refs #9131 lock name should be less than 64 characters for MySQL compatibility

core/DataAccess/Model.php

@@ -281,7 +281,12 @@ class Model
 
     public function deletePreviousArchiveStatus($numericTable, $archiveId, $doneFlag)
     {
-        $dbLockName = "deletePreviousArchiveStatus.$numericTable.$archiveId";
+        $tableWithoutLeadingPrefix = $numericTable;
+        if (strlen($numericTable) >= 23) {
+            $tableWithoutLeadingPrefix = substr($numericTable, strlen($numericTable) - 23);
+            // we need to make sure lock name is less than 64 characters see https://github.com/piwik/piwik/issues/9131
+        }
+        $dbLockName = "rmPrevArchiveStatus.$tableWithoutLeadingPrefix.$archiveId";
 
         // without advisory lock here, the DELETE would acquire Exclusive Lock
         $this->acquireArchiveTableLock($dbLockName);

core/Db.php

@@ -90,6 +90,17 @@ class Db
         return $dbConfig;
     }
 
+    /**
+     * For tests only.
+     * @param $connection
+     * @ignore
+     * @internal
+     */
+    public static function setDatabaseObject($connection)
+    {
+        self::$connection = $connection;
+    }
+
     /**
      * Connects to the database.
      *
@@ -638,9 +649,14 @@ class Db
      * @param string $lockName The lock name.
      * @param int $maxRetries The max number of times to retry.
      * @return bool `true` if the lock was obtained, `false` if otherwise.
+     * @throws \Exception if Lock name is too long
      */
     public static function getDbLock($lockName, $maxRetries = 30)
     {
+        if (strlen($lockName) > 64) {
+            throw new \Exception('DB lock name has to be 64 characters or less for MySQL 5.7 compatibility.');
+        }
+
         /*
          * the server (e.g., shared hosting) may have a low wait timeout
          * so instead of a single GET_LOCK() with a 30 second timeout,
@@ -652,7 +668,8 @@ class Db
         $db = self::get();
 
         while ($maxRetries > 0) {
-            if ($db->fetchOne($sql, array($lockName)) == '1') {
+            $result = $db->fetchOne($sql, array($lockName));
+            if ($result == '1') {
                 return true;
             }
             $maxRetries--;

tests/PHPUnit/Integration/DbTest.php

@@ -56,6 +56,41 @@ class DbTest extends IntegrationTestCase
         $this->assertSame($expected, $result);
     }
 
+    /**
+     * @expectedException \Exception
+     * @expectedExceptionMessagelock name has to be 64 characters or less
+     */
+    public function test_getDbLock_shouldThrowAnException_IfDbLockNameIsTooLong()
+    {
+        Db::getDbLock(str_pad('test', 65, '1'));
+    }
+
+    public function test_getDbLock_shouldGetLock()
+    {
+        $db = Db::get();
+        $this->assertTrue(Db::getDbLock('MyLock'));
+        // same session still has lock
+        $this->assertTrue(Db::getDbLock('MyLock'));
+
+        Db::setDatabaseObject(null);
+        // different session, should not be able to acquire lock
+        $this->assertFalse(Db::getDbLock('MyLock', 1));
+        // different session cannot release lock
+        $this->assertFalse(Db::releaseDbLock('MyLock'));
+        Db::destroyDatabaseObject();
+
+        // release lock again by using previous session
+        Db::setDatabaseObject($db);
+        $this->assertTrue(Db::releaseDbLock('MyLock'));
+        Db::destroyDatabaseObject();
+    }
+
+    public function test_tableExists()
+    {
+        $this->assertFalse(Db::tableExists('noTExistIngTable'));
+        $this->assertTrue(Db::tableExists(Common::prefixTable('log_visit')));
+    }
+
     public function getDbAdapter()
     {
         return array(