我又来更新辣 没想的那么难 维护好状态机是关键 这次提交还有不少bug:有几处可能的数据竞争 状态机中的bolt事务应该合并到一个函数执行，否则会导致一些数据被篡改

.gitignore

@@ -13,4 +13,5 @@
 
 # Dependency directories (remove the comment below to include it)
 # vendor/
-raftd
+cmd/raftd/raftd
+cmd/client/client

httpd/service.go

@@ -20,10 +20,11 @@ type Store interface {
 	Get(key string, lvl store.ConsistencyLevel) ([]byte, error)
 	Set(key string, value []byte) error
 	Delete(key string) error
-	LeaseGrant(ttl int) (uint64, error)
+	LeaseGrant(name string, ttl int) (uint64, error)
 	LeaseKeepAlive(leaseId, key string, value []byte) error
 	LeaseRevoke() error
 	LeaseTimeToAlive() error
+	GetLeaseKV(key string) ([]string, error)
 	Join(nodeID string, httpAddress string, addr string) error
 	LeaderAPIAddr() string
 	SetMeta(key, value string) error
@@ -99,6 +100,7 @@ func (s *Service) newRouter() (r *gin.Engine) {
 		leaseGroup.POST("/keepalive/:id", s.LeaseKeepAliveHandler())
 		leaseGroup.POST("/revoke/:id")
 		leaseGroup.POST("/timetolive/:id")
+		leaseGroup.GET("/kv/:name", s.GetKeyByLeaseHandler())
 	}
 
 	r.POST("/join", s.JoinHandler())
@@ -157,6 +159,33 @@ func (s *Service) GetKeyHandler() gin.HandlerFunc {
 	}
 }
 
+func (s *Service) GetKeyByLeaseHandler() gin.HandlerFunc {
+	return func(ctx *gin.Context) {
+		k := ctx.Param("name")
+		if k == "" {
+			ctx.JSON(http.StatusBadRequest, nil)
+			return
+		}
+
+		v, err := s.store.GetLeaseKV(k)
+		if err != nil {
+			if err == store.ErrNotLeader {
+				leader := s.store.LeaderAPIAddr()
+				if leader == "" {
+					ctx.JSON(http.StatusServiceUnavailable, err)
+					return
+				}
+				redirect := s.FormRedirect(ctx.Request, leader)
+				ctx.Redirect(http.StatusTemporaryRedirect, redirect)
+				return
+			}
+			ctx.JSON(http.StatusInternalServerError, err)
+			return
+		}
+		ctx.JSON(http.StatusOK, v)
+	}
+}
+
 func (s *Service) SetKeyHandler() gin.HandlerFunc {
 	return func(ctx *gin.Context) {
 		k := ctx.Param("key")
@@ -260,7 +289,7 @@ func (s *Service) JoinHandler() gin.HandlerFunc {
 	}
 }
 
-/* 租约机制 TODO 暂时是独立的*/
+/* 租约机制 NOTICE 是独立的*/
 
 // LeaseGrant 创建一个租约
 func (s *Service) LeaseGrantHandler() gin.HandlerFunc {
@@ -277,7 +306,13 @@ func (s *Service) LeaseGrantHandler() gin.HandlerFunc {
 			return
 		}
 
-		v, err := s.store.LeaseGrant(ttlnum)
+		name := strings.TrimSpace(q.Get("name"))
+		if name == "" {
+			ctx.JSON(http.StatusBadRequest, nil)
+			return
+		}
+
+		v, err := s.store.LeaseGrant(name, ttlnum) // TODO 这里还可以承载更多的数据
 		if err != nil {
 			if err == store.ErrNotLeader {
 				leader := s.store.LeaderAPIAddr()

store/store.go

@@ -11,6 +11,7 @@ import (
 	"os"
 	"path/filepath"
 	"strconv"
+	"strings"
 	"sync"
 	"time"
 
