udp, common: rename request workers to swarm workers

aquatic_udp/src/workers/swarm/mod.rs

@@ -0,0 +1,185 @@
+mod storage;
+
+use std::net::IpAddr;
+use std::sync::atomic::Ordering;
+use std::time::Duration;
+use std::time::Instant;
+
+use crossbeam_channel::Receiver;
+use rand::{rngs::SmallRng, SeedableRng};
+
+use aquatic_common::{CanonicalSocketAddr, PanicSentinel, ValidUntil};
+
+use aquatic_udp_protocol::*;
+
+use crate::common::*;
+use crate::config::Config;
+
+use storage::{Peer, TorrentMap, TorrentMaps};
+
+pub fn run_swarm_worker(
+    _sentinel: PanicSentinel,
+    config: Config,
+    state: State,
+    request_receiver: Receiver<(SocketWorkerIndex, ConnectedRequest, CanonicalSocketAddr)>,
+    response_sender: ConnectedResponseSender,
+    worker_index: SwarmWorkerIndex,
+) {
+    let mut torrents = TorrentMaps::default();
+    let mut rng = SmallRng::from_entropy();
+
+    let timeout = Duration::from_millis(config.request_channel_recv_timeout_ms);
+    let mut peer_valid_until = ValidUntil::new(config.cleaning.max_peer_age);
+
+    let cleaning_interval = Duration::from_secs(config.cleaning.torrent_cleaning_interval);
+    let statistics_update_interval = Duration::from_secs(config.statistics.interval);
+
+    let mut last_cleaning = Instant::now();
+    let mut last_statistics_update = Instant::now();
+
+    let mut iter_counter = 0usize;
+
+    loop {
+        if let Ok((sender_index, request, src)) = request_receiver.recv_timeout(timeout) {
+            let response = match (request, src.get().ip()) {
+                (ConnectedRequest::Announce(request), IpAddr::V4(ip)) => {
+                    let response = handle_announce_request(
+                        &config,
+                        &mut rng,
+                        &mut torrents.ipv4,
+                        request,
+                        ip,
+                        peer_valid_until,
+                    );
+
+                    ConnectedResponse::AnnounceIpv4(response)
+                }
+                (ConnectedRequest::Announce(request), IpAddr::V6(ip)) => {
+                    let response = handle_announce_request(
+                        &config,
+                        &mut rng,
+                        &mut torrents.ipv6,
+                        request,
+                        ip,
+                        peer_valid_until,
+                    );
+
+                    ConnectedResponse::AnnounceIpv6(response)
+                }
+                (ConnectedRequest::Scrape(request), IpAddr::V4(_)) => {
+                    ConnectedResponse::Scrape(handle_scrape_request(&mut torrents.ipv4, request))
+                }
+                (ConnectedRequest::Scrape(request), IpAddr::V6(_)) => {
+                    ConnectedResponse::Scrape(handle_scrape_request(&mut torrents.ipv6, request))
+                }
+            };
+
+            response_sender.try_send_to(sender_index, response, src);
+        }
+
+        // Run periodic tasks
+        if iter_counter % 128 == 0 {
+            let now = Instant::now();
+
+            peer_valid_until = ValidUntil::new_with_now(now, config.cleaning.max_peer_age);
+
+            if now > last_cleaning + cleaning_interval {
+                let (ipv4, ipv6) = torrents.clean_and_get_num_peers(&config, &state.access_list);
+
+                if config.statistics.active() {
+                    state.statistics_ipv4.peers[worker_index.0].store(ipv4, Ordering::Release);
+                    state.statistics_ipv6.peers[worker_index.0].store(ipv6, Ordering::Release);
+                }
+
+                last_cleaning = now;
+            }
