CachedCurrencies.php

<?php
 
namespace Money\Currencies;
 
use Cache\Taggable\TaggableItemInterface;
use Money\Currencies;
use Money\Currency;
use Psr\Cache\CacheItemPoolInterface;
 
final class CachedCurrencies implements Currencies
{
    private $currencies;
 
    private $pool;
 
    public function __construct(Currencies $currencies, CacheItemPoolInterface $pool)
    {
        $this->currencies = $currencies;
        $this->pool = $pool;
    }
 
    public function contains(Currency $currency)
    {
        $item = $this->pool->getItem('currency|availability|'.$currency->getCode());
 
        if (false === $item->isHit()) {
            $item->set($this->currencies->contains($currency));
 
            if ($item instanceof TaggableItemInterface) {
                $item->addTag('currency.availability');
            }
 
            $this->pool->save($item);
        }
 
        return $item->get();
    }
 
    public function subunitFor(Currency $currency)
    {
        $item = $this->pool->getItem('currency|subunit|'.$currency->getCode());
 
        if (false === $item->isHit()) {
            $item->set($this->currencies->subunitFor($currency));
 
            if ($item instanceof TaggableItemInterface) {
                $item->addTag('currency.subunit');
            }
 
            $this->pool->save($item);
        }
 
        return $item->get();
    }
 
    public function getIterator()
    {
        return new \CallbackFilterIterator(
            $this->currencies->getIterator(),
            function (Currency $currency) {
                $item = $this->pool->getItem('currency|availability|'.$currency->getCode());
                $item->set(true);
 
                if ($item instanceof TaggableItemInterface) {
                    $item->addTag('currency.availability');
                }
 
                $this->pool->save($item);
 
                return true;
            }
        );
    }
}