* APCu/PHP7: fixed not used APCu under PHP7, as it has no APC compatible interface

Apcu class is basicly a copy of Apc, but as its methods are called quite a lot, I dont want to add the overhad of checking to call apc_ or apcu_ on every call, anyway APC died with PHP 5.5 so we can remove Apcu class once we no longer support PHP 5.4

api/src/Cache.php

@@ -555,7 +555,7 @@ class Cache
 			}
 			if (!$providers[$level] && $log_not_found) error_log(__METHOD__."($level) no provider found ($reason)!".function_backtrace());
 		}
-		//error_log(__METHOD__."($level) = ".array2string($providers[$level]).', cache_provider='.array2string($GLOBALS['egw_info']['server']['cache_provider_'.strtolower($level)]));
+		error_log(__METHOD__."($level) = ".array2string($providers[$level]).', cache_provider='.array2string($GLOBALS['egw_info']['server']['cache_provider_'.strtolower($level)]));
 		return $providers[$level];
 	}
 
@@ -730,11 +730,13 @@ class Cache
 	}
 }
 
-// setting apc as default provider, if apc_fetch function exists AND further checks in Api\Cache\Apc recommed it
+// setting apc(u) as default provider, if apc(u)_fetch function exists AND further checks in Api\Cache\Apc(u) recommed it
 if (is_null(Cache::$default_provider))
 {
-	Cache::$default_provider = function_exists('apc_fetch') && Cache\Apc::available() ?
+	Cache::$default_provider =
-		'EGroupware\Api\Cache\Apc' : 'EGroupware\Api\Cache\Files';
+		function_exists('apcu_fetch') && Cache\Apcu::available() ? 'EGroupware\Api\Cache\Apcu' :
+			(function_exists('apc_fetch') && Cache\Apc::available() ? 'EGroupware\Api\Cache\Apc' :
+				'EGroupware\Api\Cache\Files');
 }
 
 //error_log('Cache::$default_provider='.array2string(Cache::$default_provider));

