Adding multihost - locking

Adding Unit-Tests for it

src/Core/Cache/ArrayCache.php

@@ -0,0 +1,83 @@
+<?php
+
+namespace Friendica\Core\Cache;
+
+
+use Friendica\Core\Cache;
+
+/**
+ * @brief Implementation of the IMemoryCacheDriver mainly for testing purpose
+ *
+ * Class ArrayCache
+ *
+ * @package Friendica\Core\Cache
+ */
+class ArrayCache implements IMemoryCacheDriver
+{
+	use TraitCompareDelete;
+
+	/** @var array Array with the cached data */
+	protected $cachedData = array();
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function get($key)
+	{
+		if (isset($this->cachedData[$key])) {
+			return $this->cachedData[$key];
+		}
+		return null;
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function set($key, $value, $ttl = Cache::FIVE_MINUTES)
+	{
+		$this->cachedData[$key] = $value;
+		return true;
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function delete($key)
+	{
+		unset($this->cachedData[$key]);
+		return true;
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function clear()
+	{
+		$this->cachedData = [];
+		return true;
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function add($key, $value, $ttl = Cache::FIVE_MINUTES)
+	{
+		if (isset($this->cachedData[$key])) {
+			return false;
+		} else {
+			return $this->set($key, $value, $ttl);
+		}
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function compareSet($key, $oldValue, $newValue, $ttl = Cache::FIVE_MINUTES)
+	{
+		if ($this->get($key) === $oldValue) {
+			return $this->set($key, $newValue);
+		} else {
+			return false;
+		}
+	}
+}

src/Core/Cache/DatabaseCacheDriver.php

@@ -33,11 +33,11 @@ class DatabaseCacheDriver implements ICacheDriver
 		return null;
 	}
 
-	public function set($key, $value, $duration = Cache::MONTH)
+	public function set($key, $value, $ttl = Cache::FIVE_MINUTES)
 	{
 		$fields = [
 			'v'       => serialize($value),
-			'expires' => DateTimeFormat::utc('now + ' . $duration . ' seconds'),
+			'expires' => DateTimeFormat::utc('now + ' . $ttl . ' seconds'),
 			'updated' => DateTimeFormat::utcNow()
 		];
 

src/Core/Cache/ICacheDriver.php

@@ -12,7 +12,7 @@ use Friendica\Core\Cache;
 interface ICacheDriver
 {
 	/**
-	 * Fetches cached data according to the key
+	 * @brief Fetches cached data according to the key
 	 *
 	 * @param string $key The key to the cached data
 	 *
@@ -21,28 +21,27 @@ interface ICacheDriver
 	public function get($key);
 
 	/**
-	 * Stores data in the cache identified by the key. The input $value can have multiple formats.
+	 * @brief Stores data in the cache identified by the key. The input $value can have multiple formats.
 	 *
 	 * @param string  $key      The cache key
 	 * @param mixed   $value    The value to store
-	 * @param integer $duration The cache lifespan, must be one of the Cache constants
+	 * @param integer $ttl 		 The cache lifespan, must be one of the Cache constants
 	 *
 	 * @return bool
 	 */
-	public function set($key, $value, $duration = Cache::MONTH);
-
+	public function set($key, $value, $ttl = Cache::FIVE_MINUTES);
 
 	/**
-	 * Delete a key from the cache
+	 * @brief Delete a key from the cache
 	 *
-	 * @param string $key
+	 * @param string $key      The cache key
 	 *
 	 * @return bool
 	 */
 	public function delete($key);
 
