// Do interprets r and performs an operation on s.store according to r.Method
// and other fields. If r.Method is "POST", "PUT", "DELETE", or a "GET" with
// Quorum == true, r will be sent through consensus before performing its
// respective operation. Do will block until an action is performed or there is
// an error.
func (s *EtcdServer) Do(ctx context.Context, r pb.Request) (Response, error) {
	r.ID = s.reqIDGen.Next()
	if r.Method == "GET" && r.Quorum {
		r.Method = "QGET"
	}
	switch r.Method {
	case "POST", "PUT", "DELETE", "QGET":
		var raftReq pb.InternalRaftRequest
		raftReq.V2 = &r
		data, err := raftReq.Marshal()
		if err != nil {
			return Response{}, err
		}
		ch := s.w.Register(r.ID)

		// TODO: benchmark the cost of time.Now()
		// might be sampling?
		start := time.Now()
		s.r.Propose(ctx, data)

		proposePending.Inc()
		defer proposePending.Dec()

		select {
		case x := <-ch:
			proposeDurations.Observe(float64(time.Since(start).Nanoseconds() / int64(time.Millisecond)))
			resp := x.(Response)
			return resp, resp.err
		case <-ctx.Done():
			proposeFailed.Inc()
			s.w.Trigger(r.ID, nil) // GC wait
			return Response{}, parseCtxErr(ctx.Err())
		case <-s.done:
			return Response{}, ErrStopped
		}
	case "GET":
		switch {
		case r.Wait:
			wc, err := s.store.Watch(r.Path, r.Recursive, r.Stream, r.Since)
			if err != nil {
				return Response{}, err
			}
			return Response{Watcher: wc}, nil
		default:
			ev, err := s.store.Get(r.Path, r.Recursive, r.Sorted)
			if err != nil {
				return Response{}, err
			}
			return Response{Event: ev}, nil
		}
	case "HEAD":
		ev, err := s.store.Get(r.Path, r.Recursive, r.Sorted)
		if err != nil {
			return Response{}, err
		}
		return Response{Event: ev}, nil
	default:
		return Response{}, ErrUnknownMethod
	}
}

// TestSync tests sync 1. is nonblocking 2. proposes SYNC request.
func TestSync(t *testing.T) {
	n := newNodeRecorder()
	srv := &EtcdServer{
		r:        raftNode{Node: n},
		reqIDGen: idutil.NewGenerator(0, time.Time{}),
	}
	// check that sync is non-blocking
	done := make(chan struct{})
	go func() {
		srv.sync(10 * time.Second)
		done <- struct{}{}
	}()

	select {
	case <-done:
	case <-time.After(time.Second):
		t.Fatal("sync should be non-blocking but did not return after 1s!")
	}

	action, _ := n.Wait(1)
	if len(action) != 1 {
		t.Fatalf("len(action) = %d, want 1", len(action))
	}
	if action[0].Name != "Propose" {
		t.Fatalf("action = %s, want Propose", action[0].Name)
	}
	data := action[0].Params[0].([]byte)
	var r pb.Request
	if err := r.Unmarshal(data); err != nil {
		t.Fatalf("unmarshal request error: %v", err)
	}
	if r.Method != "SYNC" {
		t.Errorf("method = %s, want SYNC", r.Method)
	}
}

func (s *EtcdServer) run() {
	var syncC <-chan time.Time
	for {
		select {
		case <-s.Ticker:
			s.Node.Tick()
		case rd := <-s.Node.Ready():
			s.Save(rd.HardState, rd.Entries)
			s.Send(rd.Messages)

			// TODO(bmizerany): do this in the background, but take
			// care to apply entries in a single goroutine, and not
			// race them.
			for _, e := range rd.CommittedEntries {
				var r pb.Request
				if err := r.Unmarshal(e.Data); err != nil {
					panic("TODO: this is bad, what do we do about it?")
				}
				s.w.Trigger(r.Id, s.apply(r))
			}

			if rd.SoftState != nil {
				if rd.RaftState == raft.StateLeader {
					syncC = s.SyncTicker
				} else {
					syncC = nil
				}
			}
		case <-syncC:
			s.sync(defaultSyncTimeout)
		case <-s.done:
			return
		}
	}
}

func (a *v2apiStore) processRaftRequest(ctx context.Context, r *pb.Request) (Response, error) {
	data, err := r.Marshal()
	if err != nil {
		return Response{}, err
	}
	ch := a.s.w.Register(r.ID)