api/src/Cache/Apcu.php

@@ -0,0 +1,184 @@
+<?php
+/**
+ * EGroupware API: Caching provider storing data in PHP's APCu extension
+ *
+ * @link http://www.egroupware.org
+ * @license http://opensource.org/licenses/gpl-license.php GPL - GNU General Public License
+ * @package api
+ * @subpackage cache
+ * @author Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @copyright (c) 2010-16 by Ralf Becker <RalfBecker-AT-outdoor-training.de>
+ * @version $Id$
+ */
+
+namespace EGroupware\Api\Cache;
+
+/**
+ * Caching provider storing data in PHP's APCu extension / shared memory.
+ *
+ * The provider concats all $keys with '::' to get a single string.
+ *
+ * This provider is used by default, if it is available or explicit enabled in your header.inc.php:
+ * $GLOBALS['egw_info']['server']['cache_provider_instance'] = array('EGroupware\Api\Cache\Apc');
+ * and optional also $GLOBALS['egw_info']['server']['cache_provider_tree'] (defaults to instance)
+ *
+ * APC(u) and CLI:
+ * --------------
+ * APC(u) is not enabled by default for CLI (apc.enable_cli), nor would it access same shared memory!
+ * It makes no sense to fall back to files cache, as this is probably quite outdated,
+ * if PHP via Webserver uses APC. Better to use no cache at all.
+ * Api\Cache::get*() will return NULL for not found and Api\Cache::[un]set*()
+ * false for not being able to (un)set anything.
+ * It also does not make sense to report failure by throwing an Exception and filling
+ * up cron logs.
+ * --> if APC(u) is available for Webserver, we report availability for CLI too,
+ *     but use no cache at all!
+ */
+class Apcu extends Base implements Provider
+{
+	/**
+	 * Constructor, eg. opens the connection to the backend
+	 *
+	 * @throws Exception if connection to backend could not be established
+	 * @param array $params eg. array('localhost'[,'localhost:11211',...])
+	 */
+	function __construct(array $params)
+	{
+		if (!function_exists('apcu_fetch'))	// apc >= 3.0
+		{
+			throw new Exception (__METHOD__.'('.array2string($params).") No function apcu_fetch()!");
+		}
+	}
+
+	/**
+	 * Check if APC is available for caching user data
+	 *
+	 * Default shared memory size of 32M is just enough for the byte code cache,
+	 * but not for caching user data, we only use APC by default if we have at least 64M.
+	 *
+	 * @return boolean true: apc available, false: not
+	 */
+	public static function available()
+	{
+		if (($available = (bool)ini_get('apc.enabled') && function_exists('apcu_fetch')))
+		{
+			$size = ini_get('apc.shm_size');
+
+			switch(strtoupper(substr($size, -1)))
+			{
+				case 'G':
+					$size *= 1024;
+				case 'M':
+					$size *= 1024;
+				case 'K':
+					$size *= 1024;
+			}
+			$size *= ini_get('apc.shm_segments');
+
+			// only cache in APC, if we have at least 64M available (default is 32M)
+			$available = $size >= 67108864;
+		}
+		//error_log(__METHOD__."() size=$size returning ".array2string($available));
+		return $available;
+	}
+
+	/**
+	 * Stores some data in the cache, if it does NOT already exists there
+	 *
+	 * @param array $keys eg. array($level,$app,$location)
+	 * @param mixed $data
+	 * @param int $expiration =0
+	 * @return boolean true on success, false on error, incl. key already exists in cache
+	 */
+	function add(array $keys,$data,$expiration=0)
+	{
+		return apcu_add(self::key($keys),$data,$expiration);
+	}
+
+	/**
+	 * Stores some data in the cache
+	 *
+	 * @param array $keys eg. array($level,$app,$location)
+	 * @param mixed $data
+	 * @param int $expiration =0
+	 * @return boolean true on success, false on error
+	 */
+	function set(array $keys,$data,$expiration=0)
+	{
+		return apcu_store(self::key($keys),$data,$expiration);
+	}
+
+	/**
+	 * Get some data from the cache
+	 *
+	 * @param array $keys eg. array($level,$app,$location)
+	 * @return mixed data stored or NULL if not found in cache
+	 */
+	function get(array $keys)
+	{
+		$success = null;
+		$data = apcu_fetch($key=self::key($keys),$success);
+
+		if (!$success)
+		{
+			//error_log(__METHOD__."(".array2string($keys).") key='$key' NOT found!");
+			return null;
+		}
+		//error_log(__METHOD__."(".array2string($keys).") key='$key' found ".bytes(serialize($data))." bytes).");
+		return $data;
+	}
+
+	/**
+	 * Delete some data from the cache
+	 *
+	 * @param array $keys eg. array($level,$app,$location)
+	 * @return boolean true on success, false on error (eg. $key not set)
+	 */
+	function delete(array $keys)
+	{
+		return apcu_delete(self::key($keys));
+	}
+
+	/**
+	 * Delete all data under given keys
+	 *
+	 * @param array $keys eg. array($level,$app,$location)
+	 * @return boolean true on success, false on error (eg. $key not set)
+	 */
+	function flush(array $keys)
+	{
+		// APCu > 5 has APCUIterator
+		if (class_exists('APCUIterator'))
+		{
+			$iterator = new \APCUIterator($preg='/^'.preg_quote(self::key($keys).'/'));
+		}
+		// APC >= 3.1.1, but also seems to be missing if apc is disabled eg. for cli
+		elseif(class_exists('APCIterator'))
+		{
+			$iterator = new \APCIterator('user', $preg='/^'.preg_quote(self::key($keys).'/'));
+		}
+		else
+		{
+			if (function_exists('apcu_clear_cache')) apcu_clear_cache ();
+
+			return false;
+		}
+		foreach($iterator as $item)
+		{
+			//error_log(__METHOD__."(".array2string($keys).") preg='$preg': calling apcu_delete('$item[key]')");
+			apcu_delete($item['key']);
+		}
+		return true;
+	}
+
+	/**
+	 * Create a single key from $keys
+	 *
+	 * @param array $keys
+	 * @return string
+	 */
+	private static function key(array $keys)
+	{
+		return implode('::',$keys);
+	}
+}