Storage Component¶

Overview¶

The Phalcon\Storage namespace contains components that help with storing data in different storages. The component is heavily integrated into Phalcon\Cache\Cache as well as Phalcon\Session. It offers serialization of data based on various serialization adapters, and storage of data based on various storage adapters. Factories help with the creation of all necessary objects for the component to work.

Serializers¶

The Phalcon\Storage\Serializer namespace offers classes that implement the Serializable interface and thus expose the serialize and unserialize methods. The purpose of these classes is to transform the data before saving it to the storage and after retrieving it from the storage.

The storage adapter can be configured to use a different serializer. The available serializers are:

Base64¶

This serializer uses the base64_encode and base64_decode methods to serialize data. The input must be of type string, therefore this serializer has obvious limitations

Igbinary¶

The igbinary serializes relies on the igbinary_serialize and igbinary_unserialize methods. Those methods are exposed via the igbinary PHP extension, which has to be installed and loaded on the target system.

Json¶

The JSON serializer uses json_encode and json_decode. The target system must have JSON support available for PHP.

MemcachedIgbinary¶

This serializer can be used when using Memcached. It corresponds to the built-in Igbinary serializer that Memcached has.

MemcachedJson¶

This serializer can be used when using Memcached. It corresponds to the built-in JSON serializer that Memcached has.

MemcachedPhp¶

This serializer can be used when using Memcached. It corresponds to the built-in PHP serializer that Memcached has.

Msgpack¶

Similar to igbinary the msgpack serializer uses msgpack_pack and msgpack_unpack for serializing and unserializing data. This, along with igbinary is one of the fastest and most efficient serializers. However, it requires that the msgpack PHP extension is loaded on the target system.

None¶

This serializer does not transform the data at all. Both its serialize and unserialize get and set the data without altering it.

Php¶

This is the default serializer. It uses PHP's serialize and unserialize methods for data transformations.

RedisIgbinary¶

This serializer can be used when using Redis. It corresponds to the built-in Igbinary serializer that Redis has.

RedisJson¶

This serializer can be used when using Redis. It corresponds to the built-in JSON serializer that Redis has.

RedisMsgpack¶

This serializer can be used when using Redis. It corresponds to the built-in Msgpack serializer that Redis has.

RedisNone¶

This serializer can be used when using Redis. It corresponds to the built-in None serializer that Redis has.

RedisPhp¶

This serializer can be used when using Redis. It corresponds to the built-in PHP serializer that Redis has.

Custom¶

Phalcon also offers the Phalcon\Storage\Serializer\SerializerInterface` which can be implemented in a custom class. The class can offer the serialization you require.

<?php

namespace MyApp\Storage\Serializer;

use Phalcon\Storage\SerializerInterface;

class Garble implements SerializerInterface
{
    /**
     * Data storage
     * 
     * @var string
     */
    private $data = '';

    /**
     * Return the stored data
     * 
     * @return string
     */
    public function getData(): string
    {
        return $this->data;
    }       

    /**
     * Serializes data
     */
    public function serialize(): string
    {
        return rot13($this->data);
    }

    /**
     * Set the data
     * 
     * @var Garble
     *
     * @return Garble
     */
    public function setData($data): Garble
    {
        $this->data = (string) $data;

        return $this;
    }       

    /**
     * Unserializes data
     */
    public function unserialize($data): void
    {
        $this->data = str_rot13($data);
    }
}

Using it:

<?php

namespace MyApp;

use MyApp\Storage\Serializer\Garble;

$data = 'I came, I saw, I conquered.';
$garble = new Garble();

$garble
    ->setData($data)
    ->serialize()  
;

echo $garble->getData(); // "V pnzr, V fnj, V pbadhrerq."

$encrypted = 'V pnzr, V fnj, V pbadhrerq.';

$garble->unserialize($encrypted);

echo $garble->getData(); // "I came, I saw, I conquered."

