40             self::logError("Failed to open file for reading: $filepath");
56             self::logError("Failed to acquire read lock: $filepath");
74             self::logError("JSON decode error in $filepath: " . json_last_error_msg());
95                 self::logError("Failed to create directory: $dir");
106             self::logError("JSON encode error: " . json_last_error_msg());
113             self::logError("Failed to create temp file: $tempFile");
121             self::logError("Failed to lock temp file: $tempFile");
132             self::logError("Failed to write to temp file: $tempFile");
154                     self::logError("Failed to lock target file: $filepath");
166                     self::logError("Failed to rename temp to target: $filepath");
173                     self::logError("Failed to rename (no handle): $filepath");
181                 self::logError("Failed to rename new file: $filepath");
286     private static function logError($message) {  function in CalendarFileHandler