	// TODO: benchmark the cost of time.Now()
	// might be sampling?
	start := time.Now()
	a.s.r.Propose(ctx, data)

	proposePending.Inc()
	defer proposePending.Dec()

	select {
	case x := <-ch:
		proposeDurations.Observe(float64(time.Since(start)) / float64(time.Second))
		resp := x.(Response)
		return resp, resp.err
	case <-ctx.Done():
		proposeFailed.Inc()
		a.s.w.Trigger(r.ID, nil) // GC wait
		return Response{}, a.s.parseProposeCtxErr(ctx.Err(), start)
	case <-a.s.done:
	}
	return Response{}, ErrStopped
}

// Do interprets r and performs an operation on s.store according to r.Method
// and other fields. If r.Method is "POST", "PUT", "DELETE", or a "GET" with
// Quorum == true, r will be sent through consensus before performing its
// respective operation. Do will block until an action is performed or there is
// an error.
func (s *EtcdServer) Do(ctx context.Context, r pb.Request) (Response, error) {
	if r.ID == 0 {
		log.Panicf("request ID should never be 0")
	}
	if r.Method == "GET" && r.Quorum {
		r.Method = "QGET"
	}
	switch r.Method {
	case "POST", "PUT", "DELETE", "QGET":
		data, err := r.Marshal()
		if err != nil {
			return Response{}, err
		}
		ch := s.w.Register(r.ID)
		s.node.Propose(ctx, data)
		select {
		case x := <-ch:
			resp := x.(Response)
			return resp, resp.err
		case <-ctx.Done():
			s.w.Trigger(r.ID, nil) // GC wait
			return Response{}, parseCtxErr(ctx.Err())
		case <-s.done:
			return Response{}, ErrStopped
		}
	case "GET":
		switch {
		case r.Wait:
			wc, err := s.store.Watch(r.Path, r.Recursive, r.Stream, r.Since)
			if err != nil {
				return Response{}, err
			}
			return Response{Watcher: wc}, nil
		default:
			ev, err := s.store.Get(r.Path, r.Recursive, r.Sorted)
			if err != nil {
				return Response{}, err
			}
			return Response{Event: ev}, nil
		}
	case "HEAD":
		ev, err := s.store.Get(r.Path, r.Recursive, r.Sorted)
		if err != nil {
			return Response{}, err
		}
		return Response{Event: ev}, nil
	default:
		return Response{}, ErrUnknownMethod
	}
}

// TestSyncTrigger tests that the server proposes a SYNC request when its sync timer ticks
func TestSyncTrigger(t *testing.T) {
	n := newReadyNode()
	st := make(chan time.Time, 1)
	srv := &EtcdServer{
		cfg: &ServerConfig{TickMs: 1},
		r: raftNode{
			Node:        n,
			raftStorage: raft.NewMemoryStorage(),
			transport:   rafthttp.NewNopTransporter(),
			storage:     mockstorage.NewStorageRecorder(""),
		},
		store:      mockstore.NewNop(),
		SyncTicker: st,
		reqIDGen:   idutil.NewGenerator(0, time.Time{}),
	}

	// trigger the server to become a leader and accept sync requests
	go func() {
		srv.start()
		n.readyc <- raft.Ready{
			SoftState: &raft.SoftState{
				RaftState: raft.StateLeader,
			},
		}
		// trigger a sync request
		st <- time.Time{}
	}()

	action, _ := n.Wait(1)
	go srv.Stop()

	if len(action) != 1 {
		t.Fatalf("len(action) = %d, want 1", len(action))
	}
	if action[0].Name != "Propose" {
		t.Fatalf("action = %s, want Propose", action[0].Name)
	}
	data := action[0].Params[0].([]byte)
	var req pb.Request
	if err := req.Unmarshal(data); err != nil {
		t.Fatalf("error unmarshalling data: %v", err)
	}
	if req.Method != "SYNC" {
		t.Fatalf("unexpected proposed request: %#v", req.Method)
	}

