Title: [221250] releases/WebKitGTK/webkit-2.18
- Revision
- 221250
- Author
- [email protected]
- Date
- 2017-08-28 06:22:47 -0700 (Mon, 28 Aug 2017)
Log Message
Merge r220982 - StringView could use a function to strip leading/trailing characters without allocation
https://bugs.webkit.org/show_bug.cgi?id=175757
Reviewed by Darin Adler.
Source/WTF:
There are many places in WebCore/WebKit that we call functions like,
WebCore::stripLeadingAndTrailingHTMLSpaces, or String::stripWhiteSpace() only to use
the allocated String as a temporary for either another transformation or a comparison.
Now that we have StringView, we can avoid that extra allocation, by having returning a
StringView substring in these scenarios.
For instance, the check (from ScriptElement.cpp:287):
if (!stripLeadingAndTrailingHTMLSpaces(sourceURL).isEmpty()) {
...
}
currently allocates a string just to make this check. With a new
stripLeadingAndTrailingHTMLSpaces such as:
StringView stripLeadingAndTrailingHTMLSpaces(StringView stringView)
{
return stringView.stripLeadingAndTrailingMatchedCharacters([] (auto c) {
return isHTMLSpace(c);
});
}
We could instead have exact same code from ScriptElement.cpp now avoid an allocation.
* wtf/text/StringView.h:
(WTF::StringView::stripLeadingAndTrailingMatchedCharacters):
Tools:
* TestWebKitAPI/Tests/WTF/StringView.cpp:
Add tests for StringView::stripLeadingAndTrailingMatchedCharacters().
Modified Paths
Diff
Modified: releases/WebKitGTK/webkit-2.18/Source/WTF/ChangeLog (221249 => 221250)
--- releases/WebKitGTK/webkit-2.18/Source/WTF/ChangeLog 2017-08-28 12:46:19 UTC (rev 221249)
+++ releases/WebKitGTK/webkit-2.18/Source/WTF/ChangeLog 2017-08-28 13:22:47 UTC (rev 221250)
@@ -1,3 +1,37 @@
+2017-08-20 Sam Weinig <[email protected]>
+
+ StringView could use a function to strip leading/trailing characters without allocation
+ https://bugs.webkit.org/show_bug.cgi?id=175757
+
+ Reviewed by Darin Adler.
+
+ There are many places in WebCore/WebKit that we call functions like,
+ WebCore::stripLeadingAndTrailingHTMLSpaces, or String::stripWhiteSpace() only to use
+ the allocated String as a temporary for either another transformation or a comparison.
+ Now that we have StringView, we can avoid that extra allocation, by having returning a
+ StringView substring in these scenarios.
+
+ For instance, the check (from ScriptElement.cpp:287):
+
+ if (!stripLeadingAndTrailingHTMLSpaces(sourceURL).isEmpty()) {
+ ...
+ }
+
+ currently allocates a string just to make this check. With a new
+ stripLeadingAndTrailingHTMLSpaces such as:
+
+ StringView stripLeadingAndTrailingHTMLSpaces(StringView stringView)
+ {
+ return stringView.stripLeadingAndTrailingMatchedCharacters([] (auto c) {
+ return isHTMLSpace(c);
+ });
+ }
+
+ We could instead have exact same code from ScriptElement.cpp now avoid an allocation.
+
+ * wtf/text/StringView.h:
+ (WTF::StringView::stripLeadingAndTrailingMatchedCharacters):
+
2017-08-14 Simon Fraser <[email protected]>
Remove Proximity Events and related code
Modified: releases/WebKitGTK/webkit-2.18/Source/WTF/wtf/text/StringView.h (221249 => 221250)
--- releases/WebKitGTK/webkit-2.18/Source/WTF/wtf/text/StringView.h 2017-08-28 12:46:19 UTC (rev 221249)
+++ releases/WebKitGTK/webkit-2.18/Source/WTF/wtf/text/StringView.h 2017-08-28 13:22:47 UTC (rev 221250)
@@ -119,6 +119,9 @@
StringView left(unsigned len) const { return substring(0, len); }
StringView right(unsigned len) const { return substring(length() - len, len); }
+ template<typename MatchedCharacterPredicate>
+ StringView stripLeadingAndTrailingMatchedCharacters(const MatchedCharacterPredicate&);
+
class SplitResult;
SplitResult split(UChar) const;
@@ -157,6 +160,9 @@
void initialize(const LChar*, unsigned length);
void initialize(const UChar*, unsigned length);
+ template<typename CharacterType, typename MatchedCharacterPredicate>
+ StringView stripLeadingAndTrailingMatchedCharacters(const CharacterType*, const MatchedCharacterPredicate&);
+
#if CHECK_STRINGVIEW_LIFETIME
