Add some documentation to the README

README.md

@@ -1,3 +1,69 @@
 # Banker
 
-A Caching library implementing the PSR-6 interface for several common cache backends
+A Caching library implementing the PSR-6 interface for several common cache 
+backends
+
+## Cache Backends
+* Memcache
+* Memcached
+* Redis
+* Null - no persistence
+
+### Basic Usage
+```php
+// Create the pool
+$pool = new Aviat\Banker\Pool($config, $logger);
+
+// Grab an item from the cache
+$item = $pool->getItem('foo');
+
+// Was there a cache hit?
+if ( ! $item->isHit())
+{
+	// ... Generation of value to cache
+	$item->set($value);
+	$item->save();
+}
+else
+{
+	$value = $item->get();
+}
+```
+
+#### Configuration / Connection array
+
+The config array passed to the Pool class constructor determines 
+which server to connect to. Regardless of the backend, the basic 
+structure is like so:
+
+```php
+[
+	'driver' => 'null', // null, redis, memcache, memcached
+	'connection' => [
+		// driver setup, see below for the structure for each
+		// driver
+	],
+	'options' => [
+		// Optional:
+		// Set additional driver-specific options, like persistence for
+		// Memcached, or a prefix for Redis keys
+	]
+]
+```
+
+Below are the connection arrays for each backend:
+
+Memcache / Memcached:
+```php
+[
+	'host' => 'localhost', // hostname or socket
+	'port' => 11211,       // Port needs to be 0 if socket
+	'persistent' => false, // Use persistent connection
+]
+```
+
+Redis:
+See [Predis](https://github.com/nrk/predis#connecting-to-redis) documentation. An empty array will connect to localhost on port 6379.
+
+Null:
+No connection parameters

src/Driver/AbstractDriver.php

@@ -22,7 +22,7 @@ use Psr\Log\LoggerAwareInterface;
  * Base class for cache backends
  */
 abstract class AbstractDriver implements DriverInterface, LoggerAwareInterface {
-	
+
 	use \Aviat\Banker\LoggerTrait;
 
 	/**
@@ -31,7 +31,7 @@ abstract class AbstractDriver implements DriverInterface, LoggerAwareInterface {
 	 * @var mixed
 	 */
 	protected $conn;
-	
+
 	/**
 	 * Data to be stored later
 	 *
@@ -43,9 +43,10 @@ abstract class AbstractDriver implements DriverInterface, LoggerAwareInterface {
 	 * Common constructor interface for driver classes
 	 *
 	 * @param array $config - Connection parameters for the specified backend
+	 * @param array $options - Special connection options for the specified backend
 	 */
-	abstract public function __construct(array $config = []);
-	
+	abstract public function __construct(array $config = [], array $options = []);
+
 	/**
 	 * Common destructor
 	 */

src/Driver/MemcacheDriver.php

@@ -27,9 +27,10 @@ class MemcacheDriver extends AbstractDriver {
 	 * Driver for PHP Memcache extension
 	 *
 	 * @param array $config
+	 * @param array $options
 	 * @throws CacheException
 	 */
-	public function __construct(array $config = [])
+	public function __construct(array $config = [], array $options = [])
 	{
 		// @codeCoverageIgnoreStart
 		if ( ! class_exists('Memcache'))

src/Driver/MemcachedDriver.php

@@ -30,9 +30,10 @@ class MemcachedDriver extends AbstractDriver {
 	 * Driver for PHP Memcache extension
 	 *
 	 * @param array $config
+	 * @param array $options
 	 * @throws CacheException
 	 */
-	public function __construct(array $config = [])
+	public function __construct(array $config = [], array $options = [])
 	{
 		// @codeCoverageIgnoreStart
 		if ( ! class_exists('Memcached'))
@@ -46,8 +47,13 @@ class MemcachedDriver extends AbstractDriver {
 			$this->conn = new Memcached();
 			$this->conn->setOption(Memcached::OPT_BINARY_PROTOCOL, true);
 			$this->conn->addServer($config['host'], $config['port']);
+
+			// @codeCoverageIgnoreStart
+			if ( ! empty($options))
+			{
+				$this->conn->setOptions($options);
+			}
 		}
-		// @codeCoverageIgnoreStart
 		catch (MemcachedException $e)
 		{
 			// Rewrite MemcachedException as a CacheException to