	// wait on stop message
	<-n.Chan()
}

func main() {
	version := flag.Int("version", 5, "4 or 5")
	from := flag.String("data-dir", "", "")
	flag.Parse()

	if *from == "" {
		log.Fatal("Must provide -data-dir flag")
	}

	var ents []raftpb.Entry
	var err error
	switch *version {
	case 4:
		ents, err = dump4(*from)
	case 5:
		ents, err = dump5(*from)
	default:
		err = errors.New("value of -version flag must be 4 or 5")
	}

	if err != nil {
		log.Fatalf("Failed decoding log: %v", err)
	}

	for _, e := range ents {
		msg := fmt.Sprintf("%2d %5d: ", e.Term, e.Index)
		switch e.Type {
		case raftpb.EntryNormal:
			msg = fmt.Sprintf("%s norm", msg)
			var r etcdserverpb.Request
			if err := r.Unmarshal(e.Data); err != nil {
				msg = fmt.Sprintf("%s ???", msg)
			} else {
				msg = fmt.Sprintf("%s %s %s %s", msg, r.Method, r.Path, r.Val)
			}
		case raftpb.EntryConfChange:
			msg = fmt.Sprintf("%s conf", msg)
			var r raftpb.ConfChange
			if err := r.Unmarshal(e.Data); err != nil {
				msg = fmt.Sprintf("%s ???", msg)
			} else {
				msg = fmt.Sprintf("%s %s %s %s", msg, r.Type, types.ID(r.NodeID), r.Context)
			}
		}
		fmt.Println(msg)
	}
}

func TestPublish(t *testing.T) {
	n := newNodeRecorder()
	ch := make(chan interface{}, 1)
	// simulate that request has gone through consensus
	ch <- Response{}
	w := wait.NewWithResponse(ch)
	srv := &EtcdServer{
		readych:    make(chan struct{}),
		cfg:        &ServerConfig{TickMs: 1},
		id:         1,
		r:          raftNode{Node: n},
		attributes: membership.Attributes{Name: "node1", ClientURLs: []string{"http://a", "http://b"}},
		cluster:    &membership.RaftCluster{},
		w:          w,
		reqIDGen:   idutil.NewGenerator(0, time.Time{}),
	}
	srv.publish(time.Hour)

	action := n.Action()
	if len(action) != 1 {
		t.Fatalf("len(action) = %d, want 1", len(action))
	}
	if action[0].Name != "Propose" {
		t.Fatalf("action = %s, want Propose", action[0].Name)
	}
	data := action[0].Params[0].([]byte)
	var r pb.Request
	if err := r.Unmarshal(data); err != nil {
		t.Fatalf("unmarshal request error: %v", err)
	}
	if r.Method != "PUT" {
		t.Errorf("method = %s, want PUT", r.Method)
	}
	wm := membership.Member{ID: 1, Attributes: membership.Attributes{Name: "node1", ClientURLs: []string{"http://a", "http://b"}}}
	if wpath := membership.MemberAttributesStorePath(wm.ID); r.Path != wpath {
		t.Errorf("path = %s, want %s", r.Path, wpath)
	}
	var gattr membership.Attributes
	if err := json.Unmarshal([]byte(r.Val), &gattr); err != nil {
		t.Fatalf("unmarshal val error: %v", err)
	}
	if !reflect.DeepEqual(gattr, wm.Attributes) {
		t.Errorf("member = %v, want %v", gattr, wm.Attributes)
	}
}

// Do interprets r and performs an operation on s.Store according to r.Method
// and other fields. If r.Method is "POST", "PUT", "DELETE", or a "GET with
// Quorum == true, r will be sent through consensus before performing its
// respective operation. Do will block until an action is performed or there is
// an error.
func (s *Server) Do(ctx context.Context, r pb.Request) (Response, error) {
	if r.Id == 0 {
		panic("r.Id cannot be 0")
	}
	if r.Method == "GET" && r.Quorum {
		r.Method = "QGET"
	}
	switch r.Method {
	case "POST", "PUT", "DELETE", "QGET":
		data, err := r.Marshal()
		if err != nil {
			return Response{}, err
		}
		ch := s.w.Register(r.Id)
		s.Node.Propose(ctx, data)
		select {
		case x := <-ch:
			resp := x.(Response)
			return resp, resp.err
		case <-ctx.Done():
			s.w.Trigger(r.Id, nil) // GC wait
			return Response{}, ctx.Err()
		case <-s.done:
			return Response{}, ErrStopped
		}
	case "GET":
		switch {
		case r.Wait:
			wc, err := s.Store.Watch(r.Path, r.Recursive, false, r.Since)
			if err != nil {
				return Response{}, err
			}
			return Response{Watcher: wc}, nil
		default:
			ev, err := s.Store.Get(r.Path, r.Recursive, r.Sorted)
			if err != nil {
				return Response{}, err
			}
			return Response{Event: ev}, nil
		}
	default:
		return Response{}, ErrUnknownMethod
	}
}

