Golang context.TODO函数代码示例

// TestBlockProposal ensures that node will block proposal when it does not
// know who is the current leader; node will accept proposal when it knows
// who is the current leader.
func TestBlockProposal(t *testing.T) {
	n := newNode()
	r := newRaft(1, []uint64{1}, 10, 1, NewMemoryStorage(), 0)
	go n.run(r)
	defer n.Stop()

	errc := make(chan error, 1)
	go func() {
		errc <- n.Propose(context.TODO(), []byte("somedata"))
	}()

	testutil.ForceGosched()
	select {
	case err := <-errc:
		t.Errorf("err = %v, want blocking", err)
	default:
	}

	n.Campaign(context.TODO())
	testutil.ForceGosched()
	select {
	case err := <-errc:
		if err != nil {
			t.Errorf("err = %v, want %v", err, nil)
		}
	default:
		t.Errorf("blocking proposal, want unblocking")
	}
}

// TestNodePropose ensures that node.Propose sends the given proposal to the underlying raft.
func TestNodePropose(t *testing.T) {
	msgs := []raftpb.Message{}
	appendStep := func(r *raft, m raftpb.Message) {
		msgs = append(msgs, m)
	}

	n := newNode()
	s := NewMemoryStorage()
	r := newRaft(1, []uint64{1}, 10, 1, s, 0)
	go n.run(r)
	n.Campaign(context.TODO())
	for {
		rd := <-n.Ready()
		s.Append(rd.Entries)
		// change the step function to appendStep until this raft becomes leader
		if rd.SoftState.Lead == r.id {
			r.step = appendStep
			n.Advance()
			break
		}
		n.Advance()
	}
	n.Propose(context.TODO(), []byte("somedata"))
	n.Stop()

	if len(msgs) != 1 {
		t.Fatalf("len(msgs) = %d, want %d", len(msgs), 1)
	}
	if msgs[0].Type != raftpb.MsgProp {
		t.Errorf("msg type = %d, want %d", msgs[0].Type, raftpb.MsgProp)
	}
	if !reflect.DeepEqual(msgs[0].Entries[0].Data, []byte("somedata")) {
		t.Errorf("data = %v, want %v", msgs[0].Entries[0].Data, []byte("somedata"))
	}
}

// TestMultiNodeProposeConfig ensures that multiNode.ProposeConfChange
// sends the given configuration proposal to the underlying raft.
func TestMultiNodeProposeConfig(t *testing.T) {
	mn := newMultiNode(1)
	go mn.run()
	s := NewMemoryStorage()
	mn.CreateGroup(1, newTestConfig(1, nil, 10, 1, s), []Peer{{ID: 1}})
	mn.Campaign(context.TODO(), 1)
	proposed := false
	var lastIndex uint64
	var ccdata []byte
	for {
		rds := <-mn.Ready()
		rd := rds[1]
		s.Append(rd.Entries)
		// change the step function to appendStep until this raft becomes leader
		if !proposed && rd.SoftState.Lead == mn.id {
			cc := raftpb.ConfChange{Type: raftpb.ConfChangeAddNode, NodeID: 1}
			var err error
			ccdata, err = cc.Marshal()
			if err != nil {
				t.Fatal(err)
			}
			mn.ProposeConfChange(context.TODO(), 1, cc)
			proposed = true
		}
		mn.Advance(rds)

		var err error
		lastIndex, err = s.LastIndex()
		if err != nil {
			t.Fatal(err)
		}
		if lastIndex >= 3 {
			break
		}
	}
	mn.Stop()

	entries, err := s.Entries(lastIndex, lastIndex+1, noLimit)
	if err != nil {
		t.Fatal(err)
	}
	if len(entries) != 1 {
		t.Fatalf("len(entries) = %d, want %d", len(entries), 1)
	}
	if entries[0].Type != raftpb.EntryConfChange {
		t.Fatalf("type = %v, want %v", entries[0].Type, raftpb.EntryConfChange)
	}
	if !bytes.Equal(entries[0].Data, ccdata) {
		t.Errorf("data = %v, want %v", entries[0].Data, ccdata)
	}
}

