# HG changeset patch
# User aflett
# Date 1207697780 0
# Node ID 0e8b92905741e25f4a68f7837e6e3c4dd7482762
# Parent  b33c14a1f5796bdbcc1f77ef3cd0992b058b2a9f
a performance breakthrough - bring this branch inline with the bigtable benchmark by lazily creating ctxt._match_set in a way that doesn't barf

diff --git a/genshi/template/base.py b/genshi/template/base.py
--- a/genshi/template/base.py
+++ b/genshi/template/base.py
@@ -25,7 +25,6 @@
 
 from genshi.core import Attrs, Stream, StreamEventKind, START, TEXT, _ensure
 from genshi.input import ParseError
-from genshi.template.match import MatchSet
 
 __all__ = ['Context', 'Template', 'TemplateError', 'TemplateRuntimeError',
            'TemplateSyntaxError', 'BadDirectiveError']
@@ -137,7 +136,7 @@
         self.frames = deque([data])
         self.pop = self.frames.popleft
         self.push = self.frames.appendleft
-        self._match_set = MatchSet()
+        self._match_set = None
         self._choice_stack = []
 
         # Helper functions for use in expressions
diff --git a/genshi/template/directives.py b/genshi/template/directives.py
--- a/genshi/template/directives.py
+++ b/genshi/template/directives.py
@@ -457,6 +457,10 @@
     attach = classmethod(attach)
 
     def __call__(self, stream, directives, ctxt, **vars):
+        # create this lazily because it's much faster to check 'if
+        # match_set' when match_set is None
+        if ctxt._match_set is None:
+            ctxt._match_set = MatchSet()
         ctxt._match_set.add((self.path.test(ignore_context=True),
                              self.path, list(stream), self.hints,
                              self.namespaces, directives))
diff --git a/genshi/template/markup.py b/genshi/template/markup.py
--- a/genshi/template/markup.py
+++ b/genshi/template/markup.py
@@ -229,9 +229,6 @@
         """Internal stream filter that applies any defined match templates
         to the stream.
         """
-        if match_set is None:
-            match_set = ctxt._match_set
-
         tail = []
         def _strip(stream):
             depth = 1
@@ -249,6 +246,11 @@
 
         for event in stream:
 
+            # we may have discovered a py:match while processing the
+            # stream.. so keep checking for ctxt._match_set
+            if match_set is None:
+                match_set = ctxt._match_set
+
             # We (currently) only care about start and end events for matching
             # We might care about namespace events in the future, though
             if not match_set or (event[0] is not START and