// NewDHT creates a new DHT object with the given peer as the 'local' host
func NewDHT(ctx context.Context, h host.Host, dstore ds.Datastore) *IpfsDHT {
dht := new(IpfsDHT)
dht.datastore = dstore
dht.self = h.ID()
dht.peerstore = h.Peerstore()
dht.host = h
// register for network notifs.
dht.host.Network().Notify((*netNotifiee)(dht))
dht.proc = goprocess.WithTeardown(func() error {
// remove ourselves from network notifs.
dht.host.Network().StopNotify((*netNotifiee)(dht))
return nil
})
dht.ctx = ctx
h.SetStreamHandler(ProtocolDHT, dht.handleNewStream)
dht.providers = NewProviderManager(dht.ctx, dht.self)
dht.proc.AddChild(dht.providers.proc)
goprocessctx.CloseAfterContext(dht.proc, ctx)
dht.routingTable = kb.NewRoutingTable(20, kb.ConvertPeerID(dht.self), time.Minute, dht.peerstore)
dht.birth = time.Now()
dht.Validator = make(record.Validator)
dht.Validator["pk"] = record.PublicKeyValidator
dht.Selector = make(record.Selector)
dht.Selector["pk"] = record.PublicKeySelector
return dht
}
func (r *dhtQueryRunner) Run(ctx context.Context, peers []peer.ID) (*dhtQueryResult, error) {
r.log = log
r.runCtx = ctx
if len(peers) == 0 {
log.Warning("Running query with no peers!")
return nil, nil
}
// setup concurrency rate limiting
for i := 0; i < r.query.concurrency; i++ {
r.rateLimit <- struct{}{}
}
// add all the peers we got first.
for _, p := range peers {
r.addPeerToQuery(p)
}
// go do this thing.
// do it as a child proc to make sure Run exits
// ONLY AFTER spawn workers has exited.
r.proc.Go(r.spawnWorkers)
// so workers are working.
// wait until they're done.
err := routing.ErrNotFound
// now, if the context finishes, close the proc.
// we have to do it here because the logic before is setup, which
// should run without closing the proc.
ctxproc.CloseAfterContext(r.proc, ctx)
select {
case <-r.peersRemaining.Done():
r.proc.Close()
r.RLock()
defer r.RUnlock()
err = routing.ErrNotFound
// if every query to every peer failed, something must be very wrong.
if len(r.errs) > 0 && len(r.errs) == r.peersSeen.Size() {
log.Debugf("query errs: %s", r.errs)
err = r.errs[0]
}
case <-r.proc.Closed():
r.RLock()
defer r.RUnlock()
err = context.DeadlineExceeded
}
if r.result != nil && r.result.success {
return r.result, nil
}
return nil, err
}
// New initializes a BitSwap instance that communicates over the provided
// BitSwapNetwork. This function registers the returned instance as the network
// delegate.
// Runs until context is cancelled.
func New(parent context.Context, p peer.ID, network bsnet.BitSwapNetwork,
bstore blockstore.Blockstore, nice bool) exchange.Interface {
// important to use provided parent context (since it may include important
// loggable data). It's probably not a good idea to allow bitswap to be
// coupled to the concerns of the IPFS daemon in this way.
//
// FIXME(btc) Now that bitswap manages itself using a process, it probably
// shouldn't accept a context anymore. Clients should probably use Close()
// exclusively. We should probably find another way to share logging data
ctx, cancelFunc := context.WithCancel(parent)
notif := notifications.New()
px := process.WithTeardown(func() error {
notif.Shutdown()
return nil
})
bs := &Bitswap{
self: p,
blockstore: bstore,
notifications: notif,
engine: decision.NewEngine(ctx, bstore), // TODO close the engine with Close() method
network: network,
findKeys: make(chan *blockRequest, sizeBatchRequestChan),
process: px,
newBlocks: make(chan *blocks.Block, HasBlockBufferSize),
provideKeys: make(chan key.Key, provideKeysBufferSize),
wm: NewWantManager(ctx, network),
}
go bs.wm.Run()
network.SetDelegate(bs)
// Start up bitswaps async worker routines
bs.startWorkers(px, ctx)
// bind the context and process.
// do it over here to avoid closing before all setup is done.
go func() {
<-px.Closing() // process closes first
cancelFunc()
}()
procctx.CloseAfterContext(px, ctx) // parent cancelled first
return bs
}
func (s *Swarm) dialAddrs(ctx context.Context, d *conn.Dialer, p peer.ID, remoteAddrs []ma.Multiaddr) (conn.Conn, error) {
// try to connect to one of the peer's known addresses.
// we dial concurrently to each of the addresses, which:
// * makes the process faster overall
// * attempts to get the fastest connection available.
// * mitigates the waste of trying bad addresses
log.Debugf("%s swarm dialing %s %s", s.local, p, remoteAddrs)
ctx, cancel := context.WithCancel(ctx)
defer cancel() // cancel work when we exit func
foundConn := make(chan struct{})
conns := make(chan conn.Conn, len(remoteAddrs))
errs := make(chan error, len(remoteAddrs))
// dialSingleAddr is used in the rate-limited async thing below.
dialSingleAddr := func(addr ma.Multiaddr) {
connC, err := s.dialAddr(ctx, d, p, addr)
// check parent still wants our results
select {
case <-foundConn:
if connC != nil {
connC.Close()
}
return
default:
}
if err != nil {
errs <- err
} else if connC == nil {
errs <- fmt.Errorf("failed to dial %s %s", p, addr)
} else {
conns <- connC
}
}
// this whole thing is in a goroutine so we can use foundConn
// to end early.
go func() {
// rate limiting just in case. at most 10 addrs at once.
limiter := ratelimit.NewRateLimiter(process.Background(), 10)
limiter.Go(func(worker process.Process) {
// permute addrs so we try different sets first each time.
for _, i := range rand.Perm(len(remoteAddrs)) {
select {
case <-foundConn: // if one of them succeeded already
break
case <-worker.Closing(): // our context was cancelled
break
default:
}
workerAddr := remoteAddrs[i] // shadow variable to avoid race
limiter.LimitedGo(func(worker process.Process) {
dialSingleAddr(workerAddr)
})
}
})
processctx.CloseAfterContext(limiter, ctx)
}()
// wair fot the results.
exitErr := fmt.Errorf("failed to dial %s", p)
for i := 0; i < len(remoteAddrs); i++ {
select {
case exitErr = <-errs: //
log.Debug("dial error: ", exitErr)
case connC := <-conns:
// take the first + return asap
close(foundConn)
return connC, nil
}
}
return nil, exitErr
}