+            if config.statistics.active()
+                && now > last_statistics_update + statistics_update_interval
+            {
+                state.statistics_ipv4.torrents[worker_index.0]
+                    .store(torrents.ipv4.num_torrents(), Ordering::Release);
+                state.statistics_ipv6.torrents[worker_index.0]
+                    .store(torrents.ipv6.num_torrents(), Ordering::Release);
+
+                last_statistics_update = now;
+            }
+        }
+
+        iter_counter = iter_counter.wrapping_add(1);
+    }
+}
+
+fn handle_announce_request<I: Ip>(
+    config: &Config,
+    rng: &mut SmallRng,
+    torrents: &mut TorrentMap<I>,
+    request: AnnounceRequest,
+    peer_ip: I,
+    peer_valid_until: ValidUntil,
+) -> AnnounceResponse<I> {
+    let max_num_peers_to_take = if request.peers_wanted.0 <= 0 {
+        config.protocol.max_response_peers as usize
+    } else {
+        ::std::cmp::min(
+            config.protocol.max_response_peers as usize,
+            request.peers_wanted.0.try_into().unwrap(),
+        )
+    };
+
+    let peer = Peer {
+        ip_address: peer_ip,
+        port: request.port,
+        status: PeerStatus::from_event_and_bytes_left(request.event, request.bytes_left),
+        valid_until: peer_valid_until,
+    };
+
+    let torrent_data = torrents.0.entry(request.info_hash).or_default();
+
+    torrent_data.update_peer(request.peer_id, peer);
+
+    let response_peers =
+        torrent_data.extract_response_peers(rng, request.peer_id, max_num_peers_to_take);
+
+    AnnounceResponse {
+        transaction_id: request.transaction_id,
+        announce_interval: AnnounceInterval(config.protocol.peer_announce_interval),
+        leechers: NumberOfPeers(torrent_data.num_leechers() as i32),
+        seeders: NumberOfPeers(torrent_data.num_seeders() as i32),
+        peers: response_peers,
+    }
+}
+
+fn handle_scrape_request<I: Ip>(
+    torrents: &mut TorrentMap<I>,
+    request: PendingScrapeRequest,
+) -> PendingScrapeResponse {
+    const EMPTY_STATS: TorrentScrapeStatistics = create_torrent_scrape_statistics(0, 0);
+
+    let torrent_stats = request
+        .info_hashes
+        .into_iter()
+        .map(|(i, info_hash)| {
+            let stats = torrents
+                .0
+                .get(&info_hash)
+                .map(|torrent_data| torrent_data.scrape_statistics())
+                .unwrap_or(EMPTY_STATS);
+
+            (i, stats)
+        })
+        .collect();
+
+    PendingScrapeResponse {
+        slab_key: request.slab_key,
+        torrent_stats,
+    }
+}
+
+#[inline(always)]
+const fn create_torrent_scrape_statistics(seeders: i32, leechers: i32) -> TorrentScrapeStatistics {
+    TorrentScrapeStatistics {
+        seeders: NumberOfPeers(seeders),
+        completed: NumberOfDownloads(0), // No implementation planned
+        leechers: NumberOfPeers(leechers),
+    }
+}

aquatic_udp/src/workers/swarm/storage.rs

@@ -0,0 +1,297 @@
+use std::net::Ipv4Addr;
+use std::net::Ipv6Addr;
+use std::sync::Arc;
+use std::time::Instant;
+
+use aquatic_common::{
+    access_list::{create_access_list_cache, AccessListArcSwap, AccessListCache, AccessListMode},
+    extract_response_peers, AmortizedIndexMap, ValidUntil,
+};
+
+use aquatic_udp_protocol::*;
+use rand::prelude::SmallRng;
+
+use crate::common::*;
+use crate::config::Config;
+
+use super::create_torrent_scrape_statistics;
+
+#[derive(Clone, Debug)]
+pub struct Peer<I: Ip> {
+    pub ip_address: I,
+    pub port: Port,
+    pub status: PeerStatus,
+    pub valid_until: ValidUntil,
+}
+
+impl<I: Ip> Peer<I> {
+    pub fn to_response_peer(&self) -> ResponsePeer<I> {
