diff options
| author | Daniel Teske <daniel.teske@digia.com> | 2014-09-05 11:51:01 +0200 |
|---|---|---|
| committer | Daniel Teske <daniel.teske@digia.com> | 2014-09-15 17:44:52 +0200 |
| commit | 46ebcb6176c25c294c5edbeaaa757fe0ce53903e (patch) | |
| tree | 3a301525d2d3b63528f6b70a8f9c61c2c9a33831 /src/corelib/tools | |
| parent | f5b53c8e3ececbdac1a7da56cbdc850e542316b9 (diff) | |
Speed up QStringList::removeDuplicates by ~2x
QSet::contains needs to hash the string, which is unnecessary, since we
can just check if the size of the set changed.
Change-Id: I2c7a42bae6cdf351533d5a582a42079658fa7729
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@digia.com>
Diffstat (limited to 'src/corelib/tools')
| -rw-r--r-- | src/corelib/tools/qstringlist.cpp | 6 |
1 files changed, 4 insertions, 2 deletions
diff --git a/src/corelib/tools/qstringlist.cpp b/src/corelib/tools/qstringlist.cpp index 0d37b6ea58..cd14bb8b78 100644 --- a/src/corelib/tools/qstringlist.cpp +++ b/src/corelib/tools/qstringlist.cpp @@ -751,11 +751,13 @@ int QtPrivate::QStringList_removeDuplicates(QStringList *that) int j = 0; QSet<QString> seen; seen.reserve(n); + int setSize = 0; for (int i = 0; i < n; ++i) { const QString &s = that->at(i); - if (seen.contains(s)) - continue; seen.insert(s); + if (setSize == seen.size()) // unchanged size => was already seen + continue; + ++setSize; if (j != i) that->swap(i, j); ++j; |