// sync proposes a SYNC request and is non-blocking.
// This makes no guarantee that the request will be proposed or performed.
// The request will be cancelled after the given timeout.
func (s *EtcdServer) sync(timeout time.Duration) {
	ctx, cancel := context.WithTimeout(context.Background(), timeout)
	req := pb.Request{
		Method: "SYNC",
		Id:     GenID(),
		Time:   time.Now().UnixNano(),
	}
	data, err := req.Marshal()
	if err != nil {
		log.Printf("marshal request %#v error: %v", req, err)
		return
	}
	// There is no promise that node has leader when do SYNC request,
	// so it uses goroutine to propose.
	go func() {
		s.Node.Propose(ctx, data)
		cancel()
	}()
}

func TestUpdateVersion(t *testing.T) {
	n := newNodeRecorder()
	ch := make(chan interface{}, 1)
	// simulate that request has gone through consensus
	ch <- Response{}
	w := wait.NewWithResponse(ch)
	srv := &EtcdServer{
		id:         1,
		cfg:        &ServerConfig{TickMs: 1},
		r:          raftNode{Node: n},
		attributes: membership.Attributes{Name: "node1", ClientURLs: []string{"http://node1.com"}},
		cluster:    &membership.RaftCluster{},
		w:          w,
		reqIDGen:   idutil.NewGenerator(0, time.Time{}),
	}
	srv.updateClusterVersion("2.0.0")

	action := n.Action()
	if len(action) != 1 {
		t.Fatalf("len(action) = %d, want 1", len(action))
	}
	if action[0].Name != "Propose" {
		t.Fatalf("action = %s, want Propose", action[0].Name)
	}
	data := action[0].Params[0].([]byte)
	var r pb.Request
	if err := r.Unmarshal(data); err != nil {
		t.Fatalf("unmarshal request error: %v", err)
	}
	if r.Method != "PUT" {
		t.Errorf("method = %s, want PUT", r.Method)
	}
	if wpath := path.Join(StoreClusterPrefix, "version"); r.Path != wpath {
		t.Errorf("path = %s, want %s", r.Path, wpath)
	}
	if r.Val != "2.0.0" {
		t.Errorf("val = %s, want %s", r.Val, "2.0.0")
	}
}

// Do interprets r and performs an operation on s.store according to r.Method
// and other fields. If r.Method is "POST", "PUT", "DELETE", or a "GET" with
// Quorum == true, r will be sent through consensus before performing its
// respective operation. Do will block until an action is performed or there is
// an error.
func (s *EtcdServer) Do(ctx context.Context, r pb.Request) (Response, error) {
	r.ID = s.reqIDGen.Next()
	if r.Method == "GET" && r.Quorum {
		r.Method = "QGET"
	}
	v2api := (v2API)(&v2apiStore{s})
	switch r.Method {
	case "POST":
		return v2api.Post(ctx, &r)
	case "PUT":
		return v2api.Put(ctx, &r)
	case "DELETE":
		return v2api.Delete(ctx, &r)
	case "QGET":
		return v2api.QGet(ctx, &r)
	case "GET":
		return v2api.Get(ctx, &r)
	case "HEAD":
		return v2api.Head(ctx, &r)
	}
	return Response{}, ErrUnknownMethod
}

func (a *v2apiStore) processRaftRequest(ctx context.Context, r *pb.Request) (Response, error) {
	data, err := r.Marshal()
	if err != nil {
		return Response{}, err
	}
	ch := a.s.w.Register(r.ID)

	start := time.Now()
	a.s.r.Propose(ctx, data)
	proposalsPending.Inc()
	defer proposalsPending.Dec()

	select {
	case x := <-ch:
		resp := x.(Response)
		return resp, resp.err
	case <-ctx.Done():
		proposalsFailed.Inc()
		a.s.w.Trigger(r.ID, nil) // GC wait
		return Response{}, a.s.parseProposeCtxErr(ctx.Err(), start)
	case <-a.s.stopping:
	}
	return Response{}, ErrStopped
}

func (s *Server) run() {
	for {
		select {
		case <-s.Ticker:
			s.Node.Tick()
		case rd := <-s.Node.Ready():
			s.Save(rd.State, rd.Entries)
			s.Send(rd.Messages)

