package kafkatimer
  
  import (
  	"sync"
  	"time"
  )
  
  // truncate returns the result of rounding x toward zero to a multiple of m.
  // If m <= 0, Truncate returns x unchanged.
  func truncate(x, m int64) int64 {
  	if m <= 0 {
  		return x
  	}
  	return x - x%m
  }
  
  // timeToMs returns an integer number, which represents t in milliseconds.
  func timeToMs(t time.Time) int64 {
  	return t.UnixNano() / int64(time.Millisecond)
  }
  
  // msToTime returns the UTC time corresponding to the given Unix time,
  // t milliseconds since January 1, 1970 UTC.
  func msToTime(t int64) time.Time {
  	return time.Unix(0, t*int64(time.Millisecond)).UTC()
  }
  
  type waitGroupWrapper struct {
  	sync.WaitGroup
  }
  
  func (w *waitGroupWrapper) Wrap(cb func()) {
  	w.Add(1)
  	go func() {
  		cb()
  		w.Done()
  	}()
  }