aquatic_ws: rewrite to use glommio

aquatic_ws/src/lib/handlers.rs

@@ -0,0 +1,308 @@
+use std::cell::RefCell;
+use std::rc::Rc;
+use std::time::Duration;
+
+use aquatic_common::access_list::AccessList;
+use aquatic_common::extract_response_peers;
+use futures_lite::StreamExt;
+use glommio::channels::channel_mesh::{MeshBuilder, Partial, Role, Senders};
+use glommio::enclose;
+use glommio::prelude::*;
+use glommio::timer::TimerActionRepeat;
+use hashbrown::HashMap;
+use rand::{rngs::SmallRng, Rng, SeedableRng};
+
+use aquatic_ws_protocol::*;
+
+use crate::common::*;
+use crate::config::Config;
+
+pub async fn run_request_worker(
+    config: Config,
+    in_message_mesh_builder: MeshBuilder<(ConnectionMeta, InMessage), Partial>,
+    out_message_mesh_builder: MeshBuilder<(ConnectionMeta, OutMessage), Partial>,
+    access_list: AccessList,
+) {
+    let (_, mut in_message_receivers) = in_message_mesh_builder.join(Role::Consumer).await.unwrap();
+    let (out_message_senders, _) = out_message_mesh_builder.join(Role::Producer).await.unwrap();
+
+    let out_message_senders = Rc::new(out_message_senders);
+
+    let torrents = Rc::new(RefCell::new(TorrentMaps::default()));
+    let access_list = Rc::new(RefCell::new(access_list));
+
+    // Periodically clean torrents and update access list
+    TimerActionRepeat::repeat(enclose!((config, torrents, access_list) move || {
+        enclose!((config, torrents, access_list) move || async move {
+            update_access_list(&config, access_list.clone()).await;
+
+            torrents.borrow_mut().clean(&config, &*access_list.borrow());
+
+            Some(Duration::from_secs(config.cleaning.interval))
+        })()
+    }));
+
+    let mut handles = Vec::new();
+
+    for (_, receiver) in in_message_receivers.streams() {
+        let handle = spawn_local(handle_request_stream(
+            config.clone(),
+            torrents.clone(),
+            out_message_senders.clone(),
+            receiver,
+        ))
+        .detach();
+
+        handles.push(handle);
+    }
+
+    for handle in handles {
+        handle.await;
+    }
+}
+
+async fn handle_request_stream<S>(
+    config: Config,
+    torrents: Rc<RefCell<TorrentMaps>>,
+    out_message_senders: Rc<Senders<(ConnectionMeta, OutMessage)>>,
+    mut stream: S,
+) where
+    S: futures_lite::Stream<Item = (ConnectionMeta, InMessage)> + ::std::marker::Unpin,
+{
+    let mut rng = SmallRng::from_entropy();
+
+    let max_peer_age = config.cleaning.max_peer_age;
+    let peer_valid_until = Rc::new(RefCell::new(ValidUntil::new(max_peer_age)));
+
+    TimerActionRepeat::repeat(enclose!((peer_valid_until) move || {
+        enclose!((peer_valid_until) move || async move {
+            *peer_valid_until.borrow_mut() = ValidUntil::new(max_peer_age);
+
+            Some(Duration::from_secs(1))
+        })()
+    }));
+
+    while let Some((meta, in_message)) = stream.next().await {
+        match in_message {
+            InMessage::AnnounceRequest(request) => {
+                handle_announce_request(
+                    &config,
+                    &mut rng,
+                    &mut torrents.borrow_mut(),
+                    &out_message_senders,
+                    peer_valid_until.borrow().to_owned(),
+                    meta,
+                    request,
+                )
+                .await;
+            }
+            InMessage::ScrapeRequest(request) => {
+                handle_scrape_request(
+                    &config,
+                    &mut torrents.borrow_mut(),
+                    &out_message_senders,
+                    meta,
+                    request,
+                )
+                .await;
+            }
+        };
+
+        yield_if_needed().await;
+    }
+}
+
+pub async fn handle_announce_request(
+    config: &Config,
+    rng: &mut impl Rng,
+    torrent_maps: &mut TorrentMaps,
+    out_message_senders: &Rc<Senders<(ConnectionMeta, OutMessage)>>,
+    valid_until: ValidUntil,
+    request_sender_meta: ConnectionMeta,
+    request: AnnounceRequest,
+) {
+    let torrent_data: &mut TorrentData = if request_sender_meta.converted_peer_ip.is_ipv4() {
+        torrent_maps.ipv4.entry(request.info_hash).or_default()
+    } else {
+        torrent_maps.ipv6.entry(request.info_hash).or_default()
+    };
+
+    // If there is already a peer with this peer_id, check that socket
+    // addr is same as that of request sender. Otherwise, ignore request.
+    // Since peers have access to each others peer_id's, they could send
+    // requests using them, causing all sorts of issues. Checking naive
+    // (non-converted) socket addresses is enough, since state is split
+    // on converted peer ip.
