Golang context.WithTimeout函数代码示例

func pingPeer(ctx context.Context, n *core.IpfsNode, pid peer.ID, numPings int) <-chan interface{} {
	outChan := make(chan interface{})
	go func() {
		defer close(outChan)

		if len(n.Peerstore.Addrs(pid)) == 0 {
			// Make sure we can find the node in question
			outChan <- &PingResult{
				Text: fmt.Sprintf("Looking up peer %s", pid.Pretty()),
			}

			ctx, cancel := context.WithTimeout(ctx, kPingTimeout)
			defer cancel()
			p, err := n.Routing.FindPeer(ctx, pid)
			if err != nil {
				outChan <- &PingResult{Text: fmt.Sprintf("Peer lookup error: %s", err)}
				return
			}
			n.Peerstore.AddAddrs(p.ID, p.Addrs, peer.TempAddrTTL)
		}

		outChan <- &PingResult{Text: fmt.Sprintf("PING %s.", pid.Pretty())}

		ctx, cancel := context.WithTimeout(ctx, kPingTimeout*time.Duration(numPings))
		defer cancel()
		pings, err := n.Ping.Ping(ctx, pid)
		if err != nil {
			log.Debugf("Ping error: %s", err)
			outChan <- &PingResult{Text: fmt.Sprintf("Ping error: %s", err)}
			return
		}

		var done bool
		var total time.Duration
		for i := 0; i < numPings && !done; i++ {
			select {
			case <-ctx.Done():
				done = true
				break
			case t, ok := <-pings:
				if !ok {
					done = true
					break
				}

				outChan <- &PingResult{
					Success: true,
					Time:    t,
				}
				total += t
				time.Sleep(time.Second)
			}
		}
		averagems := total.Seconds() * 1000 / float64(numPings)
		outChan <- &PingResult{
			Text: fmt.Sprintf("Average latency: %.2fms", averagems),
		}
	}()
	return outChan
}

func (mq *msgQueue) doWork(ctx context.Context) {
	// allow ten minutes for connections
	// this includes looking them up in the dht
	// dialing them, and handshaking
	conctx, cancel := context.WithTimeout(ctx, time.Minute*10)
	defer cancel()

	err := mq.network.ConnectTo(conctx, mq.p)
	if err != nil {
		log.Infof("cant connect to peer %s: %s", mq.p, err)
		// TODO: cant connect, what now?
		return
	}

	// grab outgoing message
	mq.outlk.Lock()
	wlm := mq.out
	if wlm == nil || wlm.Empty() {
		mq.outlk.Unlock()
		return
	}
	mq.out = nil
	mq.outlk.Unlock()

	sendctx, cancel := context.WithTimeout(ctx, time.Minute*5)
	defer cancel()

	// send wantlist updates
	err = mq.network.SendMessage(sendctx, mq.p, wlm)
	if err != nil {
		log.Infof("bitswap send error: %s", err)
		// TODO: what do we do if this fails?
		return
	}
}

func TestPinRecursiveFail(t *testing.T) {
	ctx := context.Background()
	dstore := dssync.MutexWrap(ds.NewMapDatastore())
	bstore := blockstore.NewBlockstore(dstore)
	bserv := bs.New(bstore, offline.Exchange(bstore))
	dserv := mdag.NewDAGService(bserv)

	p := NewPinner(dstore, dserv)

	a, _ := randNode()
	b, _ := randNode()
	err := a.AddNodeLinkClean("child", b)
	if err != nil {
		t.Fatal(err)
	}

	// NOTE: This isnt a time based test, we expect the pin to fail
	mctx, _ := context.WithTimeout(ctx, time.Millisecond)
	err = p.Pin(mctx, a, true)
	if err == nil {
		t.Fatal("should have failed to pin here")
	}

	_, err = dserv.Add(b)
	if err != nil {
		t.Fatal(err)
	}

	// this one is time based... but shouldnt cause any issues
	mctx, _ = context.WithTimeout(ctx, time.Second)
	err = p.Pin(mctx, a, true)
	if err != nil {
		t.Fatal(err)
	}
}

