rust_ipfs/p2p/

bitswap.rs

mod message;
mod pb;
mod prefix;
mod protocol;
mod sessions;

use std::{
    collections::{hash_map::Entry, BTreeSet, HashMap, HashSet, VecDeque},
    fmt::Debug,
    task::{Context, Poll, Waker},
    time::Duration,
};

use futures::StreamExt;
use ipld_core::cid::Cid;
use libp2p::core::transport::PortUse;
use libp2p::{
    core::Endpoint,
    swarm::{
        behaviour::ConnectionEstablished, dial_opts::DialOpts, ConnectionClosed, ConnectionDenied,
        ConnectionId, DialFailure, FromSwarm, NetworkBehaviour, NotifyHandler, OneShotHandler,
        THandler, THandlerInEvent, THandlerOutEvent, ToSwarm,
    },
    Multiaddr, PeerId,
};
use pollable_map::stream::StreamMap;

mod bitswap_pb {
    pub use super::pb::bitswap_pb::Message;
    pub mod message {
        use super::super::pb::bitswap_pb::mod_Message as message;
        pub use message::mod_Wantlist as wantlist;
        pub use message::Wantlist;
        pub use message::{Block, BlockPresence, BlockPresenceType};
    }
}

use crate::{repo::Repo, Block};

use self::{
    message::{BitswapMessage, BitswapRequest, BitswapResponse, RequestType},
    protocol::{BitswapProtocol, Message},
    sessions::{HaveSession, HaveSessionEvent, WantSession, WantSessionEvent},
};

const CAP_THRESHOLD: usize = 100;

#[derive(Default, Debug, Clone, Copy)]
pub struct Config {
    pub max_wanted_blocks: Option<u8>,
    pub timeout: Option<Duration>,
}

#[derive(Debug)]
pub enum Event {
    NeedBlock { cid: Cid },
    BlockRetrieved { cid: Cid },
    CancelBlock { cid: Cid },
}

pub struct Behaviour {
    events: VecDeque<ToSwarm<<Self as NetworkBehaviour>::ToSwarm, THandlerInEvent<Self>>>,
    connections: HashMap<PeerId, HashSet<ConnectionId>>,
    blacklist_connections: HashMap<PeerId, BTreeSet<ConnectionId>>,
    store: Repo,
    want_session: StreamMap<Cid, WantSession>,
    have_session: StreamMap<Cid, HaveSession>,
    waker: Option<Waker>,
}

impl Behaviour {
    pub fn new(store: &Repo) -> Self {
        Self {
            events: Default::default(),
            connections: Default::default(),
            blacklist_connections: Default::default(),
            store: store.clone(),
            want_session: StreamMap::new(),
            have_session: StreamMap::new(),
            waker: None,
        }
    }

    pub fn get(&mut self, cid: &Cid, providers: &[PeerId], timeout: Option<Duration>) {
        self.gets(vec![*cid], providers, timeout)
    }

    pub fn gets(&mut self, cids: Vec<Cid>, providers: &[PeerId], timeout: Option<Duration>) {
        let peers = match providers.is_empty() {
            true => {
                //If no providers are provided, we can send requests connected peers
                self.connections
                    .keys()
                    .filter(|peer_id| !self.blacklist_connections.contains_key(peer_id))
                    .copied()
                    .collect::<Vec<_>>()
            }
            false => {
                let mut connected = VecDeque::new();
                for peer_id in providers
                    .iter()
                    .filter(|peer_id| !self.blacklist_connections.contains_key(peer_id))
                {
                    if self.connections.contains_key(peer_id) {
                        connected.push_back(*peer_id);
                        continue;
                    }
                    let opts = DialOpts::peer_id(*peer_id).build();

                    self.events.push_back(ToSwarm::Dial { opts });
                }
                Vec::from_iter(connected)
            }
        };

        for cid in &cids {
            if self.want_session.contains_key(cid) {
                continue;
            }
            let session = WantSession::new(&self.store, *cid, timeout);
            self.want_session.insert(*cid, session);
        }

        if peers.is_empty() {
            // Since no connections, peers or providers are provided, we need to notify swarm to attempt a form of content discovery
            for cid in cids {
                self.events
                    .push_back(ToSwarm::GenerateEvent(Event::NeedBlock { cid }));
            }
            return;
        }

        self.send_wants(peers, cids)
    }

    pub fn local_wantlist(&self) -> Vec<Cid> {
        self.want_session.keys().copied().collect()
    }

    pub fn peer_wantlist(&self, peer_id: PeerId) -> Vec<Cid> {
        let mut blocks = HashSet::new();

        for (cid, session) in self.have_session.iter() {
            if session.has_peer(peer_id) {
                blocks.insert(*cid);
            }
        }

