func NewHashSelector() PumpSelector {
	return &HashSelector{
		Pumps: make([]*PumpStatus, 0, 10),
	}
}
NewHashSelector returns a new HashSelector.
package client
import (
	"sync"
	"github.com/pingcap/log"
	pb "github.com/pingcap/tipb/go-binlog"
	"go.uber.org/zap"
)
const (
	Range = "range"
	Hash = "hash"
	Score = "score"
	LocalUnix = "local unix"
)
var (
	tsMap = make(map[int64]*PumpStatus)
	selectorLock sync.RWMutex
)
type PumpSelector interface {
	SetPumps([]*PumpStatus)
	Select(binlog *pb.Binlog, retryTime int) *PumpStatus
	Feedback(startTS int64, binlogType pb.BinlogType, pump *PumpStatus)
}
type HashSelector struct {
	Pumps []*PumpStatus
}