// GetValue searches for the value corresponding to given Key.
func (dht *IpfsDHT) GetValue(ctx context.Context, key key.Key) ([]byte, error) {
	ctx, cancel := context.WithTimeout(ctx, time.Minute)
	defer cancel()

	vals, err := dht.GetValues(ctx, key, 16)
	if err != nil {
		return nil, err
	}

	var recs [][]byte
	for _, v := range vals {
		if v.Val != nil {
			recs = append(recs, v.Val)
		}
	}

	i, err := dht.Selector.BestRecord(key, recs)
	if err != nil {
		return nil, err
	}

	best := recs[i]
	log.Debugf("GetValue %v %v", key, best)
	if best == nil {
		log.Errorf("GetValue yielded correct record with nil value.")
		return nil, routing.ErrNotFound
	}

	fixupRec, err := record.MakePutRecord(dht.peerstore.PrivKey(dht.self), key, best, true)
	if err != nil {
		// probably shouldnt actually 'error' here as we have found a value we like,
		// but this call failing probably isnt something we want to ignore
		return nil, err
	}

	for _, v := range vals {
		// if someone sent us a different 'less-valid' record, lets correct them
		if !bytes.Equal(v.Val, best) {
			go func(v routing.RecvdVal) {
				if v.From == dht.self {
					err := dht.putLocal(key, fixupRec)
					if err != nil {
						log.Error("Error correcting local dht entry:", err)
					}
					return
				}
				ctx, cancel := context.WithTimeout(dht.Context(), time.Second*30)
				defer cancel()
				err := dht.putValueToPeer(ctx, v.From, key, fixupRec)
				if err != nil {
					log.Error("Error correcting DHT entry: ", err)
				}
			}(v)
		}
	}

	return best, nil
}

func TestValueGetSet(t *testing.T) {
	// t.Skip("skipping test to debug another")

	ctx := context.Background()

	dhtA := setupDHT(ctx, t)
	dhtB := setupDHT(ctx, t)

	defer dhtA.Close()
	defer dhtB.Close()
	defer dhtA.host.Close()
	defer dhtB.host.Close()

	vf := &record.ValidChecker{
		Func: func(key.Key, []byte) error {
			return nil
		},
		Sign: false,
	}
	nulsel := func(_ key.Key, bs [][]byte) (int, error) {
		return 0, nil
	}

	dhtA.Validator["v"] = vf
	dhtB.Validator["v"] = vf
	dhtA.Selector["v"] = nulsel
	dhtB.Selector["v"] = nulsel

	connect(t, ctx, dhtA, dhtB)

	ctxT, _ := context.WithTimeout(ctx, time.Second)
	dhtA.PutValue(ctxT, "/v/hello", []byte("world"))

	ctxT, _ = context.WithTimeout(ctx, time.Second*2)
	val, err := dhtA.GetValue(ctxT, "/v/hello")
	if err != nil {
		t.Fatal(err)
	}

	if string(val) != "world" {
		t.Fatalf("Expected 'world' got '%s'", string(val))
	}

	ctxT, _ = context.WithTimeout(ctx, time.Second*2)
	val, err = dhtB.GetValue(ctxT, "/v/hello")
	if err != nil {
		t.Fatal(err)
	}

	if string(val) != "world" {
		t.Fatalf("Expected 'world' got '%s'", string(val))
	}
}

// GetDiagnostic runs a diagnostics request across the entire network
func (d *Diagnostics) GetDiagnostic(ctx context.Context, timeout time.Duration) ([]*DiagInfo, error) {
	log.Debug("getting diagnostic")
	ctx, cancel := context.WithTimeout(ctx, timeout)
	defer cancel()

	diagID := newID()
	d.diagLock.Lock()
	d.diagMap[diagID] = time.Now()
	d.diagLock.Unlock()

	log.Debug("begin diagnostic")

	peers := d.getPeers()
	log.Debugf("Sending diagnostic request to %d peers.", len(peers))

	pmes := newMessage(diagID)

	pmes.SetTimeoutDuration(timeout - HopTimeoutDecrement) // decrease timeout per hop
	dpeers, err := d.getDiagnosticFromPeers(ctx, d.getPeers(), pmes)
	if err != nil {
		return nil, fmt.Errorf("diagnostic from peers err: %s", err)
	}

	di := d.getDiagInfo()
	out := []*DiagInfo{di}
	for dpi := range dpeers {
		out = append(out, dpi)
	}
	return out, nil
}