        Vec::from_iter(blocks)
    }

    // Note: This is called specifically to cancel the request and not just emitting a request
    //       after receiving a request.
    pub fn cancel(&mut self, cid: Cid) {
        if self.want_session.remove(&cid).is_none() {
            return;
        }

        self.events
            .push_back(ToSwarm::GenerateEvent(Event::CancelBlock { cid }));

        if let Some(waker) = self.waker.take() {
            waker.wake();
        }
    }

    // This will notify connected peers who have the bitswap protocol that we have this block
    // if they wanted it
    // TODO: Maybe have a general `Session` where we could collectively notify a peer of new blocks
    //       in a single message
    pub fn notify_new_blocks(&mut self, cid: impl IntoIterator<Item = Cid>) {
        let blocks = cid.into_iter().collect::<Vec<_>>();

        for (cid, session) in self.have_session.iter_mut() {
            if !blocks.contains(cid) {
                continue;
            }

            session.reset();
        }

        if !self.have_session.is_empty() {
            if let Some(waker) = self.waker.take() {
                waker.wake();
            }
        }
    }

    fn on_connection_established(
        &mut self,
        ConnectionEstablished {
            connection_id,
            peer_id,
            other_established,
            ..
        }: ConnectionEstablished,
    ) {
        tracing::info!(%peer_id, %connection_id, "connection established");
        self.connections
            .entry(peer_id)
            .or_default()
            .insert(connection_id);

        if other_established > 0 {
            return;
        }

        self.send_wants(vec![peer_id], vec![]);
    }

    fn on_connection_close(
        &mut self,
        ConnectionClosed {
            connection_id,
            peer_id,
            remaining_established,
            ..
        }: ConnectionClosed,
    ) {
        tracing::debug!(%connection_id, %peer_id, "connection closed");
        if let Entry::Occupied(mut entry) = self.connections.entry(peer_id) {
            let list = entry.get_mut();
            list.remove(&connection_id);
            if list.is_empty() {
                entry.remove();
            }
        }

        if let Entry::Occupied(mut entry) = self.blacklist_connections.entry(peer_id) {
            let list = entry.get_mut();
            list.remove(&connection_id);
            if list.is_empty() {
                entry.remove();
            }
        }

        if remaining_established == 0 {
            tracing::debug!(%connection_id, %peer_id, "peer disconnected");
            for (cid, session) in self.want_session.iter_mut() {
                tracing::debug!(session=%*cid, %peer_id, "marking peer as disconnected");
                session.peer_disconnected(peer_id);
            }
        }
    }

    fn on_dial_failure(
        &mut self,
        DialFailure {
            connection_id,
            peer_id,
            error,
        }: DialFailure,
    ) {
        let Some(peer_id) = peer_id else {
            return;
        };

        tracing::warn!(%peer_id, %connection_id, error = %error, "unable to dial peer");

        if self.connections.contains_key(&peer_id) {
            // Since there is still an existing connection for the peer
            // we can ignore the dial failure
            return;
        }

        for session in self.want_session.values_mut() {
            session.remove_peer(peer_id);
        }

        for session in self.have_session.values_mut() {
            session.remove_peer(peer_id);
        }
    }

    fn send_wants(&mut self, peers: Vec<PeerId>, cids: Vec<Cid>) {
        if let Some(waker) = self.waker.take() {
            waker.wake();
        }

        match cids.is_empty() {
            false => {
                for cid in cids {
                    let Some(session) = self.want_session.get_mut(&cid) else {
                        continue;
                    };
                    for peer_id in &peers {
                        session.send_have_block(*peer_id)
                    }
                }
            }
            true => {
                for session in self.want_session.values_mut() {
                    for peer_id in &peers {
                        session.send_have_block(*peer_id)
                    }
                }
            }
        }
    }
}

