⚙ settings saving improvements + refactor - DB lock v0.1 #685

front/php/server/db.php

@@ -12,6 +12,8 @@
 // DB File Path
 $DBFILE = dirname(__FILE__).'/../../../db/app.db';
 
+$db_locked = false;
+
 //------------------------------------------------------------------------------
 // Connect DB
 //------------------------------------------------------------------------------
@@ -20,12 +22,21 @@ function SQLite3_connect ($trytoreconnect) {
   try
   {
     // connect to database
+
+    global $db_locked; 
+
+    $db_locked = false;
+
     // return new SQLite3($DBFILE, SQLITE3_OPEN_READONLY);
     return new SQLite3($DBFILE, SQLITE3_OPEN_READWRITE);
   }
   catch (Exception $exception)
   {
     // sqlite3 throws an exception when it is unable to connect
+    global $db_locked; 
+
+    $db_locked = true;
+
     // try to reconnect one time after 3 seconds
     
     if($trytoreconnect)

front/php/server/dbHelper.php

@@ -269,16 +269,26 @@ function delete($columnName, $id, $dbtable)
 //  check if the database is locked
 //------------------------------------------------------------------------------
 function checkLock() {
-  global $db;
-  try {
-      $db->exec('BEGIN EXCLUSIVE TRANSACTION');
-      $db->exec('COMMIT');
-      echo 0; // Not locked
-      return 0;
-  } catch (Exception $e) {
-      echo 1; // Locked
-      return 1;
+  global $DBFILE, $db_locked;
+
+  $file = fopen($DBFILE, 'r+');
+
+  if (!$file or $db_locked) {
+      echo 1; // Could not open the file
+      return;
   }
+
+  if (flock($file, LOCK_EX | LOCK_NB)) {
+      // Lock acquired, meaning the database is not locked by another process
+      flock($file, LOCK_UN); // Release the lock
+      echo 0; // Not locked
+  } else {
+      // Could not acquire lock, meaning the database is locked
+      echo 1; // Locked
+  }
+
+  fclose($file);
 }
 
+
 ?>

front/php/server/util.php

@@ -387,8 +387,10 @@ function saveSettings()
   // Replace the original file with the temporary file
   rename($tempConfPath, $fullConfPath);
 
-  displayMessage("<br/>Settings saved to the <code>app.conf</code> file.<br/><br/>A time-stamped backup of the previous file created. <br/><br/> Reloading...<br/>", 
-    FALSE, TRUE, TRUE, TRUE);    
+  // displayMessage(lang('settings_saved'), 
+  //   FALSE, TRUE, TRUE, TRUE);    
+
+  echo "OK";
 
 }