1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161

use crate::Peer;
use core::hash::Hash;
use dashmap::DashMap;

/// A keyed mapping of [Peer]s with ownership semantics.
///
/// Dropping will disconnect all owned peers.
///
/// [Peer]: crate::Peer
#[derive(Debug)]
pub struct Peers<T>(DashMap<T, Peer>)
where
    T: Eq + Hash;

impl<T: Eq + Hash> Peers<T> {
    /// Gets a [Peer] by it's ID, if available.
    ///
    /// [Peer]: crate::Peer
    pub fn get(&self, id: &T) -> Option<Peer> {
        self.0.get(&id).and_then(|kv| {
            let peer = kv.value().clone();
            if peer.is_connected() {
                Some(peer)
            } else {
                None
            }
        })
    }

    /// Gets the number of active connections managed by it.
    pub fn len(&self) -> usize {
        self.0.iter().filter(|kv| kv.value().is_connected()).count()
    }

    /// Checks if the store has a connection to the given ID.
    pub fn contains(&self, id: &T) -> bool {
        self.0
            .get(&id)
            .map(|kv| kv.value().is_connected())
            .unwrap_or(false)
    }

    /// Creates a new unbounded peer pair and stores one end, mapping it to
    /// the provided ID, returning the other end.
    ///
    /// If a peer was previous stored at the given ID, it will be replaced and
    /// disconnected.
    #[must_use]
    pub fn create_unbounded(&self, id: T) -> Peer {
        let (a, b) = Peer::create_unbounded_pair();
        if let Some(prior) = self.0.insert(id, a) {
            prior.disconnect();
        }
        b
    }

    /// Creates an bounded peer pair and stores one end, mapping it to the
    /// provided ID, returning the other end.
    ///
    /// If a peer was previous stored at the given ID, it will be dropped and
    /// replaced.
    #[must_use]
    pub fn create_bounded(&self, id: T, capacity: usize) -> Peer {
        let (a, b) = Peer::create_bounded_pair(capacity);
        self.0.insert(id, a);
        b
    }

    /// Disconnects and removes a connection by it's ID
    ///
    /// A no-op if there no Peer with the given ID.
    pub fn disconnect(&self, id: &T) {
        if let Some((_, peer)) = self.0.remove(&id) {
            peer.disconnect();
        }
    }

    /// Removes all peers that are disconnected.
    pub fn flush_disconnected(&self) {
        self.0.retain(|_, peer| peer.is_connected())
    }
}

impl<T: Eq + Hash> Default for Peers<T> {
    fn default() -> Self {
        Self(DashMap::<T, Peer>::new())
    }
}

impl<T: Eq + Hash> Drop for Peers<T> {
    fn drop(&mut self) {
        for kv in self.0.iter() {
            kv.value().disconnect();
        }
    }
}

#[cfg(test)]
mod test {
    use super::*;

    static_assertions::assert_impl_all!(Peers<i32>: Default, Drop, Send, Sync);

    #[test]
    pub fn test_contains_works() {
        const ID: i32 = 420;
        let peers = Peers::<i32>::default();
        let _peer = peers.create_unbounded(ID);
        assert!(peers.contains(&ID));
        assert!(peers.get(&ID).is_some());
    }

    #[test]
    pub fn disconnecting_removes_peer() {
        const ID: i32 = 420;
        let peers = Peers::<i32>::default();
        let peer = peers.create_unbounded(ID);
        assert!(peers.contains(&ID));
        assert!(peers.get(&ID).is_some());
        peer.disconnect();
        assert!(!peers.contains(&ID));
        assert!(peers.get(&ID).is_none());
    }

    #[test]
    pub fn disconnecting_via_drop_removes_peer() {
        const ID: i32 = 420;
        let peers = Peers::<i32>::default();
        let peer = peers.create_unbounded(ID);
        assert!(peers.contains(&ID));
        assert!(peers.get(&ID).is_some());
        drop(peer);
        assert!(!peers.contains(&ID));
        assert!(peers.get(&ID).is_none());
    }

    #[test]
    pub fn disconnecting_local_disconnects_remote() {
        const ID: i32 = 420;
        let peers = Peers::<i32>::default();
        let peer_remote = peers.create_unbounded(ID);
        peers.disconnect(&ID);
        assert!(!peer_remote.is_connected());
    }

    #[test]
    pub fn dropping_disconnects_all_remotes() {
        let peers = Peers::<i32>::default();
        let a = peers.create_unbounded(1);
        let b = peers.create_unbounded(2);
        let c = peers.create_unbounded(3);

        assert!(a.is_connected());
        assert!(b.is_connected());
        assert!(c.is_connected());
        drop(peers);
        assert!(!a.is_connected());
        assert!(!b.is_connected());
        assert!(!c.is_connected());
    }
}