Viewing file:  SquaredCapacity.php (1.45 KB) -rw-r--r--
Select action/file-type:
 (+) |  (+) |  (+) | Code (+) | Session (+) |  (+) | SDB (+) |  (+) |  (+) |  (+) |  (+) |  (+) |
<?php
namespace Ds\Traits;
/**
* Common to structures that require a capacity which is a power of two.
*/
trait SquaredCapacity
{
use Capacity;
/**
* Rounds an integer to the next power of two if not already a power of two.
*
* @param int $capacity
*
* @return int
*/
private function square(int $capacity): int
{
return pow(2, ceil(log($capacity, 2)));
}
/**
* Ensures that enough memory is allocated for a specified capacity. This
* potentially reduces the number of reallocations as the size increases.
*
* @param int $capacity The number of values for which capacity should be
* allocated. Capacity will stay the same if this value
* is less than or equal to the current capacity.
*/
public function allocate(int $capacity)
{
$this->capacity = max($this->square($capacity), $this->capacity);
}
/**
* Called when capacity should be increased to accommodate new values.
*/
protected function increaseCapacity()
{
$this->capacity = $this->square(
max(
count($this) + 1,
$this->capacity * $this->getGrowthFactor()
)
);
}
/**
* @param int $total
*/
protected function ensureCapacity(int $total)
{
while ($total > $this->capacity()) {
$this->increaseCapacity();
}
}
}
|