schastsp/util/timeid/timeid.go

51 lines
1.1 KiB
Go

package timeid
import (
"math"
"time"
)
/* (1) Generates the current time id
*
* @wsize<float64> Window Size in seconds
*
* @return id<uint32> Current time id
* @return parity<uint32> Current time parity
*
---------------------------------------------------------*/
func Generate(wsize float64) (uint32, uint32){
/* (1) If wsize is 0 (div by zero possible error) */
if wsize == 0 { return 0, 0 }
/* (2) Get current timestamp */
timestamp := float64( time.Now().Unix() );
/* (3) Calculate the time id */
var id = uint32( timestamp / wsize );
/* (4) Calculate parity */
var parity = id % 2;
return id, parity;
}
/* (2) Try to guess a previous time id from its parity
*
* @wsize<float64> Window Size in seconds
* @parity<uint32> Received parity
*
* @return id<uint32> The guessed time id
*
---------------------------------------------------------*/
func Guess(wsize float64, parity uint32) uint32{
/* (1) Get current time id */
var idNow, parityNow = Generate(wsize);
/* (2) Update ID with tidNow parity difference */
return idNow - uint32(math.Abs( float64(parityNow) - float64(parity) ));
}