@@ -21,7 +22,8 @@ import (
 )
 
 const (
-	DefaultBucketName = "impact-eintr"
+	DefaultKVBucketName    = "impact-eintr"
+	DefaultLeaseBucketName = "raftd-lease-system"
 )
 
 var (
@@ -44,10 +46,12 @@ const (
 )
 
 type command struct {
-	Op      string `json:"op,omitempty"`
-	Key     string `json:"key,omitempty"`
-	Value   []byte `json:"value,omitempty"`
+	Op    string `json:"op,omitempty"`
+	Key   string `json:"key,omitempty"`
+	Value []byte `json:"value,omitempty"`
+
 	LeaseId uint64 `json:"leaseId,omitempty"`
+	Name    string `json:"name,omitempty"`
 	TTL     int    `json:"ttl,omitempty"`
 }
 
@@ -82,8 +86,10 @@ type Store struct {
 
 	raft *raft.Raft // 一致性机制
 
+	// 租约系统相关实现
 	snowflake *utils.Snowflake
 	wg        WaitGroupWrapper
+	leases    map[uint64][]string // LeaseId:[]key
 
 	logger *log.Logger
 }
@@ -95,6 +101,7 @@ func New(bindID int64) *Store {
 	}
 	return &Store{
 		m:         make(map[string][]byte),
+		leases:    make(map[uint64][]string),
 		snowflake: sn,
 		logger:    log.New(os.Stderr, "[store] ", log.LstdFlags),
 	}
@@ -143,7 +150,7 @@ func (s *Store) Open(enableSingle bool, localID string) error {
 
 	// 新建一个桶
 	err = db.Update(func(tx *bolt.Tx) error {
-		_, err := tx.CreateBucketIfNotExists([]byte(DefaultBucketName))
+		_, err := tx.CreateBucketIfNotExists([]byte(DefaultKVBucketName))
 		if err != nil {
 			log.Fatalf("CreateBucketIfNotExists err:%s", err.Error())
 			return err
@@ -309,7 +316,7 @@ func (s *Store) Get(key string, lvl ConsistencyLevel) ([]byte, error) {
 
 	val := make([]byte, 0)
 	s.db.View(func(tx *bolt.Tx) error {
-		bucket := tx.Bucket([]byte(DefaultBucketName))
+		bucket := tx.Bucket([]byte(DefaultKVBucketName))
 		val = bucket.Get([]byte(key))
 		return nil
 	})
@@ -351,19 +358,31 @@ func (s *Store) Delete(key string) error {
 	return f.Error()
 }
 
+const (
+	CREATE = iota
+	ALIVE
+	DEAD
+)
+
 type LeaseMeta struct {
-	TTL int `json:"ttl"`
+	Name   string `json:"name"`
+	TTL    int    `json:"ttl"`
+	Status int    `json:"status"`
+	Count  int    `json:"count"`
 }
 
 // 创建新的租约
-func (s *Store) LeaseGrant(ttl int) (uint64, error) {
+func (s *Store) LeaseGrant(name string, ttl int) (uint64, error) {
 	if s.raft.State() != raft.Leader {
 		return 0, ErrNotLeader
 	}
 