			// TODO(bmizerany): do this in the background, but take
			// care to apply entries in a single goroutine, and not
			// race them.
			for _, e := range rd.CommittedEntries {
				var r pb.Request
				if err := r.Unmarshal(e.Data); err != nil {
					panic("TODO: this is bad, what do we do about it?")
				}
				s.w.Trigger(r.Id, s.apply(r))
			}
		case <-s.done:
			return
		}
	}
}

func main() {
	from := flag.String("data-dir", "", "")
	snapfile := flag.String("start-snap", "", "The base name of snapshot file to start dumping")
	index := flag.Uint64("start-index", 0, "The index to start dumping")
	flag.Parse()
	if *from == "" {
		log.Fatal("Must provide -data-dir flag.")
	}
	if *snapfile != "" && *index != 0 {
		log.Fatal("start-snap and start-index flags cannot be used together.")
	}

	var (
		walsnap  walpb.Snapshot
		snapshot *raftpb.Snapshot
		err      error
	)

	isIndex := *index != 0

	if isIndex {
		fmt.Printf("Start dumping log entries from index %d.\n", *index)
		walsnap.Index = *index
	} else {
		if *snapfile == "" {
			ss := snap.New(snapDir(*from))
			snapshot, err = ss.Load()
		} else {
			snapshot, err = snap.Read(path.Join(snapDir(*from), *snapfile))
		}

		switch err {
		case nil:
			walsnap.Index, walsnap.Term = snapshot.Metadata.Index, snapshot.Metadata.Term
			nodes := genIDSlice(snapshot.Metadata.ConfState.Nodes)
			fmt.Printf("Snapshot:\nterm=%d index=%d nodes=%s\n",
				walsnap.Term, walsnap.Index, nodes)
		case snap.ErrNoSnapshot:
			fmt.Printf("Snapshot:\nempty\n")
		default:
			log.Fatalf("Failed loading snapshot: %v", err)
		}
		fmt.Println("Start dupmping log entries from snapshot.")
	}

	w, err := wal.OpenForRead(walDir(*from), walsnap)
	if err != nil {
		log.Fatalf("Failed opening WAL: %v", err)
	}
	wmetadata, state, ents, err := w.ReadAll()
	w.Close()
	if err != nil && (!isIndex || err != wal.ErrSnapshotNotFound) {
		log.Fatalf("Failed reading WAL: %v", err)
	}
	id, cid := parseWALMetadata(wmetadata)
	vid := types.ID(state.Vote)
	fmt.Printf("WAL metadata:\nnodeID=%s clusterID=%s term=%d commitIndex=%d vote=%s\n",
		id, cid, state.Term, state.Commit, vid)

	fmt.Printf("WAL entries:\n")
	fmt.Printf("lastIndex=%d\n", ents[len(ents)-1].Index)
	fmt.Printf("%4s\t%10s\ttype\tdata\n", "term", "index")
	for _, e := range ents {
		msg := fmt.Sprintf("%4d\t%10d", e.Term, e.Index)
		switch e.Type {
		case raftpb.EntryNormal:
			msg = fmt.Sprintf("%s\tnorm", msg)

			var rr etcdserverpb.InternalRaftRequest
			if err := rr.Unmarshal(e.Data); err == nil {
				msg = fmt.Sprintf("%s\t%s", msg, rr.String())
				break
			}

			var r etcdserverpb.Request
			if err := r.Unmarshal(e.Data); err == nil {
				switch r.Method {
				case "":
					msg = fmt.Sprintf("%s\tnoop", msg)
				case "SYNC":
					msg = fmt.Sprintf("%s\tmethod=SYNC time=%q", msg, time.Unix(0, r.Time))
				case "QGET", "DELETE":
					msg = fmt.Sprintf("%s\tmethod=%s path=%s", msg, r.Method, excerpt(r.Path, 64, 64))
				default:
					msg = fmt.Sprintf("%s\tmethod=%s path=%s val=%s", msg, r.Method, excerpt(r.Path, 64, 64), excerpt(r.Val, 128, 0))
				}
				break
			}
			msg = fmt.Sprintf("%s\t???", msg)
		case raftpb.EntryConfChange:
			msg = fmt.Sprintf("%s\tconf", msg)
			var r raftpb.ConfChange
			if err := r.Unmarshal(e.Data); err != nil {
				msg = fmt.Sprintf("%s\t???", msg)
			} else {
				msg = fmt.Sprintf("%s\tmethod=%s id=%s", msg, r.Type, types.ID(r.NodeID))
			}
		}
		fmt.Println(msg)
	}
//.........这里部分代码省略.........

