diff options
author | Lars Knoll <lars.knoll@qt.io> | 2020-09-23 19:32:24 +0200 |
---|---|---|
committer | Lars Knoll <lars.knoll@qt.io> | 2020-10-07 14:57:51 +0200 |
commit | 8a7b74f6e71d6b8264f365148bf5a04db4038617 (patch) | |
tree | be16b5d1fb3299f75fa9641f5c113db4ed3791e0 /src/corelib/text/qstring.cpp | |
parent | 3807559d3779d2d6df4fb9180d2c4093ea1706ae (diff) |
Optimize equality operators for string classes
Using compare() for those operators is not a good idea, as we can't
shortcut comparisons if the string sizes are different. This alone
made our HTML parser in QtGui around 15% slower.
Don't go through QAnyStringView to implement compare() for
QUtf8StringView, use QtPrivate::compareStrings() directly instead.
Task-number: QTBUG-86354
Change-Id: I04869c29c9918161990dc1baf8e943b3a264ff3c
Reviewed-by: Karsten Heimrich <karsten.heimrich@qt.io>
Diffstat (limited to 'src/corelib/text/qstring.cpp')
-rw-r--r-- | src/corelib/text/qstring.cpp | 57 |
1 files changed, 57 insertions, 0 deletions
diff --git a/src/corelib/text/qstring.cpp b/src/corelib/text/qstring.cpp index 2838e513f1..71e51ab0fc 100644 --- a/src/corelib/text/qstring.cpp +++ b/src/corelib/text/qstring.cpp @@ -1325,6 +1325,63 @@ int QAnyStringView::compare(QAnyStringView lhs, QAnyStringView rhs, Qt::CaseSens }); } +bool QtPrivate::equalStrings(QStringView lhs, QStringView rhs) noexcept +{ + return ucstrcmp(lhs.begin(), lhs.size(), rhs.begin(), rhs.size()) == 0; +} + +bool QtPrivate::equalStrings(QStringView lhs, QLatin1String rhs) noexcept +{ + return ucstrcmp(lhs.begin(), lhs.size(), rhs.begin(), rhs.size()) == 0; +} + +bool QtPrivate::equalStrings(QLatin1String lhs, QStringView rhs) noexcept +{ + return QtPrivate::equalStrings(rhs, lhs); +} + +bool QtPrivate::equalStrings(QLatin1String lhs, QLatin1String rhs) noexcept +{ + return lhs.size() == rhs.size() && (!lhs.size() || qstrncmp(lhs.data(), rhs.data(), lhs.size()) == 0); +} + +bool QtPrivate::equalStrings(QBasicUtf8StringView<false> lhs, QStringView rhs) noexcept +{ + return QUtf8::compareUtf8(lhs, rhs) == 0; +} + +bool QtPrivate::equalStrings(QStringView lhs, QBasicUtf8StringView<false> rhs) noexcept +{ + return QtPrivate::equalStrings(rhs, lhs); +} + +bool QtPrivate::equalStrings(QLatin1String lhs, QBasicUtf8StringView<false> rhs) noexcept +{ + QString r = rhs.toString(); + return QtPrivate::equalStrings(lhs, r); // ### optimize! +} + +bool QtPrivate::equalStrings(QBasicUtf8StringView<false> lhs, QLatin1String rhs) noexcept +{ + return QtPrivate::equalStrings(rhs, lhs); +} + +bool QtPrivate::equalStrings(QBasicUtf8StringView<false> lhs, QBasicUtf8StringView<false> rhs) noexcept +{ + return lhs.size() == rhs.size() && (!lhs.size() || qstrncmp(lhs.data(), rhs.data(), lhs.size()) == 0); +} + +bool QAnyStringView::equal(QAnyStringView lhs, QAnyStringView rhs) noexcept +{ + if (lhs.size() != rhs.size() && lhs.isUtf8() == rhs.isUtf8()) + return false; + return lhs.visit([rhs](auto lhs) { + return rhs.visit([lhs](auto rhs) { + return QtPrivate::equalStrings(lhs, rhs); + }); + }); +} + /*! \relates QStringView \internal |