Make syntax highlighting for XML lazy, to only call pygments when debug logs are enabled.

Makes poezio about 11% faster when sending/receiving messages.

slixmpp/xmlstream/tostring.py

@@ -169,7 +169,14 @@ def _get_highlight():
         LEXER = get_lexer_by_name('xml')
         FORMATTER = Terminal256Formatter()
 
-        return lambda x: highlight(x, LEXER, FORMATTER)
+        class Highlighter:
+            __slots__ = ['string']
+            def __init__(self, string):
+                self.string = string
+            def __str__(self):
+                return highlight(str(self.string).strip(), LEXER, FORMATTER)
+
+        return Highlighter
     except ImportError:
         return lambda x: x
 

slixmpp/xmlstream/xmlstream.py

@@ -354,7 +354,7 @@ class XMLStream(asyncio.BaseProtocol):
                     log.debug('RECV: %s', highlight(tostring(self.xml_root, xmlns=self.default_ns,
                                                          stream=self,
                                                          top_level=True,
-                                                         open_only=True)).strip())
+                                                         open_only=True)))
                     self.start_stream_handler(self.xml_root)
                 self.xml_depth += 1
             if event == 'end':
@@ -845,7 +845,7 @@ class XMLStream(asyncio.BaseProtocol):
 
         :param string data: Any bytes or utf-8 string value.
         """
-        log.debug("SEND: %s", highlight(data).strip())
+        log.debug("SEND: %s", highlight(data))
         if not self.transport:
             raise NotConnectedError()
         if isinstance(data, str):
@@ -898,7 +898,7 @@ class XMLStream(asyncio.BaseProtocol):
         if stanza is None:
             return
 
-        log.debug("RECV: %s", highlight(str(stanza)).strip())
+        log.debug("RECV: %s", highlight(stanza))
 
         # Match the stanza against registered handlers. Handlers marked
         # to run "in stream" will be executed immediately; the rest will