// ResolveLinks iteratively resolves names by walking the link hierarchy.
// Every node is fetched from the DAGService, resolving the next name.
// Returns the list of nodes forming the path, starting with ndd. This list is
// guaranteed never to be empty.
//
// ResolveLinks(nd, []string{"foo", "bar", "baz"})
// would retrieve "baz" in ("bar" in ("foo" in nd.Links).Links).Links
func (s *Resolver) ResolveLinks(ctx context.Context, ndd *merkledag.Node, names []string) ([]*merkledag.Node, error) {

	result := make([]*merkledag.Node, 0, len(names)+1)
	result = append(result, ndd)
	nd := ndd // dup arg workaround

	// for each of the path components
	for _, name := range names {

		var cancel context.CancelFunc
		ctx, cancel = context.WithTimeout(ctx, time.Minute)
		defer cancel()

		nextnode, err := nd.GetLinkedNode(ctx, s.DAG, name)
		if err == merkledag.ErrLinkNotFound {
			n, _ := nd.Multihash()
			return result, ErrNoLink{Name: name, Node: n}
		} else if err != nil {
			return append(result, nextnode), err
		}

		nd = nextnode
		result = append(result, nextnode)
	}
	return result, nil
}

func TestHasIsBloomCached(t *testing.T) {
	cd := &callbackDatastore{f: func() {}, ds: ds.NewMapDatastore()}
	bs := NewBlockstore(syncds.MutexWrap(cd))

	for i := 0; i < 1000; i++ {
		bs.Put(blocks.NewBlock([]byte(fmt.Sprintf("data: %d", i))))
	}
	ctx, _ := context.WithTimeout(context.Background(), 1*time.Second)
	cachedbs, err := testBloomCached(bs, ctx)
	if err != nil {
		t.Fatal(err)
	}

	select {
	case <-cachedbs.rebuildChan:
	case <-ctx.Done():
		t.Fatalf("Timeout wating for rebuild: %d", cachedbs.bloom.ElementsAdded())
	}

	cacheFails := 0
	cd.SetFunc(func() {
		cacheFails++
	})

	for i := 0; i < 1000; i++ {
		cachedbs.Has(blocks.NewBlock([]byte(fmt.Sprintf("data: %d", i+2000))).Key())
	}

	if float64(cacheFails)/float64(1000) > float64(0.05) {
		t.Fatal("Bloom filter has cache miss rate of more than 5%")
	}
}

func TestDeadlineFractionCancel(t *testing.T) {

	ctx1, cancel1 := context.WithTimeout(context.Background(), 10*time.Millisecond)
	ctx2, cancel2 := WithDeadlineFraction(ctx1, 0.5)

	select {
	case <-ctx1.Done():
		t.Fatal("ctx1 ended too early")
	case <-ctx2.Done():
		t.Fatal("ctx2 ended too early")
	default:
	}

	cancel2()

	select {
	case <-ctx1.Done():
		t.Fatal("ctx1 should NOT be cancelled")
	case <-ctx2.Done():
	default:
		t.Fatal("ctx2 should be cancelled")
	}

	cancel1()

	select {
	case <-ctx1.Done():
	case <-ctx2.Done():
	default:
		t.Fatal("ctx1 should be cancelled")
	}

}

func TestBasicBitswap(t *testing.T) {
	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	sg := NewTestSessionGenerator(net)
	defer sg.Close()
	bg := blocksutil.NewBlockGenerator()

	t.Log("Test a one node trying to get one block from another")

	instances := sg.Instances(2)
	blocks := bg.Blocks(1)
	err := instances[0].Exchange.HasBlock(blocks[0])
	if err != nil {
		t.Fatal(err)
	}

	ctx, cancel := context.WithTimeout(context.Background(), time.Second*5)
	defer cancel()
	blk, err := instances[1].Exchange.GetBlock(ctx, blocks[0].Key())
	if err != nil {
		t.Fatal(err)
	}

	t.Log(blk)
	for _, inst := range instances {
		err := inst.Exchange.Close()
		if err != nil {
			t.Fatal(err)
		}
	}
}

func TestGetBlocksSequential(t *testing.T) {
	var servs = Mocks(4)
	for _, s := range servs {
		defer s.Close()
	}
	bg := blocksutil.NewBlockGenerator()
	blks := bg.Blocks(50)

	var keys []key.Key
	for _, blk := range blks {
		keys = append(keys, blk.Key())
		servs[0].AddBlock(blk)
	}