func TestBasicProgress(t *testing.T) {
	peers := []raft.Peer{{1, nil}, {2, nil}, {3, nil}, {4, nil}, {5, nil}}
	nt := newRaftNetwork(1, 2, 3, 4, 5)

	nodes := make([]*node, 0)

	for i := 1; i <= 5; i++ {
		n := startNode(uint64(i), peers, nt.nodeNetwork(uint64(i)))
		nodes = append(nodes, n)
	}

	time.Sleep(10 * time.Millisecond)

	for i := 0; i < 10000; i++ {
		nodes[0].Propose(context.TODO(), []byte("somedata"))
	}

	time.Sleep(500 * time.Millisecond)
	for _, n := range nodes {
		n.stop()
		if n.state.Commit != 10006 {
			t.Errorf("commit = %d, want = 10006", n.state.Commit)
		}
	}
}

// TestMultiNodeStep ensures that multiNode.Step sends MsgProp to propc
// chan and other kinds of messages to recvc chan.
func TestMultiNodeStep(t *testing.T) {
	for i, msgn := range raftpb.MessageType_name {
		mn := &multiNode{
			propc: make(chan multiMessage, 1),
			recvc: make(chan multiMessage, 1),
		}
		msgt := raftpb.MessageType(i)
		mn.Step(context.TODO(), 1, raftpb.Message{Type: msgt})
		// Proposal goes to proc chan. Others go to recvc chan.
		if msgt == raftpb.MsgProp {
			select {
			case <-mn.propc:
			default:
				t.Errorf("%d: cannot receive %s on propc chan", msgt, msgn)
			}
		} else {
			if msgt == raftpb.MsgBeat || msgt == raftpb.MsgHup || msgt == raftpb.MsgUnreachable || msgt == raftpb.MsgSnapStatus {
				select {
				case <-mn.recvc:
					t.Errorf("%d: step should ignore %s", msgt, msgn)
				default:
				}
			} else {
				select {
				case <-mn.recvc:
				default:
					t.Errorf("%d: cannot receive %s on recvc chan", msgt, msgn)
				}
			}
		}
	}
}

func BenchmarkProposal3Nodes(b *testing.B) {
	peers := []raft.Peer{{1, nil}, {2, nil}, {3, nil}}
	nt := newRaftNetwork(1, 2, 3)

	nodes := make([]*node, 0)

	for i := 1; i <= 3; i++ {
		n := startNode(uint64(i), peers, nt.nodeNetwork(uint64(i)))
		nodes = append(nodes, n)
	}
	// get ready and warm up
	time.Sleep(50 * time.Millisecond)

	b.ResetTimer()
	for i := 0; i < b.N; i++ {
		nodes[0].Propose(context.TODO(), []byte("somedata"))
	}

	for _, n := range nodes {
		if n.state.Commit != uint64(b.N+4) {
			continue
		}
	}
	b.StopTimer()

	for _, n := range nodes {
		n.stop()
	}
}

func (n *node) start() {
	n.stopc = make(chan struct{})
	ticker := time.Tick(5 * time.Millisecond)

	go func() {
		for {
			select {
			case <-ticker:
				n.Tick()
			case rd := <-n.Ready():
				if !raft.IsEmptyHardState(rd.HardState) {
					n.state = rd.HardState
					n.storage.SetHardState(n.state)
				}
				n.storage.Append(rd.Entries)
				time.Sleep(time.Millisecond)
				// TODO: make send async, more like real world...
				for _, m := range rd.Messages {
					n.iface.send(m)
				}
				n.Advance()
			case m := <-n.iface.recv():
				n.Step(context.TODO(), m)
			case <-n.stopc:
				n.Stop()
				log.Printf("raft.%d: stop", n.id)
				n.Node = nil
				close(n.stopc)
				return
			case p := <-n.pausec:
				recvms := make([]raftpb.Message, 0)
				for p {
					select {
					case m := <-n.iface.recv():
						recvms = append(recvms, m)
					case p = <-n.pausec:
					}
				}
				// step all pending messages
				for _, m := range recvms {
					n.Step(context.TODO(), m)
				}
			}
		}
	}()
}