 	leaseId := s.snowflake.Generate()
+
+	// 向状态机写入：create 新建一个Lease
 	c := &command{
 		Op:      "grant",
+		Name:    name,
 		LeaseId: leaseId,
 		TTL:     ttl,
 	}
@@ -372,27 +391,102 @@ func (s *Store) LeaseGrant(ttl int) (uint64, error) {
 	if err != nil {
 		return 0, err
 	}
-
 	f := s.raft.Apply(b, raftTimeout)
+
+	s.wg.Wrap(func() {
+		ticker := time.NewTicker(time.Second)
+		defer log.Println("退出LoopCheck")
+		defer ticker.Stop()
+
+		var start bool
+		// 操作状态机 alive dead
+		for {
+			var count int
+			select {
+			case <-ticker.C:
+				s.db.Update(func(tx *bolt.Tx) error {
+					bucket := tx.Bucket([]byte(DefaultLeaseBucketName)).Bucket([]byte(fmt.Sprintf("%d", leaseId)))
+
+					// 判断是否有租客
+					if bucket.Stats().KeyN == 1 {
+						start = false
+					} else if bucket.Stats().KeyN > 1 {
+						start = true
+					}
+
+					// 向状态机写入：alive 修改Lease中键值对的存活时间 TTL--
+					if start {
+						cur := bucket.Cursor()
+						for k, v := cur.First(); k != nil; k, v = cur.Next() {
+							// 跳过元数据
+							if string(k) == "meta" {
+								return nil
+							}
+
+							// 修改存活时间
+							ttl := binary.BigEndian.Uint32(v[:4])
+							ttl = ttl - 1
+							// 注意由于bolt的实现机制 遍历中的value原值只可以读 不可以修改 需要先复制再Put
+							b := make([]byte, len(v))
+							copy(b, v)
+							binary.BigEndian.PutUint32(b[:4], uint32(ttl))
+							c := &command{
+								Op:      "loopcheck",
+								Key:     string(k),
+								Value:   b,
+								LeaseId: leaseId,
+							}
+							b, err := json.Marshal(c)
+							if err != nil {
+								return err
+							}
+
+							s.raft.Apply(b, raftTimeout)
+						}
+					}
+					return nil
+				})
+				// 查看Lease中存活的值
+				s.db.View(func(tx *bolt.Tx) error {
+					bucket := tx.Bucket([]byte(DefaultLeaseBucketName)).Bucket([]byte(fmt.Sprintf("%d", leaseId)))
+					if bucket == nil {
+						log.Println("没有找到对应的Lease", leaseId)
+						return fmt.Errorf("Lease[%d] hash been removed", leaseId)
+					}
+
+					b := bucket.Get([]byte("meta"))
+					meta := new(LeaseMeta)
+					err := json.Unmarshal(b, meta)
+					if err != nil {
+						return err
+					}
+					count = meta.Count
+					return nil
+				})
+
+				// 租约已经生效 并且 没有存活的键值 撤销该Lease
+				if count == 0 && start {
+					log.Printf("%d 租约已经失效 count=%d", leaseId, count)
+					c := &command{
+						Op:      "revoke",
+						LeaseId: leaseId,
+					}
+					b, err := json.Marshal(c)
+					if err != nil {
+						continue
+					}
+					// 向状态机写入：dead 撤销该Lease
+					s.raft.Apply(b, raftTimeout)
+					return
+				}
+				// case exitCh:
+			}
+		}
+	})
+
 	return leaseId, f.Error()
 }
 
-func (s *Store) LeaseRevoke() error {
-	if s.raft.State() != raft.Leader {
-		return ErrNotLeader
-	}
-	c := &command{
-		Op: "revoke",
-	}
-	b, err := json.Marshal(c)
-	if err != nil {
-		return err
-	}
-
-	f := s.raft.Apply(b, raftTimeout)
-	return f.Error()
-}
-
 func (s *Store) LeaseKeepAlive(leaseId, key string, value []byte) error {
 	if s.raft.State() != raft.Leader {
 		return ErrNotLeader
@@ -419,6 +513,22 @@ func (s *Store) LeaseKeepAlive(leaseId, key string, value []byte) error {
 	return f.Error()
 }
 
+func (s *Store) LeaseRevoke() error {
+	if s.raft.State() != raft.Leader {
+		return ErrNotLeader
+	}
+	c := &command{
+		Op: "revoke",
+	}
+	b, err := json.Marshal(c)
+	if err != nil {
+		return err
+	}
+
+	f := s.raft.Apply(b, raftTimeout)
+	return f.Error()
+}
+
 func (s *Store) LeaseTimeToAlive() error {
 	if s.raft.State() != raft.Leader {
 		return ErrNotLeader
@@ -435,6 +545,34 @@ func (s *Store) LeaseTimeToAlive() error {
 	return f.Error()
 }
 