impl NetworkBehaviour for Behaviour {
    type ConnectionHandler = OneShotHandler<BitswapProtocol, BitswapMessage, Message>;
    type ToSwarm = Event;

    fn handle_pending_inbound_connection(
        &mut self,
        _: ConnectionId,
        _: &Multiaddr,
        _: &Multiaddr,
    ) -> Result<(), ConnectionDenied> {
        Ok(())
    }

    fn handle_pending_outbound_connection(
        &mut self,
        _: ConnectionId,
        _: Option<PeerId>,
        _: &[Multiaddr],
        _: Endpoint,
    ) -> Result<Vec<Multiaddr>, ConnectionDenied> {
        Ok(vec![])
    }

    fn handle_established_inbound_connection(
        &mut self,
        _: ConnectionId,
        _: PeerId,
        _: &Multiaddr,
        _: &Multiaddr,
    ) -> Result<THandler<Self>, ConnectionDenied> {
        Ok(OneShotHandler::default())
    }

    fn handle_established_outbound_connection(
        &mut self,
        _: ConnectionId,
        _: PeerId,
        _: &Multiaddr,
        _: Endpoint,
        _: PortUse,
    ) -> Result<THandler<Self>, ConnectionDenied> {
        Ok(OneShotHandler::default())
    }

    fn on_connection_handler_event(
        &mut self,
        peer_id: PeerId,
        connection_id: ConnectionId,
        event: THandlerOutEvent<Self>,
    ) {
        let message = match event {
            Ok(Message::Receive { message }) => {
                tracing::trace!(%peer_id, %connection_id, "message received");
                if let Entry::Occupied(mut e) = self.blacklist_connections.entry(peer_id) {
                    let list = e.get_mut();
                    list.remove(&connection_id);
                    if list.is_empty() {
                        e.remove();
                    }
                }

                message
            }
            Ok(Message::Sent) => {
                tracing::trace!(%peer_id, %connection_id, "message sent");
                return;
            }
            Err(e) => {
                tracing::error!(%peer_id, %connection_id, error = %e, "error sending or receiving message");
                //TODO: Depending on the underlining error, maybe blacklist the peer from further sending/receiving
                //      until a valid response or request is produced?
                self.blacklist_connections
                    .entry(peer_id)
                    .or_default()
                    .insert(connection_id);
                return;
            }
        };

        if message.is_empty() {
            tracing::warn!(%peer_id, %connection_id, "received an empty message");
            return;
        }

        let BitswapMessage {
            requests,
            responses,
            ..
        } = message;

        for request in requests {
            let BitswapRequest {
                ty,
                cid,
                send_dont_have,
                cancel,
                priority: _,
            } = &request;

            if !self.have_session.contains_key(cid) && !cancel {
                // Lets build out have new sessions
                let have_session = HaveSession::new(&self.store, *cid);
                self.have_session.insert(*cid, have_session);
            }

            let Some(session) = self.have_session.get_mut(cid) else {
                if !*cancel {
                    tracing::warn!(block = %cid, %peer_id, %connection_id, "have session does not exist. Skipping request");
                }
                continue;
            };

            if *cancel {
                session.cancel(peer_id);
                continue;
            }

            match ty {
                RequestType::Have => {
                    session.want_block(peer_id, *send_dont_have);
                }
                RequestType::Block => {
                    session.need_block(peer_id);
                }
            }
        }

        for (cid, response) in responses {
            let Some(session) = self.want_session.get_mut(&cid) else {
                tracing::warn!(block = %cid, %peer_id, %connection_id, "want session does not exist. Skipping response");
                continue;
            };
            match response {
                BitswapResponse::Have(have) => match have {
                    true => {
                        session.has_block(peer_id);
                    }
                    false => {
                        session.dont_have_block(peer_id);
                    }
                },
                BitswapResponse::Block(bytes) => {
                    let Ok(block) = Block::new(cid, bytes) else {
                        // The block is invalid so we will notify the session that we still dont have the block
                        // from said peer
                        // TODO: In the future, mark the peer as a bad sender
                        tracing::error!(block = %cid, %peer_id, %connection_id, "block is invalid or corrupted");
                        session.dont_have_block(peer_id);
                        continue;
                    };
                    session.put_block(peer_id, block);
                }
            }
        }
    }

