package chain import ( "sort" "sync" "time" lru "github.com/hashicorp/golang-lru" "github.com/libp2p/go-libp2p-core/peer" "github.com/filecoin-project/lotus/build" "github.com/filecoin-project/lotus/chain/types" ) type blockReceiptTracker struct { lk sync.Mutex // using an LRU cache because i don't want to handle all the edge cases for // manual cleanup and maintenance of a fixed size set cache *lru.Cache } type peerSet struct { peers map[peer.ID]time.Time } func newBlockReceiptTracker() *blockReceiptTracker { c, _ := lru.New(512) return &blockReceiptTracker{ cache: c, } } func (brt *blockReceiptTracker) Add(p peer.ID, ts *types.TipSet) { brt.lk.Lock() defer brt.lk.Unlock() val, ok := brt.cache.Get(ts.Key()) if !ok { pset := &peerSet{ peers: map[peer.ID]time.Time{ p: build.Clock.Now(), }, } brt.cache.Add(ts.Key(), pset) return } val.(*peerSet).peers[p] = build.Clock.Now() } func (brt *blockReceiptTracker) GetPeers(ts *types.TipSet) []peer.ID { brt.lk.Lock() defer brt.lk.Unlock() val, ok := brt.cache.Get(ts.Key()) if !ok { return nil } ps := val.(*peerSet) out := make([]peer.ID, 0, len(ps.peers)) for p := range ps.peers { out = append(out, p) } sort.Slice(out, func(i, j int) bool { return ps.peers[out[i]].Before(ps.peers[out[j]]) }) return out }