udp: remove glommio implementation

aquatic_udp/src/lib/handlers.rs

@@ -0,0 +1,351 @@
+use std::net::IpAddr;
+use std::net::SocketAddr;
+use std::time::Duration;
+
+use aquatic_common::ValidUntil;
+use crossbeam_channel::{Receiver, Sender};
+use rand::{rngs::SmallRng, SeedableRng};
+
+use aquatic_common::convert_ipv4_mapped_ipv6;
+use aquatic_common::extract_response_peers;
+
+use aquatic_udp_protocol::*;
+
+use crate::common::*;
+use crate::config::Config;
+
+pub fn run_request_worker(
+    state: State,
+    config: Config,
+    request_receiver: Receiver<(ConnectedRequest, SocketAddr)>,
+    response_sender: Sender<(ConnectedResponse, SocketAddr)>,
+) {
+    let mut announce_requests: Vec<(AnnounceRequest, SocketAddr)> = Vec::new();
+    let mut scrape_requests: Vec<(ScrapeRequest, SocketAddr)> = Vec::new();
+    let mut responses: Vec<(ConnectedResponse, SocketAddr)> = Vec::new();
+
+    let mut small_rng = SmallRng::from_entropy();
+
+    let timeout = Duration::from_micros(config.handlers.channel_recv_timeout_microseconds);
+
+    loop {
+        let mut opt_torrents = None;
+
+        // Collect requests from channel, divide them by type
+        //
+        // Collect a maximum number of request. Stop collecting before that
+        // number is reached if having waited for too long for a request, but
+        // only if TorrentMaps mutex isn't locked.
+        for i in 0..config.handlers.max_requests_per_iter {
+            let (request, src): (ConnectedRequest, SocketAddr) = if i == 0 {
+                match request_receiver.recv() {
+                    Ok(r) => r,
+                    Err(_) => break, // Really shouldn't happen
+                }
+            } else {
+                match request_receiver.recv_timeout(timeout) {
+                    Ok(r) => r,
+                    Err(_) => {
+                        if let Some(guard) = state.torrents.try_lock() {
+                            opt_torrents = Some(guard);
+
+                            break;
+                        } else {
+                            continue;
+                        }
+                    }
+                }
+            };
+
+            match request {
+                ConnectedRequest::Announce(request) => announce_requests.push((request, src)),
+                ConnectedRequest::Scrape { request, .. } => scrape_requests.push((request, src)),
+            }
+        }
+
+        // Generate responses for announce and scrape requests, then drop MutexGuard.
+        {
+            let mut torrents = opt_torrents.unwrap_or_else(|| state.torrents.lock());
+
+            let peer_valid_until = ValidUntil::new(config.cleaning.max_peer_age);
+
+            responses.extend(announce_requests.drain(..).map(|(request, src)| {
+                let response = handle_announce_request(
+                    &config,
+                    &mut small_rng,
+                    &mut torrents,
+                    request,
+                    src,
+                    peer_valid_until,
+                );
+
+                (ConnectedResponse::Announce(response), src)
+            }));
+
+            responses.extend(scrape_requests.drain(..).map(|(request, src)| {
+                let response = ConnectedResponse::Scrape {
+                    response: handle_scrape_request(&mut torrents, src, request),
+                    original_indices: Vec::new(),
+                };
+
+                (response, src)
+            }));
+        }
+
+        for r in responses.drain(..) {
+            if let Err(err) = response_sender.send(r) {
+                ::log::error!("error sending response to channel: {}", err);
+            }
+        }
+    }
+}
+
+pub fn handle_announce_request(
+    config: &Config,
+    rng: &mut SmallRng,
+    torrents: &mut TorrentMaps,
+    request: AnnounceRequest,
+    src: SocketAddr,
+    peer_valid_until: ValidUntil,
+) -> AnnounceResponse {
+    match convert_ipv4_mapped_ipv6(src.ip()) {
+        IpAddr::V4(ip) => handle_announce_request_inner(
+            config,
+            rng,
+            &mut torrents.ipv4,
+            request,
+            ip,
+            peer_valid_until,
+        ),
+        IpAddr::V6(ip) => handle_announce_request_inner(
+            config,
+            rng,
+            &mut torrents.ipv6,
+            request,
+            ip,
+            peer_valid_until,
+        ),
+    }
+}
+
+fn handle_announce_request_inner<I: Ip>(
+    config: &Config,
