An implementation of the PSR-16 SimpleCache Interface for Redis with optional AEAD encryption

1.2.2 2018-04-30 23:02 UTC


This is an implementation of PSR-16 for the Redis caching engine.

Two different classes are provided. The first just provides a PSR-16 compliant interface to Redis and the second provides encryption of the cached data via the libsodium extension.

Please refer to the files,, and for more information specific to SimpleCacheRedis.

For instructions specific to the encryption option. see the file

Please refer to the file for the terms of the MIT License this software is released under.

About Redis Caching

Redis does far more than just behave as a caching engine, according to the web site it provides an in-memory data structure that can be used as a database, cache, and message broker.

For this PSR-16 implementation, using it as a PHP object cache is all that matters, but redis itself is capable of some incredible things beyond the scope of this class.

While looking at various benchmarks, it appears to me that in the use case scenarios that best match a PSR-16 implementation, APCu is faster than Redis. However there are several compelling reasons as to why Redis may be the better choice for some situations:

  • Redis cache survives a web server daemon restart.
  • Redis cache (unless configured not to) survives a server reboot.
  • Redis cache can be made accessible to other servers in your network.
  • Redis cache can use a cluster if you have a lot of data you need to have handled by a caching engine.

If you just have a single server scenario that does not need to share its cached with other servers, APCu may be the better choice for PSR-16 caching needs, see
SimpleCacheAPCu for a PSR-16 implementation for APCu.

About PHP-FIG and PSR-16

PHP-FIG is the PHP Framework Interop Group. They exist largely to create standards that make it easier for different developers around the world to create different projects that will work well with each other. PHP-FIG was a driving force behind the PSR-0 and PSR-4 auto-load standards for example that make it much much easier to integrate PHP class libraries written by other people into your web applications.

The PHP-FIG previously released PSR-6 as a Caching Interface standard but the interface requirements of PSR-6 are beyond the needs of many web application developers. KISS - ‘Keep It Simple Silly’ applies for many of us who do not need some of the features PSR-6 requires.

To meet the needs of those of us who do not need what PSR-6 implements, PSR-16 was developed and is now an accepted standard.

When I read PSR-16, the defined interface it was not that different from my own APCu caching class that I have personally been using for years. So I decided to make my class meet the interface requirements.

Then a Redis user asked me if I could possibly adapt the library for Redis. So I did and this is the result.

Coding Standard

The coding standard used is primarily PSR-2 except with the closing ?> allowed, and the addition of some PHPDoc requirements largely but not completely borrowed from the PEAR standard.

The intent is switch PHPDoc standard to PSR-5 if it ever becomes an accepted standard.

The phpcs sniff rules being used: psr2.phpcs.xml

About AWonderPHP

I may become homeless before the end of 2018. I do not know how to survive, I try but what I try, it always seems to fail. This just is not a society people like me are meant to be a part of.

If I do become homeless, I fear my mental health will deteriorate at an accelerated rate and I do not want to witness that happening to myself.

AWonderPHP is my attempt to clean up and package a lot of the PHP classes I personally use so that something of me will be left behind.

If you wish to help, please see the file.

Thank you for your time.