fix: 机器文件下载问题修复&dbm重构

server/internal/db/dbm/dbm.go

@@ -0,0 +1,115 @@
+package dbm
+
+import (
+	"fmt"
+	"mayfly-go/internal/common/consts"
+	"mayfly-go/internal/db/dbm/dbi"
+	"mayfly-go/internal/db/dbm/dm"
+	"mayfly-go/internal/db/dbm/mysql"
+	"mayfly-go/internal/db/dbm/postgres"
+	"mayfly-go/internal/machine/mcm"
+	"mayfly-go/pkg/cache"
+	"mayfly-go/pkg/logx"
+	"sync"
+	"time"
+)
+
+// 客户端连接缓存，指定时间内没有访问则会被关闭, key为数据库连接id
+var connCache = cache.NewTimedCache(consts.DbConnExpireTime, 5*time.Second).
+	WithUpdateAccessTime(true).
+	OnEvicted(func(key any, value any) {
+		logx.Info(fmt.Sprintf("删除db连接缓存 id = %s", key))
+		value.(*dbi.DbConn).Close()
+	})
+
+func init() {
+	mcm.AddCheckSshTunnelMachineUseFunc(func(machineId int) bool {
+		// 遍历所有db连接实例，若存在db实例使用该ssh隧道机器，则返回true，表示还在使用中...
+		items := connCache.Items()
+		for _, v := range items {
+			if v.Value.(*dbi.DbConn).Info.SshTunnelMachineId == machineId {
+				return true
+			}
+		}
+		return false
+	})
+}
+
+var mutex sync.Mutex
+
+func getDbMetaByType(dt dbi.DbType) dbi.Meta {
+	switch dt {
+	case dbi.DbTypeMysql, dbi.DbTypeMariadb:
+		return mysql.GetMeta()
+	case dbi.DbTypePostgres:
+		return postgres.GetMeta()
+	case dbi.DbTypeDM:
+		return dm.GetMeta()
+	default:
+		panic(fmt.Sprintf("invalid database type: %s", dt))
+	}
+}
+
+// 从缓存中获取数据库连接信息，若缓存中不存在则会使用回调函数获取dbInfo进行连接并缓存
+func GetDbConn(dbId uint64, database string, getDbInfo func() (*dbi.DbInfo, error)) (*dbi.DbConn, error) {
+	connId := GetDbConnId(dbId, database)
+
+	// connId不为空，则为需要缓存
+	needCache := connId != ""
+	if needCache {
+		load, ok := connCache.Get(connId)
+		if ok {
+			return load.(*dbi.DbConn), nil
+		}
+	}
+
+	mutex.Lock()
+	defer mutex.Unlock()
+
+	// 若缓存中不存在，则从回调函数中获取DbInfo
+	dbInfo, err := getDbInfo()
+	if err != nil {
+		return nil, err
+	}
+
+	// 连接数据库
+	dbConn, err := Conn(dbInfo)
+	if err != nil {
+		return nil, err
+	}
+
+	if needCache {
+		connCache.Put(connId, dbConn)
+	}
+	return dbConn, nil
+}
+
+// 使用指定dbInfo信息进行连接
+func Conn(di *dbi.DbInfo) (*dbi.DbConn, error) {
+	return di.Conn(getDbMetaByType(di.Type))
+}
+
+// 根据实例id获取连接
+func GetDbConnByInstanceId(instanceId uint64) *dbi.DbConn {
+	for _, connItem := range connCache.Items() {
+		conn := connItem.Value.(*dbi.DbConn)
+		if conn.Info.InstanceId == instanceId {
+			return conn
+		}
+	}
+	return nil
+}
+
+// 删除db缓存并关闭该数据库所有连接
+func CloseDb(dbId uint64, db string) {
+	connCache.Delete(GetDbConnId(dbId, db))
+}
+
+// 获取连接id
+func GetDbConnId(dbId uint64, db string) string {
+	if dbId == 0 {
+		return ""
+	}
+
+	return fmt.Sprintf("%d:%s", dbId, db)
+}