+func (s *Store) GetLeaseKV(key string) ([]string, error) {
+	res := []string{}
+	s.db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(DefaultLeaseBucketName))
+		if bucket == nil {
+			return fmt.Errorf("No any KV in LeaseSystem")
+		}
+		return bucket.ForEach(func(k, v []byte) error {
+			b := bucket.Bucket(k)
+			metabytes := b.Get([]byte("meta"))
+			log.Println(string(metabytes))
+			meta := &LeaseMeta{}
+			json.Unmarshal(metabytes, meta)
+			if strings.HasPrefix(meta.Name, key) {
+				b.ForEach(func(k, v []byte) error {
+					if string(k) == "meta" {
+						return nil
+					}
+					res = append(res, string(v[4:]))
+					return nil
+				})
+			}
+			return nil
+		})
+	})
+	return res, nil
+}
+
 func (s *Store) SetMeta(key, value string) error {
 	return s.Set(key, []byte(value))
 }
@@ -506,11 +644,13 @@ func (f *fsm) Apply(l *raft.Log) interface{} {
 	case "delete":
 		return f.applyDelete(c.Key)
 	case "grant":
-		return f.applyLeaseGrant(c.LeaseId, c.TTL)
+		return f.applyLeaseGrant(c.Name, c.LeaseId, c.TTL)
+	case "loopcheck":
+		return f.applyLeaseLoopCheck(c.LeaseId, c.Key, c.Value)
 	case "keepalive":
 		return f.applyLeaseKeepAlive(c.LeaseId, c.Key, c.Value)
 	case "revoke":
-		return f.applyLeaseRevoke()
+		return f.applyLeaseRevoke(c.LeaseId)
 	case "timetolive":
 		return f.applyLeaseTimeToLive()
 	default:
@@ -522,7 +662,7 @@ func (f *fsm) applySet(key string, value []byte) interface{} {
 	f.mu.Lock()
 	defer f.mu.Unlock()
 	f.db.Update(func(tx *bolt.Tx) error {
-		bucket := tx.Bucket([]byte(DefaultBucketName))
+		bucket := tx.Bucket([]byte(DefaultKVBucketName))
 		if err := bucket.Put([]byte(key), value); err != nil {
 			log.Fatalln(err)
 			return err
@@ -538,7 +678,7 @@ func (f *fsm) applyDelete(key string) interface{} {
 	f.mu.Lock()
 	defer f.mu.Unlock()
 	f.db.Update(func(tx *bolt.Tx) error {
-		bucket := tx.Bucket([]byte(DefaultBucketName))
+		bucket := tx.Bucket([]byte(DefaultKVBucketName))
 		if err := bucket.Delete([]byte(key)); err != nil {
 			log.Fatalln(err)
 			return err
@@ -550,96 +690,44 @@ func (f *fsm) applyDelete(key string) interface{} {
 	return nil
 }
 
-func (f *fsm) applyLeaseGrant(leaseId uint64, ttl int) interface{} {
+func (f *fsm) applyLeaseGrant(name string, leaseId uint64, ttl int) interface{} {
 	key := fmt.Sprintf("%d", leaseId)
 
 	// 创建子桶
 	if err := f.db.Update(func(tx *bolt.Tx) error {
-		bucket, err := tx.CreateBucketIfNotExists([]byte(key))
+		bucket, err := tx.CreateBucketIfNotExists([]byte(DefaultLeaseBucketName))
 		if err != nil {
 			return err
 		}
 
-		b, err := json.Marshal(LeaseMeta{TTL: ttl})
+		bucket, err = bucket.CreateBucketIfNotExists([]byte(key))
+		if err != nil {
+			return err
+		}
+
+		b, err := json.Marshal(LeaseMeta{Name: name, TTL: ttl, Status: CREATE, Count: 0})
 		if err != nil {
 			return err
 		}
 		// 保存元数据
 		return bucket.Put([]byte("meta"), b)
 	}); err != nil {
-		log.Fatalln(err)
+		log.Println(err)
 		return err
 	}
 