// parseKeyRequest converts a received http.Request on keysPrefix to
// a server Request, performing validation of supplied fields as appropriate.
// If any validation fails, an empty Request and non-nil error is returned.
func parseKeyRequest(r *http.Request, clock clockwork.Clock) (etcdserverpb.Request, error) {
	emptyReq := etcdserverpb.Request{}

	err := r.ParseForm()
	if err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidForm,
			err.Error(),
		)
	}

	if !strings.HasPrefix(r.URL.Path, keysPrefix) {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidForm,
			"incorrect key prefix",
		)
	}
	p := path.Join(etcdserver.StoreKeysPrefix, r.URL.Path[len(keysPrefix):])

	var pIdx, wIdx uint64
	if pIdx, err = getUint64(r.Form, "prevIndex"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeIndexNaN,
			`invalid value for "prevIndex"`,
		)
	}
	if wIdx, err = getUint64(r.Form, "waitIndex"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeIndexNaN,
			`invalid value for "waitIndex"`,
		)
	}

	var rec, sort, wait, dir, quorum, stream bool
	if rec, err = getBool(r.Form, "recursive"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "recursive"`,
		)
	}
	if sort, err = getBool(r.Form, "sorted"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "sorted"`,
		)
	}
	if wait, err = getBool(r.Form, "wait"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "wait"`,
		)
	}
	// TODO(jonboulle): define what parameters dir is/isn't compatible with?
	if dir, err = getBool(r.Form, "dir"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "dir"`,
		)
	}
	if quorum, err = getBool(r.Form, "quorum"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "quorum"`,
		)
	}
	if stream, err = getBool(r.Form, "stream"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "stream"`,
		)
	}

	if wait && r.Method != "GET" {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`"wait" can only be used with GET requests`,
		)
	}

	pV := r.FormValue("prevValue")
	if _, ok := r.Form["prevValue"]; ok && pV == "" {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodePrevValueRequired,
			`"prevValue" cannot be empty`,
		)
	}

	// TTL is nullable, so leave it null if not specified
	// or an empty string
	var ttl *uint64
	if len(r.FormValue("ttl")) > 0 {
		i, err := getUint64(r.Form, "ttl")
		if err != nil {
			return emptyReq, etcdErr.NewRequestError(
				etcdErr.EcodeTTLNaN,
				`invalid value for "ttl"`,
			)
//.........这里部分代码省略.........

func main() {
	from := flag.String("data-dir", "", "")
	flag.Parse()
	if *from == "" {
		log.Fatal("Must provide -data-dir flag")
	}

	ss := snap.New(snapDir(*from))
	snapshot, err := ss.Load()
	var walsnap walpb.Snapshot
	switch err {
	case nil:
		walsnap.Index, walsnap.Term = snapshot.Metadata.Index, snapshot.Metadata.Term
		nodes := genIDSlice(snapshot.Metadata.ConfState.Nodes)
		fmt.Printf("Snapshot:\nterm=%d index=%d nodes=%s\n",
			walsnap.Term, walsnap.Index, nodes)
	case snap.ErrNoSnapshot:
		fmt.Printf("Snapshot:\nempty\n")
	default:
		log.Fatalf("Failed loading snapshot: %v", err)
	}

	w, err := wal.Open(walDir(*from), walsnap)
	if err != nil {
		log.Fatalf("Failed opening WAL: %v", err)
	}
	wmetadata, state, ents, err := w.ReadAll()
	w.Close()
	if err != nil {
		log.Fatalf("Failed reading WAL: %v", err)
	}
	id, cid := parseWALMetadata(wmetadata)
	vid := types.ID(state.Vote)
	fmt.Printf("WAL metadata:\nnodeID=%s clusterID=%s term=%d commitIndex=%d vote=%s\n",
		id, cid, state.Term, state.Commit, vid)

