TreasureChest

A simple key/value store with namespace support and backends for memcached, apc, filesystem and more.

TreasureChest's biggest feature is namespaces. Most existing key/value stores place your data in a single global environment, this can lead to clashing key names in large datasets. They also don't support wildcards when deleting keys. It's impossible to do something like store('user1_username', 'bob') and then delete('user1_*');. This makes tracking and invalidating large sets of related keys difficult. TreasureChest provides a wrapper around your favourite key/value store (memcached, apc, xcache etc) making this possible.

Internally, TreasureChest uses a pointer which keeps track of the version number of each namespace. This version number is prefixed to all keys which get passed into the class. When a namespace is invalidateed the pointer is incremented by 1, thereby changing the key which gets passed to the datastore.

Requirements

PHP 5.3 or higher
Composer
APC 3.1.1 or higher (if using APC as backend)
Memcached 1.2.0 and PECL memcached 0.1.0 or higher (if using Memcached as backend)

Installation

Use Composer to install the treasure-chest/treasure-chest package. Package details can be found on Packagist.org.

Add the following to your composer.json and run composer install (or composer update).

"require": {
    "treasure-chest/treasure-chest": "0.1.*"
}

Usage

Create an instance of the TreasureChest\Instance class, passing in an instance of the datastore you wish to use.

$bounty = new \TreasureChest\Instance(new \TreasureChest\Cache\APC);

Use the add, store, fetch, replace, exists, inc, dec and delete methods to store, retrieve and manipulate your data. e.g

$bounty->store('email', 'bob@example.org');
$bounty->store('age', 45);
$bounty->fetch('email'); // returns bob@example.org
$bounty->inc('age', 5); // returns 50
$bounty->dec('age', 10); // returns 40
$bounty->delete('email');
$bounty->fetch('email'); // returns boolean FALSE

Namespaces can be used to logically group sets of key/value pairs. Simply append the key with the desired namespace, separated by a colon (this delimiter character can be changed) e.g

$bounty->add('user123:username', 'bob');
$bounty->add('user123:email', 'bob@example.org');
$bounty->add('user123:age', 21);

// Clear the entire user123 namespace
$cache->invalidate('user123');

$cache->fetch('user123:username'); // returns boolean FALSE
$cache->fetch('user123:email'); // returns boolean FALSE
$cache->fetch('user123:age'); // returns boolean FALSE

Known issues

There is currently a concurrency issue which can lead to TreasureChest returning data which should have been invalidated. This happens if another PHP process calls invalidate whilst the first process is still running. This could be fixed by checking the namespace version number before each call to fetch, store etc. This has a performance impact so I'll be making it a user enabled option.

To do