<https://webkit.org/b/119850> Speed up test importing by doing all the regex matching in a single pass

bemjb · bemjb · commit d1482c93e316 · 2013-08-15T20:26:35.000Z
Reviewed by Dirk Pranke. This is a port from Blink of https://src.chromium.org/viewvc/blink?revision=155647&view=revision originally by Dirk Pranke. From the original commit: This gives something like a 15x speedup over compiling and matching one property at a time and doing multiple passes over the file. * Scripts/webkitpy/w3c/test_converter.py: (W3CTestConverter.__init__): (W3CTestConverter.convert_prefixed_properties): (W3CTestConverter.add_webkit_prefix_to_unprefixed_properties): Canonical link: https://commits.webkit.org/137805@main git-svn-id: https://svn.webkit.org/repository/webkit/trunk@154126 268f45cc-cd09-0410-ab3c-d52691b4dbfc
diff --git a/Tools/ChangeLog b/Tools/ChangeLog
@@ -1,3 +1,23 @@
+2013-08-15  Bem Jones-Bey  <bjonesbe@adobe.com>
+
+        <https://webkit.org/b/119850> Speed up test importing by doing all the regex matching in a single pass
+
+        Reviewed by Dirk Pranke.
+
+        This is a port from Blink of
+        https://src.chromium.org/viewvc/blink?revision=155647&view=revision
+        originally by Dirk Pranke.
+
+        From the original commit:
+
+        This gives something like a 15x speedup over compiling and matching
+        one property at a time and doing multiple passes over the file.
+
+        * Scripts/webkitpy/w3c/test_converter.py:
+        (W3CTestConverter.__init__):
+        (W3CTestConverter.convert_prefixed_properties):
+        (W3CTestConverter.add_webkit_prefix_to_unprefixed_properties):
+
 2013-08-15  Dan Bernstein  <mitz@apple.com>
 
         <https://webkit.org/b/119856> Improve extract-localizable-strings messages
diff --git a/Tools/Scripts/webkitpy/w3c/test_converter.py b/Tools/Scripts/webkitpy/w3c/test_converter.py
@@ -51,6 +51,9 @@ def __init__(self):
 
         self.prefixed_properties = self.read_webkit_prefixed_css_property_list()
 
+        prop_regex = '([\s{]|^)(' + "|".join(prop.replace('-webkit-', '') for prop in self.prefixed_properties) + ')(\s+:|:)'
+        self.prop_re = re.compile(prop_regex)
+
     def path_from_webkit_root(self, *comps):
         return self._filesystem.abspath(self._filesystem.join(self._webkit_root, *comps))
 
@@ -157,35 +160,37 @@ def convert_prefixed_properties(self, doc, filename):
 
             # Rewrite tag only if changes were made.
             if updated_style_text[0]:
-                converted_properties.extend(updated_style_text[0])
+                converted_properties.extend(list(updated_style_text[0]))
 
                 new_tag = Tag(doc, tag.name, tag.attrs)
                 new_tag.insert(0, updated_style_text[1])
 
                 self.replace_tag(tag, new_tag)
 
+        # FIXME: Doing the replace in the parsed document and then writing it back out
+        # is normalizing the HTML, which may in fact alter the intent of some tests.
+        # We should probably either just do basic string-replaces, or have some other
+        # way of flagging tests that are sensitive to being rewritten.
+        # https://bugs.webkit.org/show_bug.cgi?id=119159
+
         return (converted_properties, doc.prettify())
 
     def add_webkit_prefix_to_unprefixed_properties(self, text, filename):
         """ Searches |text| for instances of properties requiring the -webkit- prefix and adds the prefix to them.
 
         Returns the list of converted properties and the modified text."""
 
-        converted_properties = []
-
-        for raw_property in self.prefixed_properties:
-            # FIXME: add in both the prefixed and unprefixed versions, rather than just replacing them?
-            # That might allow the imported test to work in other browsers more easily.
-
-            # Look for the various ways it might be in the CSS
-            # Match the the property preceded by either whitespace or left curly brace
-            # or at the beginning of the string (for inline style attribute)
-            pattern = '([\s{]|^)' + raw_property + '(\s+:|:)'
-            if re.search(pattern, text):
-                replacement_property = '-webkit-%s' % raw_property
-                _log.info('converting %s -> %s' % (raw_property, replacement_property))
-                converted_properties.append(replacement_property)
-                text = re.sub(pattern, replacement_property + ':', text)
+        converted_properties = set()
+        text_chunks = []
+        cur_pos = 0
+        for m in self.prop_re.finditer(text):
+            text_chunks.extend([text[cur_pos:m.start()], m.group(1), '-webkit-', m.group(2), m.group(3)])
+            converted_properties.add(m.group(2))
+            cur_pos = m.end()
+        text_chunks.append(text[cur_pos:])
+
+        for prop in converted_properties:
+            _log.info('  converting %s', prop)
 
         # FIXME: Handle the JS versions of these properties and GetComputedStyle, too.
         return (converted_properties, text)
