rename pacakge

weed/cluster/cluster.go

@@ -0,0 +1,207 @@
+package cluster
+
+import (
+	"github.com/chrislusf/seaweedfs/weed/pb"
+	"github.com/chrislusf/seaweedfs/weed/pb/master_pb"
+	"math"
+	"sync"
+	"time"
+)
+
+type ClusterNode struct {
+	Address   pb.ServerAddress
+	Version   string
+	counter   int
+	createdTs time.Time
+}
+
+type Leaders struct {
+	leaders [3]pb.ServerAddress
+}
+
+type Cluster struct {
+	nodes     map[pb.ServerAddress]*ClusterNode
+	nodesLock sync.RWMutex
+	leaders   *Leaders
+}
+
+func NewCluster() *Cluster {
+	return &Cluster{
+		nodes:   make(map[pb.ServerAddress]*ClusterNode),
+		leaders: &Leaders{},
+	}
+}
+
+func (cluster *Cluster) AddClusterNode(nodeType string, address pb.ServerAddress, version string) []*master_pb.KeepConnectedResponse {
+	switch nodeType {
+	case "filer":
+		cluster.nodesLock.Lock()
+		defer cluster.nodesLock.Unlock()
+		if existingNode, found := cluster.nodes[address]; found {
+			existingNode.counter++
+			return nil
+		}
+		cluster.nodes[address] = &ClusterNode{
+			Address:   address,
+			Version:   version,
+			counter:   1,
+			createdTs: time.Now(),
+		}
+		return cluster.ensureLeader(true, nodeType, address)
+	case "master":
+	}
+	return nil
+}
+
+func (cluster *Cluster) RemoveClusterNode(nodeType string, address pb.ServerAddress) []*master_pb.KeepConnectedResponse {
+	switch nodeType {
+	case "filer":
+		cluster.nodesLock.Lock()
+		defer cluster.nodesLock.Unlock()
+		if existingNode, found := cluster.nodes[address]; !found {
+			return nil
+		} else {
+			existingNode.counter--
+			if existingNode.counter <= 0 {
+				delete(cluster.nodes, address)
+				return cluster.ensureLeader(false, nodeType, address)
+			}
+		}
+	case "master":
+	}
+	return nil
+}
+
+func (cluster *Cluster) ListClusterNode(nodeType string) (nodes []*ClusterNode) {
+	switch nodeType {
+	case "filer":
+		cluster.nodesLock.RLock()
+		defer cluster.nodesLock.RUnlock()
+		for _, node := range cluster.nodes {
+			nodes = append(nodes, node)
+		}
+	case "master":
+	}
+	return
+}
+
+func (cluster *Cluster) IsOneLeader(address pb.ServerAddress) bool {
+	return cluster.leaders.isOneLeader(address)
+}
+
+func (cluster *Cluster) ensureLeader(isAdd bool, nodeType string, address pb.ServerAddress) (result []*master_pb.KeepConnectedResponse) {
+	if isAdd {
+		if cluster.leaders.addLeaderIfVacant(address) {
+			// has added the address as one leader
+			result = append(result, &master_pb.KeepConnectedResponse{
+				ClusterNodeUpdate: &master_pb.ClusterNodeUpdate{
+					NodeType: nodeType,
+					Address:  string(address),
+					IsLeader: true,
+					IsAdd:    true,
+				},
+			})
+		} else {
+			result = append(result, &master_pb.KeepConnectedResponse{
+				ClusterNodeUpdate: &master_pb.ClusterNodeUpdate{
+					NodeType: nodeType,
+					Address:  string(address),
+					IsLeader: false,
+					IsAdd:    true,
+				},
+			})
+		}
+	} else {
+		if cluster.leaders.removeLeaderIfExists(address) {
+
+			result = append(result, &master_pb.KeepConnectedResponse{
+				ClusterNodeUpdate: &master_pb.ClusterNodeUpdate{
+					NodeType: nodeType,
+					Address:  string(address),
+					IsLeader: true,
+					IsAdd:    false,
+				},
+			})
+
+			// pick the freshest one, since it is less likely to go away
+			var shortestDuration int64 = math.MaxInt64
+			now := time.Now()
+			var candidateAddress pb.ServerAddress
+			for _, node := range cluster.nodes {
+				if cluster.leaders.isOneLeader(node.Address) {
+					continue
+				}
+				duration := now.Sub(node.createdTs).Nanoseconds()
+				if duration < shortestDuration {
+					shortestDuration = duration
+					candidateAddress = node.Address
+				}
+			}
+			if candidateAddress != "" {
+				cluster.leaders.addLeaderIfVacant(candidateAddress)
+				// added a new leader
+				result = append(result, &master_pb.KeepConnectedResponse{
+					ClusterNodeUpdate: &master_pb.ClusterNodeUpdate{
+						NodeType: nodeType,
+						Address:  string(candidateAddress),
+						IsLeader: true,
+						IsAdd:    true,
+					},
+				})
+			}
+		} else {
+			result = append(result, &master_pb.KeepConnectedResponse{
+				ClusterNodeUpdate: &master_pb.ClusterNodeUpdate{
+					NodeType: nodeType,
+					Address:  string(address),
+					IsLeader: false,
+					IsAdd:    false,
+				},
+			})
+		}
+	}
+	return
+}
+
+func (leaders *Leaders) addLeaderIfVacant(address pb.ServerAddress) (hasChanged bool) {
+	if leaders.isOneLeader(address) {
+		return
+	}
+	for i := 0; i < len(leaders.leaders); i++ {
+		if leaders.leaders[i] == "" {
+			leaders.leaders[i] = address
+			hasChanged = true
+			return
+		}
+	}
+	return
+}
+func (leaders *Leaders) removeLeaderIfExists(address pb.ServerAddress) (hasChanged bool) {
+	if !leaders.isOneLeader(address) {
+		return
+	}
+	for i := 0; i < len(leaders.leaders); i++ {
+		if leaders.leaders[i] == address {
+			leaders.leaders[i] = ""
+			hasChanged = true
+			return
+		}
+	}
+	return
+}
+func (leaders *Leaders) isOneLeader(address pb.ServerAddress) bool {
+	for i := 0; i < len(leaders.leaders); i++ {
+		if leaders.leaders[i] == address {
+			return true
+		}
+	}
+	return false
+}
+func (leaders *Leaders) GetLeaders() (addresses []pb.ServerAddress) {
+	for i := 0; i < len(leaders.leaders); i++ {
+		if leaders.leaders[i] != "" {
+			addresses = append(addresses, leaders.leaders[i])
+		}
+	}
+	return
+}