1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
|
// Copyright 2016 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#ifndef CSSLazyParsingState_h
#define CSSLazyParsingState_h
#include "core/css/CSSSelectorList.h"
#include "core/css/StyleSheetContents.h"
#include "core/css/parser/CSSParserMode.h"
#include "wtf/Vector.h"
#include "wtf/text/WTFString.h"
namespace blink {
class CSSLazyPropertyParserImpl;
class CSSParserTokenRange;
// This class helps lazy parsing by retaining necessary state. It should not
// outlive the StyleSheetContents that initiated the parse, as it retains a raw
// reference to the UseCounter associated with the style sheet.
class CSSLazyParsingState
: public GarbageCollectedFinalized<CSSLazyParsingState> {
public:
CSSLazyParsingState(const CSSParserContext*,
Vector<String> escapedStrings,
const String& sheetText,
StyleSheetContents*);
// Helper method used to bump m_totalStyleRules.
CSSLazyPropertyParserImpl* createLazyParser(const CSSParserTokenRange& block);
const CSSParserContext* context();
void countRuleParsed();
bool shouldLazilyParseProperties(const CSSSelectorList&,
const CSSParserTokenRange& block) const;
DECLARE_TRACE();
// Exposed for tests. This enum is used to back a histogram, so new values
// must be appended to the end, before UsageLastValue.
enum CSSRuleUsage {
UsageGe0 = 0,
UsageGt10 = 1,
UsageGt25 = 2,
UsageGt50 = 3,
UsageGt75 = 4,
UsageGt90 = 5,
UsageAll = 6,
// This value must be last.
UsageLastValue = 7
};
private:
void recordUsageMetrics();
Member<const CSSParserContext> m_context;
Vector<String> m_escapedStrings;
// Also referenced on the css resource.
String m_sheetText;
// Weak to ensure lazy state will never cause the contents to live longer than
// it should (we DCHECK this fact).
WeakMember<StyleSheetContents> m_owningContents;
// Cache the document as a proxy for caching the UseCounter. Grabbing the
// UseCounter per every property parse is a bit more expensive.
WeakMember<Document> m_document;
// Used for calculating the % of rules that ended up being parsed.
int m_parsedStyleRules;
int m_totalStyleRules;
int m_styleRulesNeededForNextMilestone;
int m_usage;
// Whether or not use counting is enabled for parsing. This will usually be
// true, except for when stylesheets with @imports are removed from the page.
// See StyleRuleImport::setCSSStyleSheet.
const bool m_shouldUseCount;
};
} // namespace blink
#endif // CSSLazyParsingState_h
|
