WIP refactoring DatPeer

- use Key in some more spots (instead of [u8])
- threaded Peer implementation, with chan for communication

1 files changed, 110 insertions, 127 deletions

diff --git a/src/peer.rs b/src/peer.rs
index f88e8fc..3310a13 100644
--- a/src/peer.rs
+++ b/src/peer.rs
@@ -1,32 +1,120 @@
 
 use errors::*;
-use std::convert::From;
+use std::thread;
+use std::net::ToSocketAddrs;
+use std::fmt::Display;
+use std::time::Duration;
 use protocol::{DatConnection, DatNetMessage};
 use network_msgs::*;
-use metadata_msgs::Index;
-use bitfield::Bitfield;
 use sodiumoxide::crypto::stream::Key;
-use protobuf::parse_from_bytes;
 use make_discovery_key;
+use chan;
+
+/// Wraps a low-level DatConnection in a thread (or two). Contains very little context about
+/// itself.
+pub struct DatPeerThread {
+    handle: u64,
+    feeds: Vec<(u8, Key)>,
+    outbound_chan: chan::Sender<(DatNetMessage, u8)>,
+}
 
-/// Wraps a low-level DatConnection with extra state about active feeds, bitfields that the
-/// remote has declared they Have, etc.
-pub struct DatPeer {
-    feeds: Vec<Key>,
-    conn: DatConnection,
-    remote_has: Vec<Vec<Bitfield>>,
+pub struct PeerMsg {
+    peer_handle: u64,
+    feed_index: u8,
+    msg: DatNetMessage,
 }
 
-impl DatPeer {
+/// This is what the "receive" loop does: simply blocking reads on the TCP socket, passing any
+/// received messages into a channel back to the worker thread.
+fn receiver_loop(mut dc: DatConnection, peer_rx: chan::Sender<Result<(DatNetMessage, u8)>>) {
+    loop {
+        match dc.recv_msg() {
+            Ok((msg, feed_index)) => {
+                peer_rx.send(Ok((msg, feed_index)));
+            },
+            Err(e) => {
+                peer_rx.send(Err(e));
+                return
+            },
+        }
+    }
+}
 
-    /// Has the remote peer indicated they have the given chunk in the given feed?
-    pub fn has(self, feed: u64, index: u64) -> Result<bool> {
-        for bitfield in self.remote_has[feed as usize].iter() {
-            if bitfield.get(index)? {
-                return Ok(true)
+/// Worker thread. After initializing the connection, loops endlessly. Looks for outgoing PeerMsg
+/// on the command channel, and sends these directly (blocking). Also looks for raw received
+/// messages (via a spawned receiver thread), and enhances these with extra context then passes
+/// upwards on the unified peer message channel.
+fn worker_thread(mut dc: DatConnection, handle: u64, outbound_chan: chan::Receiver<(DatNetMessage, u8)>, unified_chan: chan::Sender<Result<PeerMsg>>) {
+
+    dc.tcp.set_write_timeout(Some(Duration::new(2, 0)));
+
+    let rx_dc = dc.clone();
+    let (receiver_chan, raw_peer_rx) = chan::async();
+    thread::spawn(move || {
+        receiver_loop(rx_dc, receiver_chan);
+    });
+
+    loop {
+        chan_select!{
+            outbound_chan.recv() -> val => {
+                if let Some((msg, feed_index)) = val {
+                    match dc.send_msg(&msg, feed_index) {
+                        Ok(_) => {},
+                        Err(e) => {
+                            // TODO: error chain!
+                            unified_chan.send(Err(e));
+                            return
+                        }
+                    }
+                };
+            },
+            raw_peer_rx.recv() -> val => {
+                if let Some(Ok((msg, feed_index))) = val {
+                    // do mapping between feed index and feed pubkey here
+                    let pm = PeerMsg {
+                        peer_handle: handle,
+                        feed_index: feed_index,
+                        msg,
+                    };
+                    unified_chan.send(Ok(pm));
+                };
             }
-        }
-        Ok(false)
+        };
+    }
+}
+
+impl DatPeerThread {
+
+    pub fn connect<A: ToSocketAddrs + Display>(addr: A, feed_key: Key, handle: u64, is_live: bool, unified_chan: chan::Sender<Result<PeerMsg>>) -> Result<DatPeerThread> {
+
+        let addr = addr.to_socket_addrs().unwrap().nth(0).unwrap();
+        let (outbound_chan, tx_chan) = chan::async();
+        let feed_key2 = feed_key.clone();
+        thread::spawn(move || {
+
+            let dc = match DatConnection::connect(addr, &feed_key, is_live) {
+                Ok(c) => c,
+                Err(e) => {
+                    // TODO: error chain!
+                    unified_chan.send(Err(e));
+                    return;
+                },
+            };
+
+            worker_thread(dc, handle, tx_chan, unified_chan);
+        });
+
+        let dp = DatPeerThread {
+            handle,
+            outbound_chan,
+            feeds: vec![(0, feed_key2)],
+        };
+        Ok(dp)
+    }
+
+    pub fn send(&mut self, net_msg: DatNetMessage, feed_index: u8) -> Result<()> {
+        self.outbound_chan.send((net_msg, feed_index));
+        Ok(())
     }
 