    fn on_swarm_event(&mut self, event: FromSwarm) {
        match event {
            FromSwarm::ConnectionEstablished(event) => self.on_connection_established(event),
            FromSwarm::ConnectionClosed(event) => self.on_connection_close(event),
            FromSwarm::DialFailure(event) => self.on_dial_failure(event),
            _ => {}
        }
    }

    fn poll(&mut self, ctx: &mut Context) -> Poll<ToSwarm<Self::ToSwarm, THandlerInEvent<Self>>> {
        if let Some(event) = self.events.pop_front() {
            return Poll::Ready(event);
        } else if self.events.capacity() > CAP_THRESHOLD {
            self.events.shrink_to_fit();
        }

        while let Poll::Ready(Some((cid, event))) = self.have_session.poll_next_unpin(ctx) {
            match event {
                HaveSessionEvent::Have { peer_id } => {
                    return Poll::Ready(ToSwarm::NotifyHandler {
                        peer_id,
                        handler: NotifyHandler::Any,
                        event: BitswapMessage::default()
                            .add_response(cid, BitswapResponse::Have(true)),
                    });
                }
                HaveSessionEvent::DontHave { peer_id } => {
                    return Poll::Ready(ToSwarm::NotifyHandler {
                        peer_id,
                        handler: NotifyHandler::Any,
                        event: BitswapMessage::default()
                            .add_response(cid, BitswapResponse::Have(false)),
                    })
                }
                HaveSessionEvent::Block { peer_id, bytes } => {
                    return Poll::Ready(ToSwarm::NotifyHandler {
                        peer_id,
                        handler: NotifyHandler::Any,
                        event: BitswapMessage::default()
                            .add_response(cid, BitswapResponse::Block(bytes)),
                    })
                }
                HaveSessionEvent::Cancelled => {
                    //TODO: Maybe notify peers from this session about any cancelled request?
                    self.have_session.remove(&cid);
                }
            };
        }

        match self.want_session.poll_next_unpin(ctx) {
            Poll::Ready(Some((cid, event))) => match event {
                WantSessionEvent::SendWant { peer_id } => {
                    return Poll::Ready(ToSwarm::NotifyHandler {
                        peer_id,
                        handler: NotifyHandler::Any,
                        event: BitswapMessage::default()
                            .add_request(BitswapRequest::have(cid).send_dont_have(true)),
                    });
                }
                WantSessionEvent::SendCancel { peer_id } => {
                    return Poll::Ready(ToSwarm::NotifyHandler {
                        peer_id,
                        handler: NotifyHandler::Any,
                        event: BitswapMessage::default().add_request(BitswapRequest::cancel(cid)),
                    });
                }
                WantSessionEvent::SendBlock { peer_id } => {
                    ctx.waker().wake_by_ref();

                    return Poll::Ready(ToSwarm::NotifyHandler {
                        peer_id,
                        handler: NotifyHandler::Any,
                        event: BitswapMessage::default()
                            .add_request(BitswapRequest::block(cid).send_dont_have(true)),
                    });
                }
                WantSessionEvent::NeedBlock => {
                    return Poll::Ready(ToSwarm::GenerateEvent(Event::NeedBlock { cid }));
                }
                WantSessionEvent::BlockStored => {
                    return Poll::Ready(ToSwarm::GenerateEvent(Event::BlockRetrieved { cid }))
                }
                WantSessionEvent::Dial { peer_id } => {
                    let opts = DialOpts::peer_id(peer_id).build();
                    return Poll::Ready(ToSwarm::Dial { opts });
                }
                WantSessionEvent::Cancelled => {
                    self.want_session.remove(&cid);
                    return Poll::Ready(ToSwarm::GenerateEvent(Event::CancelBlock { cid }));
                }
            },
            Poll::Pending | Poll::Ready(None) => {}
        }

        self.waker = Some(ctx.waker().clone());

