func (t *DelayRecent) Init(interval int, bucketSize int, bucketNum int) {
	t.currTime = time.Now()
	t.currTime = t.currTime.Truncate(time.Duration(interval) * time.Second)
	t.interval = interval
	t.current.Init(bucketSize, bucketNum)
	t.past.Init(bucketSize, bucketNum)
}
Init initializes delay table

Params:
- interval: interval for move current to past
- bucketSize: size of each delay bucket, e.g., 1(ms) or 2(ms)
- number of bucket
package delay_counter
import (
	"bytes"
	"encoding/json"
	"fmt"
	"sync"
	"time"
)
import (
	"github.com/baidu/go-lib/web-monitor/module_state2"
	"github.com/baidu/go-lib/web-monitor/web_params"
)
type DelayRecent struct {
	lock sync.Mutex
	interval int  
	currTime time.Time
	current  DelaySummary  
	pastTime time.Time
	past     DelaySummary  
	KeyPrefix   string  
	ProgramName string  
}
type DelayOutput struct {
	Interval    int
	KeyPrefix   string
	ProgramName string
	CurrTime string
	Current  DelaySummary
	PastTime string
	Past     DelaySummary
}