Golang context.Background函数代码示例

func TestClientOverMax(t *testing.T) {
	rs := NewServer()
	k := key.Key("hello")
	numProvidersForHelloKey := 100
	for i := 0; i < numProvidersForHelloKey; i++ {
		pi := testutil.RandIdentityOrFatal(t)
		err := rs.Client(pi).Provide(context.Background(), k)
		if err != nil {
			t.Fatal(err)
		}
	}

	max := 10
	pi := testutil.RandIdentityOrFatal(t)
	client := rs.Client(pi)

	providersFromClient := client.FindProvidersAsync(context.Background(), k, max)
	i := 0
	for _ = range providersFromClient {
		i++
	}
	if i != max {
		t.Fatal("Too many providers returned")
	}
}

func TestRoutingResolve(t *testing.T) {
	d := mockrouting.NewServer().Client(testutil.RandIdentityOrFatal(t))

	resolver := NewRoutingResolver(d)
	publisher := NewRoutingPublisher(d)

	privk, pubk, err := testutil.RandTestKeyPair(512)
	if err != nil {
		t.Fatal(err)
	}

	h := path.FromString("/ipfs/QmZULkCELmmk5XNfCgTnCyFgAVxBRBXyDHGGMVoLFLiXEN")
	err = publisher.Publish(context.Background(), privk, h)
	if err != nil {
		t.Fatal(err)
	}

	pubkb, err := pubk.Bytes()
	if err != nil {
		t.Fatal(err)
	}

	pkhash := u.Hash(pubkb)
	res, err := resolver.Resolve(context.Background(), key.Key(pkhash).Pretty())
	if err != nil {
		t.Fatal(err)
	}

	if res != h {
		t.Fatal("Got back incorrect value.")
	}
}

func TestAddLink(t *testing.T) {
	ds := mdtest.Mock()
	fishnode := &dag.Node{
		Data: []byte("fishcakes!"),
	}

	fk, err := ds.Add(fishnode)
	if err != nil {
		t.Fatal(err)
	}

	nd := new(dag.Node)
	nnode, err := addLink(context.Background(), ds, nd, "fish", fishnode)
	if err != nil {
		t.Fatal(err)
	}

	fnprime, err := nnode.GetLinkedNode(context.Background(), ds, "fish")
	if err != nil {
		t.Fatal(err)
	}

	fnpkey, err := fnprime.Key()
	if err != nil {
		t.Fatal(err)
	}

	if fnpkey != fk {
		t.Fatal("wrong child node found!")
	}
}

func TestClientFindProviders(t *testing.T) {
	pi := testutil.RandIdentityOrFatal(t)
	rs := NewServer()
	client := rs.Client(pi)

	k := key.Key("hello")
	err := client.Provide(context.Background(), k)
	if err != nil {
		t.Fatal(err)
	}

	// This is bad... but simulating networks is hard
	time.Sleep(time.Millisecond * 300)
	max := 100

	providersFromClient := client.FindProvidersAsync(context.Background(), key.Key("hello"), max)
	isInClient := false
	for pi := range providersFromClient {
		if pi.ID == pi.ID {
			isInClient = true
		}
	}
	if !isInClient {
		t.Fatal("Despite client providing key, client didn't receive peer when finding providers")
	}
}

// TODO does dht ensure won't receive self as a provider? probably not.
func TestCanceledContext(t *testing.T) {
	rs := NewServer()
	k := key.Key("hello")

	// avoid leaking goroutine, without using the context to signal
	// (we want the goroutine to keep trying to publish on a
	// cancelled context until we've tested it doesnt do anything.)
	done := make(chan struct{})
	defer func() { done <- struct{}{} }()

	t.Log("async'ly announce infinite stream of providers for key")
	i := 0
	go func() { // infinite stream
		for {
			select {
			case <-done:
				t.Log("exiting async worker")
				return
			default:
			}

			pi, err := testutil.RandIdentity()
			if err != nil {
				t.Error(err)
			}
			err = rs.Client(pi).Provide(context.Background(), k)
			if err != nil {
				t.Error(err)
			}
			i++
		}
	}()

	local := testutil.RandIdentityOrFatal(t)
	client := rs.Client(local)

	t.Log("warning: max is finite so this test is non-deterministic")
	t.Log("context cancellation could simply take lower priority")
	t.Log("and result in receiving the max number of results")
	max := 1000

	t.Log("cancel the context before consuming")
	ctx, cancelFunc := context.WithCancel(context.Background())
	cancelFunc()
	providers := client.FindProvidersAsync(ctx, k, max)

	numProvidersReturned := 0
	for _ = range providers {
		numProvidersReturned++
	}
	t.Log(numProvidersReturned)

	if numProvidersReturned == max {
		t.Fatal("Context cancel had no effect")
	}
}

func ExampleEventLogger() {
	{
		log := EventLogger(nil)
		e := log.EventBegin(context.Background(), "dial")
		e.Done()
	}
	{
		log := EventLogger(nil)
		e := log.EventBegin(context.Background(), "dial")
		_ = e.Close() // implements io.Closer for convenience
	}
}

func TestMultiWrite(t *testing.T) {
	dserv, pins := getMockDagServ(t)
	_, n := getNode(t, dserv, 0, pins)

