Title: [274872] trunk/Source/WTF
- Revision
- 274872
- Author
- [email protected]
- Date
- 2021-03-23 08:56:50 -0700 (Tue, 23 Mar 2021)
Log Message
Optimize StringView::CodePoints::Iterator
https://bugs.webkit.org/show_bug.cgi?id=162315
Reviewed by Darin Adler.
This stores range pointers in the iterator instead of a pointer to a pointer.
* wtf/text/StringView.h:
(WTF::StringView::CodePoints::Iterator::Iterator):
(WTF::StringView::CodePoints::Iterator::operator++):
(WTF::StringView::CodePoints::Iterator::operator* const):
(WTF::StringView::CodePoints::Iterator::operator== const):
Modified Paths
Diff
Modified: trunk/Source/WTF/ChangeLog (274871 => 274872)
--- trunk/Source/WTF/ChangeLog 2021-03-23 15:33:36 UTC (rev 274871)
+++ trunk/Source/WTF/ChangeLog 2021-03-23 15:56:50 UTC (rev 274872)
@@ -1,3 +1,18 @@
+2021-03-23 Alex Christensen <[email protected]>
+
+ Optimize StringView::CodePoints::Iterator
+ https://bugs.webkit.org/show_bug.cgi?id=162315
+
+ Reviewed by Darin Adler.
+
+ This stores range pointers in the iterator instead of a pointer to a pointer.
+
+ * wtf/text/StringView.h:
+ (WTF::StringView::CodePoints::Iterator::Iterator):
+ (WTF::StringView::CodePoints::Iterator::operator++):
+ (WTF::StringView::CodePoints::Iterator::operator* const):
+ (WTF::StringView::CodePoints::Iterator::operator== const):
+
2021-03-23 Chris Dumez <[email protected]>
Add assertions to guard against heap allocations on the audio thread
Modified: trunk/Source/WTF/wtf/text/StringView.h (274871 => 274872)
--- trunk/Source/WTF/wtf/text/StringView.h 2021-03-23 15:33:36 UTC (rev 274871)
+++ trunk/Source/WTF/wtf/text/StringView.h 2021-03-23 15:56:50 UTC (rev 274872)
@@ -837,9 +837,12 @@
bool operator!=(const Iterator&) const;
private:
- std::reference_wrapper<const StringView> m_stringView;
- Optional<unsigned> m_nextCodePointOffset;
- UChar32 m_codePoint;
+ const void* m_current;
+ const void* m_end;
+ bool m_is8Bit;
+#if CHECK_STRINGVIEW_LIFETIME
+ StringView m_stringView;
+#endif
};
class StringView::CodeUnits::Iterator {
@@ -894,37 +897,61 @@
}
inline StringView::CodePoints::Iterator::Iterator(const StringView& stringView, unsigned index)
- : m_stringView(stringView)
- , m_nextCodePointOffset(index)
+ : m_is8Bit(stringView.is8Bit())
+#if CHECK_STRINGVIEW_LIFETIME
+ , m_stringView(stringView)
+#endif
{
- operator++();
+ if (m_is8Bit) {
+ const LChar* begin = stringView.characters8();
+ m_current = begin + index;
+ m_end = begin + stringView.length();
+ } else {
+ const UChar* begin = stringView.characters16();
+ m_current = begin + index;
+ m_end = begin + stringView.length();
+ }
}
inline auto StringView::CodePoints::Iterator::operator++() -> Iterator&
{
- ASSERT(m_nextCodePointOffset);
- if (m_nextCodePointOffset.value() == m_stringView.get().length()) {
- m_nextCodePointOffset = WTF::nullopt;
- return *this;
+#if CHECK_STRINGVIEW_LIFETIME
+ ASSERT(m_stringView.underlyingStringIsValid());
+#endif
+ ASSERT(m_current < m_end);
+ if (m_is8Bit)
+ m_current = static_cast<const LChar*>(m_current) + 1;
+ else {
+ unsigned i = 0;
+ size_t length = static_cast<const UChar*>(m_end) - static_cast<const UChar*>(m_current);
+ U16_FWD_1(static_cast<const UChar*>(m_current), i, length);
+ m_current = static_cast<const UChar*>(m_current) + i;
}
- if (m_stringView.get().is8Bit())
- m_codePoint = m_stringView.get().characters8()[m_nextCodePointOffset.value()++];
- else
- U16_NEXT(m_stringView.get().characters16(), m_nextCodePointOffset.value(), m_stringView.get().length(), m_codePoint);
- ASSERT(m_nextCodePointOffset.value() <= m_stringView.get().length());
return *this;
}
inline UChar32 StringView::CodePoints::Iterator::operator*() const
{
- ASSERT(m_nextCodePointOffset);
- return m_codePoint;
+#if CHECK_STRINGVIEW_LIFETIME
+ ASSERT(m_stringView.underlyingStringIsValid());
+#endif
+ ASSERT(m_current < m_end);
+ if (m_is8Bit)
+ return *static_cast<const LChar*>(m_current);
+ UChar32 codePoint;
+ size_t length = static_cast<const UChar*>(m_end) - static_cast<const UChar*>(m_current);
+ U16_GET(static_cast<const UChar*>(m_current), 0, 0, length, codePoint);
+ return codePoint;
}
inline bool StringView::CodePoints::Iterator::operator==(const Iterator& other) const
{
- ASSERT(&m_stringView.get() == &other.m_stringView.get());
- return m_nextCodePointOffset == other.m_nextCodePointOffset;
+#if CHECK_STRINGVIEW_LIFETIME
+ ASSERT(m_stringView.underlyingStringIsValid());
+#endif
+ ASSERT(m_is8Bit == other.m_is8Bit);
+ ASSERT(m_end == other.m_end);
+ return m_current == other.m_current;
}
inline bool StringView::CodePoints::Iterator::operator!=(const Iterator& other) const
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