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本文主要研究一下dbsync的Schedulable
Schedulable
//Schedulable represent an abstraction that can be schedule
type Schedulable struct {
URL string
ID string
*contract.Sync
Schedule *contract.Schedule
Status string
status uint32
}
//NewSchedulableFromURL create a new scheduleable from URL
func NewSchedulableFromURL(URL string) (*Schedulable, error) {
result := &Schedulable{}
resource := url.NewResource(URL)
err := resource.Decode(result)
return result, err
}
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Schedulable定义了URL、ID、*contract.Sync、Schedule、Status、status属性;NewSchedulableFromURL方法根据URL来创建Schedulable
Clone
func (s *Schedulable) Clone() *Schedulable {
return &Schedulable{
URL: s.URL,
ID: s.ID,
Sync: s.Sync.Clone(),
Schedule: s.Schedule,
Status: s.Status,
}
}
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Clone方法会复制一份Schedulable
Done
//Done return true if schedulable is not running
func (s *Schedulable) Done() {
atomic.StoreUint32(&s.status, statusScheduled)
}
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Done方法更新status为statusScheduled
IsRunning
//IsRunning return true if schedulable is running
func (s *Schedulable) IsRunning() bool {
return atomic.LoadUint32(&s.status) == statusRunning
}
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IsRunning方法更新status为statusRunning
ScheduleNexRun
//ScheduleNexRun schedules next run
func (s *Schedulable) ScheduleNexRun(baseTime time.Time) error {
return s.Schedule.Next(baseTime)
}
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ScheduleNexRun方法执行Schedule.Next(baseTime)
Init
//Init initializes scheduleable
func (s *Schedulable) Init() error {
if s.ID == "" {
s.ID = uRLToID(s.URL)
}
now := time.Now()
if s.Schedule == nil {
return nil
}
if s.Schedule.Frequency != nil && s.Schedule.Frequency.Value == 0 {
s.Schedule.Frequency.Value = 1
}
if s.Schedule.NextRun == nil {
if s.Schedule.Frequency != nil {
s.Schedule.NextRun = &now
} else {
return s.Schedule.Next(now)
}
}
return nil
}
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Init方法执行Schedulable的初始化
Validate
//Validate checks if Schedulable is valid
func (s *Schedulable) Validate() error {
if s.Schedule == nil {
return fmt.Errorf("schedule was emtpy")
}
if s.Schedule.Frequency == nil && s.Schedule.At == nil {
return fmt.Errorf("schedule.Frequency and schedule.At were emtpy")
}
if s.ID == "" {
return fmt.Errorf("ID were emtpy")
}
return nil
}
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Validate方法校验Schedule、Schedule.Frequency、Schedule.At、ID值
小结
dbsync的Schedulable定义了URL、ID、*contract.Sync、Schedule、Status、status属性,它提供了Clone、Done、IsRunning、ScheduleNexRun、Init、Validate方法。