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

	dagmod, err := NewDagModifier(ctx, n, dserv, pins, sizeSplitterGen(512))
	if err != nil {
		t.Fatal(err)
	}

	data := make([]byte, 4000)
	u.NewTimeSeededRand().Read(data)

	for i := 0; i < len(data); i++ {
		n, err := dagmod.WriteAt(data[i:i+1], int64(i))
		if err != nil {
			t.Fatal(err)
		}
		if n != 1 {
			t.Fatal("Somehow wrote the wrong number of bytes! (n != 1)")
		}

		size, err := dagmod.Size()
		if err != nil {
			t.Fatal(err)
		}

		if size != int64(i+1) {
			t.Fatal("Size was reported incorrectly")
		}
	}
	nd, err := dagmod.GetNode()
	if err != nil {
		t.Fatal(err)
	}

	read, err := uio.NewDagReader(context.Background(), nd, dserv)
	if err != nil {
		t.Fatal(err)
	}
	rbuf, err := ioutil.ReadAll(read)
	if err != nil {
		t.Fatal(err)
	}

	err = arrComp(rbuf, data)
	if err != nil {
		t.Fatal(err)
	}
}

func TestGetBlocks(t *testing.T) {
	store := bstore()
	ex := Exchange(store)
	g := blocksutil.NewBlockGenerator()

	expected := g.Blocks(2)

	for _, b := range expected {
		if err := ex.HasBlock(b); err != nil {
			t.Fail()
		}
	}

	request := func() []key.Key {
		var ks []key.Key

		for _, b := range expected {
			ks = append(ks, b.Key())
		}
		return ks
	}()

	received, err := ex.GetBlocks(context.Background(), request)
	if err != nil {
		t.Fatal(err)
	}

	var count int
	for _ = range received {
		count++
	}
	if len(expected) != count {
		t.Fail()
	}
}

func TestConnHandler(t *testing.T) {
	// t.Skip("skipping for another test")
	t.Parallel()

	ctx := context.Background()
	swarms := makeSwarms(ctx, t, 5)

	gotconn := make(chan struct{}, 10)
	swarms[0].SetConnHandler(func(conn *Conn) {
		gotconn <- struct{}{}
	})

	connectSwarms(t, ctx, swarms)

	<-time.After(time.Millisecond)
	// should've gotten 5 by now.

	swarms[0].SetConnHandler(nil)

	expect := 4
	for i := 0; i < expect; i++ {
		select {
		case <-time.After(time.Second):
			t.Fatal("failed to get connections")
		case <-gotconn:
		}
	}

	select {
	case <-gotconn:
		t.Fatalf("should have connected to %d swarms", expect)
	default:
	}
}

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 BenchmarkDagmodWrite(b *testing.B) {
	b.StopTimer()
	dserv, pins := getMockDagServ(b)
	_, n := getNode(b, dserv, 0, pins)
	ctx, cancel := context.WithCancel(context.Background())
	defer cancel()

	wrsize := 4096

	dagmod, err := NewDagModifier(ctx, n, dserv, pins, sizeSplitterGen(512))
	if err != nil {
		b.Fatal(err)
	}

	buf := make([]byte, b.N*wrsize)
	u.NewTimeSeededRand().Read(buf)
	b.StartTimer()
	b.SetBytes(int64(wrsize))
	for i := 0; i < b.N; i++ {
		n, err := dagmod.Write(buf[i*wrsize : (i+1)*wrsize])
		if err != nil {
			b.Fatal(err)
		}
		if n != wrsize {
			b.Fatal("Wrote bad size")
		}
	}
}

func TestBuilderConsistency(t *testing.T) {
	nbytes := 100000
	buf := new(bytes.Buffer)
	io.CopyN(buf, u.NewTimeSeededRand(), int64(nbytes))
	should := dup(buf.Bytes())
	dagserv := mdtest.Mock()
	nd, err := buildTestDag(dagserv, chunk.DefaultSplitter(buf))
	if err != nil {
		t.Fatal(err)
	}
	r, err := uio.NewDagReader(context.Background(), nd, dagserv)
	if err != nil {
		t.Fatal(err)
	}

	out, err := ioutil.ReadAll(r)
	if err != nil {
		t.Fatal(err)
	}

	err = arrComp(out, should)
	if err != nil {
		t.Fatal(err)
	}
}

func TestSeekEndSingleBlockFile(t *testing.T) {
	nbytes := int64(100)
	should := make([]byte, nbytes)
	u.NewTimeSeededRand().Read(should)

	read := bytes.NewReader(should)
	ds := mdtest.Mock()
	nd, err := buildTestDag(ds, chunk.NewSizeSplitter(read, 5000))
	if err != nil {
		t.Fatal(err)
	}

	rs, err := uio.NewDagReader(context.Background(), nd, ds)
	if err != nil {
		t.Fatal(err)
	}

	seeked, err := rs.Seek(0, os.SEEK_END)
	if err != nil {
		t.Fatal(err)
	}
	if seeked != nbytes {
		t.Fatal("Failed to seek to end")
	}
}

func testInsert(t *testing.T, e *Editor, path, data string, create bool, experr string) {
	child := &dag.Node{Data: []byte(data)}
	ck, err := e.ds.Add(child)
	if err != nil {
		t.Fatal(err)
	}

	var c func() *dag.Node
	if create {
		c = func() *dag.Node {
			return &dag.Node{}
		}
	}

	err = e.InsertNodeAtPath(context.Background(), path, child, c)
	if experr != "" {
		var got string
		if err != nil {
			got = err.Error()
		}
		if got != experr {
			t.Fatalf("expected '%s' but got '%s'", experr, got)
		}
		return
	}

	if err != nil {
		t.Fatal(err)
	}

	assertNodeAtPath(t, e.ds, e.root, path, ck)
}

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")
	}

}