 	/**
-	 * Remove outdated data from the cache
+	 * @brief Remove outdated data from the cache
 	 *
 	 * @return bool
 	 */

src/Core/Cache/IMemoryCacheDriver.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace Friendica\Core\Cache;
+use Friendica\Core\Cache;
+
+/**
+ * @brief This interface defines methods for Memory-Caches only
+ *
+ * Interface IMemoryCacheDriver
+ *
+ * @package Friendica\Core\Cache
+ */
+interface IMemoryCacheDriver extends ICacheDriver
+{
+	/**
+	 * @brief Sets a value if it's not already stored
+	 *
+	 * @param string $key      The cache key
+	 * @param mixed  $value    The old value we know from the cache
+	 * @param int    $ttl      The cache lifespan, must be one of the Cache constants
+	 * @return bool
+	 */
+	public function add($key, $value, $ttl = Cache::FIVE_MINUTES);
+
+	/**
+	 * @brief Compares if the old value is set and sets the new value
+	 *
+	 * @param string $key         The cache key
+	 * @param mixed  $oldValue    The old value we know from the cache
+	 * @param mixed  $newValue    The new value we want to set
+	 * @param int    $ttl      	   The cache lifespan, must be one of the Cache constants
+	 *
+	 * @return bool
+	 */
+	public function compareSet($key, $oldValue, $newValue, $ttl = Cache::FIVE_MINUTES);
+
+	/**
+	 * @brief Compares if the old value is set and removes it
+	 *
+	 * @param string $key          The cache key
+	 * @param mixed  $value        The old value we know and want to delete
+	 * @return bool
+	 */
+	public function compareDelete($key, $value);
+}

src/Core/Cache/MemcacheCacheDriver.php

@@ -10,10 +10,13 @@ use Friendica\Core\Cache;
  *
  * @author Hypolite Petovan <mrpetovan@gmail.com>
  */
-class MemcacheCacheDriver extends BaseObject implements ICacheDriver
+class MemcacheCacheDriver extends BaseObject implements IMemoryCacheDriver
 {
+	use TraitCompareSet;
+	use TraitCompareDelete;
+
 	/**
-	 * @var Memcache
+	 * @var \Memcache
 	 */
 	private $memcache;
 
@@ -30,6 +33,9 @@ class MemcacheCacheDriver extends BaseObject implements ICacheDriver
 		}
 	}
 
+	/**
+	 * (@inheritdoc)
+	 */
 	public function get($key)
 	{
 		$return = null;
@@ -54,17 +60,31 @@ class MemcacheCacheDriver extends BaseObject implements ICacheDriver
 		return $return;
 	}
 
-	public function set($key, $value, $duration = Cache::MONTH)
+	/**
+	 * (@inheritdoc)
+	 */
+	public function set($key, $value, $ttl = Cache::FIVE_MINUTES)
 	{
 		// We store with the hostname as key to avoid problems with other applications
-		return $this->memcache->set(
-			self::getApp()->get_hostname() . ":" . $key,
-			serialize($value),
-			MEMCACHE_COMPRESSED,
-			time() + $duration
-		);
+		if ($ttl > 0) {
+			return $this->memcache->set(
+				self::getApp()->get_hostname() . ":" . $key,
+				serialize($value),
+				MEMCACHE_COMPRESSED,
+				time() + $ttl
+			);
+		} else {
+			return $this->memcache->set(
+				self::getApp()->get_hostname() . ":" . $key,
+				serialize($value),
+				MEMCACHE_COMPRESSED
+			);
+		}
 	}
 
+	/**
+	 * (@inheritdoc)
+	 */
 	public function delete($key)
 	{
 		return $this->memcache->delete($key);
@@ -72,6 +92,14 @@ class MemcacheCacheDriver extends BaseObject implements ICacheDriver
 
 	public function clear()
 	{
-		return true;
+		return $this->memcache->flush();
+	}
+
+	/**
+	 * (@inheritdoc)
+	 */
+	public function add($key, $value, $ttl = Cache::FIVE_MINUTES)
+	{
+		return $this->memcache->add(self::getApp()->get_hostname() . ":" . $key, $value, $ttl);
 	}
 }

src/Core/Cache/MemcachedCacheDriver.php

@@ -10,8 +10,11 @@ use Friendica\Core\Cache;
  *
  * @author Hypolite Petovan <mrpetovan@gmail.com>
  */
-class MemcachedCacheDriver extends BaseObject implements ICacheDriver
+class MemcachedCacheDriver extends BaseObject implements IMemoryCacheDriver
 {
+	use TraitCompareSet;
+	use TraitCompareDelete;
+
 	/**
 	 * @var Memcached
 	 */
@@ -46,14 +49,22 @@ class MemcachedCacheDriver extends BaseObject implements ICacheDriver
 		return $return;
 	}
 
