support printing tracebacks

git-svn-id: https://linkchecker.svn.sourceforge.net/svnroot/linkchecker/trunk/linkchecker@2394 e7d03fd6-7b0d-0410-9947-9c21f3af8025

linkcheck/log.py

@@ -22,60 +22,114 @@ Logging and debug functions.
 __all__ = ["debug", "info", "warn", "error", "critical", "exception", ]
 
 import logging
+import traceback
+import inspect
+import cStringIO as StringIO
 
 # memory leak debugging
 #import gc
 #gc.enable()
 #gc.set_debug(gc.DEBUG_LEAK)
-def debug (log, msg, *args):
+
+PRINT_LOCALVARS = False
+
+def _stack_format (stack):
+    """
+    Format a stack trace to a message.
+
+    @return: formatted stack message
+    @rtype: string
+    """
+    s = StringIO.StringIO()
+    traceback.print_stack(stack, file=s)
+    if PRINT_LOCALVARS:
+        s.write("Locals by frame, innermost last%s" % os.linesep)
+        for frame in stack:
+            s.write(os.linesep)
+            s.write("Frame %s in %s at line %s%s" % (frame.f_code.co_name,
+                                                     frame.f_code.co_filename,
+                                                     frame.f_lineno,
+                                                     os.linesep))
+            for key, value in frame.f_locals.items():
+                s.write("\t%20s = " % key)
+                # be careful not to cause a new error in the error output
+                try:
+                    s.write(str(value))
+                    s.write(os.linesep)
+                except:
+                    s.write("error in str() call%s" % os.linesep)
+    return s.getvalue()
+
+
+def _log (fun, msg, args, tb=False):
+    """
+    Log a message with given function and an optional traceback.
+
+    @return: None
+    """
+    fun(msg, *args)
+    if tb:
+        # note: get rid of last parts of the stack
+        s = _stack_format(inspect.stack()[2:])
+        fun(s)
+
+
+def debug (log, msg, *args, **kwargs):
     """
     Log a debug message.
 
     return: None
     """
-    logging.getLogger(log).debug(msg, *args)
+    _log(logging.getLogger(log).debug, msg, args, tb=kwargs.get("tb"))
 
 
-def info (log, msg, *args):
+def info (log, msg, *args, **kwargs):
     """
     Log an informational message.
 
     return: None
     """
-    logging.getLogger(log).info(msg, *args)
+    _log(logging.getLogger(log).info, msg, args, tb=kwargs.get("tb"))
 
 
-def warn (log, msg, *args):
+def warn (log, msg, *args, **kwargs):
     """
     Log a warning.
 
     return: None
     """
-    logging.getLogger(log).warn(msg, *args)
+    _log(logging.getLogger(log).warn, msg, args, tb=kwargs.get("tb"))
 
 
-def error (log, msg, *args):
+def error (log, msg, *args, **kwargs):
     """
     Log an error.
 
     return: None
     """
-    logging.getLogger(log).error(msg, *args)
+    _log(logging.getLogger(log).error, msg, args, tb=kwargs.get("tb"))
 
 
-def critical (log, msg, *args):
+def critical (log, msg, *args, **kwargs):
     """
     Log a critical error.
 
     return: None
     """
-    logging.getLogger(log).critical(msg, *args)
+    _log(logging.getLogger(log).critical, msg, args, tb=kwargs.get("tb"))
 
 
-def exception (log, msg, *args):
+def exception (log, msg, *args, **kwargs):
     """
     Log an exception.
 
     return: None
     """
-    logging.getLogger(log).exception(msg, *args)
+    _log(logging.getLogger(log).exception, msg, args, tb=kwargs.get("tb"))
+
+
+def is_debug (log):
+    """
+    See if logger is on debug level.
+    """
+    return logging.getLogger(log).isEnabledFor(logging.DEBUG)