feat(api): add trace log level

api/onnx_web/logging.py

@@ -1,3 +1,4 @@
+import logging
 from logging.config import dictConfig
 from os import environ, path
 
@@ -5,11 +6,65 @@ from yaml import safe_load
 
 logging_path = environ.get("ONNX_WEB_LOGGING_PATH", "./logging.yaml")
 
+
+def addLoggingLevel(levelName, levelNum, methodName=None):
+    """
+    From https://stackoverflow.com/a/35804945
+
+    Comprehensively adds a new logging level to the `logging` module and the
+    currently configured logging class.
+
+    `levelName` becomes an attribute of the `logging` module with the value
+    `levelNum`. `methodName` becomes a convenience method for both `logging`
+    itself and the class returned by `logging.getLoggerClass()` (usually just
+    `logging.Logger`). If `methodName` is not specified, `levelName.lower()` is
+    used.
+
+    To avoid accidental clobberings of existing attributes, this method will
+    raise an `AttributeError` if the level name is already an attribute of the
+    `logging` module or if the method name is already present
+
+    Example
+    -------
+    >>> addLoggingLevel('TRACE', logging.DEBUG - 5)
+    >>> logging.getLogger(__name__).setLevel("TRACE")
+    >>> logging.getLogger(__name__).trace('that worked')
+    >>> logging.trace('so did this')
+    >>> logging.TRACE
+    5
+
+    """
+    if not methodName:
+        methodName = levelName.lower()
+
+    if hasattr(logging, levelName):
+       raise AttributeError('{} already defined in logging module'.format(levelName))
+    if hasattr(logging, methodName):
+       raise AttributeError('{} already defined in logging module'.format(methodName))
+    if hasattr(logging.getLoggerClass(), methodName):
+       raise AttributeError('{} already defined in logger class'.format(methodName))
+
+    # This method was inspired by the answers to Stack Overflow post
+    # http://stackoverflow.com/q/2183233/2988730, especially
+    # http://stackoverflow.com/a/13638084/2988730
+    def logForLevel(self, message, *args, **kwargs):
+        if self.isEnabledFor(levelNum):
+            self._log(levelNum, message, args, **kwargs)
+    def logToRoot(message, *args, **kwargs):
+        logging.log(levelNum, message, *args, **kwargs)
+
+    logging.addLevelName(levelNum, levelName)
+    setattr(logging, levelName, levelNum)
+    setattr(logging.getLoggerClass(), methodName, logForLevel)
+    setattr(logging, methodName, logToRoot)
+
+
 # setup logging config before anything else loads
 try:
     if path.exists(logging_path):
         with open(logging_path, "r") as f:
             config_logging = safe_load(f)
             dictConfig(config_logging)
+            addLoggingLevel('TRACE', logging.DEBUG - 5)
 except Exception as err:
     print("error loading logging config: %s" % (err))