-	f.wg.Wrap(func() {
-		ticker := time.NewTicker(time.Second)
-		defer ticker.Stop()
-
-		var start bool
-		for {
-			var count int
-			select {
-			case <-ticker.C:
-				// 每秒遍历当前桶 所有值TTL--
-				f.db.Update(func(tx *bolt.Tx) error {
-					bucket := tx.Bucket([]byte(key))
-
-					// 判断是否有租客
-					if bucket.Stats().KeyN == 1 {
-						start = false
-					} else if bucket.Stats().KeyN > 1 {
-						start = true
-					}
-
-					cur := bucket.Cursor()
-					for k, v := cur.First(); k != nil; k, v = cur.Next() {
-						// 跳过元数据
-						if string(k) == "meta" {
-							return nil
-						}
-						// key:value => key:[ttl(int32 4bytes)][raw value]
-						ttl := binary.BigEndian.Uint32(v[:4])
-						if ttl > 0 {
-							count = count + 1
-							ttl = ttl - 1
-							// 注意由于bolt的实现机制 遍历中的value原值只可以读 不可以修改 需要先复制再Put
-							b := make([]byte, len(v))
-							copy(b, v)
-							binary.BigEndian.PutUint32(b[:4], uint32(ttl))
-							bucket.Put([]byte(k), b)
-						} else if ttl == 0 {
-							// 删除这个键值对
-							cur.Delete()
-						}
-					}
-					return nil
-				})
-				// 租约已经生效 并且 没有存活的键值 退出该租约 并删除对应的桶
-				if count == 0 && start {
-					log.Printf("%d 租约已经失效", leaseId)
-					f.db.Update(func(tx *bolt.Tx) error {
-						return tx.DeleteBucket([]byte(key))
-					})
-					return
-				}
-				// case exitCh:
-			}
-		}
-	})
-	return leaseId
-}
-
-func (f *fsm) applyLeaseRevoke() interface{} {
 	return nil
 }
 
-func (f *fsm) applyLeaseKeepAlive(leaseId uint64, key string, value []byte) interface{} {
-	var ttl int
-	Id := fmt.Sprintf("%d", leaseId)
+// value是带有ttl头部的值
+func (f *fsm) applyLeaseLoopCheck(leaseId uint64, key string, value []byte) interface{} {
+	var ttl, status, count int
+	var name string
 	err := f.db.View(func(tx *bolt.Tx) error {
-		bucket := tx.Bucket([]byte(Id))
+		bucket := tx.Bucket([]byte(DefaultLeaseBucketName)).Bucket([]byte(fmt.Sprintf("%d", leaseId)))
 		if bucket == nil {
-			return fmt.Errorf("Lease[%s] hash been removed", Id)
+			log.Println("没有找到对应的Lease", leaseId)
+			return fmt.Errorf("Lease[%d] hash been removed", leaseId)
 		}
 
 		b := bucket.Get([]byte("meta"))
@@ -648,28 +736,118 @@ func (f *fsm) applyLeaseKeepAlive(leaseId uint64, key string, value []byte) inte
 		if err != nil {
 			return err
 		}
+		name = meta.Name
 		ttl = meta.TTL
+		status = meta.Status
+		count = meta.Count
 		return nil
 	})
 	if err != nil {
 		return err
 	}
 
-	err = f.db.Update(func(tx *bolt.Tx) error {
-		bucket := tx.Bucket([]byte(Id))
+	if status == DEAD {
+		log.Println("一个已经被撤销的Lease")
+		return nil
+	}
+
+	// Lease仍然有效 改变对应键值对的状态
+	return f.db.Update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(DefaultLeaseBucketName)).Bucket([]byte(fmt.Sprintf("%d", leaseId)))
 		if bucket == nil {
-			return fmt.Errorf("Lease[%s] hash been removed", Id)
+			return fmt.Errorf("Lease[%d] hash been removed", leaseId)
 		}
 