Serializer Factory¶

Although all serializer classes can be instantiated using the new keyword, Phalcon offers the Phalcon\Storage\SerializerFactory class, so that developers can easily instantiate serializer classes. All the above serializers are registered in the factory and lazy loaded when called. The factory also allows you to register additional (custom) serializer classes. The only thing to consider is choosing the name of the serializer in comparison to the existing ones. If you define the same name, you will overwrite the built-in one. The objects are cached in the factory so if you call the newInstance() method with the same parameters during the same request, you will get the same object back.

The example below shows how you can create a Json serializer either using the new keyword or the factory:

<?php

use Phalcon\Storage\Serializer\Json; 
use Phalcon\Storage\SerializerFactory;

$jsonSerializer = new Json();

$factory        = new SerializerFactory();
$jsonSerializer = $factory->newInstance('json');

Adapters¶

The Phalcon\Storage\Adapter namespace offers classes that implement the Phalcon\Storage\Adapter\AdapterInterface interface. It exposes common methods that are used to perform operations on the storage adapter. These adapters act as wrappers to respective backend code.

The available methods are:

To construct one of these objects, you will need to pass a Phalcon\Storage\SerializerFactory object in the constructor and optionally some parameters required for the adapter of your choice. The list of options is outlined below.

The available adapters are:

Apcu¶

This adapter uses Apcu to store the data. In order to use this adapter, you will need to have apcu enabled in your target system. This class does not use an actual adapter, since the apcu functionality is exposed using the apcu_* PHP functions.

The following example demonstrates how to create a new Apcu storage adapter, which will use the Phalcon\Storage\Serializer\Json serializer and have a default lifetime of 7200.

<?php

use Phalcon\Storage\Adapter\Apcu;
use Phalcon\Storage\SerializerFactory;

$serializerFactory = new SerializerFactory();

$options = [
    'defaultSerializer' => 'Json',
    'lifetime'          => 7200,
];

$adapter = new Apcu($serializerFactory, $options);

The above example used a Phalcon\Storage\SerializerFactory object and the defaultSerializer option to tell the adapter to instantiate the relevant serializer.

Libmemcached¶

This adapter utilizes PHP's memcached extension to connect to Memcached servers. The adapter used is an instance of the Memcached class, created after the first event that requires the connection to be active.

You can specify more than one server in the options array passed in the constructor. If SASL data is defined, the adapter will try to authenticate using the passed data. If there is an error in the options or the class cannot add one or more servers in the pool, a Phalcon\Storage\Exception will be thrown.

The following example demonstrates how to create a new Libmemcached storage adapter, which will use the Phalcon\Storage\Serializer\Json serializer and have a default lifetime of 7200. It will use the 10.4.13.100 as the first server with weight 1 connecting to port 11211 and 10.4.13.110 as the second server with weight 5 again connecting to port 11211.

<?php

use Phalcon\Storage\Adapter\Libmemcached;
use Phalcon\Storage\SerializerFactory;

$serializerFactory = new SerializerFactory();

$options = [
    'defaultSerializer' => 'Json',
    'lifetime'          => 7200,
    'servers'           => [
        0 => [
            'host'   => '10.4.13.100',
            'port'   => 11211,
            'weight' => 1,
        ],
        1 => [
            'host'   => '10.4.13.110',
            'port'   => 11211,
            'weight' => 5,
        ],
    ],
];

$adapter = new Libmemcached($serializerFactory, $options);

The above example used a Phalcon\Storage\SerializerFactory object and the defaultSerializer option to tell the adapter to instantiate the relevant serializer.

Serializers: The Memcached class which is the adapter that the Phalcon\Storage\Adapter\Libmemcached uses, offers support for serializing out of the box. The built-in serializers are:

• \Memcached::SERIALIZER_PHP
• \Memcached::SERIALIZER_JSON
• \Memcached::SERIALIZER_IGBINARY

The igbinary built-in serializer is only available if igbinary is present in the target system and Memcached extension is compiled with it. To enable these serializers, you can use the Phalcon\Storage\Serializer\MemcachedIgbinary, Phalcon\Storage\Serializer\MemcachedJson or Phalcon\Storage\Serializer\MemcachedPhp

Memory¶

This adapter uses the computer's memory to store the data. As all data is stored in memory, there is no persistence, meaning that once the request is completed, the data is lost. This adapter can be used for testing or temporary storage during a particular request. The options available for the constructor are:

The following example demonstrates how to create a new Memory storage adapter, which will use the Phalcon\Storage\Serializer\Json serializer and have a default lifetime of 7200.