// TestMultiNodePropose ensures that node.Propose sends the given proposal to the underlying raft.
func TestMultiNodePropose(t *testing.T) {
	mn := newMultiNode(1)
	go mn.run()
	s := NewMemoryStorage()
	mn.CreateGroup(1, newTestConfig(1, nil, 10, 1, s), []Peer{{ID: 1}})
	mn.Campaign(context.TODO(), 1)
	proposed := false
	for {
		rds := <-mn.Ready()
		rd := rds[1]
		s.Append(rd.Entries)
		// Once we are the leader, propose a command.
		if !proposed && rd.SoftState.Lead == mn.id {
			mn.Propose(context.TODO(), 1, []byte("somedata"))
			proposed = true
		}
		mn.Advance(rds)

		// Exit when we have three entries: one ConfChange, one no-op for the election,
		// and our proposed command.
		lastIndex, err := s.LastIndex()
		if err != nil {
			t.Fatal(err)
		}
		if lastIndex >= 3 {
			break
		}
	}
	mn.Stop()

	lastIndex, err := s.LastIndex()
	if err != nil {
		t.Fatal(err)
	}
	entries, err := s.Entries(lastIndex, lastIndex+1, noLimit)
	if err != nil {
		t.Fatal(err)
	}
	if len(entries) != 1 {
		t.Fatalf("len(entries) = %d, want %d", len(entries), 1)
	}
	if !bytes.Equal(entries[0].Data, []byte("somedata")) {
		t.Errorf("entries[0].Data = %v, want %v", entries[0].Data, []byte("somedata"))
	}
}

func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	if r.Method != "POST" {
		w.Header().Set("Allow", "POST")
		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
		return
	}

	if err := checkVersionCompability(r.Header.Get("X-Server-From"), serverVersion(r.Header), minClusterVersion(r.Header)); err != nil {
		plog.Errorf("request received was ignored (%v)", err)
		http.Error(w, errIncompatibleVersion.Error(), http.StatusPreconditionFailed)
		return
	}

	wcid := h.cid.String()
	w.Header().Set("X-Etcd-Cluster-ID", wcid)

	gcid := r.Header.Get("X-Etcd-Cluster-ID")
	if gcid != wcid {
		plog.Errorf("request received was ignored (cluster ID mismatch got %s want %s)", gcid, wcid)
		http.Error(w, errClusterIDMismatch.Error(), http.StatusPreconditionFailed)
		return
	}

	// Limit the data size that could be read from the request body, which ensures that read from
	// connection will not time out accidentally due to possible block in underlying implementation.
	limitedr := pioutil.NewLimitedBufferReader(r.Body, ConnReadLimitByte)
	b, err := ioutil.ReadAll(limitedr)
	if err != nil {
		plog.Errorf("failed to read raft message (%v)", err)
		http.Error(w, "error reading raft message", http.StatusBadRequest)
		return
	}
	var m raftpb.Message
	if err := m.Unmarshal(b); err != nil {
		plog.Errorf("failed to unmarshal raft message (%v)", err)
		http.Error(w, "error unmarshaling raft message", http.StatusBadRequest)
		return
	}
	if err := h.r.Process(context.TODO(), m); err != nil {
		switch v := err.(type) {
		case writerToResponse:
			v.WriteTo(w)
		default:
			plog.Warningf("failed to process raft message (%v)", err)
			http.Error(w, "error processing raft message", http.StatusInternalServerError)
		}
		return
	}
	// Write StatusNoContet header after the message has been processed by
	// raft, which faciliates the client to report MsgSnap status.
	w.WriteHeader(http.StatusNoContent)
}

func TestPause(t *testing.T) {
	peers := []raft.Peer{{1, nil}, {2, nil}, {3, nil}, {4, nil}, {5, nil}}
	nt := newRaftNetwork(1, 2, 3, 4, 5)

	nodes := make([]*node, 0)

	for i := 1; i <= 5; i++ {
		n := startNode(uint64(i), peers, nt.nodeNetwork(uint64(i)))
		nodes = append(nodes, n)
	}

	time.Sleep(50 * time.Millisecond)
	for i := 0; i < 300; i++ {
		nodes[0].Propose(context.TODO(), []byte("somedata"))
	}
	nodes[1].pause()
	for i := 0; i < 300; i++ {
		nodes[0].Propose(context.TODO(), []byte("somedata"))
	}
	nodes[2].pause()
	for i := 0; i < 300; i++ {
		nodes[0].Propose(context.TODO(), []byte("somedata"))
	}
	nodes[2].resume()
	for i := 0; i < 300; i++ {
		nodes[0].Propose(context.TODO(), []byte("somedata"))
	}
	nodes[1].resume()

