Mercurial > genshi > mirror
comparison genshi/template/match.py @ 687:3d7288f373bd experimental-match-fastpaths
land first cut at fast-path matching - needs some cleanup
| author | aflett |
|---|---|
| date | Mon, 25 Feb 2008 20:44:04 +0000 |
| parents | |
| children | 1240ada13334 |
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| 686:92efe764ec81 | 687:3d7288f373bd |
|---|---|
| 1 from genshi.core import START | |
| 2 from genshi.path import CHILD, LocalNameTest | |
| 3 | |
| 4 from copy import copy | |
| 5 | |
| 6 def is_simple_path(path): | |
| 7 """ | |
| 8 Is the path merely a tag match like "foo"? | |
| 9 """ | |
| 10 if len(path.paths) == 1 and len(path.paths[0]) == 1: | |
| 11 axis, nodetest, predicates = path.paths[0][0] | |
| 12 if (axis is CHILD and | |
| 13 not predicates and | |
| 14 isinstance(nodetest, LocalNameTest)): | |
| 15 return True | |
| 16 | |
| 17 return False | |
| 18 | |
| 19 | |
| 20 class MatchSet(object): | |
| 21 | |
| 22 def __init__(self, parent=None, exclude=None): | |
| 23 """ | |
| 24 If a parent is given, it means this is a wrapper around another | |
| 25 set. Just copy references to member variables in parent, but | |
| 26 also set exclude | |
| 27 """ | |
| 28 self.parent = parent | |
| 29 if parent is None: | |
| 30 self.tag_templates = {} | |
| 31 self.other_templates = [] | |
| 32 self.exclude = [] | |
| 33 if exclude is not None: | |
| 34 self.exclude.append(exclude) | |
| 35 else: | |
| 36 self.tag_templates = parent.tag_templates | |
| 37 self.other_templates = parent.other_templates | |
| 38 self.exclude = copy(parent.exclude) | |
| 39 if exclude is not None: | |
| 40 self.exclude.append(exclude) | |
| 41 | |
| 42 def add(self, match_template): | |
| 43 """ | |
| 44 match_template is a tuple the form | |
| 45 test, path, template, hints, namespace, directives | |
| 46 """ | |
| 47 path = match_template[1] | |
| 48 | |
| 49 if is_simple_path(path): | |
| 50 # special cache of tag | |
| 51 tag_name = path.paths[0][0][1].name | |
| 52 # setdefault is wasteful | |
| 53 if tag_name not in self.tag_templates: | |
| 54 self.tag_templates[tag_name] = [match_template] | |
| 55 else: | |
| 56 self.tag_templates[tag_name].append(match_template) | |
| 57 | |
| 58 else: | |
| 59 self.other_templates.append(match_template) | |
| 60 | |
| 61 def remove(self, match_template): | |
| 62 """ | |
| 63 Permanently remove a match_template - mainly for match_once | |
| 64 """ | |
| 65 path = match_template[1] | |
| 66 | |
| 67 if is_simple_path(path): | |
| 68 tag_name = path.paths[0][0][1].name | |
| 69 if tag_name in self.tag_templates: | |
| 70 template_list = self.tag_templates[tag_name] | |
| 71 template_list.remove(match_template) | |
| 72 if not template_list: | |
| 73 del self.tag_templates[tag_name] | |
| 74 | |
| 75 else: | |
| 76 self.other_templates.remove(match_template) | |
| 77 | |
| 78 def single_match(cls, match_template): | |
| 79 """ | |
| 80 Factory for creating a MatchSet with just one match | |
| 81 """ | |
| 82 match_set = cls() | |
| 83 match_set.add(match_template) | |
| 84 return match_set | |
| 85 single_match = classmethod(single_match) | |
| 86 | |
| 87 def with_exclusion(self, exclude): | |
| 88 """ | |
| 89 Factory for creating a MatchSet based on another MatchSet, but | |
| 90 with certain templates excluded | |
| 91 """ | |
| 92 cls = self.__class__ | |
| 93 new_match_set = cls(parent=self, exclude=exclude) | |
| 94 return new_match_set | |
| 95 | |
| 96 def find_matches(self, event): | |
| 97 """ | |
| 98 Return a list of all valid templates that can be used for the given event. | |
| 99 """ | |
| 100 kind, data, pos = event[:3] | |
| 101 | |
| 102 # todo: get the order right | |
| 103 if kind is START: | |
| 104 tag, attrs = data | |
| 105 if tag.localname in self.tag_templates: | |
| 106 for template in self.tag_templates[tag.localname]: | |
| 107 if template not in self.exclude: | |
| 108 yield template | |
| 109 | |
| 110 for template in self.other_templates: | |
| 111 if template not in self.exclude: | |
| 112 yield template | |
| 113 | |
| 114 | |
| 115 def __nonzero__(self): | |
| 116 """ | |
| 117 allow this to behave as a list | |
| 118 """ | |
| 119 return bool(self.tag_templates or self.other_templates) | |
| 120 | |
| 121 def __iter__(self): | |
| 122 """ | |
| 123 I don't think we really need this, but it lets us behave like a list | |
| 124 """ | |
| 125 for template_list in self.tag_templates.iteritems(): | |
| 126 for template in template_list: | |
| 127 yield template | |
| 128 for template in self.other_templates: | |
| 129 yield template | |
| 130 | |
| 131 def __str__(self): | |
| 132 parent = "" | |
| 133 if self.parent: | |
| 134 parent = ": child of 0x%x" % id(self.parent) | |
| 135 | |
| 136 exclude = "" | |
| 137 if self.exclude: | |
| 138 exclude = " / excluding %d items" % len(self.exclude) | |
| 139 | |
| 140 return "<MatchSet 0x%x %d tag templates, %d other templates%s%s>" % (id(self), len(self.tag_templates), len(self.other_templates), parent, exclude) |