<?php

use Phalcon\Storage\Adapter\Memory;
use Phalcon\Storage\SerializerFactory;

$serializerFactory = new SerializerFactory();

$options = [
    'defaultSerializer' => 'Json',
    'lifetime'          => 7200,
];

$adapter = new Memory($serializerFactory, $options);

The above example used a Phalcon\Storage\SerializerFactory object and the defaultSerializer option to tell the adapter to instantiate the relevant serializer.

Redis¶

This adapter utilizes PHP's redis extension to connect to a Redis server. The adapter used is an instance of the Redis class, created after the first event that requires the connection to be active.

If auth data is defined, the adapter will try to authenticate using the passed data. If there is an error in the options, or the server cannot connect or authenticate, a Phalcon\Storage\Exception will be thrown.

The following example demonstrates how to create a new Redis storage adapter, which will use the Phalcon\Storage\Serializer\Json serializer and have a default lifetime of 7200. It will use the 10.4.13.100 as the host, connect to port 6379, and select the index 1.

<?php

use Phalcon\Storage\Adapter\Redis;
use Phalcon\Storage\SerializerFactory;

$serializerFactory = new SerializerFactory();

$options = [
    'defaultSerializer' => 'Json',
    'lifetime'          => 7200,
    'host'              => '10.4.13.100',
    'port'              => 6379,
    'index'             => 1,
];

$adapter = new Redis($serializerFactory, $options);

The above example used a Phalcon\Storage\SerializerFactory object and the defaultSerializer option to tell the adapter to instantiate the relevant serializer.

Serializers: The Redis class which is the adapter that the Phalcon\Storage\Adapter\Redis uses, offers support for serializing out of the box. The built-in serializers are:

• \Redis::SERIALIZER_NONE
• \Redis::SERIALIZER_PHP
• \Redis::SERIALIZER_IGBINARY
• \Redis::SERIALIZER_MSGPACK

The igbinary and built-in serializer are only available if igbinary is present in the target system and Redis extension is compiled with it. The same applies to msgpack built-in serializer. It is only available if msgpack is present in the target system and the Redis extension is compiled with it. To enable these serializers, you can use the Phalcon\Storage\Serializer\RedisIgbinary, Phalcon\Storage\Serializer\RedisJson, Phalcon\Storage\Serializer\RedisMsgpack, Phalcon\Storage\Serializer\RedisNone or Phalcon\Storage\Serializer\RedisPhp.

NOTE increment - decrement

At this point in time, there is an issue with Redis, where the internal Redis serializer does not skip scalar values because it can only store strings. As a result, if you use increment after a set for a number, will not return a number:

The way to store numbers and use the increment (or decrement) is to either remove the internal serializer for Redis

$storage->getAdapter()->setOption(\Redis::OPT_SERIALIZER, \Redis::SERIALIZER_NONE);

or you could use increment instead of using set at the first setting of the value to the key:

$storage->delete('my-key');
$storage->increment('my-key', 2);
echo $storage->get('my-key');      // 2
$storage->increment('my-key', 3);
echo $storage->get('my-key');      // 3

Stream¶

This adapter is the simplest to set up since it uses the target system's file system (it only requires a storage path that is writeable). It is one of the slowest storage adapters since the data has to be written to the file system. Each file created corresponds to a key stored. The file contains additional metadata to calculate the lifetime of the storage element, resulting in additional reads and writes to the file system.

If the storageDir is not defined a Phalcon\Storage\Exception will be thrown.