	// give some time for nodes to catch up with the raft leader
	time.Sleep(300 * time.Millisecond)
	for _, n := range nodes {
		n.stop()
		if n.state.Commit != 1206 {
			t.Errorf("commit = %d, want = 1206", n.state.Commit)
		}
	}
}

// Cancel and Stop should unblock Step()
func TestMultiNodeStepUnblock(t *testing.T) {
	// a node without buffer to block step
	mn := &multiNode{
		propc: make(chan multiMessage),
		done:  make(chan struct{}),
	}

	ctx, cancel := context.WithCancel(context.Background())
	stopFunc := func() { close(mn.done) }

	tests := []struct {
		unblock func()
		werr    error
	}{
		{stopFunc, ErrStopped},
		{cancel, context.Canceled},
	}

	for i, tt := range tests {
		errc := make(chan error, 1)
		go func() {
			err := mn.Step(ctx, 1, raftpb.Message{Type: raftpb.MsgProp})
			errc <- err
		}()
		tt.unblock()
		select {
		case err := <-errc:
			if err != tt.werr {
				t.Errorf("#%d: err = %v, want %v", i, err, tt.werr)
			}
			//clean up side-effect
			if ctx.Err() != nil {
				ctx = context.TODO()
			}
			select {
			case <-mn.done:
				mn.done = make(chan struct{})
			default:
			}
		case <-time.After(time.Millisecond * 100):
			t.Errorf("#%d: failed to unblock step", i)
		}
	}
}

func (h *handler) ServeHTTP(w http.ResponseWriter, r *http.Request) {
	if r.Method != "POST" {
		w.Header().Set("Allow", "POST")
		http.Error(w, "Method Not Allowed", http.StatusMethodNotAllowed)
		return
	}

	wcid := h.cid.String()
	w.Header().Set("X-Etcd-Cluster-ID", wcid)

	gcid := r.Header.Get("X-Etcd-Cluster-ID")
	if gcid != wcid {
		log.Printf("rafthttp: request ignored due to cluster ID mismatch got %s want %s", gcid, wcid)
		http.Error(w, "clusterID mismatch", http.StatusPreconditionFailed)
		return
	}

	// Limit the data size that could be read from the request body, which ensures that read from
	// connection will not time out accidentally due to possible block in underlying implementation.
	limitedr := pioutil.NewLimitedBufferReader(r.Body, ConnReadLimitByte)
	b, err := ioutil.ReadAll(limitedr)
	if err != nil {
		log.Println("rafthttp: error reading raft message:", err)
		http.Error(w, "error reading raft message", http.StatusBadRequest)
		return
	}
	var m raftpb.Message
	if err := m.Unmarshal(b); err != nil {
		log.Println("rafthttp: error unmarshaling raft message:", err)
		http.Error(w, "error unmarshaling raft message", http.StatusBadRequest)
		return
	}
	if err := h.r.Process(context.TODO(), m); err != nil {
		switch v := err.(type) {
		case writerToResponse:
			v.WriteTo(w)
		default:
			log.Printf("rafthttp: error processing raft message: %v", err)
			http.Error(w, "error processing raft message", http.StatusInternalServerError)
		}
		return
	}
	w.WriteHeader(http.StatusNoContent)
}

func (s *streamReader) handle(r io.Reader) {
	defer func() {
		close(s.done)
		log.Printf("rafthttp: client streaming to %s at term %d has been stopped", s.to, s.term)
	}()

	er := newEntryReader(r, s.to)
	defer er.stop()
	for {
		ents, err := er.readEntries()
		if err != nil {
			if err != io.EOF {
				log.Printf("rafthttp: encountered error reading the client log stream: %v", err)
			}
			return
		}
		if len(ents) == 0 {
			continue
		}
		// The commit index field in appendEntry message is not recovered.
		// The follower updates its commit index through heartbeat.
		msg := raftpb.Message{
			Type:    raftpb.MsgApp,
			From:    uint64(s.to),
			To:      uint64(s.id),
			Term:    s.term,
			LogTerm: s.term,
			Index:   ents[0].Index - 1,
			Entries: ents,
		}
		if err := s.r.Process(context.TODO(), msg); err != nil {
			log.Printf("rafthttp: process raft message error: %v", err)
			return
		}
	}
}