	t.Log("one instance at a time, get blocks concurrently")

	for i := 1; i < len(servs); i++ {
		ctx, cancel := context.WithTimeout(context.Background(), time.Second*50)
		defer cancel()
		out := servs[i].GetBlocks(ctx, keys)
		gotten := make(map[key.Key]blocks.Block)
		for blk := range out {
			if _, ok := gotten[blk.Key()]; ok {
				t.Fatal("Got duplicate block!")
			}
			gotten[blk.Key()] = blk
		}
		if len(gotten) != len(blks) {
			t.Fatalf("Didnt get enough blocks back: %d/%d", len(gotten), len(blks))
		}
	}
}

func TestGetBlockFromPeerAfterPeerAnnounces(t *testing.T) {

	net := tn.VirtualNetwork(mockrouting.NewServer(), delay.Fixed(kNetworkDelay))
	block := blocks.NewBlock([]byte("block"))
	g := NewTestSessionGenerator(net)
	defer g.Close()

	peers := g.Instances(2)
	hasBlock := peers[0]
	defer hasBlock.Exchange.Close()

	if err := hasBlock.Exchange.HasBlock(block); err != nil {
		t.Fatal(err)
	}

	wantsBlock := peers[1]
	defer wantsBlock.Exchange.Close()

	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
	defer cancel()
	received, err := wantsBlock.Exchange.GetBlock(ctx, block.Key())
	if err != nil {
		t.Log(err)
		t.Fatal("Expected to succeed")
	}

	if !bytes.Equal(block.Data, received.Data) {
		t.Fatal("Data doesn't match")
	}
}

func TestFindPeer(t *testing.T) {
	// t.Skip("skipping test to debug another")
	if testing.Short() {
		t.SkipNow()
	}

	ctx := context.Background()

	_, peers, dhts := setupDHTS(ctx, 4, t)
	defer func() {
		for i := 0; i < 4; i++ {
			dhts[i].Close()
			dhts[i].host.Close()
		}
	}()

	connect(t, ctx, dhts[0], dhts[1])
	connect(t, ctx, dhts[1], dhts[2])
	connect(t, ctx, dhts[1], dhts[3])

	ctxT, _ := context.WithTimeout(ctx, time.Second)
	p, err := dhts[0].FindPeer(ctxT, peers[2])
	if err != nil {
		t.Fatal(err)
	}

	if p.ID == "" {
		t.Fatal("Failed to find peer.")
	}

	if p.ID != peers[2] {
		t.Fatal("Didnt find expected peer.")
	}
}

func (bs *Bitswap) connectToProviders(ctx context.Context, entries []wantlist.Entry) {

	ctx, cancel := context.WithCancel(ctx)
	defer cancel()

	// Get providers for all entries in wantlist (could take a while)
	wg := sync.WaitGroup{}
	for _, e := range entries {
		wg.Add(1)
		go func(k key.Key) {
			defer wg.Done()

			child, cancel := context.WithTimeout(ctx, providerRequestTimeout)
			defer cancel()
			providers := bs.network.FindProvidersAsync(child, k, maxProvidersPerRequest)
			for prov := range providers {
				go func(p peer.ID) {
					bs.network.ConnectTo(ctx, p)
				}(prov)
			}
		}(e.Key)
	}

	wg.Wait() // make sure all our children do finish.
}

// connects to providers for the given keys
func (bs *Bitswap) providerConnector(parent context.Context) {
	defer log.Info("bitswap client worker shutting down...")

	for {
		log.Event(parent, "Bitswap.ProviderConnector.Loop")
		select {
		case req := <-bs.findKeys:
			keys := req.keys
			if len(keys) == 0 {
				log.Warning("Received batch request for zero blocks")
				continue
			}
			log.Event(parent, "Bitswap.ProviderConnector.Work", logging.LoggableMap{"Keys": keys})

			// NB: Optimization. Assumes that providers of key[0] are likely to
			// be able to provide for all keys. This currently holds true in most
			// every situation. Later, this assumption may not hold as true.
			child, cancel := context.WithTimeout(req.ctx, providerRequestTimeout)
			providers := bs.network.FindProvidersAsync(child, keys[0], maxProvidersPerRequest)
			for p := range providers {
				go bs.network.ConnectTo(req.ctx, p)
			}
			cancel()

		case <-parent.Done():
			return
		}
	}
}