[Fix] Fix duplicated warning (#992)

* [Fix] Fix repeated warning

* Add type hint

* Fix unit test

* Rename recorder_dict to seen

* Fix as comment

mmengine/logging/logger.py

@@ -11,6 +11,35 @@ from mmengine.utils import ManagerMixin
 from mmengine.utils.manager import _accquire_lock, _release_lock
 
 
+class FilterDuplicateWarning(logging.Filter):
+    """Filter the repeated warning message.
+
+    Args:
+        name (str): name of the filter.
+    """
+
+    def __init__(self, name: str = 'mmengine'):
+        super().__init__(name)
+        self.seen: set = set()
+
+    def filter(self, record: LogRecord) -> bool:
+        """Filter the repeated warning message.
+
+        Args:
+            record (LogRecord): The log record.
+
+        Returns:
+            bool: Whether to output the log record.
+        """
+        if record.levelno != logging.WARNING:
+            return True
+
+        if record.msg not in self.seen:
+            self.seen.add(record.msg)
+            return True
+        return False
+
+
 class MMFormatter(logging.Formatter):
     """Colorful format for MMLogger. If the log level is error, the logger will
     additionally output the location of the code.
@@ -164,6 +193,7 @@ class MMLogger(Logger, ManagerMixin):
         # Only rank0 `StreamHandler` will log messages below error level.
         stream_handler.setLevel(log_level) if rank == 0 else \
             stream_handler.setLevel(logging.ERROR)
+        stream_handler.addFilter(FilterDuplicateWarning(logger_name))
         self.handlers.append(stream_handler)
 
         if log_file is not None:
@@ -191,6 +221,7 @@ class MMLogger(Logger, ManagerMixin):
                 file_handler.setFormatter(
                     MMFormatter(color=False, datefmt='%Y/%m/%d %H:%M:%S'))
                 file_handler.setLevel(log_level)
+                file_handler.addFilter(FilterDuplicateWarning(logger_name))
                 self.handlers.append(file_handler)
 
     @classmethod

tests/test_logging/test_logger.py

@@ -184,3 +184,17 @@ class TestLogger:
         logger.warning('hello')
         out, _ = capsys.readouterr()
         assert 'WARNING' in out
+
+    def test_filter(self, capsys):
+        logger = MMLogger.get_instance('test_filter')
+        logger.warning('hello')
+        out, _ = capsys.readouterr()
+        assert 'WARNING' in out
+        # Filter repeated warning.
+        logger.warning('hello')
+        out, _ = capsys.readouterr()
+        assert not out
+        # Pass new warning
+        logger.warning('hello1')
+        out, _ = capsys.readouterr()
+        assert 'WARNING' in out