        Poll::Pending
    }
}

#[cfg(test)]
mod test {
    use std::time::Duration;

    use crate::block::BlockCodec;
    use futures::StreamExt;
    use ipld_core::cid::Cid;
    use libp2p::{
        core::{transport::MemoryTransport, upgrade::Version},
        swarm::{dial_opts::DialOpts, NetworkBehaviour, SwarmEvent},
        Multiaddr, PeerId, Swarm, SwarmBuilder, Transport,
    };
    use multihash_codetable::{Code, MultihashDigest};

    use crate::{repo::Repo, Block};

    fn create_block() -> Block {
        let data = b"hello block\n".to_vec();
        let cid = Cid::new_v1(BlockCodec::Raw.into(), Code::Sha2_256.digest(&data));

        Block::new_unchecked(cid, data)
    }

    #[tokio::test]
    async fn exchange_blocks() -> anyhow::Result<()> {
        let (_, _, mut swarm1, repo) = build_swarm().await;
        let (peer2, addr2, mut swarm2, repo2) = build_swarm().await;

        let block = create_block();

        let cid = *block.cid();

        repo.put_block(&block).await?;

        let opt = DialOpts::peer_id(peer2)
            .addresses(vec![addr2.clone()])
            .build();

        swarm1.dial(opt)?;

        loop {
            futures::select! {
                event = swarm1.select_next_some() => {
                    if let SwarmEvent::ConnectionEstablished { peer_id, .. } = event {
                        assert_eq!(peer_id, peer2);
                        break;
                    }
                }
                _ = swarm2.next() => {}
            }
        }

        swarm2.behaviour_mut().bitswap.get(&cid, &[], None);

        loop {
            tokio::select! {
                _ = swarm1.next() => {}
                e = swarm2.select_next_some() => {
                    match e {
                        SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::BlockRetrieved { cid: inner_cid })) => {
                            assert_eq!(inner_cid, cid);
                        }
                        SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::CancelBlock { cid: inner_cid })) => {
                            assert_eq!(inner_cid, cid);
                            unreachable!("exchange should not timeout");
                        }
                        _ => {}
                    }
                },
                Ok(true) = repo2.contains(&cid) => {
                    break;
                }
            }
        }

        let b = repo2
            .get_block_now(&cid)
            .await
            .unwrap()
            .expect("block exist");

        assert_eq!(b, block);

        Ok(())
    }

    #[tokio::test]
    async fn notify_swarm() -> anyhow::Result<()> {
        let (_, _, mut swarm1, _) = build_swarm().await;

        let block = create_block();

        let cid = *block.cid();

        swarm1
            .behaviour_mut()
            .bitswap
            .get(&cid, &[], Some(Duration::from_millis(500)));

        let mut notified_counter = 0;

        loop {
            tokio::select! {
                e = swarm1.select_next_some() => {
                    match e {
                        SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::NeedBlock { cid: inner_cid })) => {
                            assert_eq!(inner_cid, cid);
                            notified_counter += 1;
                        }
                        SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::CancelBlock { cid: inner_cid })) => {
                            assert_eq!(inner_cid, cid);
                            unreachable!()
                        }
                        _ => {}
                    }
                },
            }

            if notified_counter == 2 {
                break;
            }
        }

        Ok(())
    }

    #[tokio::test]
    async fn bitswap_timeout() -> anyhow::Result<()> {
        let (_, _, mut swarm1, _) = build_swarm().await;
        let (peer2, addr2, mut swarm2, _) = build_swarm().await;

        let block = create_block();

        let cid = *block.cid();

        let opt = DialOpts::peer_id(peer2)
            .addresses(vec![addr2.clone()])
            .build();

        swarm1.dial(opt)?;

        loop {
            futures::select! {
                event = swarm1.select_next_some() => {
                    if let SwarmEvent::ConnectionEstablished { peer_id, .. } = event {
                        assert_eq!(peer_id, peer2);
                        break;
                    }
                }
                _ = swarm2.next() => {}
            }
        }

        swarm2
            .behaviour_mut()
            .bitswap
            .get(&cid, &[], Some(Duration::from_millis(150)));

        loop {
            tokio::select! {
                _ = swarm1.next() => {}
                e = swarm2.select_next_some() => {
                    if let SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::CancelBlock { cid: inner_cid })) = e {
                        assert_eq!(inner_cid, cid);
                        break;
                    }
                },
            }
        }

