use separate lock-file to prevent race conditions (#146)

Co-authored-by: Markus Staab <[email protected]>

Author: staabm

.phpunit-phpstan-dba.cache

@@ -2,64 +2,6 @@
   'schemaVersion' => 'v3-rename-props',
   'records' => 
   array (
-    '
-            SELECT email adaid
-            WHERE gesperrt = \'1\' AND email LIKE \'%@example.com\'
-            FROM ada
-            LIMIT        1
-        ' => 
-    array (
-      'error' => 
-      staabm\PHPStanDba\Error::__set_state(array(
-         'message' => 'You have an error in your SQL syntax; check the manual that corresponds to your MySQL/MariaDB server version for the right syntax to use near \'FROM ada LIMIT 0\' at line 3',
-         'code' => 1064,
-      )),
-    ),
-    '
-            SELECT email, adaid
-            FROM ada
-            WHERE gesperrt = \'1\'
-            LIMIT        \'1\'
-        ' => 
-    array (
-      'error' => NULL,
-    ),
-    '
-            SELECT email, adaid
-            FROM ada
-            WHERE gesperrt = \'1\'
-            LIMIT        \'1\',  \'1\'
-        ' => 
-    array (
-      'error' => NULL,
-    ),
-    '
-            SELECT email, adaid
-            FROM ada
-            WHERE gesperrt = \'1\'
-            LIMIT   \'1\',     \'1\'
-        ' => 
-    array (
-      'error' => NULL,
-    ),
-    '
-            SELECT email, adaid
-            FROM ada
-            WHERE gesperrt = \'1\' AND email LIKE \'%@example%\'
-            LIMIT        1
-        ' => 
-    array (
-      'error' => NULL,
-    ),
-    '
-            SELECT email, adaid
-            FROM ada
-            WHERE gesperrt = \'1\' AND email LIKE NULL
-            LIMIT        1
-        ' => 
-    array (
-      'error' => NULL,
-    ),
     '
             SELECT email adaid
             WHERE gesperrt = \'1\' AND email LIKE \'%@example.com\'
@@ -2775,11 +2717,6 @@ Simulated query: SELECT email, adaid FROM ada . WHERE email=\'my_other_table\' L
     array (
       'error' => NULL,
     ),
-    'SELECT email, adaid, gesperrt, freigabe1u1 FROM ada
-            WHERE (gesperrt=\'1\' AND freigabe1u1=1) OR (gesperrt=\'1\' AND freigabe1u1=0)' => 
-    array (
-      'error' => NULL,
-    ),
     'SELECT email, adaid, gesperrt, freigabe1u1 FROM ada  WHERE email=\'my_other_table\' LIMIT 1' => 
     array (
       'error' => NULL,

src/QueryReflection/ReflectionCache.php

@@ -74,15 +74,22 @@ public function persist(): void
             return;
         }
 
+        // prevent parallel phpstan-worker-process from writing into the cache file at the same time
+        // XXX we use a single system-wide lock file, which might get problematic if multiple users run phpstan on the same machine at the same time
+        $lockFile = sys_get_temp_dir().'/staabm-phpstan-dba-cache.lock';
+        $lockHandle = fopen($lockFile, 'w+');
+        if (false === $lockHandle) {
+            throw new DbaException(sprintf('Could not open cache file "%s" for writing', $this->cacheFile));
+        }
+        flock($lockHandle, LOCK_EX);
+
         // freshly read the cache as it might have changed in the meantime
         $cachedRecords = $this->readCache();
 
-        // actually we should lock even earlier, but we could no longer read the cache-file with require()
         $handle = fopen($this->cacheFile, 'w+');
         if (false === $handle) {
             throw new DbaException(sprintf('Could not open cache file "%s" for writing', $this->cacheFile));
         }
-        flock($handle, LOCK_EX);
 
         // re-apply all changes to the current cache-state
         if (null === $cachedRecords) {
@@ -105,8 +112,9 @@ public function persist(): void
             throw new DbaException(sprintf('Unable to write cache file "%s"', $this->cacheFile));
         }
 
-        // will free the lock implictly
         fclose($handle);
+        // will free the lock implictly
+        fclose($lockHandle);
     }
 
     public function hasValidationError(string $queryString): bool