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

database/database.go

@@ -33,6 +33,10 @@ type DB struct {
 	// use this mutex for complicated command only, eg. rpush, incr ...
 	locker *lock.Locks
 	addAof func(CmdLine)
+
+	// callbacks
+	insertCallback database.KeyEventCallback
+	deleteCallback database.KeyEventCallback
 }
 
 // ExecFunc is interface for command executor
@@ -165,7 +169,13 @@ func (db *DB) GetEntity(key string) (*database.DataEntity, bool) {
 
 // PutEntity a DataEntity into DB
 func (db *DB) PutEntity(key string, entity *database.DataEntity) int {
-	return db.data.Put(key, entity)
+	ret := db.data.Put(key, entity)
+	// db.insertCallback may be set as nil, during `if` and actually callback
+	// so introduce a local variable `cb`
+	if cb := db.insertCallback; ret > 0 && cb != nil {
+		cb(db.index, key, entity)
+	}
+	return ret
 }
 
 // PutIfExists edit an existing DataEntity
@@ -175,15 +185,28 @@ func (db *DB) PutIfExists(key string, entity *database.DataEntity) int {
 
 // PutIfAbsent insert an DataEntity only if the key not exists
 func (db *DB) PutIfAbsent(key string, entity *database.DataEntity) int {
-	return db.data.PutIfAbsent(key, entity)
+	ret := db.data.PutIfAbsent(key, entity)
+	// db.insertCallback may be set as nil, during `if` and actually callback
+	// so introduce a local variable `cb`
+	if cb := db.insertCallback; ret > 0 && cb != nil {
+		cb(db.index, key, entity)
+	}
+	return ret
 }
 
 // Remove the given key from db
 func (db *DB) Remove(key string) {
-	db.data.Remove(key)
+	raw, deleted := db.data.Remove(key)
 	db.ttlMap.Remove(key)
 	taskKey := genExpireTask(key)
 	timewheel.Cancel(taskKey)
+	if cb := db.deleteCallback; cb != nil {
+		var entity *database.DataEntity
+		if deleted > 0 {
+			entity = raw.(*database.DataEntity)
+		}
+		cb(db.index, key, entity)
+	}
 }
 
 // Removes the given keys from db

database/hash.go

@@ -149,7 +149,7 @@ func execHDel(db *DB, args [][]byte) redis.Reply {
 
 	deleted := 0
 	for _, field := range fields {
-		result := dict.Remove(field)
+		_, result := dict.Remove(field)
 		deleted += result
 	}
 	if dict.Len() == 0 {

database/server.go

@@ -30,6 +30,10 @@ type Server struct {
 	role         int32
 	slaveStatus  *slaveStatus
 	masterStatus *masterStatus
+
+	// hooks
+	insertCallback database.KeyEventCallback
+	deleteCallback database.KeyEventCallback
 }
 
 // NewStandaloneServer creates a standalone redis server, with multi database and all other funtions
@@ -247,6 +251,20 @@ func (server *Server) ForEach(dbIndex int, cb func(key string, data *database.Da
 	server.mustSelectDB(dbIndex).ForEach(cb)
 }
 
+// GetEntity returns the data entity to the given key
+func (server *Server) GetEntity(dbIndex int, key string) (*database.DataEntity, bool) {
+	return server.mustSelectDB(dbIndex).GetEntity(key)
+}
+
+func (server *Server) GetExpiration(dbIndex int, key string) *time.Time {
+	raw, ok := server.mustSelectDB(dbIndex).ttlMap.Get(key)
+	if !ok {
+		return nil
+	}
+	expireTime, _ := raw.(time.Time)
+	return &expireTime
+}
+
 // ExecMulti executes multi commands transaction Atomically and Isolated
 func (server *Server) ExecMulti(conn redis.Connection, watching map[string]uint32, cmdLines []CmdLine) redis.Reply {
 	selectedDB, errReply := server.selectDB(conn.GetDBIndex())
@@ -349,3 +367,20 @@ func (server *Server) startReplCron() {
 		}
 	}(server)
 }
+
+func (server *Server) SetKeyInsertedCallback(cb database.KeyEventCallback) {
+	server.insertCallback = cb
+	for i := range server.dbSet {
+		db := server.mustSelectDB(i)
+		db.insertCallback = cb
+	}
+
+}
+
+func (server *Server) SetKeyDeletedCallback(cb database.KeyEventCallback) {
+	server.deleteCallback = cb
+	for i := range server.dbSet {
+		db := server.mustSelectDB(i)
+		db.deleteCallback = cb
+	}
+}