Add TRACE logging level (Fixes #149)

1 files changed, 29 insertions, 9 deletions

diff --git a/bot/__init__.py b/bot/__init__.py
index dc97df3d..54b242ee 100644
--- a/bot/__init__.py
+++ b/bot/__init__.py
@@ -1,3 +1,4 @@
+import logging
 import logging.handlers
 import os
 from pathlib import Path
@@ -6,25 +7,44 @@ import arrow
 
 from bot.constants import Client
 
-# start datetime
+
+# Configure the "TRACE" logging level (e.g. "log.trace(message)")
+logging.TRACE = 5
+logging.addLevelName(logging.TRACE, "TRACE")
+
+
+def monkeypatch_trace(self, msg, *args, **kwargs):
+    """
+    Log 'msg % args' with severity 'TRACE'.
+    To pass exception information, use the keyword argument exc_info with
+    a true value, e.g.
+    logger.trace("Houston, we have an %s", "interesting problem", exc_info=1)
+    """
+    if self.isEnabledFor(logging.TRACE):
+        self._log(logging.TRACE, msg, args, **kwargs)
+
+
+logging.Logger.trace = monkeypatch_trace
+
+# Set timestamp of when execution started (approximately)
 start_time = arrow.utcnow()
 
-# set up logging
+# Set up file logging
 log_dir = Path("bot", "log")
 log_file = log_dir / "hackbot.log"
 os.makedirs(log_dir, exist_ok=True)
 
-# file handler sets up rotating logs every 5 MB
+# File handler rotates logs every 5 MB
 file_handler = logging.handlers.RotatingFileHandler(
     log_file, maxBytes=5*(2**20), backupCount=10)
-file_handler.setLevel(logging.DEBUG)
+file_handler.setLevel(logging.TRACE if Client.debug else logging.DEBUG)
 
-# console handler prints to terminal
+# Console handler prints to terminal
 console_handler = logging.StreamHandler()
-level = logging.DEBUG if Client.debug else logging.INFO
+level = logging.TRACE if Client.debug else logging.INFO
 console_handler.setLevel(level)
 
-# remove old loggers if any
+# Remove old loggers, if any
 root = logging.getLogger()
 if root.handlers:
     for handler in root.handlers:
@@ -34,11 +54,11 @@ if root.handlers:
 logging.getLogger("discord").setLevel(logging.ERROR)
 logging.getLogger("websockets").setLevel(logging.ERROR)
 
-# setup new logging configuration
+# Setup new logging configuration
 logging.basicConfig(
     format='%(asctime)s - %(name)s %(levelname)s: %(message)s',
     datefmt="%D %H:%M:%S",
-    level=logging.DEBUG,
+    level=logging.TRACE if Client.debug else logging.DEBUG,
     handlers=[console_handler, file_handler]
 )
 logging.getLogger().info('Logging initialization complete')