        Ok(())
    }

    #[tokio::test]
    async fn exchange_blocks_with_explicit_peer() -> anyhow::Result<()> {
        let (peer1, _, mut swarm1, repo) = build_swarm().await;
        let (peer2, addr2, mut swarm2, repo2) = build_swarm().await;

        let block = create_block();

        let cid = *block.cid();

        repo.put_block(&block).await?;

        let opt = DialOpts::peer_id(peer2)
            .addresses(vec![addr2.clone()])
            .build();

        swarm1.dial(opt)?;

        loop {
            futures::select! {
                event = swarm1.select_next_some() => {
                    if let SwarmEvent::ConnectionEstablished { peer_id, .. } = event {
                        assert_eq!(peer_id, peer2);
                        break;
                    }
                }
                _ = swarm2.next() => {}
            }
        }

        swarm2.behaviour_mut().bitswap.get(&cid, &[peer1], None);

        loop {
            tokio::select! {
                _ = swarm1.next() => {}
                e = swarm2.select_next_some() => {
                    if let SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::BlockRetrieved { cid: inner_cid })) = e {
                        assert_eq!(inner_cid, cid);
                    }
                },
                Ok(true) = repo2.contains(&cid) => {
                    break;
                }
            }
        }

        let b = repo2
            .get_block_now(&cid)
            .await
            .unwrap()
            .expect("block exist");

        assert_eq!(b, block);

        Ok(())
    }

    #[tokio::test]
    async fn notify_after_block_exchange() -> anyhow::Result<()> {
        let (peer1, _, mut swarm1, repo) = build_swarm().await;
        let (peer2, addr2, mut swarm2, _) = build_swarm().await;
        let (peer3, addr3, mut swarm3, repo3) = build_swarm().await;

        let block = create_block();

        let cid = *block.cid();

        repo.put_block(&block).await?;

        let opt = DialOpts::peer_id(peer2)
            .addresses(vec![addr2.clone()])
            .build();
        swarm1.dial(opt)?;

        let opt = DialOpts::peer_id(peer3)
            .addresses(vec![addr3.clone()])
            .build();

        swarm2.dial(opt)?;
        let mut peer_1_connected = false;
        let mut peer_2_connected = false;
        let mut peer_3_connected = false;

        loop {
            futures::select! {
                event = swarm1.select_next_some() => {
                    if let SwarmEvent::ConnectionEstablished { .. } = event {
                        peer_1_connected = true;
                    }
                }
                event = swarm2.select_next_some() => {
                    if let SwarmEvent::ConnectionEstablished { peer_id, .. } = event {
                        if peer_id == peer1 {
                            peer_2_connected = true;
                        }
                    }
                }

                event = swarm3.select_next_some() => {
                    if let SwarmEvent::ConnectionEstablished { peer_id, .. } = event {
                        assert_eq!(peer_id, peer2);
                        peer_3_connected = true;
                    }
                }
            }
            if peer_1_connected && peer_2_connected && peer_3_connected {
                break;
            }
        }
        swarm2.behaviour_mut().bitswap.get(&cid, &[peer1], None);
        swarm3.behaviour_mut().bitswap.get(&cid, &[], None);

        loop {
            tokio::select! {
                _ = swarm1.next() => {}
                e = swarm2.select_next_some() => {
                    if let SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::BlockRetrieved { cid: inner_cid })) = e {
                        assert_eq!(inner_cid, cid);
                        swarm2.behaviour_mut().bitswap.notify_new_blocks(std::iter::once(cid));
                    }
                },
                e = swarm3.select_next_some() => {
                    if let SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::BlockRetrieved { cid: inner_cid })) = e {
                        assert_eq!(inner_cid, cid);
                        break;
                    }
                },
            }
        }

        let b = repo3
            .get_block_now(&cid)
            .await
            .unwrap()
            .expect("block exist");

        assert_eq!(b, block);

