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Random\Engine\Xoshiro256StarStar::jumpLong

(PHP 8 >= 8.2.0)

Random\Engine\Xoshiro256StarStar::jumpLongEfficiently move the engine ahead by 2^192 steps

Beschreibung

public Random\Engine\Xoshiro256StarStar::jumpLong(): void

Moves the algorithm’s state ahead by 2192 steps, as if Random\Engine\Xoshiro256StarStar::generate() was called 2192 times.

The purpose of a long jump is to facilitate the creation of a new Random\Engine\Xoshiro256StarStar engine from an existing seeded Random\Engine\Xoshiro256StarStar engine. The seeded engine acts as a blueprint, which can be cloned and repeatedly jumped to create 264 non-overlapping sequences with 2192 values each.

Long jumping may be combined with Random\Engine\Xoshiro256StarStar::jump()ing to further split each of the 264 sequences generated by long jumping, into 264 sequences of 2128 values each.

Parameter-Liste

Diese Funktion besitzt keine Parameter.

Rückgabewerte

Es wird kein Wert zurückgegeben.

Beispiele

Beispiel #1 Random\Engine\Xoshiro256StarStar::jumpLong() example

<?php
$blueprintRng
= new \Random\Engine\Xoshiro256StarStar(0);

// Each parent engine will have its own chunk of 2**192 values.
$parent1 = clone $blueprintRng;
$blueprintRng->jumpLong();

$parent2 = clone $blueprintRng;
$blueprintRng->jumpLong();

// Each of the child engines will have its own chunk of 2**128 values
// taken from their parent engine’s chunk of 2**192 values.
$child1a = clone $parent1;
$parent1->jump();
$child1b = clone $parent1;
$parent1->jump();

$child2a = clone $parent2;
$parent2->jump();
$child2b = clone $parent2;
$parent2->jump();

echo
"Child 1A: ", bin2hex( $child1a->generate() ), "\n";
echo
"Child 1B: ", bin2hex( $child1b->generate() ), "\n";
echo
"Child 2A: ", bin2hex( $child2a->generate() ), "\n";
echo
"Child 2B: ", bin2hex( $child2b->generate() ), "\n";
?>

Das oben gezeigte Beispiel erzeugt folgende Ausgabe:

Child 1A: b4f275cb365fec99
Child 1B: 2cd646c8ed156237
Child 2A: eb3729a722a504e7
Child 2B: d4208dc85bdd6dc3

Siehe auch

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