+        ResponsePeer {
+            ip_address: self.ip_address,
+            port: self.port,
+        }
+    }
+}
+
+pub type PeerMap<I> = AmortizedIndexMap<PeerId, Peer<I>>;
+
+pub struct TorrentData<I: Ip> {
+    peers: PeerMap<I>,
+    num_seeders: usize,
+    num_leechers: usize,
+}
+
+impl<I: Ip> TorrentData<I> {
+    pub fn update_peer(&mut self, peer_id: PeerId, peer: Peer<I>) {
+        let opt_removed_peer = match peer.status {
+            PeerStatus::Leeching => {
+                self.num_leechers += 1;
+
+                self.peers.insert(peer_id, peer)
+            }
+            PeerStatus::Seeding => {
+                self.num_seeders += 1;
+
+                self.peers.insert(peer_id, peer)
+            }
+            PeerStatus::Stopped => self.peers.remove(&peer_id),
+        };
+
+        match opt_removed_peer.map(|peer| peer.status) {
+            Some(PeerStatus::Leeching) => {
+                self.num_leechers -= 1;
+            }
+            Some(PeerStatus::Seeding) => {
+                self.num_seeders -= 1;
+            }
+            _ => {}
+        }
+    }
+
+    pub fn extract_response_peers(
+        &self,
+        rng: &mut SmallRng,
+        peer_id: PeerId,
+        max_num_peers_to_take: usize,
+    ) -> Vec<ResponsePeer<I>> {
+        extract_response_peers(
+            rng,
+            &self.peers,
+            max_num_peers_to_take,
+            peer_id,
+            Peer::to_response_peer,
+        )
+    }
+
+    pub fn num_leechers(&self) -> usize {
+        self.num_leechers
+    }
+
+    pub fn num_seeders(&self) -> usize {
+        self.num_seeders
+    }
+
+    pub fn scrape_statistics(&self) -> TorrentScrapeStatistics {
+        create_torrent_scrape_statistics(
+            self.num_seeders.try_into().unwrap_or(i32::MAX),
+            self.num_leechers.try_into().unwrap_or(i32::MAX),
+        )
+    }
+
+    /// Remove inactive peers and reclaim space
+    fn clean(&mut self, now: Instant) {
+        self.peers.retain(|_, peer| {
+            if peer.valid_until.0 > now {
+                true
+            } else {
+                match peer.status {
+                    PeerStatus::Seeding => {
+                        self.num_seeders -= 1;
+                    }
+                    PeerStatus::Leeching => {
+                        self.num_leechers -= 1;
+                    }
+                    _ => (),
+                };
+
+                false
+            }
+        });
+
+        if !self.peers.is_empty() {
+            self.peers.shrink_to_fit();
+        }
+    }
+}
+
+impl<I: Ip> Default for TorrentData<I> {
+    fn default() -> Self {
+        Self {
+            peers: Default::default(),
+            num_seeders: 0,
+            num_leechers: 0,
+        }
+    }
+}
+
+#[derive(Default)]
+pub struct TorrentMap<I: Ip>(pub AmortizedIndexMap<InfoHash, TorrentData<I>>);
+
+impl<I: Ip> TorrentMap<I> {
+    /// Remove forbidden or inactive torrents, reclaim space and return number of remaining peers
+    fn clean_and_get_num_peers(
+        &mut self,
+        access_list_cache: &mut AccessListCache,
+        access_list_mode: AccessListMode,
+        now: Instant,
+    ) -> usize {
+        let mut num_peers = 0;
+
+        self.0.retain(|info_hash, torrent| {
+            if !access_list_cache
+                .load()
+                .allows(access_list_mode, &info_hash.0)
+            {
+                return false;
+            }
+
+            torrent.clean(now);
+
+            num_peers += torrent.peers.len();
+
+            !torrent.peers.is_empty()
+        });
+
+        self.0.shrink_to_fit();
+
+        num_peers
