Golang context.Background函数代码示例

func TestHTTPMembersAPIAddSuccess(t *testing.T) {
	wantAction := &membersAPIActionAdd{
		peerURLs: types.URLs([]url.URL{
			{Scheme: "http", Host: "127.0.0.1:7002"},
		}),
	}

	mAPI := &httpMembersAPI{
		client: &actionAssertingHTTPClient{
			t:   t,
			act: wantAction,
			resp: http.Response{
				StatusCode: http.StatusCreated,
			},
			body: []byte(`{"id":"94088180e21eb87b","peerURLs":["http://127.0.0.1:7002"]}`),
		},
	}

	wantResponseMember := &Member{
		ID:       "94088180e21eb87b",
		PeerURLs: []string{"http://127.0.0.1:7002"},
	}

	m, err := mAPI.Add(context.Background(), "http://127.0.0.1:7002")
	if err != nil {
		t.Errorf("got non-nil err: %#v", err)
	}
	if !reflect.DeepEqual(wantResponseMember, m) {
		t.Errorf("incorrect Member: want=%#v got=%#v", wantResponseMember, m)
	}
}

func TestHTTPKeysAPIDeleteError(t *testing.T) {
	tests := []httpClient{
		// generic HTTP client failure
		&staticHTTPClient{
			err: errors.New("fail!"),
		},

		// unusable status code
		&staticHTTPClient{
			resp: http.Response{
				StatusCode: http.StatusTeapot,
			},
		},

		// etcd Error response
		&staticHTTPClient{
			resp: http.Response{
				StatusCode: http.StatusInternalServerError,
			},
			body: []byte(`{"errorCode":300,"message":"Raft internal error","cause":"/foo","index":18}`),
		},
	}

	for i, tt := range tests {
		kAPI := httpKeysAPI{client: tt}
		resp, err := kAPI.Delete(context.Background(), "/foo", nil)
		if err == nil {
			t.Errorf("#%d: received nil error", i)
		}
		if resp != nil {
			t.Errorf("#%d: received non-nil Response: %#v", i, resp)
		}
	}
}

func TestHTTPClusterClientDoDeadlineExceedContext(t *testing.T) {
	fakeURL := url.URL{}
	tr := newFakeTransport()
	tr.finishCancel <- struct{}{}
	c := &httpClusterClient{
		clientFactory: newHTTPClientFactory(tr, DefaultCheckRedirect, 0),
		endpoints:     []url.URL{fakeURL},
	}

	errc := make(chan error)
	go func() {
		ctx, cancel := context.WithTimeout(context.Background(), time.Millisecond)
		defer cancel()
		_, _, err := c.Do(ctx, &fakeAction{})
		errc <- err
	}()

	select {
	case err := <-errc:
		if err != context.DeadlineExceeded {
			t.Errorf("err = %+v, want %+v", err, context.DeadlineExceeded)
		}
	case <-time.After(time.Second):
		t.Fatalf("unexpected timeout when waitting for request to deadline exceed")
	}
}

func TestSimpleHTTPClientDoCancelContextResponseBodyClosed(t *testing.T) {
	tr := newFakeTransport()
	c := &simpleHTTPClient{transport: tr}

	// create an already-cancelled context
	ctx, cancel := context.WithCancel(context.Background())
	cancel()

	body := &checkableReadCloser{ReadCloser: ioutil.NopCloser(strings.NewReader("foo"))}
	go func() {
		// wait that simpleHTTPClient knows the context is already timed out,
		// and calls CancelRequest
		testutil.WaitSchedule()

		// response is returned before cancel effects
		tr.respchan <- &http.Response{Body: body}
	}()

	_, _, err := c.Do(ctx, &fakeAction{})
	if err == nil {
		t.Fatalf("expected non-nil error, got nil")
	}

	if !body.closed {
		t.Fatalf("expected closed body")
	}
}

func TestHTTPClusterClientSyncFail(t *testing.T) {
	cf := newStaticHTTPClientFactory([]staticHTTPResponse{
		{err: errors.New("fail!")},
	})

	hc := &httpClusterClient{
		clientFactory: cf,
		rand:          rand.New(rand.NewSource(0)),
	}
	err := hc.reset([]string{"http://127.0.0.1:2379"})
	if err != nil {
		t.Fatalf("unexpected error during setup: %#v", err)
	}