-		b := append(make([]byte, 4), value...)
-		binary.BigEndian.PutUint32(b[:4], uint32(ttl))
-		return bucket.Put([]byte(key), b)
+		newttl := binary.BigEndian.Uint32(value[:4])
+		log.Printf("[%d]状态检测: TTL:%d Now:%d AliveKeys:%d", leaseId, ttl, newttl, count)
+		if newttl > 0 {
+			b := make([]byte, len(value))
+			copy(b, value)
+			binary.BigEndian.PutUint32(b[:4], uint32(newttl))
+			return bucket.Put([]byte(key), b)
+		} else {
+			// 这个键值对已经失效
+			count--
+			b, _ := json.Marshal(LeaseMeta{Name: name, TTL: ttl, Status: ALIVE, Count: count}) // 更新Lease状态
+			bucket.Put([]byte("meta"), b)
+			return bucket.Delete([]byte(fmt.Sprintf("%d", leaseId)))
+		}
+	})
+}
+
+// value是不带有ttl头部的值
+func (f *fsm) applyLeaseKeepAlive(leaseId uint64, key string, value []byte) interface{} {
+	var ttl, status, count int
+	var name string
+	err := f.db.View(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(DefaultLeaseBucketName)).Bucket([]byte(fmt.Sprintf("%d", leaseId)))
+		if bucket == nil {
+			log.Println("没有找到对应的Lease", leaseId)
+			return fmt.Errorf("Lease[%d] hash been removed", leaseId)
+		}
+
+		b := bucket.Get([]byte("meta"))
+		meta := new(LeaseMeta)
+		err := json.Unmarshal(b, meta)
+		if err != nil {
+			return err
+		}
+		name = meta.Name
+		ttl = meta.TTL
+		status = meta.Status
+		count = meta.Count
+		return nil
 	})
 	if err != nil {
 		return err
 	}
 
-	return nil
+	if status == DEAD {
+		log.Println("一个已经被撤销的Lease")
+		return nil
+	}
+
+	// Lease仍然有效 改变对应键值对的状态
+	return f.db.Update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(DefaultLeaseBucketName)).Bucket([]byte(fmt.Sprintf("%d", leaseId)))
+		if bucket == nil {
+			return fmt.Errorf("Lease[%d] hash been removed", leaseId)
+		}
+
+		// 检测这个值是否出现过 TODO 这里有数据竞争
+		var flag bool
+		for _, v := range f.leases[leaseId] {
+			if v == key {
+				flag = true
+				break
+			}
+		}
+		if !flag {
+			count++ // 没有出现过 是一个新值 添加一下
+			f.leases[leaseId] = append(f.leases[leaseId], key)
+		}
+
+		b, _ := json.Marshal(LeaseMeta{Name: name, TTL: ttl, Status: ALIVE, Count: count}) // 更新Lease状态
+		bucket.Put([]byte("meta"), b)
+
+		// 这里是存放新值 value是原数据 没有ttl前缀
+		b = make([]byte, 4+len(value))
+		copy(b[4:], value)
+		binary.BigEndian.PutUint32(b[:4], uint32(ttl))
+		return bucket.Put([]byte(key), b)
+	})
+}
+
+func (f *fsm) applyLeaseRevoke(leaseId uint64) interface{} {
+	return f.db.Update(func(tx *bolt.Tx) error {
+		bucket := tx.Bucket([]byte(DefaultLeaseBucketName)).Bucket([]byte(fmt.Sprintf("%d", leaseId)))
+		if bucket == nil {
+			return fmt.Errorf("Lease[%d] hash been removed", leaseId)
+		}
+		b, _ := json.Marshal(LeaseMeta{Status: DEAD}) // 更新Lease状态
+		bucket.Put([]byte("meta"), b)
+		return tx.Bucket([]byte(DefaultLeaseBucketName)).DeleteBucket([]byte(fmt.Sprintf("%d", leaseId)))
+	})
 }
 
 func (f *fsm) applyLeaseTimeToLive() interface{} {
@@ -711,7 +889,7 @@ func (f *fsm) Restore(rc io.ReadCloser) error {
 	f.db = db
 
 	err = db.Update(func(tx *bolt.Tx) error {
-		_, err := tx.CreateBucketIfNotExists([]byte(DefaultBucketName))
+		_, err := tx.CreateBucketIfNotExists([]byte(DefaultKVBucketName))
 		if err != nil {
 			log.Fatalf("CreateBucketIfNotExists err:%s", err.Error())
 			return err
@@ -725,7 +903,7 @@ func (f *fsm) Restore(rc io.ReadCloser) error {
 	// 用快照中的数据更新状态
 	for k, v := range o {
 		err = db.Batch(func(tx *bolt.Tx) error {
-			bucket := tx.Bucket([]byte(DefaultBucketName))
+			bucket := tx.Bucket([]byte(DefaultKVBucketName))
 			return bucket.Put([]byte(k), v)
 		})
 		if err != nil {