# IQParts Cache
PHP Cache library with namespace, filesystem and (p)redis implementations.

### Requirements
Requires PHP 7.0+. Older versions might work but have not been tested.

### Another cache library
This cache library has been highly inspired by [Genkgo.Cache](https://raw.githubusercontent.com/genkgo/cache). We recommend using this library as it implements more adapters. The reason for this library was the need to have a backup for redis which still was able to store cached values with a variable TTL.

### Code
This library attempts to comply with [PSR-1](https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-1-basic-coding-standard.md), [PSR-2](https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-2-coding-style-guide.md) & [PSR-4](https://github.com/php-fig/fig-standards/blob/master/accepted/PSR-4-autoloader.md).

### Create your own adapter

Create an adapter that implements CacheAdapterInterface. Take the MemoryAdapter as example:

``` php
<?php
declare(strict_types=1);

namespace IQParts\Cache\Adapter;

final class MemoryAdapter implements CacheAdapterInterface
{
    /**
     * @var array
     */
    private $data = [];
    /**
     * @var array
     */
    private $timeToLive = [];

    /**
     * @param string $key
     * @return mixed
     */
    public function get(string $key)
    {
        if (!isset($this->data[$key])) {
            return null;
        }

        if (!isset($this->timeToLive[$key])) {
            return $this->data[$key];
        }

        if ($this->ttl($key) > 0) {
            return $this->data[$key];
        }

        unset($this->timeToLive[$key]);
        unset($this->data[$key]);
        return null;
    }

    /**
     * @param string $key
     * @param $value
     * @param int|null $ttl
     * @return void
     */
    public function set(string $key, $value, int $ttl = null)
    {
        $this->data[$key] = $value;
        if ($ttl !== null) {
            $this->timeToLive[$key] = time() + $ttl;
        }
    }

    /**
     * @param string $key
     * @return mixed
     */
    public function delete(string $key)
    {
        unset($this->data[$key]);
        unset($this->timeToLive[$key]);
        return 1;
    }

    /**
     * @param string $key
     * @return mixed
     */
    public function keys($key = '*')
    {
        $matches = [];
        foreach ($this->data as $name => $value) {
            if (fnmatch($key, $name)) {
                $matches[] = $name;
            }
        }
        return $matches;
    }

    /**
     * @param $key
     * @return int
     */
    public function ttl($key): int
    {
        if (isset($this->timeToLive[$key])) {
            return max($this->timeToLive[$key] - time(), 0);
        }
        return self::NO_TTL;
    }
}
```

### Multiple Adapters
Adapters can be queued. Example:
``` php
$cache = new NamespaceAdapter(
    'my-namespace:',
    new MemoryAdapter()
);

/**
 * This will result in 'my-namespace:my-key'
 * set to 'my-value'
 */
$cache->set('my-key', 'my-value');
```