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
|
/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
/* vim: set ts=8 sts=2 et sw=2 tw=80: */
/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef mozilla_CachedInheritingStyles_h
#define mozilla_CachedInheritingStyles_h
#include "nsAtom.h"
#include "nsCOMPtr.h"
#include "nsTArray.h"
class nsWindowSizes;
namespace mozilla {
struct PseudoStyleRequest;
enum class PseudoStyleType : uint8_t;
class ComputedStyle;
// Entry in the cached inheriting styles cache. Stores the style and, for
// functional pseudo-elements like ::highlight(name), the functional parameter.
struct CachedStyleEntry {
RefPtr<ComputedStyle> mStyle;
RefPtr<nsAtom> mFunctionalPseudoParameter;
};
// Cache of anonymous box and lazy pseudo styles that inherit from a given
// style.
//
// To minimize memory footprint, the cache is word-sized with a tagged pointer
// If there is only one entry without a functional parameter, it's stored
// inline. If there are more entries, or the entry has a functional parameter,
// they're stored in an out-of-line buffer. See bug 1429126 comment 0 and
// comment 1 for the measurements and rationale that influenced the design.
class CachedInheritingStyles {
public:
void Insert(ComputedStyle* aStyle,
nsAtom* aFunctionalPseudoParameter = nullptr);
ComputedStyle* Lookup(const PseudoStyleRequest& aRequest) const;
// Appends all cached styles to the given array.
void AppendTo(nsTArray<const ComputedStyle*>& aArray) const;
CachedInheritingStyles() : mBits(0) {}
~CachedInheritingStyles() {
if (IsIndirect()) {
delete AsIndirect();
} else if (!IsEmpty()) {
RefPtr<ComputedStyle> ref = dont_AddRef(AsDirect());
}
}
void AddSizeOfIncludingThis(nsWindowSizes& aSizes, size_t* aCVsSize) const;
private:
// See bug 1429126 comment 1 for the choice of four here.
using IndirectCache = AutoTArray<CachedStyleEntry, 4>;
bool IsEmpty() const { return !mBits; }
bool IsIndirect() const { return (mBits & 1); }
ComputedStyle* AsDirect() const {
MOZ_ASSERT(!IsIndirect());
return reinterpret_cast<ComputedStyle*>(mBits);
}
IndirectCache* AsIndirect() const {
MOZ_ASSERT(IsIndirect());
return reinterpret_cast<IndirectCache*>(mBits & ~1);
}
uintptr_t mBits;
};
} // namespace mozilla
#endif // mozilla_CachedInheritingStyles_h
|