	fmt.Printf("WAL entries:\n")
	fmt.Printf("lastIndex=%d\n", ents[len(ents)-1].Index)
	fmt.Printf("%4s\t%10s\ttype\tdata\n", "term", "index")
	for _, e := range ents {
		msg := fmt.Sprintf("%4d\t%10d", e.Term, e.Index)
		switch e.Type {
		case raftpb.EntryNormal:
			msg = fmt.Sprintf("%s\tnorm", msg)
			var r etcdserverpb.Request
			if err := r.Unmarshal(e.Data); err != nil {
				msg = fmt.Sprintf("%s\t???", msg)
				break
			}
			switch r.Method {
			case "":
				msg = fmt.Sprintf("%s\tnoop", msg)
			case "SYNC":
				msg = fmt.Sprintf("%s\tmethod=SYNC time=%q", msg, time.Unix(0, r.Time))
			case "QGET", "DELETE":
				msg = fmt.Sprintf("%s\tmethod=%s path=%s", msg, r.Method, excerpt(r.Path, 64, 64))
			default:
				msg = fmt.Sprintf("%s\tmethod=%s path=%s val=%s", msg, r.Method, excerpt(r.Path, 64, 64), excerpt(r.Val, 128, 0))
			}
		case raftpb.EntryConfChange:
			msg = fmt.Sprintf("%s\tconf", msg)
			var r raftpb.ConfChange
			if err := r.Unmarshal(e.Data); err != nil {
				msg = fmt.Sprintf("%s\t???", msg)
			} else {
				msg = fmt.Sprintf("%s\tmethod=%s id=%s", msg, r.Type, types.ID(r.NodeID))
			}
		}
		fmt.Println(msg)
	}
}

// parseRequest converts a received http.Request to a server Request,
// performing validation of supplied fields as appropriate.
// If any validation fails, an empty Request and non-nil error is returned.
func parseRequest(r *http.Request, id int64) (etcdserverpb.Request, error) {
	emptyReq := etcdserverpb.Request{}

	err := r.ParseForm()
	if err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidForm,
			err.Error(),
		)
	}

	if !strings.HasPrefix(r.URL.Path, keysPrefix) {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidForm,
			"incorrect key prefix",
		)
	}
	p := r.URL.Path[len(keysPrefix):]

	var pIdx, wIdx uint64
	if pIdx, err = getUint64(r.Form, "prevIndex"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeIndexNaN,
			`invalid value for "prevIndex"`,
		)
	}
	if wIdx, err = getUint64(r.Form, "waitIndex"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeIndexNaN,
			`invalid value for "waitIndex"`,
		)
	}

	var rec, sort, wait, dir, stream bool
	if rec, err = getBool(r.Form, "recursive"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "recursive"`,
		)
	}
	if sort, err = getBool(r.Form, "sorted"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "sorted"`,
		)
	}
	if wait, err = getBool(r.Form, "wait"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "wait"`,
		)
	}
	// TODO(jonboulle): define what parameters dir is/isn't compatible with?
	if dir, err = getBool(r.Form, "dir"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "dir"`,
		)
	}
	if stream, err = getBool(r.Form, "stream"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "stream"`,
		)
	}

	if wait && r.Method != "GET" {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`"wait" can only be used with GET requests`,
		)
	}

	pV := r.FormValue("prevValue")
	if _, ok := r.Form["prevValue"]; ok && pV == "" {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`"prevValue" cannot be empty`,
		)
	}

	// TTL is nullable, so leave it null if not specified
	// or an empty string
	var ttl *uint64
	if len(r.FormValue("ttl")) > 0 {
		i, err := getUint64(r.Form, "ttl")
		if err != nil {
			return emptyReq, etcdErr.NewRequestError(
				etcdErr.EcodeTTLNaN,
				`invalid value for "ttl"`,
			)
		}
		ttl = &i
	}

	// prevExist is nullable, so leave it null if not specified
	var pe *bool
//.........这里部分代码省略.........