	want := []string{"http://127.0.0.1:2379"}
	got := hc.Endpoints()
	if !reflect.DeepEqual(want, got) {
		t.Fatalf("incorrect endpoints: want=%#v got=%#v", want, got)
	}

	err = hc.Sync(context.Background())
	if err == nil {
		t.Fatalf("got nil error during Sync")
	}

	got = hc.Endpoints()
	if !reflect.DeepEqual(want, got) {
		t.Fatalf("incorrect endpoints after failed Sync: want=%#v got=%#v", want, got)
	}
}

func TestSimpleHTTPClientDoCancelContextWaitForRoundTrip(t *testing.T) {
	tr := newFakeTransport()
	c := &simpleHTTPClient{transport: tr}

	donechan := make(chan struct{})
	ctx, cancel := context.WithCancel(context.Background())
	go func() {
		c.Do(ctx, &fakeAction{})
		close(donechan)
	}()

	// This should call CancelRequest and begin the cancellation process
	cancel()

	select {
	case <-donechan:
		t.Fatalf("simpleHTTPClient.Do should not have exited yet")
	default:
	}

	tr.finishCancel <- struct{}{}

	select {
	case <-donechan:
		//expected behavior
		return
	case <-time.After(time.Second):
		t.Fatalf("simpleHTTPClient.Do did not exit within 1s")
	}
}

func TestHTTPKeysAPIDeleteResponse(t *testing.T) {
	client := &staticHTTPClient{
		resp: http.Response{
			StatusCode: http.StatusOK,
			Header:     http.Header{"X-Etcd-Index": []string{"22"}},
		},
		body: []byte(`{"action":"delete","node":{"key":"/pants/foo/bar/baz","value":"snarf","modifiedIndex":22,"createdIndex":19},"prevNode":{"key":"/pants/foo/bar/baz","value":"snazz","modifiedIndex":20,"createdIndex":19}}`),
	}

	wantResponse := &Response{
		Action:   "delete",
		Node:     &Node{Key: "/pants/foo/bar/baz", Value: "snarf", CreatedIndex: uint64(19), ModifiedIndex: uint64(22)},
		PrevNode: &Node{Key: "/pants/foo/bar/baz", Value: "snazz", CreatedIndex: uint64(19), ModifiedIndex: uint64(20)},
		Index:    uint64(22),
	}

	kAPI := &httpKeysAPI{client: client, prefix: "/pants"}
	resp, err := kAPI.Delete(context.Background(), "/foo/bar/baz", nil)
	if err != nil {
		t.Errorf("non-nil error: %#v", err)
	}
	if !reflect.DeepEqual(wantResponse, resp) {
		t.Errorf("incorrect Response: want=%#v got=%#v", wantResponse, resp)
	}
}

func TestHTTPKeysAPIGetResponse(t *testing.T) {
	client := &staticHTTPClient{
		resp: http.Response{
			StatusCode: http.StatusOK,
			Header:     http.Header{"X-Etcd-Index": []string{"42"}},
		},
		body: []byte(`{"action":"get","node":{"key":"/pants/foo/bar","modifiedIndex":25,"createdIndex":19,"nodes":[{"key":"/pants/foo/bar/baz","value":"snarf","createdIndex":21,"modifiedIndex":25}]}}`),
	}

	wantResponse := &Response{
		Action: "get",
		Node: &Node{
			Key: "/pants/foo/bar",
			Nodes: []*Node{
				{Key: "/pants/foo/bar/baz", Value: "snarf", CreatedIndex: 21, ModifiedIndex: 25},
			},
			CreatedIndex:  uint64(19),
			ModifiedIndex: uint64(25),
		},
		Index: uint64(42),
	}

	kAPI := &httpKeysAPI{client: client, prefix: "/pants"}
	resp, err := kAPI.Get(context.Background(), "/foo/bar", &GetOptions{Recursive: true})
	if err != nil {
		t.Errorf("non-nil error: %#v", err)
	}
	if !reflect.DeepEqual(wantResponse, resp) {
		t.Errorf("incorrect Response: want=%#v got=%#v", wantResponse, resp)
	}
}

func TestHTTPMembersAPIListError(t *testing.T) {
	tests := []httpClient{
		// generic httpClient failure
		&staticHTTPClient{err: errors.New("fail!")},

		// unrecognized HTTP status code
		&staticHTTPClient{
			resp: http.Response{StatusCode: http.StatusTeapot},
		},