-	public function set($key, $value, $duration = Cache::MONTH)
+	public function set($key, $value, $ttl = Cache::FIVE_MINUTES)
 	{
 		// We store with the hostname as key to avoid problems with other applications
-		return $this->memcached->set(
-			self::getApp()->get_hostname() . ':' . $key,
-			$value,
-			time() + $duration
-		);
+		if ($ttl > 0) {
+			return $this->memcached->set(
+				self::getApp()->get_hostname() . ':' . $key,
+				$value,
+				time() + $ttl
+			);
+		} else {
+			return $this->memcached->set(
+				self::getApp()->get_hostname() . ':' . $key,
+				$value
+			);
+		}
+
 	}
 
 	public function delete($key)
@@ -67,4 +78,17 @@ class MemcachedCacheDriver extends BaseObject implements ICacheDriver
 	{
 		return true;
 	}
+
+	/**
+	 * @brief Sets a value if it's not already stored
+	 *
+	 * @param string $key      The cache key
+	 * @param mixed  $value    The old value we know from the cache
+	 * @param int    $ttl      The cache lifespan, must be one of the Cache constants
+	 * @return bool
+	 */
+	public function add($key, $value, $ttl = Cache::FIVE_MINUTES)
+	{
+		return $this->memcached->add(self::getApp()->get_hostname() . ":" . $key, $value, $ttl);
+	}
 }

src/Core/Cache/RedisCacheDriver.php

@@ -11,7 +11,7 @@ use Friendica\Core\Cache;
  * @author Hypolite Petovan <mrpetovan@gmail.com>
  * @author Roland Haeder <roland@mxchange.org>
  */
-class RedisCacheDriver extends BaseObject implements ICacheDriver
+class RedisCacheDriver extends BaseObject implements IMemoryCacheDriver
 {
 	/**
 	 * @var Redis
@@ -55,14 +55,21 @@ class RedisCacheDriver extends BaseObject implements ICacheDriver
 		return $return;
 	}
 
-	public function set($key, $value, $duration = Cache::MONTH)
+	public function set($key, $value, $ttl = Cache::FIVE_MINUTES)
 	{
 		// We store with the hostname as key to avoid problems with other applications
-		return $this->redis->set(
-			self::getApp()->get_hostname() . ":" . $key,
-			serialize($value),
-			time() + $duration
-		);
+		if ($ttl > 0) {
+			return $this->redis->setex(
+				self::getApp()->get_hostname() . ":" . $key,
+				time() + $ttl,
+				serialize($value)
+			);
+		} else {
+			return $this->redis->set(
+				self::getApp()->get_hostname() . ":" . $key,
+				serialize($value)
+			);
+		}
 	}
 
 	public function delete($key)
@@ -74,4 +81,75 @@ class RedisCacheDriver extends BaseObject implements ICacheDriver
 	{
 		return true;
 	}
+
+
+	/**
+	 * @brief Sets a value if it's not already stored
+	 *
+	 * @param string $key The cache key
+	 * @param mixed $value The old value we know from the cache
+	 * @param int    $ttl      The cache lifespan, must be one of the Cache constants
+	 * @return bool
+	 */
+	public function add($key, $value, $ttl = Cache::FIVE_MINUTES)
+	{
+		if (!is_int($value)) {
+			$value = serialize($value);
+		}
+
+		return $this->redis->setnx(self::getApp()->get_hostname() . ":" . $key, $value);
+	}
+
+	/**
+	 * @brief Compares if the old value is set and sets the new value
+	 *
+	 * @param string $key The cache key
+	 * @param mixed $oldValue The old value we know
+	 * @param mixed $newValue The new value we want to set
+	 * @param int    $ttl      The cache lifespan, must be one of the Cache constants
+	 * @return bool
+	 */
+	public function compareSet($key, $oldValue, $newValue, $ttl = Cache::FIVE_MINUTES)
+	{
+		if (!is_int($newValue)) {
+			$newValue = serialize($newValue);
+		}
+
+		$this->redis->watch(self::getApp()->get_hostname() . ":" . $key);
+		// If the old value isn't what we expected, somebody else changed the key meanwhile
+		if ($this->get($key) === $oldValue) {
+			if ($ttl > 0) {
+				$result = $this->redis->multi()
+					->setex(self::getApp()->get_hostname() . ":" . $ttl, $key, $newValue)
+					->exec();
+			} else {
+				$result = $this->redis->multi()
+					->set(self::getApp()->get_hostname() . ":" . $key, $newValue)
+					->exec();
+			}
+			return $result !== false;
+		}
+		$this->redis->unwatch();
+		return false;
+	}
+	/**
+	 * @brief Compares if the old value is set and removes it
+	 *
+	 * @param string $key The cache key
+	 * @param mixed $value The old value we know and want to delete
+	 * @return bool
+	 */
+	public function compareDelete($key, $value)
+	{
+		$this->redis->watch(self::getApp()->get_hostname() . ":" . $key);
+		// If the old value isn't what we expected, somebody else changed the key meanwhile
+		if ($this->get($key) === $value) {
+			$result = $this->redis->multi()
+				->del(self::getApp()->get_hostname() . ":" . $key)
+				->exec();
+			return $result !== false;
+		}
+		$this->redis->unwatch();
+		return false;
+	}
 }