+    }
+
+    pub fn num_torrents(&self) -> usize {
+        self.0.len()
+    }
+}
+
+pub struct TorrentMaps {
+    pub ipv4: TorrentMap<Ipv4Addr>,
+    pub ipv6: TorrentMap<Ipv6Addr>,
+}
+
+impl Default for TorrentMaps {
+    fn default() -> Self {
+        Self {
+            ipv4: TorrentMap(Default::default()),
+            ipv6: TorrentMap(Default::default()),
+        }
+    }
+}
+
+impl TorrentMaps {
+    /// Remove forbidden or inactive torrents, reclaim space and return number of remaining peers
+    pub fn clean_and_get_num_peers(
+        &mut self,
+        config: &Config,
+        access_list: &Arc<AccessListArcSwap>,
+    ) -> (usize, usize) {
+        let mut cache = create_access_list_cache(access_list);
+        let mode = config.access_list.mode;
+        let now = Instant::now();
+
+        let ipv4 = self.ipv4.clean_and_get_num_peers(&mut cache, mode, now);
+        let ipv6 = self.ipv6.clean_and_get_num_peers(&mut cache, mode, now);
+
+        (ipv4, ipv6)
+    }
+}
+
+#[cfg(test)]
+mod tests {
+    use std::collections::HashSet;
+    use std::net::Ipv4Addr;
+
+    use quickcheck::{quickcheck, TestResult};
+    use rand::thread_rng;
+
+    use super::*;
+
+    fn gen_peer_id(i: u32) -> PeerId {
+        let mut peer_id = PeerId([0; 20]);
+
+        peer_id.0[0..4].copy_from_slice(&i.to_ne_bytes());
+
+        peer_id
+    }
+    fn gen_peer(i: u32) -> Peer<Ipv4Addr> {
+        Peer {
+            ip_address: Ipv4Addr::from(i.to_be_bytes()),
+            port: Port(1),
+            status: PeerStatus::Leeching,
+            valid_until: ValidUntil::new(0),
+        }
+    }
+
+    #[test]
+    fn test_extract_response_peers() {
+        fn prop(data: (u16, u16)) -> TestResult {
+            let gen_num_peers = data.0 as u32;
+            let req_num_peers = data.1 as usize;
+
+            let mut peer_map: PeerMap<Ipv4Addr> = Default::default();
+
+            let mut opt_sender_key = None;
+            let mut opt_sender_peer = None;
+
+            for i in 0..gen_num_peers {
+                let key = gen_peer_id(i);
+                let peer = gen_peer((i << 16) + i);
+
+                if i == 0 {
+                    opt_sender_key = Some(key);
+                    opt_sender_peer = Some(peer.to_response_peer());
+                }
+
+                peer_map.insert(key, peer);
+            }
+
+            let mut rng = thread_rng();
+
+            let peers = extract_response_peers(
+                &mut rng,
+                &peer_map,
+                req_num_peers,
+                opt_sender_key.unwrap_or_else(|| gen_peer_id(1)),
+                Peer::to_response_peer,
+            );
+
+            // Check that number of returned peers is correct
+
+            let mut success = peers.len() <= req_num_peers;
+
+            if req_num_peers >= gen_num_peers as usize {
+                success &= peers.len() == gen_num_peers as usize
+                    || peers.len() + 1 == gen_num_peers as usize;
+            }
+
+            // Check that returned peers are unique (no overlap) and that sender
+            // isn't returned
+
+            let mut ip_addresses = HashSet::with_capacity(peers.len());
+
+            for peer in peers {
+                if peer == opt_sender_peer.clone().unwrap()
+                    || ip_addresses.contains(&peer.ip_address)
+                {
+                    success = false;
+
+                    break;
+                }
+
+                ip_addresses.insert(peer.ip_address);
+            }
+
+            TestResult::from_bool(success)
+        }
+
+        quickcheck(prop as fn((u16, u16)) -> TestResult);
+    }
+}