+    rng: &mut SmallRng,
+    torrents: &mut TorrentMap<I>,
+    request: AnnounceRequest,
+    peer_ip: I,
+    peer_valid_until: ValidUntil,
+) -> AnnounceResponse {
+    let peer_key = PeerMapKey {
+        ip: peer_ip,
+        peer_id: request.peer_id,
+    };
+
+    let peer_status = PeerStatus::from_event_and_bytes_left(request.event, request.bytes_left);
+
+    let peer = Peer {
+        ip_address: peer_ip,
+        port: request.port,
+        status: peer_status,
+        valid_until: peer_valid_until,
+    };
+
+    let torrent_data = torrents.entry(request.info_hash).or_default();
+
+    let opt_removed_peer = match peer_status {
+        PeerStatus::Leeching => {
+            torrent_data.num_leechers += 1;
+
+            torrent_data.peers.insert(peer_key, peer)
+        }
+        PeerStatus::Seeding => {
+            torrent_data.num_seeders += 1;
+
+            torrent_data.peers.insert(peer_key, peer)
+        }
+        PeerStatus::Stopped => torrent_data.peers.remove(&peer_key),
+    };
+
+    match opt_removed_peer.map(|peer| peer.status) {
+        Some(PeerStatus::Leeching) => {
+            torrent_data.num_leechers -= 1;
+        }
+        Some(PeerStatus::Seeding) => {
+            torrent_data.num_seeders -= 1;
+        }
+        _ => {}
+    }
+
+    let max_num_peers_to_take = calc_max_num_peers_to_take(config, request.peers_wanted.0);
+
+    let response_peers = extract_response_peers(
+        rng,
+        &torrent_data.peers,
+        max_num_peers_to_take,
+        peer_key,
+        Peer::to_response_peer,
+    );
+
+    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,
+    }
+}
+
+#[inline]
+fn calc_max_num_peers_to_take(config: &Config, peers_wanted: i32) -> usize {
+    if peers_wanted <= 0 {
+        config.protocol.max_response_peers as usize
+    } else {
+        ::std::cmp::min(
+            config.protocol.max_response_peers as usize,
+            peers_wanted as usize,
+        )
+    }
+}
+
+pub fn handle_scrape_request(
+    torrents: &mut TorrentMaps,
+    src: SocketAddr,
+    request: ScrapeRequest,
+) -> ScrapeResponse {
+    const EMPTY_STATS: TorrentScrapeStatistics = create_torrent_scrape_statistics(0, 0);
+
+    let mut stats: Vec<TorrentScrapeStatistics> = Vec::with_capacity(request.info_hashes.len());
+
+    let peer_ip = convert_ipv4_mapped_ipv6(src.ip());
+
+    if peer_ip.is_ipv4() {
+        for info_hash in request.info_hashes.iter() {
+            if let Some(torrent_data) = torrents.ipv4.get(info_hash) {
+                stats.push(create_torrent_scrape_statistics(
+                    torrent_data.num_seeders as i32,
+                    torrent_data.num_leechers as i32,
+                ));
+            } else {
+                stats.push(EMPTY_STATS);
+            }
+        }
+    } else {
+        for info_hash in request.info_hashes.iter() {
+            if let Some(torrent_data) = torrents.ipv6.get(info_hash) {
+                stats.push(create_torrent_scrape_statistics(
+                    torrent_data.num_seeders as i32,
+                    torrent_data.num_leechers as i32,
+                ));
+            } else {
+                stats.push(EMPTY_STATS);
+            }
+        }
+    }
+
+    ScrapeResponse {
+        transaction_id: request.transaction_id,
+        torrent_stats: 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),
+    }
+}
+
+#[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_map_key_and_value(i: u32) -> (PeerMapKey<Ipv4Addr>, Peer<Ipv4Addr>) {
+        let ip_address = Ipv4Addr::from(i.to_be_bytes());
+        let peer_id = PeerId([0; 20]);
+
+        let key = PeerMapKey {
+            ip: ip_address,
+            peer_id,
+        };
+        let value = Peer {
+            ip_address,
+            port: Port(1),
+            status: PeerStatus::Leeching,
+            valid_until: ValidUntil::new(0),
+        };
+
+        (key, value)
+    }
+
+    #[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, value) = gen_peer_map_key_and_value((i << 16) + i);
+
+                if i == 0 {
+                    opt_sender_key = Some(key);
+                    opt_sender_peer = Some(value.to_response_peer());
+                }
+
+                peer_map.insert(key, value);
+            }
+
+            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_map_key_and_value(1).0),
+                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);
+    }
+}