重构数据库备份与恢复模块 (#80)

* fix: 保存 LastResult 时截断字符串过长部分，以避免数据库报错

* refactor: 新增 entity.DbTaskBase 和 persistence.dbTaskBase, 用于实现数据库备份和恢复任务处理相关部分

* fix: aeskey变更后，解密密码出现数组越界访问错误

* fix: 时间属性为零值时，保存到 mysql 数据库报错

* refactor db.infrastructure.service.scheduler

* feat: 实现立即备份功能

* refactor db.infrastructure.service.db_instance

* refactor: 从数据库中获取数据库备份目录、mysql文件路径等配置信息

* fix: 数据库备份和恢复问题

* fix: 修改 .gitignore 文件，忽略数据库备份目录和数据库程序目录

server/internal/db/domain/entity/db_binlog.go

@@ -2,86 +2,34 @@ package entity
 
 import (
 	"mayfly-go/pkg/model"
+	"mayfly-go/pkg/utils/timex"
 	"time"
 )
 
-const BinlogDownloadInterval = time.Minute * 15
-
-var _ DbTask = (*DbBinlog)(nil)
-
 // DbBinlog 数据库备份任务
 type DbBinlog struct {
 	model.Model
 
-	StartTime    time.Time     `gorm:"column(start_time)" json:"startTime"`   // 开始时间: 2023-11-08 02:00:00
-	Interval     time.Duration `gorm:"column(interval)" json:"interval"`      // 间隔时间: 为零表示单次执行，为正表示反复执行
-	Enabled      bool          `gorm:"column(enabled)" json:"enabled"`        // 是否启用
-	LastStatus   TaskStatus    `gorm:"column(last_status)" json:"lastStatus"` // 最近一次执行状态
-	LastResult   string        `gorm:"column(last_result)" json:"lastResult"` // 最近一次执行结果
-	LastTime     time.Time     `gorm:"column(last_time)" json:"lastTime"`     // 最近一次执行时间: 2023-11-08 02:00:00
-	DbInstanceId uint64        `gorm:"column(db_instance_id)" json:"dbInstanceId"`
-	Deadline     time.Time     `gorm:"-" json:"-"`
+	LastStatus   TaskStatus     // 最近一次执行状态
+	LastResult   string         // 最近一次执行结果
+	LastTime     timex.NullTime // 最近一次执行时间
+	DbInstanceId uint64         `json:"dbInstanceId"` // 数据库实例ID
 }
 
-func NewDbBinlog(history *DbBackupHistory) *DbBinlog {
-	binlogTask := &DbBinlog{
-		StartTime:    time.Now(),
-		Enabled:      true,
-		Interval:     BinlogDownloadInterval,
-		DbInstanceId: history.DbInstanceId,
-		LastTime:     time.Now(),
-	}
-	binlogTask.Id = binlogTask.DbInstanceId
+func NewDbBinlog(instanceId uint64) *DbBinlog {
+	binlogTask := &DbBinlog{}
+	binlogTask.Id = instanceId
+	binlogTask.DbInstanceId = instanceId
 	return binlogTask
 }
 
-func (d *DbBinlog) TableName() string {
-	return "t_db_binlog"
-}
+// BinlogFile is the metadata of the MySQL binlog file.
+type BinlogFile struct {
+	Name string
+	Size int64
 
-func (d *DbBinlog) GetId() uint64 {
-	if d == nil {
-		return 0
-	}
-	return d.Id
-}
-
-func (d *DbBinlog) GetDeadline() time.Time {
-	return d.Deadline
-}
-
-func (d *DbBinlog) Schedule() bool {
-	if !d.Enabled {
-		return false
-	}
-	switch d.LastStatus {
-	case TaskSuccess:
-		if d.Interval == 0 {
-			return false
-		}
-		lastTime := d.LastTime
-		if d.LastTime.Sub(d.StartTime) < 0 {
-			lastTime = d.StartTime.Add(-d.Interval)
-		}
-		d.Deadline = lastTime.Add(d.Interval - d.LastTime.Sub(d.StartTime)%d.Interval)
-	case TaskFailed:
-		d.Deadline = time.Now().Add(time.Minute)
-	default:
-		d.Deadline = d.StartTime
-	}
-	return true
-}
-
-func (d *DbBinlog) IsFinished() bool {
-	return false
-}
-
-func (d *DbBinlog) Update(task DbTask) bool {
-	switch t := task.(type) {
-	case *DbBinlog:
-		d.StartTime = t.StartTime
-		d.Interval = t.Interval
-		return true
-	}
-	return false
+	// Sequence is parsed from Name and is for the sorting purpose.
+	Sequence       int64
+	FirstEventTime time.Time
+	Downloaded     bool
 }