i6000-pusher/cmd/i6000pusher/timerangegen.go

package main

import (
	"context"
	log "github.com/sirupsen/logrus"
	"time"
)

type TimeRange struct {
	begin time.Time
	end   time.Time
}

func (tr TimeRange) SimpleString() string {
	return "[" + tr.begin.Format("15:04:05") + "-" + tr.end.Format("15:04:05") + ")"
}

type TimeRangeGen struct {
	lastGenTimeUpper         time.Time
	upperTimeDurationFromNow time.Duration
	timeRangeChannel         chan TimeRange
	minRangeDuration         time.Duration
	maxRangeDuration         time.Duration
	cancel                   context.CancelFunc
	logger                   *log.Entry
}

func NewTimeRangeGen(upperTimeDurationFromNow time.Duration, trRangeCh chan TimeRange, lastGenTimeUpper time.Time, minRangeDuration time.Duration,
	maxRangeDuration time.Duration) *TimeRangeGen {
	logger := log.WithFields(log.Fields{"loggerName": "TimeRangeGen"})
	return &TimeRangeGen{
		upperTimeDurationFromNow: upperTimeDurationFromNow,
		lastGenTimeUpper:         lastGenTimeUpper,
		minRangeDuration:         minRangeDuration,
		maxRangeDuration:         maxRangeDuration,
		logger:                   logger,
		timeRangeChannel:         trRangeCh,
	}
}

func (tr *TimeRangeGen) start(parentContext context.Context) {
	ctx, cancel := context.WithCancel(parentContext)
	tr.cancel = cancel
	go tr.startGen(ctx)
	tr.logger.Infof("started")
}

func (tr *TimeRangeGen) startGen(ctx context.Context) {
	tm := time.NewTicker(1 * time.Second)
forLoop:
	for {
		select {
		case <-ctx.Done():
			tr.logger.Infof("stop signal received, quit")
			break forLoop
		case <-tm.C:
			tr.checkGenTimeRange()
		}
	}
}

func (tr *TimeRangeGen) stop() {
	tr.logger.Infof("stopping")
	tr.cancel()
	tr.logger.Infof("stoped")
}

func (tr *TimeRangeGen) checkGenTimeRange() {
	now := time.Now()
	upper := now.Add(-tr.upperTimeDurationFromNow)
	range2Gen := upper.Sub(tr.lastGenTimeUpper)
	if range2Gen < tr.minRangeDuration {
		tr.logger.Debugf("%v < %v, skip gen", range2Gen, tr.minRangeDuration)
		return
	}
	tr.logger.Debugf("start check gen time range in [%v, %v)", tr.lastGenTimeUpper, upper)
	for i := tr.lastGenTimeUpper; i.Before(upper); i = i.Add(tr.maxRangeDuration) {
		end := i.Add(tr.minRangeDuration)
		if end.After(upper) {
			end = upper
		}
		tr.timeRangeChannel <- TimeRange{begin: i, end: end}
		tr.lastGenTimeUpper = end
	}
}