src/Core/Cache/TraitCompareDelete.php

@@ -0,0 +1,45 @@
+<?php
+
+namespace Friendica\Core\Cache;
+
+use Friendica\Core\Cache;
+
+/**
+ * Trait TraitCompareSetDelete
+ *
+ * @brief This Trait is to compensate non native "exclusive" sets/deletes in caches
+ *
+ * @package Friendica\Core\Cache
+ */
+trait TraitCompareDelete
+{
+	abstract public function get($key);
+
+	abstract public function set($key, $value, $ttl = Cache::FIVE_MINUTES);
+
+	abstract public function delete($key);
+
+	abstract public function add($key, $value, $ttl = Cache::FIVE_MINUTES);
+
+	/**
+	 * @brief NonNative - Compares if the old value is set and removes it
+	 *
+	 * @param string $key          The cache key
+	 * @param mixed  $value        The old value we know and want to delete
+	 * @return bool
+	 */
+	public function compareDelete($key, $value) {
+		if ($this->add($key . "_lock", true)) {
+			if ($this->get($key) === $value) {
+				$this->delete($key);
+				$this->delete($key . "_lock");
+				return true;
+			} else {
+				$this->delete($key . "_lock");
+				return false;
+			}
+		} else {
+			return false;
+		}
+	}
+}

src/Core/Cache/TraitCompareSet.php

@@ -0,0 +1,48 @@
+<?php
+
+namespace Friendica\Core\Cache;
+
+use Friendica\Core\Cache;
+
+/**
+ * Trait TraitCompareSetDelete
+ *
+ * @brief This Trait is to compensate non native "exclusive" sets/deletes in caches
+ *
+ * @package Friendica\Core\Cache
+ */
+trait TraitCompareSet
+{
+	abstract public function get($key);
+
+	abstract public function set($key, $value, $ttl = Cache::FIVE_MINUTES);
+
+	abstract public function delete($key);
+
+	abstract public function add($key, $value, $ttl = Cache::FIVE_MINUTES);
+
+	/**
+	 * @brief NonNative - Compares if the old value is set and sets the new value
+	 *
+	 * @param string $key         The cache key
+	 * @param mixed  $oldValue    The old value we know from the cache
+	 * @param mixed  $newValue    The new value we want to set
+	 * @param int    $ttl      The cache lifespan, must be one of the Cache constants
+	 *
+	 * @return bool
+	 */
+	public function compareSet($key, $oldValue, $newValue, $ttl = Cache::FIVE_MINUTES) {
+		if ($this->add($key . "_lock", true)) {
+			if ($this->get($key) === $oldValue) {
+				$this->set($key, $newValue, $ttl);
+				$this->delete($key . "_lock");
+				return true;
+ 			} else {
+				$this->delete($key . "_lock");
+				return false;
+			}
+		} else {
+			return false;
+		}
+	}
+}