src/Driver/NullDriver.php

@@ -34,12 +34,13 @@ class NullDriver extends AbstractDriver {
 	 * NullDriver constructor.
 	 *
 	 * @param array $config
+	 * @param array $options
 	 */
-	public function __construct(array $config = [])
+	public function __construct(array $config = [], array $options = [])
 	{
 		$this->store = [];
 	}
-	
+
 	/**
 	 * Clean up nothing
 	 */
@@ -67,8 +68,8 @@ class NullDriver extends AbstractDriver {
 	 */
 	public function get($key)
 	{
-		return ($this->exists($key)) 
-			? $this->store[$key] 
+		return ($this->exists($key))
+			? $this->store[$key]
 			: NULL;
 	}
 
@@ -144,7 +145,7 @@ class NullDriver extends AbstractDriver {
 		$this->store = [];
 		return TRUE;
 	}
-	
+
 	/**
 	 * Set the specified key to expire at the given time
 	 *

src/Driver/RedisDriver.php

@@ -35,9 +35,10 @@ class RedisDriver extends AbstractDriver {
 	 * RedisDriver constructor.
 	 *
 	 * @param array $config
+	 * @param array $options - Predis library connection options
 	 * @throws CacheException
 	 */
-	public function __construct(array $config = [])
+	public function __construct(array $config = [], array $options = [])
 	{
 		// @codeCoverageIgnoreStart
 		if ( ! class_exists('Predis\\Client'))
@@ -46,7 +47,7 @@ class RedisDriver extends AbstractDriver {
 		}
 		// @codeCoverageIgnoreEnd
 
-		$this->conn = new Client($config);
+		$this->conn = new Client($config, $options);
 	}
 
 	/**

src/Pool.php

@@ -30,7 +30,7 @@ use Aviat\Banker\ItemCollection;
  * The main cache manager
  */
 class Pool implements CacheItemPoolInterface, LoggerAwareInterface {
-	
+
 	use LoggerTrait;
 
 	/**
@@ -55,7 +55,7 @@ class Pool implements CacheItemPoolInterface, LoggerAwareInterface {
 	public function __construct(array $config, LoggerInterface $logger = NULL)
 	{
 		$this->driver = $this->loadDriver($config);
-		
+
 		if ( ! is_null($logger))
 		{
 			$this->setLogger($logger);
@@ -84,7 +84,7 @@ class Pool implements CacheItemPoolInterface, LoggerAwareInterface {
 		{
 			throw new InvalidArgumentException();
 		}
-		
+
 		// If a deferred item exists, return that
 		if (array_key_exists($key, $this->deferred))
 		{
@@ -117,7 +117,7 @@ class Pool implements CacheItemPoolInterface, LoggerAwareInterface {
 		{
 			return new ItemCollection([]);
 		}
-		
+
 		foreach($keys as $key)
 		{
 			if ( ! is_string($key))
@@ -125,7 +125,7 @@ class Pool implements CacheItemPoolInterface, LoggerAwareInterface {
 				throw new InvalidArgumentException();
 			}
 		}
-		
+
 		// Get the set of items selected
 		$items = [];
 		$rawItems = $this->driver->getMultiple($keys);
@@ -167,7 +167,7 @@ class Pool implements CacheItemPoolInterface, LoggerAwareInterface {
 		{
 			throw new InvalidArgumentException();
 		}
-		
+
 		// See if there are any deferred items
 		if (array_key_exists($key, $this->deferred))
 		{
@@ -292,7 +292,7 @@ class Pool implements CacheItemPoolInterface, LoggerAwareInterface {
 		{
 			$result = $result && $this->save($item);
 		}
-		
+
 		if ($result === TRUE)
 		{
 			$this->deferred = [];
@@ -312,6 +312,11 @@ class Pool implements CacheItemPoolInterface, LoggerAwareInterface {
 		$driver = ucfirst(strtolower($driverConfig['driver']));
 		$class = __NAMESPACE__ . "\\Driver\\${driver}Driver";
 
-		return new $class($driverConfig['connection']);
+		if ( ! array_key_exists('options', $driverConfig))
+		{
+			$driverConfig['options'] = [];
+		}
+
+		return new $class($driverConfig['connection'], $driverConfig['options']);
 	}
 }