	"io"
	"io/ioutil"
	"mime"
	"net/http"
	"net/url"
	"strconv"
	"strings"
	"sync"
	"time"

	"github.com/coreos/mantle/Godeps/_workspace/src/golang.org/x/net/context"
)

// NoContext is the default context you should supply if not using
// your own context.Context (see https://golang.org/x/net/context).
var NoContext = context.TODO()

// Config describes a typical 3-legged OAuth2 flow, with both the
// client application information and the server's endpoint URLs.
type Config struct {
	// ClientID is the application's ID.
	ClientID string

	// ClientSecret is the application's secret.
	ClientSecret string

	// Endpoint contains the resource server's token endpoint
	// URLs. These are constants specific to each server and are
	// often available via site-specific packages, such as
	// google.Endpoint or github.Endpoint.
	Endpoint Endpoint

func startPeer(tr http.RoundTripper, urls types.URLs, local, to, cid types.ID, r Raft, fs *stats.FollowerStats, errorc chan error, term uint64) *peer {
	picker := newURLPicker(urls)
	status := newPeerStatus(to)
	p := &peer{
		id:           to,
		r:            r,
		msgAppWriter: startStreamWriter(to, status, fs, r),
		writer:       startStreamWriter(to, status, fs, r),
		pipeline:     newPipeline(tr, picker, local, to, cid, status, fs, r, errorc),
		sendc:        make(chan raftpb.Message),
		recvc:        make(chan raftpb.Message, recvBufSize),
		propc:        make(chan raftpb.Message, maxPendingProposals),
		newURLsC:     make(chan types.URLs),
		termc:        make(chan uint64),
		pausec:       make(chan struct{}),
		resumec:      make(chan struct{}),
		stopc:        make(chan struct{}),
		done:         make(chan struct{}),
	}

	// Use go-routine for process of MsgProp because it is
	// blocking when there is no leader.
	ctx, cancel := context.WithCancel(context.Background())
	go func() {
		for {
			select {
			case mm := <-p.propc:
				if err := r.Process(ctx, mm); err != nil {
					plog.Warningf("failed to process raft message (%v)", err)
				}
			case <-p.stopc:
				return
			}
		}
	}()

	p.msgAppReader = startStreamReader(tr, picker, streamTypeMsgAppV2, local, to, cid, status, p.recvc, p.propc, errorc, term)
	reader := startStreamReader(tr, picker, streamTypeMessage, local, to, cid, status, p.recvc, p.propc, errorc, term)
	go func() {
		var paused bool
		for {
			select {
			case m := <-p.sendc:
				if paused {
					continue
				}
				writec, name := p.pick(m)
				select {
				case writec <- m:
				default:
					p.r.ReportUnreachable(m.To)
					if isMsgSnap(m) {
						p.r.ReportSnapshot(m.To, raft.SnapshotFailure)
					}
					if status.isActive() {
						plog.Warningf("dropped %s to %s since %s's sending buffer is full", m.Type, p.id, name)
					} else {
						plog.Debugf("dropped %s to %s since %s's sending buffer is full", m.Type, p.id, name)
					}
				}
			case mm := <-p.recvc:
				if err := r.Process(context.TODO(), mm); err != nil {
					plog.Warningf("failed to process raft message (%v)", err)
				}
			case urls := <-p.newURLsC:
				picker.update(urls)
			case <-p.pausec:
				paused = true
			case <-p.resumec:
				paused = false
			case <-p.stopc:
				cancel()
				p.msgAppWriter.stop()
				p.writer.stop()
				p.pipeline.stop()
				p.msgAppReader.stop()
				reader.stop()
				close(p.done)
				return
			}
		}
	}()

	return p
}