92 lines
2.4 KiB
PHP
92 lines
2.4 KiB
PHP
<?php
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// {{{ License
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// This file is part of GNU social - https://www.gnu.org/software/social
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//
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// GNU social is free software: you can redistribute it and/or modify
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// it under the terms of the GNU Affero General Public License as published by
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// the Free Software Foundation, either version 3 of the License, or
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// (at your option) any later version.
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//
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// GNU social is distributed in the hope that it will be useful,
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// but WITHOUT ANY WARRANTY; without even the implied warranty of
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// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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// GNU Affero General Public License for more details.
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//
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// You should have received a copy of the GNU Affero General Public License
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// along with GNU social. If not, see <http://www.gnu.org/licenses/>.
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// }}}
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namespace App\Util\ds;
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use Ds\Deque;
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use Functional as F;
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class RingBuffer implements \Serializable, \ArrayAccess
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{
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private int $capacity;
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private Deque $elements;
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public function __construct(int $c)
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{
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$this->capacity = $c;
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$this->elements = new Deque();
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}
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public function add($e)
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{
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if ($this->capacity !== 0 && $this->elements->count() >= $this->capacity) {
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$this->elements->shift();
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}
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$this->elements->unshift($e);
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}
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public function remove(int $index)
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{
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return $this->elements->remove($index);
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}
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public function get(int $index)
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{
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return $this->elements->get($index);
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}
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// ------ Serialization
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public function serialize()
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{
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return serialize($this->capacity) . serialize($this->elements);
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}
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public function unserialize($data)
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{
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list($this->capacity, $this->elements) = F\map(explode(';', $data), F\ary('unserialize', 1));
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}
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// ------ End Serialization
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// ------ Array interface
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public function offsetSet($index, $value)
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{
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if (is_null($index)) {
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$this->add($value);
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} else {
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$this->elements->set($index, $value);
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}
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}
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public function offsetExists($index)
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{
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return is_int($index) && $index >= 0 && $index < $this->elements->count();
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}
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public function offsetUnset($index)
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{
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$this->elements->remove($index);
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}
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public function offsetGet($index)
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{
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return $this->offsetExists($index) ? $this->get($index) : null;
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}
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// ------ End Array interface
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}
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