WTF_EXPORT_STRING_API bool underlyingStringIsValid() const;
WTF_EXPORT_STRING_API void setUnderlyingString(const StringImpl*);
@@ -935,6 +941,40 @@
return !(*this == other);
}
+template<typename CharacterType, typename MatchedCharacterPredicate>
+inline StringView StringView::stripLeadingAndTrailingMatchedCharacters(const CharacterType* characters, const MatchedCharacterPredicate& predicate)
+{
+ if (!m_length)
+ return *this;
+
+ unsigned start = 0;
+ unsigned end = m_length - 1;
+
+ while (start <= end && predicate(characters[start]))
+ ++start;
+
+ if (start > end)
+ return StringView::empty();
+
+ while (end && predicate(characters[end]))
+ --end;
+
+ if (!start && end == m_length - 1)
+ return *this;
+
+ StringView result(characters + start, end + 1 - start);
+ result.setUnderlyingString(*this);
+ return result;
+}
+
+template<typename MatchedCharacterPredicate>
+StringView StringView::stripLeadingAndTrailingMatchedCharacters(const MatchedCharacterPredicate& predicate)
+{
+ if (is8Bit())
+ return stripLeadingAndTrailingMatchedCharacters<LChar>(characters8(), predicate);
+ return stripLeadingAndTrailingMatchedCharacters<UChar>(characters16(), predicate);
+}
+
template<unsigned length> inline bool equalLettersIgnoringASCIICase(StringView string, const char (&lowercaseLetters)[length])
{
return equalLettersIgnoringASCIICaseCommon(string, lowercaseLetters);
Modified: releases/WebKitGTK/webkit-2.18/Tools/ChangeLog (221249 => 221250)
--- releases/WebKitGTK/webkit-2.18/Tools/ChangeLog 2017-08-28 12:46:19 UTC (rev 221249)
+++ releases/WebKitGTK/webkit-2.18/Tools/ChangeLog 2017-08-28 13:22:47 UTC (rev 221250)
@@ -1,3 +1,13 @@
+2017-08-20 Sam Weinig <[email protected]>
+
+ StringView could use a function to strip leading/trailing characters without allocation
+ https://bugs.webkit.org/show_bug.cgi?id=175757
+
+ Reviewed by Darin Adler.
+
+ * TestWebKitAPI/Tests/WTF/StringView.cpp:
+ Add tests for StringView::stripLeadingAndTrailingMatchedCharacters().
+
2017-08-17 Michael Catanzaro <[email protected]>
[GTK] Make TestContextMenu work on Fedora
Modified: releases/WebKitGTK/webkit-2.18/Tools/TestWebKitAPI/Tests/WTF/StringView.cpp (221249 => 221250)
--- releases/WebKitGTK/webkit-2.18/Tools/TestWebKitAPI/Tests/WTF/StringView.cpp 2017-08-28 12:46:19 UTC (rev 221249)
+++ releases/WebKitGTK/webkit-2.18/Tools/TestWebKitAPI/Tests/WTF/StringView.cpp 2017-08-28 13:22:47 UTC (rev 221250)
@@ -925,4 +925,26 @@
EXPECT_EQ(reference.reverseFind('c', 4), notFound);
}
+TEST(WTF, StringViewStripLeadingAndTrailingMatchedCharacters)
+{
+ auto isA = [] (UChar c) {
+ return c == 'A';
+ };
+
+ EXPECT_TRUE(stringViewFromLiteral("AAABBBAAA").stripLeadingAndTrailingMatchedCharacters(isA) == stringViewFromLiteral("BBB"));
+ EXPECT_TRUE(stringViewFromLiteral("AAABBBCCC").stripLeadingAndTrailingMatchedCharacters(isA) == stringViewFromLiteral("BBBCCC"));
+ EXPECT_TRUE(stringViewFromLiteral("CCCBBBAAA").stripLeadingAndTrailingMatchedCharacters(isA) == stringViewFromLiteral("CCCBBB"));
+ EXPECT_TRUE(stringViewFromLiteral("CCCBBBCCC").stripLeadingAndTrailingMatchedCharacters(isA) == stringViewFromLiteral("CCCBBBCCC"));
+ EXPECT_TRUE(stringViewFromLiteral("AAAAAACCC").stripLeadingAndTrailingMatchedCharacters(isA) == stringViewFromLiteral("CCC"));
+ EXPECT_TRUE(stringViewFromLiteral("BBBAAAAAA").stripLeadingAndTrailingMatchedCharacters(isA) == stringViewFromLiteral("BBB"));
+ EXPECT_TRUE(stringViewFromLiteral("CCCAAABBB").stripLeadingAndTrailingMatchedCharacters(isA) == stringViewFromLiteral("CCCAAABBB"));
+ EXPECT_TRUE(stringViewFromLiteral("AAAAAAAAA").stripLeadingAndTrailingMatchedCharacters(isA) == StringView::empty());
+
+ StringView emptyView = StringView::empty();
+ EXPECT_TRUE(emptyView.stripLeadingAndTrailingMatchedCharacters(isA) == emptyView);
+
+ StringView nullView;
+ EXPECT_TRUE(nullView.stripLeadingAndTrailingMatchedCharacters(isA) == nullView);
+}
+
} // namespace TestWebKitAPI
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