The following example demonstrates how to create a new Stream storage adapter, which will use the Phalcon\Storage\Serializer\Json serializer and have a default lifetime of 7200. It will store the data in /data/storage.

<?php

use Phalcon\Storage\Adapter\Stream;
use Phalcon\Storage\SerializerFactory;

$serializerFactory = new SerializerFactory();

$options = [
    'defaultSerializer' => 'Json',
    'lifetime'          => 7200,
    'storageDir'        => '/data/storage',
];

$adapter = new Stream($serializerFactory, $options);

The above example used a Phalcon\Storage\SerializerFactory object and the defaultSerializer option to tell the adapter to instantiate the relevant serializer.

Custom¶

Phalcon also offers the Phalcon\Storage\Adapter\AdapterInterface which can be implemented in a custom class. The class can offer the storage adapter functionality you require.

<?php

namespace MyApp\Storage\Adapter;

use Phalcon\Storage\Adapter\AdapterInterface;

class Custom implements AdapterInterface
{
    /**
     * Flushes/clears the cache
     */
    public function clear(): bool
    {
        // Custom implementation
    }

    /**
     * Decrements a stored number
     */
    public function decrement(string $key, int $value = 1)
    {
        // Custom implementation
    }

    /**
     * Deletes data from the adapter
     */
    public function delete(string $key): bool
    {
        // Custom implementation
    }

    /**
     * Reads data from the adapter
     */
    public function get(string $key)
    {
        // Custom implementation
    }

    /**
     * Returns the already connected adapter or connects to the backend server(s)
     */
    public function getAdapter()
    {
        // Custom implementation
    }

    /**
     * Returns all the keys stored. If a filter has been passed the 
     * keys that match the filter will be returned
     */
    public function getKeys(string $prefix = ""): array
    {
        // Custom implementation
    }

    /**
     * Returns the prefix for the keys
     */
    public function getPrefix(): string
    {
        // Custom implementation
    }

    /**
     * Checks if an element exists in the cache
     */
    public function has(string $key): bool
    {
        // Custom implementation
    }

    /**
     * Increments a stored number
     */
    public function increment(string $key, int $value = 1)
    {
        // Custom implementation
    }

    /**
     * Stores data in the adapter
     */
    public function set(string $key, $value, $ttl = null): bool
    {
        // Custom implementation
    }
}

Using it:

<?php

namespace MyApp;

use MyApp\Storage\Adapter\Custom;

$custom = new Custom();

$custom->set('my-key', $data);

Adapter Factory¶

Although all adapter classes can be instantiated using the new keyword, Phalcon offers the [Phalcon\Storage\AdapterFactory][cache-adapterfactory] class, so that you can easily instantiate cache adapter classes. All the above adapters are registered in the factory and lazy loaded when called. The factory also allows you to register additional (custom) adapter classes. The only thing to consider is choosing the name of the adapter in comparison to the existing ones. If you define the same name, you will overwrite the built-in one. The objects are cached in the factory so if you call the newInstance() method with the same parameters during the same request, you will get the same object back.

The example below shows how you can create an Apcu cache adapter with the new keyword or the factory:

<?php

use Phalcon\Storage\Adapter\Apcu;
use Phalcon\Storage\Serializer\Json;

$jsonSerializer = new Json();

$options = [
    'defaultSerializer' => 'Json',
    'lifetime'          => 7200,
    'serializer'        => $jsonSerializer,
];

$adapter = new Apcu(null, $options);

<?php

use Phalcon\Storage\AdapterFactory;
use Phalcon\Storage\SerializerFactory;

$serializerFactory = new SerializerFactory();
$adapterFactory    = new AdapterFactory($serializerFactory);

$options = [
    'defaultSerializer' => 'Json',
    'lifetime'          => 7200,
];

$adapter = $adapterFactory->newInstance('apcu', $options);

The parameters you can use for the factory are:

Events¶

The Phalcon\Storage\AbstractAdapter object implements the Phalcon\Events\EventsAware interfaces. As a result getEventsManager() and setEventsManager() are available for you to use.