        Ok(())
    }

    #[tokio::test]
    async fn cancel_block_exchange() -> anyhow::Result<()> {
        let (_, _, mut swarm1, _) = build_swarm().await;

        let block = create_block();

        let cid = *block.cid();

        swarm1.behaviour_mut().bitswap.get(&cid, &[], None);
        swarm1.behaviour_mut().bitswap.cancel(cid);

        loop {
            tokio::select! {
                e = swarm1.select_next_some() => {
                    if let SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::CancelBlock { cid: inner_cid })) = e {
                        assert_eq!(inner_cid, cid);
                        break;
                    }
                },
            }
        }

        Ok(())
    }

    #[tokio::test]
    async fn local_wantlist() -> anyhow::Result<()> {
        let (_, _, mut swarm1, _) = build_swarm().await;

        let block = create_block();

        let cid = *block.cid();

        swarm1.behaviour_mut().bitswap.get(&cid, &[], None);

        let list = swarm1.behaviour().bitswap.local_wantlist();

        assert_eq!(list[0], cid);

        Ok(())
    }

    #[tokio::test]
    async fn peer_wantlist() -> anyhow::Result<()> {
        let (peer1, _, mut swarm1, _) = build_swarm().await;
        let (peer2, addr2, mut swarm2, _) = build_swarm().await;

        let block = create_block();

        let cid = *block.cid();

        let opt = DialOpts::peer_id(peer2)
            .addresses(vec![addr2.clone()])
            .build();
        swarm1.dial(opt)?;

        let mut peer_1_connected = false;
        let mut peer_2_connected = false;

        loop {
            futures::select! {
                event = swarm1.select_next_some() => {
                    if let SwarmEvent::ConnectionEstablished { .. } = event {
                        peer_1_connected = true;
                    }
                }
                event = swarm2.select_next_some() => {
                    if let SwarmEvent::ConnectionEstablished { peer_id, .. } = event {
                        if peer_id == peer1 {
                            peer_2_connected = true;
                        }
                    }
                }
            }
            if peer_1_connected && peer_2_connected {
                break;
            }
        }
        swarm2.behaviour_mut().bitswap.get(&cid, &[peer1], None);

        loop {
            tokio::select! {
                _ = swarm1.next() => {}
                e = swarm2.select_next_some() => {
                    if let SwarmEvent::Behaviour(BehaviourEvent::Bitswap(super::Event::NeedBlock { cid: inner_cid })) = e {
                        assert_eq!(inner_cid, cid);
                        break;
                    }
                },
            }
        }

        let list = swarm1.behaviour().bitswap.peer_wantlist(peer2);
        assert_eq!(list[0], cid);

        Ok(())
    }

    async fn build_swarm() -> (PeerId, Multiaddr, Swarm<Behaviour>, Repo) {
        let repo = Repo::new_memory();

        let mut swarm = SwarmBuilder::with_new_identity()
            .with_tokio()
            .with_other_transport(|kp| {
                MemoryTransport::default()
                    .upgrade(Version::V1)
                    .authenticate(libp2p::noise::Config::new(kp).expect("valid config"))
                    .multiplex(libp2p::yamux::Config::default())
                    .timeout(Duration::from_secs(20))
                    .boxed()
            })
            .expect("")
            .with_behaviour(|_| Behaviour {
                bitswap: super::Behaviour::new(&repo),
                address_book: crate::p2p::addressbook::Behaviour::with_config(
                    crate::p2p::addressbook::Config {
                        store_on_connection: true,
                        ..Default::default()
                    },
                ),
            })
            .expect("")
            .with_swarm_config(|c| c.with_idle_connection_timeout(Duration::from_secs(30)))
            .build();

        Swarm::listen_on(&mut swarm, "/memory/0".parse().unwrap()).unwrap();

        if let Some(SwarmEvent::NewListenAddr { address, .. }) = swarm.next().await {
            let peer_id = swarm.local_peer_id();
            return (*peer_id, address, swarm, repo);
        }

        unreachable!()
    }

    #[derive(NetworkBehaviour)]
    struct Behaviour {
        bitswap: super::Behaviour,
        address_book: crate::p2p::addressbook::Behaviour,
    }
}