// parseRequest converts a received http.Request to a server Request,
// performing validation of supplied fields as appropriate.
// If any validation fails, an empty Request and non-nil error is returned.
func parseRequest(r *http.Request, id int64) (etcdserverpb.Request, error) {
	emptyReq := etcdserverpb.Request{}

	err := r.ParseForm()
	if err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidForm,
			err.Error(),
		)
	}

	if !strings.HasPrefix(r.URL.Path, keysPrefix) {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidForm,
			"incorrect key prefix",
		)
	}
	p := r.URL.Path[len(keysPrefix):]

	var pIdx, wIdx, ttl uint64
	if pIdx, err = getUint64(r.Form, "prevIndex"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeIndexNaN,
			`invalid value for "prevIndex"`,
		)
	}
	if wIdx, err = getUint64(r.Form, "waitIndex"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeIndexNaN,
			`invalid value for "waitIndex"`,
		)
	}
	if ttl, err = getUint64(r.Form, "ttl"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeTTLNaN,
			`invalid value for "ttl"`,
		)
	}

	var rec, sort, wait bool
	if rec, err = getBool(r.Form, "recursive"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "recursive"`,
		)
	}
	if sort, err = getBool(r.Form, "sorted"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "sorted"`,
		)
	}
	if wait, err = getBool(r.Form, "wait"); err != nil {
		return emptyReq, etcdErr.NewRequestError(
			etcdErr.EcodeInvalidField,
			`invalid value for "wait"`,
		)
	}

	// prevExists is nullable, so leave it null if not specified
	var pe *bool
	if _, ok := r.Form["prevExists"]; ok {
		bv, err := getBool(r.Form, "prevExists")
		if err != nil {
			return emptyReq, etcdErr.NewRequestError(
				etcdErr.EcodeInvalidField,
				"invalid value for prevExists",
			)
		}
		pe = &bv
	}

	rr := etcdserverpb.Request{
		Id:         id,
		Method:     r.Method,
		Path:       p,
		Val:        r.FormValue("value"),
		PrevValue:  r.FormValue("prevValue"),
		PrevIndex:  pIdx,
		PrevExists: pe,
		Recursive:  rec,
		Since:      wIdx,
		Sorted:     sort,
		Wait:       wait,
	}

	if pe != nil {
		rr.PrevExists = pe
	}

	// TODO(jonboulle): use fake clock instead of time module
	// https://github.com/coreos/etcd/issues/1021
	if ttl > 0 {
		expr := time.Duration(ttl) * time.Second
		rr.Expiration = time.Now().Add(expr).UnixNano()
	}

//.........这里部分代码省略.........

func (s *EtcdServer) run() {
	var syncC <-chan time.Time
	// snapi indicates the index of the last submitted snapshot request
	var snapi, appliedi int64
	for {
		select {
		case <-s.ticker:
			s.node.Tick()
		case rd := <-s.node.Ready():
			s.storage.Save(rd.HardState, rd.Entries)
			s.storage.SaveSnap(rd.Snapshot)
			s.send(rd.Messages)

			// TODO(bmizerany): do this in the background, but take
			// care to apply entries in a single goroutine, and not
			// race them.
			// TODO: apply configuration change into ClusterStore.
			for _, e := range rd.CommittedEntries {
				switch e.Type {
				case raftpb.EntryNormal:
					var r pb.Request
					if err := r.Unmarshal(e.Data); err != nil {
						panic("TODO: this is bad, what do we do about it?")
					}
					s.w.Trigger(r.ID, s.apply(r))
				case raftpb.EntryConfChange:
					var cc raftpb.ConfChange
					if err := cc.Unmarshal(e.Data); err != nil {
						panic("TODO: this is bad, what do we do about it?")
					}
					s.node.ApplyConfChange(cc)
					s.w.Trigger(cc.ID, nil)
				default:
					panic("unexpected entry type")
				}
				atomic.StoreInt64(&s.raftIndex, e.Index)
				atomic.StoreInt64(&s.raftTerm, e.Term)
				appliedi = e.Index
			}

			if rd.Snapshot.Index > snapi {
				snapi = rd.Snapshot.Index
			}

			// recover from snapshot if it is more updated than current applied
			if rd.Snapshot.Index > appliedi {
				if err := s.store.Recovery(rd.Snapshot.Data); err != nil {
					panic("TODO: this is bad, what do we do about it?")
				}
				appliedi = rd.Snapshot.Index
			}

			if appliedi-snapi > s.snapCount {
				s.snapshot()
				snapi = appliedi
			}

			if rd.SoftState != nil {
				if rd.RaftState == raft.StateLeader {
					syncC = s.syncTicker
				} else {
					syncC = nil
				}
				if rd.SoftState.ShouldStop {
					s.Stop()
					return
				}
			}
		case <-syncC:
			s.sync(defaultSyncTimeout)
		case <-s.done:
			return
		}
	}
}