+    if let Some(previous_peer) = torrent_data.peers.get(&request.peer_id) {
+        if request_sender_meta.naive_peer_addr != previous_peer.connection_meta.naive_peer_addr {
+            return;
+        }
+    }
+
+    ::log::trace!("received request from {:?}", request_sender_meta);
+
+    // Insert/update/remove peer who sent this request
+    {
+        let peer_status = PeerStatus::from_event_and_bytes_left(
+            request.event.unwrap_or_default(),
+            request.bytes_left,
+        );
+
+        let peer = Peer {
+            connection_meta: request_sender_meta,
+            status: peer_status,
+            valid_until,
+        };
+
+        let opt_removed_peer = match peer_status {
+            PeerStatus::Leeching => {
+                torrent_data.num_leechers += 1;
+
+                torrent_data.peers.insert(request.peer_id, peer)
+            }
+            PeerStatus::Seeding => {
+                torrent_data.num_seeders += 1;
+
+                torrent_data.peers.insert(request.peer_id, peer)
+            }
+            PeerStatus::Stopped => torrent_data.peers.remove(&request.peer_id),
+        };
+
+        match opt_removed_peer.map(|peer| peer.status) {
+            Some(PeerStatus::Leeching) => {
+                torrent_data.num_leechers -= 1;
+            }
+            Some(PeerStatus::Seeding) => {
+                torrent_data.num_seeders -= 1;
+            }
+            _ => {}
+        }
+    }
+
+    // If peer sent offers, send them on to random peers
+    if let Some(offers) = request.offers {
+        // FIXME: config: also maybe check this when parsing request
+        let max_num_peers_to_take = offers.len().min(config.protocol.max_offers);
+
+        #[inline]
+        fn f(peer: &Peer) -> Peer {
+            *peer
+        }
+
+        let offer_receivers: Vec<Peer> = extract_response_peers(
+            rng,
+            &torrent_data.peers,
+            max_num_peers_to_take,
+            request.peer_id,
+            f,
+        );
+
+        for (offer, offer_receiver) in offers.into_iter().zip(offer_receivers) {
+            let middleman_offer = MiddlemanOfferToPeer {
+                action: AnnounceAction,
+                info_hash: request.info_hash,
+                peer_id: request.peer_id,
+                offer: offer.offer,
+                offer_id: offer.offer_id,
+            };
+
+            out_message_senders.try_send_to(
+                offer_receiver.connection_meta.out_message_consumer_id.0,
+                (
+                    offer_receiver.connection_meta,
+                    OutMessage::Offer(middleman_offer),
+                ),
+            );
+            ::log::trace!(
+                "sent middleman offer to {:?}",
+                offer_receiver.connection_meta
+            );
+        }
+    }
+
+    // If peer sent answer, send it on to relevant peer
+    if let (Some(answer), Some(answer_receiver_id), Some(offer_id)) =
+        (request.answer, request.to_peer_id, request.offer_id)
+    {
+        if let Some(answer_receiver) = torrent_data.peers.get(&answer_receiver_id) {
+            let middleman_answer = MiddlemanAnswerToPeer {
+                action: AnnounceAction,
+                peer_id: request.peer_id,
+                info_hash: request.info_hash,
+                answer,
+                offer_id,
+            };
+
+            out_message_senders.try_send_to(
+                answer_receiver.connection_meta.out_message_consumer_id.0,
+                (
+                    answer_receiver.connection_meta,
+                    OutMessage::Answer(middleman_answer),
+                ),
+            );
+            ::log::trace!(
+                "sent middleman answer to {:?}",
+                answer_receiver.connection_meta
+            );
+        }
+    }
+
+    let out_message = OutMessage::AnnounceResponse(AnnounceResponse {
+        action: AnnounceAction,
+        info_hash: request.info_hash,
+        complete: torrent_data.num_seeders,
+        incomplete: torrent_data.num_leechers,
+        announce_interval: config.protocol.peer_announce_interval,
+    });
+
+    out_message_senders.send_to(
+        request_sender_meta.out_message_consumer_id.0,
+        (request_sender_meta, out_message),
+    );
+}
+
+pub async fn handle_scrape_request(
+    config: &Config,
+    torrent_maps: &mut TorrentMaps,
+    out_message_senders: &Rc<Senders<(ConnectionMeta, OutMessage)>>,
+    meta: ConnectionMeta,
+    request: ScrapeRequest,
+) {
+    let info_hashes = if let Some(info_hashes) = request.info_hashes {
+        info_hashes.as_vec()
+    } else {
+        return;
+    };
+
+    let num_to_take = info_hashes.len().min(config.protocol.max_scrape_torrents);
+
+    let mut out_message = ScrapeResponse {
+        action: ScrapeAction,
+        files: HashMap::with_capacity(num_to_take),
+    };
+
+    let torrent_map: &mut TorrentMap = if meta.converted_peer_ip.is_ipv4() {
+        &mut torrent_maps.ipv4
+    } else {
+        &mut torrent_maps.ipv6
+    };
+
+    // If request.info_hashes is empty, don't return scrape for all
+    // torrents, even though reference server does it. It is too expensive.
+    for info_hash in info_hashes.into_iter().take(num_to_take) {
+        if let Some(torrent_data) = torrent_map.get(&info_hash) {
+            let stats = ScrapeStatistics {
+                complete: torrent_data.num_seeders,
+                downloaded: 0, // No implementation planned
+                incomplete: torrent_data.num_leechers,
+            };
+
+            out_message.files.insert(info_hash, stats);
+        }
+    }
+
+    out_message_senders.try_send_to(
+        meta.out_message_consumer_id.0,
+        (meta, OutMessage::ScrapeResponse(out_message)),
+    );
+}