Use relative timestamps

Author: tvlooy

Session/Storage/Handler/MemcachedSessionHandler.php

@@ -77,7 +77,7 @@ protected function doRead(string $sessionId)
     #[\ReturnTypeWillChange]
     public function updateTimestamp($sessionId, $data)
     {
-        $this->memcached->touch($this->prefix.$sessionId, time() + (int) ($this->ttl ?? \ini_get('session.gc_maxlifetime')));
+        $this->memcached->touch($this->prefix.$sessionId, $this->getCompatibleTtl());
 
         return true;
     }
@@ -87,7 +87,20 @@ public function updateTimestamp($sessionId, $data)
      */
     protected function doWrite(string $sessionId, string $data)
     {
-        return $this->memcached->set($this->prefix.$sessionId, $data, time() + (int) ($this->ttl ?? \ini_get('session.gc_maxlifetime')));
+        return $this->memcached->set($this->prefix.$sessionId, $data, $this->getCompatibleTtl());
+    }
+
+    private function getCompatibleTtl(): int
+    {
+        $ttl = (int) ($this->ttl ?? \ini_get('session.gc_maxlifetime'));
+
+        // If the relative TTL that is used exceeds 30 days, memcached will treat the value as Unix time.
+        // We have to convert it to an absolute Unix time at this point, to make sure the TTL is correct.
+        if ($ttl > 60 * 60 * 24 * 30) {
+            $ttl += time();
+        }
+
+        return $ttl;
     }
 
     /**

Tests/Session/Storage/Handler/MemcachedSessionHandlerTest.php

@@ -16,6 +16,7 @@
 
 /**
  * @requires extension memcached
+ *
  * @group time-sensitive
  */
 class MemcachedSessionHandlerTest extends TestCase
@@ -92,13 +93,30 @@ public function testWriteSession()
         $this->memcached
             ->expects($this->once())
             ->method('set')
-            ->with(self::PREFIX.'id', 'data', $this->equalTo(time() + self::TTL, 2))
+            ->with(self::PREFIX.'id', 'data', $this->equalTo(self::TTL, 2))
             ->willReturn(true)
         ;
 
         $this->assertTrue($this->storage->write('id', 'data'));
     }
 
+    public function testWriteSessionWithLargeTTL()
+    {
+        $this->memcached
+            ->expects($this->once())
+            ->method('set')
+            ->with(self::PREFIX.'id', 'data', $this->equalTo(time() + self::TTL + 60 * 60 * 24 * 30, 2))
+            ->willReturn(true)
+        ;
+
+        $storage = new MemcachedSessionHandler(
+            $this->memcached,
+            ['prefix' => self::PREFIX, 'expiretime' => self::TTL + 60 * 60 * 24 * 30]
+        );
+
+        $this->assertTrue($storage->write('id', 'data'));
+    }
+
     public function testDestroySession()
     {
         $this->memcached