scheduler

type ScheduleItem struct {
	TaskID      int64 // used as the param in the hook
	SrcResource *model.Resource
	DstResource *model.Resource
}

type ScheduleResult struct {
	TaskID int64
	JobID  string
	Error  error
}

type Scheduler interface {
	// Preprocess the resources and returns the item list that can be scheduled
	Preprocess([]*model.Resource, []*model.Resource) ([]*ScheduleItem, error)
	// Schedule the items. If got error when scheduling one of the items,
	// the error should be put in the corresponding ScheduleResult and the
	// returning error of this function should be nil
	Schedule([]*ScheduleItem) ([]*ScheduleResult, error)
	// Stop the job specified by ID
	Stop(id string) error
}