16.2 太牛了！分库分表和智能分片竟然还能这样实现？在分布式任务调度系统中，随着业务规模的增长，单一数据库往往无法满足海量数据存储和高并发访问的需求。分库分表技术是解决这一问题的关键手段。今天我们将深入探讨如何实现分库分表和智能分片策略。分库分表架构设计分库分表是一种将数据分散存储在多个数据库和表中的技术，能够有效提升系统的存储容量和并发处理能力。packageshardingimport("database/sql""fmt""hash/crc32""math""sort""strconv""strings""sync""time")// ShardingConfig 分库分表配置typeShardingConfigstruct{DatabaseCountintTableCountintShardingKeystringShardingType ShardingType DatabasePrefixstringTablePrefixstring}// ShardingType 分片类型typeShardingTypeintconst(ShardingTypeMod ShardingType=iota// 取模分片ShardingTypeRange// 范围分片ShardingTypeHash// 哈希分片)// ShardingManager 分库分表管理器typeShardingManagerstruct{config*ShardingConfig databasesmap[string]*sql.DB mutex sync.RWMutex router*ShardingRouter}// ShardingRouter 分片路由typeShardingRouterstruct{config*ShardingConfig}// NewShardingManager 创建分库分表管理器funcNewShardingManager(config*ShardingConfig)*ShardingManager{router:=ShardingRouter{config:config,}returnShardingManager{config:config,databases:make(map[string]*sql.DB),router:router,}}// AddDatabase 添加数据库连接func(sm*ShardingManager)AddDatabase(dbNamestring,db*sql.DB){sm.mutex.Lock()defersm.mutex.Unlock()sm.databases[dbName]=db}// GetDatabase 获取数据库连接func(sm*ShardingManager)GetDatabase(dbIndexint)(*sql.DB,error){sm.mutex.RLock()defersm.mutex.RUnlock()dbName:=fmt.Sprintf("%s_%d",sm.config.DatabasePrefix,dbIndex)db,exists:=sm.databases[dbName]if!exists{returnnil,fmt.Errorf("database %s not found",dbName)}returndb,nil}// Route 路由分片func(sm*ShardingManager)Route(shardingValueinterface{})(*ShardLocation,error){returnsm.router.Route(shardingValue)}// ShardLocation 分片位置typeShardLocationstruct{DatabaseIndexintTableIndexintDatabaseNamestringTableNamestring}// Route 路由分片func(sr*ShardingRouter)Route(shardingValueinterface{})(*ShardLocation,error){vardbIndex,tableIndexintswitchsr.config.ShardingType{caseShardingTypeMod:dbIndex,tableIndex=sr.modSharding(shardingValue)caseShardingTypeRange:dbIndex,tableIndex=sr.rangeSharding(shardingValue)caseShardingTypeHash:dbIndex,tableIndex=sr.hashSharding(shardingValue)default:returnnil,fmt.Errorf("unsupported sharding type: %v",sr.config.ShardingType)}location:=ShardLocation{DatabaseIndex:dbIndex,TableIndex:tableIndex,DatabaseName:fmt.Sprintf("%s_%d",sr.config.DatabasePrefix,dbIndex),TableName:fmt.Sprintf("%s_%d",sr.config.TablePrefix,tableIndex),}returnlocation,nil}// modSharding 取模分片func(sr*ShardingRouter)modSharding(shardingValueinterface{})(int,int){// 将分片值转换为整数varvalueint64switchv:=shardingValue.(type){caseint:value=int64(v)caseint64:value=vcasestring:// 对字符串进行哈希value=int64(crc32.ChecksumIEEE([]byte(v)))default:// 默认使用字符串表示value=int64(crc32.ChecksumIEEE([]byte(fmt.Sprintf("%v",v))))}// 计算数据库和表索引dbIndex:=int(value%int64(sr.config.DatabaseCount))tableIndex:=int((value/int64(sr.config.DatabaseCount))%int64(sr.config.TableCount))returndbIndex,tableIndex}// rangeSharding 范围分片func(sr*ShardingRouter)rangeSharding(shardingValueinterface{})(int,int){varvalueint64switchv:=shardingValue.(type){caseint:value=int64(v)caseint64:value=vcasestring:// 尝试解析为整数ifi,err:=strconv.ParseInt(v,10,64);err==nil{value=i}else{// 否则使用哈希value=int64(crc32.ChecksumIEEE([]byte(v)))}default:// 默认使用字符串表示ifs,ok:=v.(fmt.Stringer);ok{ifi,err:=strconv.ParseInt(s.String(),10,64);err==nil{value=i}else{value=int64(crc32.ChecksumIEEE([]byte(s.String())))}}else{value=int64(crc32.ChecksumIEEE([]byte(fmt.Sprintf