raft cluster

wip: raft does not care about migrating

wip: optimize code

wip: raft election

wip

wip: fix raft leader missing log entries

wip

fix a dead lock

batch set slot route

wip: raft persist

wip

refactor cluster suite

remove relay

rename relay2

refactor: allow customizing client factory

test raft

refactor re-balance

avoid errors caused by inconsistent status on follower nodes during raft commits

test raft election

cluster/topo_utils.go

@@ -0,0 +1,99 @@
+package cluster
+
+import (
+	"github.com/hdt3213/godis/datastruct/set"
+	"github.com/hdt3213/godis/lib/utils"
+	"github.com/hdt3213/godis/redis/connection"
+)
+
+func (cluster *Cluster) isImportedKey(key string) bool {
+	slotId := getSlot(key)
+	cluster.slotMu.RLock()
+	slot := cluster.slots[slotId]
+	cluster.slotMu.RUnlock()
+	return slot.importedKeys.Has(key)
+}
+
+func (cluster *Cluster) setImportedKey(key string) {
+	slotId := getSlot(key)
+	cluster.slotMu.Lock()
+	slot := cluster.slots[slotId]
+	cluster.slotMu.Unlock()
+	slot.importedKeys.Add(key)
+}
+
+// initSlot init a slot when start as seed or import slot from other node
+func (cluster *Cluster) initSlot(slotId uint32, state uint32) {
+	cluster.slotMu.Lock()
+	defer cluster.slotMu.Unlock()
+	cluster.slots[slotId] = &hostSlot{
+		importedKeys: set.Make(),
+		keys:         set.Make(),
+		state:        state,
+	}
+}
+
+func (cluster *Cluster) getHostSlot(slotId uint32) *hostSlot {
+	cluster.slotMu.RLock()
+	defer cluster.slotMu.RUnlock()
+	return cluster.slots[slotId]
+}
+
+func (cluster *Cluster) finishSlotImport(slotID uint32) {
+	cluster.slotMu.Lock()
+	defer cluster.slotMu.Unlock()
+	slot := cluster.slots[slotID]
+	slot.state = slotStateHost
+	slot.importedKeys = nil
+	slot.oldNodeID = ""
+}
+
+func (cluster *Cluster) setLocalSlotImporting(slotID uint32, oldNodeID string) {
+	cluster.slotMu.Lock()
+	defer cluster.slotMu.Unlock()
+	slot := cluster.slots[slotID]
+	if slot == nil {
+		slot = &hostSlot{
+			importedKeys: set.Make(),
+			keys:         set.Make(),
+		}
+		cluster.slots[slotID] = slot
+	}
+	slot.state = slotStateImporting
+	slot.oldNodeID = oldNodeID
+}
+
+func (cluster *Cluster) setSlotMovingOut(slotID uint32, newNodeID string) {
+	cluster.slotMu.Lock()
+	defer cluster.slotMu.Unlock()
+	slot := cluster.slots[slotID]
+	if slot == nil {
+		slot = &hostSlot{
+			importedKeys: set.Make(),
+			keys:         set.Make(),
+		}
+		cluster.slots[slotID] = slot
+	}
+	slot.state = slotStateMovingOut
+	slot.newNodeID = newNodeID
+}
+
+// cleanDroppedSlot deletes keys when slot has moved out or failed to import
+func (cluster *Cluster) cleanDroppedSlot(slotID uint32) {
+	cluster.slotMu.RLock()
+	if cluster.slots[slotID] == nil {
+		cluster.slotMu.RUnlock()
+		return
+	}
+	keys := cluster.slots[slotID].importedKeys
+	cluster.slotMu.RUnlock()
+	c := connection.NewFakeConn()
+	go func() {
+		if keys != nil {
+			keys.ForEach(func(key string) bool {
+				cluster.db.Exec(c, utils.ToCmdLine("DEL", key))
+				return true
+			})
+		}
+	}()
+}