+						return Err(MultistreamSelectError::UnknownMessage);	
+					}
+					out.push(Bytes::from(proto));
+				}
+
+				// Making sure that the number of protocols was correct.
+				if iter.next().is_some() || out.len() != num_protocols {
+					return Err(MultistreamSelectError::UnknownMessage);
+				}
+
+				return Ok(Async::Ready(Some(ListenerToDialerMessage::ProtocolsListResponse {
+					list: out
+				})));
 			}
 		}
 	}

multistream-select/src/protocol/error.rs

@@ -22,13 +22,14 @@
 
 use std::error;
 use std::fmt;
-use std::io::Error as IoError;
+use std::io;
+use varint;
 
 /// Error at the multistream-select layer of communication.
 #[derive(Debug)]
 pub enum MultistreamSelectError {
 	/// I/O error.
-	IoError(IoError),
+	IoError(io::Error),
 
 	/// The remote doesn't use the same multistream-select protocol as we do.
 	FailedHandshake,
@@ -38,15 +39,26 @@ pub enum MultistreamSelectError {
 
 	/// Protocol names must always start with `/`, otherwise this error is returned.
 	WrongProtocolName,
+
+	/// Failure to parse variable-length integer.
+	// TODO: we don't include the actual error, because that would remove Send from the enum
+	VarintParseError(String),
 }
 
-impl From<IoError> for MultistreamSelectError {
+impl From<io::Error> for MultistreamSelectError {
 	#[inline]
-	fn from(err: IoError) -> MultistreamSelectError {
+	fn from(err: io::Error) -> MultistreamSelectError {
 		MultistreamSelectError::IoError(err)
 	}
 }
 
+impl From<varint::Error> for MultistreamSelectError {
+	#[inline]
+	fn from(err: varint::Error) -> MultistreamSelectError {
+		MultistreamSelectError::VarintParseError(err.to_string())
+	}
+}
+
 impl error::Error for MultistreamSelectError {
 	#[inline]
 	fn description(&self) -> &str {
@@ -63,6 +75,9 @@ impl error::Error for MultistreamSelectError {
 			MultistreamSelectError::WrongProtocolName => {
 				"protocol names must always start with `/`, otherwise this error is returned"
 			},
+			MultistreamSelectError::VarintParseError(_) => {
+				"failure to parse variable-length integer"
+			},
 		}
 	}
 

multistream-select/src/protocol/listener.rs

@@ -25,12 +25,12 @@ use futures::{Async, AsyncSink, Future, Poll, Sink, StartSend, Stream};
 use length_delimited::LengthDelimitedFramedRead;
 use protocol::DialerToListenerMessage;
 use protocol::ListenerToDialerMessage;
-
 use protocol::MULTISTREAM_PROTOCOL_WITH_LF;
 use protocol::MultistreamSelectError;
 use tokio_io::{AsyncRead, AsyncWrite};
 use tokio_io::codec::length_delimited::Builder as LengthDelimitedBuilder;
 use tokio_io::codec::length_delimited::FramedWrite as LengthDelimitedFramedWrite;
+use varint;
 
 /// Wraps around a `AsyncRead+AsyncWrite`. Assumes that we're on the listener's side. Produces and
 /// accepts messages.
@@ -112,8 +112,22 @@ impl<R> Sink for Listener<R>
 				}
 			}
 
-			ListenerToDialerMessage::ProtocolsListResponse { list: _list } => {
+			ListenerToDialerMessage::ProtocolsListResponse { list } => {
-				unimplemented!()
+				let mut out_msg = varint::encode(list.len());
+				for elem in list.iter() {
+					out_msg.push(b'\r');
+					out_msg.extend_from_slice(elem);
+					out_msg.push(b'\n');
+				}
+
+				match self.inner.start_send(BytesMut::from(out_msg)) {
+					Ok(AsyncSink::Ready) => Ok(AsyncSink::Ready),
+					Ok(AsyncSink::NotReady(_)) => {
+						let m = ListenerToDialerMessage::ProtocolsListResponse { list };
+						Ok(AsyncSink::NotReady(m))
+					}
+					Err(err) => Err(err.into()),
+				}
 			}
 		}
 	}

multistream-select/src/tests.rs

@@ -147,7 +147,6 @@ fn no_protocol_found() {
 }
 
 #[test]
-#[ignore] // TODO: not yet implemented in the listener
 fn select_proto_parallel() {
 	let mut core = Core::new().unwrap();