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- <?php
- /*
- * This file is part of the Symfony package.
- *
- * (c) Fabien Potencier <fabien@symfony.com>
- *
- * For the full copyright and license information, please view the LICENSE
- * file that was distributed with this source code.
- */
- namespace Symfony\Component\Intl\Data\Util;
- use Symfony\Component\Intl\Exception\OutOfBoundsException;
- /**
- * Implements a ring buffer.
- *
- * A ring buffer is an array-like structure with a fixed size. If the buffer
- * is full, the next written element overwrites the first bucket in the buffer,
- * then the second and so on.
- *
- * @author Bernhard Schussek <bschussek@gmail.com>
- *
- * @internal
- */
- class RingBuffer implements \ArrayAccess
- {
- private $values = [];
- private $indices = [];
- private $cursor = 0;
- private $size;
- public function __construct(int $size)
- {
- $this->size = $size;
- }
- /**
- * {@inheritdoc}
- */
- public function offsetExists($key): bool
- {
- return isset($this->indices[$key]);
- }
- /**
- * {@inheritdoc}
- */
- public function offsetGet($key)
- {
- if (!isset($this->indices[$key])) {
- throw new OutOfBoundsException(sprintf('The index "%s" does not exist.', $key));
- }
- return $this->values[$this->indices[$key]];
- }
- /**
- * {@inheritdoc}
- */
- public function offsetSet($key, $value)
- {
- if (false !== ($keyToRemove = array_search($this->cursor, $this->indices))) {
- unset($this->indices[$keyToRemove]);
- }
- $this->values[$this->cursor] = $value;
- $this->indices[$key] = $this->cursor;
- $this->cursor = ($this->cursor + 1) % $this->size;
- }
- /**
- * {@inheritdoc}
- */
- public function offsetUnset($key)
- {
- if (isset($this->indices[$key])) {
- $this->values[$this->indices[$key]] = null;
- unset($this->indices[$key]);
- }
- }
- }
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