o2system / cache

src/Item.php

<?php

/**

 * This file is part of the O2System Framework package.

 *

 * For the full copyright and license information, please view the LICENSE

 * file that was distributed with this source code.

 *

 * @author         Steeve Andrian Salim

 * @copyright      Copyright (c) Steeve Andrian Salim

 */


// ------------------------------------------------------------------------


namespace O2System\Cache;


// ------------------------------------------------------------------------


use Psr\Cache\CacheItemInterface;

The type Psr\Cache\CacheItemInterface was not found. Maybe you did not declare it correctly or list all dependencies?

/**

 * Class Item

 *

 * @package O2System\Cache\Collections

 */

class Item implements CacheItemInterface

{

    /**

     * Item::$key

     *

     * Item Key

     *

     * @var string

     */

    protected $key;


    /**

     * Item::$value

     *

     * Item Value

     *

     * @var mixed|null

     */

    protected $value = null;


    /**

     * Item::$isHit

     *

     * Item is hit flag

     *

     * @var bool

     */

    protected $isHit = false;


    /**

     * Item::$createdAt

     *

     * Item Creation Time

     *

     * @var \DateTimeInterface

     */

    protected $createdAt;


    /**

     * Item::$expiresAt

     *

     * Item Expiration Time

     *

     * @var \DateTimeInterface

     */

    protected $expiresAt;


    /**

     * Item::$expiresAfter

     *

     * Item Expiration Time Interval

     *

     * @var int|\DateInterval

     */

    protected $expiresAfter;


    // ------------------------------------------------------------------------


    /**

     * Item::__construct

     *

     * @param string            $key          Item key.

     * @param mixed|null        $value        Item value.

     * @param int|\DateInterval $expiresAfter Item expiration.

     *

     * @throws \Exception

     * @return Item

     */

    public function __construct($key, $value = null, $expiresAfter = 300)

    {

        // Set item key

        $this->key = $key;


        // Set from item metadata

        if (isset($value[ 'ctime' ]) AND isset($value[ 'etime' ]) AND isset($value[ 'ttl' ]) AND isset($value[ 'data' ])) {

            $this->set($value[ 'data' ]);

            $this->createdAt = new \DateTime(date('r', $value[ 'ctime' ]));

            $this->expiresAt = new \DateTime(date('r', $value[ 'etime' ]));

            $this->expiresAfter($value[ 'ttl' ]);

        } else {

            // Set item value

            $this->set($value);


            // Set item creation time

            $this->createdAt = new \DateTime(date('r', time()));


            // Set item expiration

            if ($expiresAfter !== false) {

The condition $expiresAfter !== false is always true.

                $this->expiresAfter($expiresAfter);

            }

        }

    }


    // ------------------------------------------------------------------------


    /**

     * Item::set

     *

     * Sets the value represented by this cache item.

     *

     * The $value argument may be any item that can be serialized by PHP,

     * although the method of serialization is left up to the Implementing

     * Library.

     *

     * @param mixed $value

     *   The serializable value to be stored.

     *

     * @return static

     *   The invoked object.

     */

    public function set($value)

    {

        $this->value = $value;


        if ( ! is_null($value)) {

            $this->isHit = true;

        }


        return $this;

    }


    // ------------------------------------------------------------------------


    /**

     * Item::expiresAfter

     *

     * Sets the expiration time for this cache item.

     *

     * @param int|\DateInterval|null $time

     *   The period of time from the present after which the item MUST be considered

     *   expired. An integer parameter is understood to be the time in seconds until

     *   expiration. If null is passed explicitly, a default value MAY be used.

     *   If none is set, the value should be stored permanently or for as long as the

     *   implementation allows.

     *

     * @return static

     *   The called object.

     * @throws \Exception

     */

    public function expiresAfter($time = null)

    {

        $time = is_null($time) ? 300 : $time;


        if (is_int($time)) {

            $this->expiresAfter = new \DateInterval('PT' . $time . 'S');

        }


        if ( ! $this->expiresAt instanceof \DateTime) {

            $this->expiresAt();

        }


        $this->expiresAt->add($this->expiresAfter);


        return $this;

    }


    // ------------------------------------------------------------------------


    /**

     * Item::expiresAt

     *

     * Sets the expiration time for this cache item.

     *

     * @param \DateTimeInterface|null $expiration

     *   The point in time after which the item MUST be considered expired.

     *   If null is passed explicitly, a default value MAY be used. If none is set,

     *   the value should be stored permanently or for as long as the

     *   implementation allows.

     *

     * @return static

     *   The called object.

     * @throws \Exception

     */

    public function expiresAt($expiration = null)

    {

        $this->expiresAt = isset($expiration) ? $expiration : new \DateTime();


        return $this;

    }


    // ------------------------------------------------------------------------


    /**

     * Item::getKey

     *

     * Returns the key for the current cache item.

     *

     * The key is loaded by the Implementing Library, but should be available to

     * the higher level callers when needed.

     *

     * @return string

     *   The key string for this cache item.

     */

    public function getKey()

    {

        return $this->key;

    }


    // ------------------------------------------------------------------------


    /**

     * Item::get

     *

     * Retrieves the value of the item from the cache associated with this object's key.

     *

     * The value returned must be identical to the value originally stored by set().

     *

     * If isHit() returns false, this method MUST return null. Note that null

     * is a legitimate cached value, so the isHit() method SHOULD be used to

     * differentiate between "null value was found" and "no value was found."

     *

     * @return mixed

     *   The value corresponding to this cache item's key, or null if not found.

     */

    public function get()

    {

        if ($this->isHit()) {

            return $this->value;

        }


        return null;

    }


    // ------------------------------------------------------------------------


    /**

     * Item::isHit

     *

     * Confirms if the cache item lookup resulted in a cache hit.

     *

     * Note: This method MUST NOT have a race condition between calling isHit()

     * and calling get().

     *

     * @return bool

     *   True if the request resulted in a cache hit. False otherwise.

     */

    public function isHit()

    {

        return $this->isHit;

    }


    // ------------------------------------------------------------------------


    /**

     * Item::getMetadata

     *

     * Gets item metadata info in array format:

     * [

     *     'ctime' => 1474609788, // creation time

     *     'etime' => '1474610088', // expires time

     *     'ttl' => 300 // time-to-live

     * ]

     *

     * @return array

     */

    public function getMetadata()

    {

        $createdTime = $this->createdAt->format('U');


        if ($this->expiresAt instanceof \DateTime) {

            $expiresTime = $this->expiresAt->format('U');

            $ttl = $expiresTime - $createdTime;

        } else {

            $expiresTime = 0;

            $ttl = 0;

        }


        return [

            'ctime' => $createdTime,

            'etime' => $expiresTime,

            'ttl'   => $ttl,

        ];

    }

}