     pub fn add_feed(&mut self, key: &[u8]) -> Result<()> {
@@ -35,8 +123,8 @@ impl DatPeer {
         let key = Key::from_slice(key_bytes).unwrap();
 
         for k in self.feeds.iter() {
-            if *k == key {
-                warn!("tried to add existing feed/key on a DatPeer connection");
+            if (*k).1 == key {
+                warn!("tried to add existing feed/key on a DatPeerThread connection");
                 return Ok(())
             }
         }
@@ -48,115 +136,10 @@ impl DatPeer {
         // Send (encrypted) Feed message for data feed
         let mut feed_msg = Feed::new();
         feed_msg.set_discoveryKey(discovery_key.to_vec());
-        self.conn.send_msg(&DatNetMessage::Feed(feed_msg), index as u8)?;
+        self.outbound_chan.send((DatNetMessage::Feed(feed_msg), index as u8));
 
-        self.feeds.push(key.clone());
-        self.remote_has.push(vec![]);
+        self.feeds.push((index as u8, key.clone()));
         Ok(())
-
-    }
-
-    /// hyperdrive-specific helper for discovering the public key for the "content" feed
-    /// from the "metadata" feed , and sending a Feed message to initialize on this connection.
-    pub fn init_data_feed(&mut self) -> Result<()> {
-
-        if self.feeds.len() > 1 {
-            return Ok(());
-        }
-
-        let data_key = self.get_drive_data_key()?;
-        self.add_feed(&data_key[0..32])
-    }
-
-
-    /// hyperdrive-specific helper for returning the "data" feed public key (aka, index=1)
-    pub fn get_drive_data_key(&mut self) -> Result<Key> {
-
-        if self.feeds.len() > 1 {
-            // we already have the key
-            let key = self.feeds[1].clone();
-            return Ok(key);
-        }
-
-        // Info: downloading, not uploading
-        let mut im = Info::new();
-        im.set_uploading(false);
-        im.set_downloading(true);
-        self.conn.send_msg(&DatNetMessage::Info(im), 0)?;
-
-        // Have: nothing (so far)
-        let mut hm = Have::new();
-        hm.set_start(0);
-        hm.set_length(0);
-        self.conn.send_msg(&DatNetMessage::Have(hm), 0)?;
-
-        // UnHave: still nothing
-        let mut uhm = Unhave::new();
-        uhm.set_start(0);
-        self.conn.send_msg(&DatNetMessage::Unhave(uhm), 0)?;
-
-        // Want: just the first element
-        let mut wm = Want::new();
-        wm.set_start(0);
-        wm.set_length(1);
-        self.conn.send_msg(&DatNetMessage::Want(wm), 0)?;
-
-        // listen for Have
-        loop {
-            let (msg, feed_index) = self.conn.recv_msg()?;
-            if feed_index == 1 {
-                continue;
-            }
-            if let DatNetMessage::Have(_) = msg {
-                break;
-            } else {
-                info!("Expected Have message, got: {:?}", &msg);
-                continue;
-            }
-        }
-
-        // Request
-        let mut rm = Request::new();
-        rm.set_index(0);
-        self.conn.send_msg(&DatNetMessage::Request(rm), 0)?;
-
-        loop {
-            let (msg, feed_index) = self.conn.recv_msg()?;
-            if feed_index == 1 {
-                info!("Expected other message channel");
-                continue;
-            }
-            if let DatNetMessage::Data(dm) = msg {
-                info!("Got metadata: {}", dm.get_index());
-                if dm.get_index() == 0 {
-                    let index_msg = parse_from_bytes::<Index>(&mut dm.get_value())?;
-                    if index_msg.get_field_type() == "hyperdrive" {
-                        let data_key = index_msg.get_content();
-                        if data_key.len() != 32 {
-                            bail!("Received data key had wrong length: {}", data_key.len());
-                        }
-                        // TODO: ok_or(), but what?
-                        return Ok(Key::from_slice(&data_key[0..32]).unwrap());
-                    } else {
-                        bail!("non-hyperdrive Index type: {}", index_msg.get_field_type());
-                    }
-                }
-            } else {
-                info!("Expected Data message, got: {:?}", &msg);
-                continue;
-            }
-        }
     }
 }
 
-impl From<DatConnection> for DatPeer {
-
-    fn from(dc: DatConnection) -> DatPeer {
-        let key = dc.key.clone();
-        DatPeer {
-            feeds: vec![key],
-            conn: dc,
-            remote_has: vec![vec![]],
-        }
-    }
-}