From 1eec7d110f2839de6c89c152e842ab33fce6a240 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Bartek=20Olewi=C5=84ski?= <bartman3000@gmail.com>
Date: Tue, 18 Dec 2018 10:07:12 +0100
Subject: [PATCH] Memcached handle (#43)

* Memcached classes reorganized

* Memcached classes reorganized

* Memcached classes reorganized - formatting

* Memcached classes reorganized - formatting
---
 src/DistributedMemcacheMutex.php  | 13 +---------
 src/DistributedMemcachedMutex.php | 40 +++++++++++++++++++++++++++----
 src/DistributedMutex.php          | 30 +++++++++++++++++++++++
 tests/MemcachedStub.php           |  7 +++---
 4 files changed, 70 insertions(+), 20 deletions(-)
 create mode 100644 src/DistributedMutex.php

diff --git a/src/DistributedMemcacheMutex.php b/src/DistributedMemcacheMutex.php
index e98ce4e..09e0e48 100644
--- a/src/DistributedMemcacheMutex.php
+++ b/src/DistributedMemcacheMutex.php
@@ -8,11 +8,8 @@
 /**
  * Utility methods for manipulating distributed locks using memcache
  */
-class DistributedMemcacheMutex
+class DistributedMemcacheMutex extends DistributedMutex
 {
-    const FIVE_MINUTES_SECONDS = 300;
-    const MEMCACHE_ERR_MSG = 'No servers added to memcache connection.';
-
     /**
      * @var Memcache
      */
@@ -50,12 +47,4 @@ protected function assertServersAddedToMemcache()
             throw new InvalidArgumentException(self::MEMCACHE_ERR_MSG);
         }
     }
-
-    /**
-     * @param string $name
-     */
-    public function unlock($name)
-    {
-        $this->memcache->delete($name);
-    }
 }
diff --git a/src/DistributedMemcachedMutex.php b/src/DistributedMemcachedMutex.php
index 7ea090c..122e73b 100644
--- a/src/DistributedMemcachedMutex.php
+++ b/src/DistributedMemcachedMutex.php
@@ -3,19 +3,20 @@
 
 namespace Assertis\Util;
 
+use InvalidArgumentException;
 use Memcached;
 
 /**
  * This class should be used when we will migrate to PHP 7.2
- * It extends DistributedMemcacheMutex because all other methods like add, remove etc.
- * are available in memcached also so there is no reason to overwrite methods.
  *
  * @author Łukasz Nowak <lukasz.nowak@assertis.co.uk>
+ * @author Bartłomiej Olewiński <bartlomiej.olewinski@assertis.co.uk>
  * Class DistributedMemcachedMutex
  * @package Assertis\Util
  */
-class DistributedMemcachedMutex extends DistributedMemcacheMutex
+class DistributedMemcachedMutex extends DistributedMutex
 {
+    const MEMCACHE_RESPOND_ERR_MSG = 'Server %s not responding.';
 
     /**
      * DistributedMemcachedMutex constructor.
@@ -25,4 +26,35 @@ public function __construct(Memcached $memcached)
     {
         $this->memcache = $memcached;
     }
-}
\ No newline at end of file
+
+    /**
+     * @param string $name
+     * @param int $expirationTimeInSeconds
+     *
+     * @throws InvalidArgumentException
+     * @throws AlreadyLockedException
+     */
+    public function lock($name, $expirationTimeInSeconds = self::FIVE_MINUTES_SECONDS)
+    {
+        $this->assertServersAddedToMemcachedAndResponding();
+
+        if (false === $this->memcache->add($name, 1, $expirationTimeInSeconds)) {
+            throw new AlreadyLockedException($name);
+        }
+    }
+
+    protected function assertServersAddedToMemcachedAndResponding()
+    {
+        $serverVersions = $this->memcache->getversion();
+
+        if (count($serverVersions) == 0) {
+            throw new InvalidArgumentException(self::MEMCACHE_ERR_MSG);
+        }
+
+        foreach ($serverVersions as $server => $version) {
+            if ($version == '255.255.255') { //https://secure.php.net/manual/en/memcached.getversion.php#111539
+                throw new InvalidArgumentException(sprintf(self::MEMCACHE_RESPOND_ERR_MSG, $server));
+            }
+        }
+    }
+}
diff --git a/src/DistributedMutex.php b/src/DistributedMutex.php
new file mode 100644
index 0000000..b86ce7d
--- /dev/null
+++ b/src/DistributedMutex.php
@@ -0,0 +1,30 @@
+<?php
+/**
+ * @author Bartłomiej Olewiński <bartlomiej.olewinski@gmail.com>
+ */
+
+namespace Assertis\Util;
+
+use Memcache;
+use Memcached;
+
+abstract class DistributedMutex
+{
+    const FIVE_MINUTES_SECONDS = 300;
+    const MEMCACHE_ERR_MSG = 'No servers added to memcache connection.';
+
+    /**
+     * @var Memcache|Memcached
+     */
+    protected $memcache;
+
+    abstract public function lock($name, $expirationTimeInSeconds);
+
+    /**
+     * @param string $name
+     */
+    public function unlock($name)
+    {
+        $this->memcache->delete($name);
+    }
+}
diff --git a/tests/MemcachedStub.php b/tests/MemcachedStub.php
index 5554df5..8d34689 100644
--- a/tests/MemcachedStub.php
+++ b/tests/MemcachedStub.php
@@ -16,15 +16,14 @@ class MemcachedStub extends Memcached
     /**
      * @var bool
      */
-    private $areServersAdded = false;
+    private $serversAdded = [];
 
     /**
      * @return MemcachedStub
      */
     public function withServersAdded()
     {
-        $this->areServersAdded = true;
-
+        $this->serversAdded = ['localhost:11211' => '1.2.6'];
         return $this;
     }
 
@@ -59,6 +58,6 @@ public function delete($key, $timeout = 0)
      */
     public function getversion()
     {
-        return $this->areServersAdded;
+        return $this->serversAdded;
     }
 }