public function testNumberOfTrailingZeros()
{
$this->assertEquals(32, BitUtils::numberOfTrailingZeros(0));
$this->assertEquals(1, BitUtils::numberOfTrailingZeros(10));
$this->assertEquals(0, BitUtils::numberOfTrailingZeros(15));
$this->assertEquals(2, BitUtils::numberOfTrailingZeros(20));
}
/**
* Gets the next unset bit position from a given position.
*
* @param integer $from
* @return integer
*/
public function getNextUnset($from)
{
if ($from >= $this->size) {
return $this->size;
}
$bitsOffset = $from >> 5;
$currentBits = ~$this->bits[$bitsOffset];
$bitsLength = count($this->bits);
$currentBits &= ~((1 << ($from & 0x1f)) - 1);
while ($currentBits === 0) {
if (++$bitsOffset === $bitsLength) {
return $this->size;
}
$currentBits = ~$this->bits[$bitsOffset];
}
$result = ($bitsOffset << 5) + BitUtils::numberOfTrailingZeros($currentBits);
return $result > $this->size ? $this->size : $result;
}