		// fail to unmarshal body on StatusOK
		&staticHTTPClient{
			resp: http.Response{
				StatusCode: http.StatusOK,
			},
			body: []byte(`[{"id":"XX`),
		},
	}

	for i, tt := range tests {
		mAPI := &httpMembersAPI{client: tt}
		ms, err := mAPI.List(context.Background())
		if err == nil {
			t.Errorf("#%d: got nil err", i)
		}
		if ms != nil {
			t.Errorf("#%d: got non-nil Member slice", i)
		}
	}
}

func TestHTTPMembersAPIListSuccess(t *testing.T) {
	wantAction := &membersAPIActionList{}
	mAPI := &httpMembersAPI{
		client: &actionAssertingHTTPClient{
			t:   t,
			act: wantAction,
			resp: http.Response{
				StatusCode: http.StatusOK,
			},
			body: []byte(`{"members":[{"id":"94088180e21eb87b","name":"node2","peerURLs":["http://127.0.0.1:7002"],"clientURLs":["http://127.0.0.1:4002"]}]}`),
		},
	}

	wantResponseMembers := []Member{
		{
			ID:         "94088180e21eb87b",
			Name:       "node2",
			PeerURLs:   []string{"http://127.0.0.1:7002"},
			ClientURLs: []string{"http://127.0.0.1:4002"},
		},
	}

	m, err := mAPI.List(context.Background())
	if err != nil {
		t.Errorf("got non-nil err: %#v", err)
	}
	if !reflect.DeepEqual(wantResponseMembers, m) {
		t.Errorf("incorrect Members: want=%#v got=%#v", wantResponseMembers, m)
	}
}

func TestHTTPKeysAPICreateInOrderAction(t *testing.T) {
	act := &createInOrderAction{
		Dir:   "/foo",
		Value: "bar",
		TTL:   0,
	}
	kAPI := httpKeysAPI{client: &actionAssertingHTTPClient{t: t, act: act}}
	kAPI.CreateInOrder(context.Background(), "/foo", "bar", nil)
}

func TestSimpleHTTPClientDoError(t *testing.T) {
	tr := newFakeTransport()
	c := &simpleHTTPClient{transport: tr}

	tr.errchan <- errors.New("fixture")

	_, _, err := c.Do(context.Background(), &fakeAction{})
	if err == nil {
		t.Fatalf("expected non-nil error, got nil")
	}
}

func TestSimpleHTTPClientDoCancelContext(t *testing.T) {
	tr := newFakeTransport()
	c := &simpleHTTPClient{transport: tr}

	tr.startCancel <- struct{}{}
	tr.finishCancel <- struct{}{}

	_, _, err := c.Do(context.Background(), &fakeAction{})
	if err == nil {
		t.Fatalf("expected non-nil error, got nil")
	}
}

func TestHTTPKeysAPIDeleteAction(t *testing.T) {
	tests := []struct {
		key        string
		value      string
		opts       *DeleteOptions
		wantAction httpAction
	}{
		// nil DeleteOptions
		{
			key:  "/foo",
			opts: nil,
			wantAction: &deleteAction{
				Key:       "/foo",
				PrevValue: "",
				PrevIndex: 0,
				Recursive: false,
			},
		},
		// empty DeleteOptions
		{
			key:  "/foo",
			opts: &DeleteOptions{},
			wantAction: &deleteAction{
				Key:       "/foo",
				PrevValue: "",
				PrevIndex: 0,
				Recursive: false,
			},
		},
		// populated DeleteOptions
		{
			key: "/foo",
			opts: &DeleteOptions{
				PrevValue: "baz",
				PrevIndex: 13,
				Recursive: true,
			},
			wantAction: &deleteAction{
				Key:       "/foo",
				PrevValue: "baz",
				PrevIndex: 13,
				Recursive: true,
			},
		},
	}

	for i, tt := range tests {
		client := &actionAssertingHTTPClient{t: t, num: i, act: tt.wantAction}
		kAPI := httpKeysAPI{client: client}
		kAPI.Delete(context.Background(), tt.key, tt.opts)
	}
}

func ExampleWithTimeout() {
	// Pass a context with a timeout to tell a blocking function that it
	// should abandon its work after the timeout elapses.
	ctx, _ := context.WithTimeout(context.Background(), 100*time.Millisecond)
	select {
	case <-time.After(200 * time.Millisecond):
		fmt.Println("overslept")
	case <-ctx.Done():
		fmt.Println(ctx.Err()) // prints "context deadline exceeded"
	}
	// Output:
	// context deadline exceeded
}