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author | Robert Löhning <robert.loehning@qt.io> | 2021-10-18 15:00:09 +0200 |
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committer | Robert Löhning <robert.loehning@qt.io> | 2021-10-23 01:22:15 +0200 |
commit | a7d1c48ca3162a805708d059da87ca3d742863f1 (patch) | |
tree | 5e1ef71696d5a49f7ae78eeab3d12b18f8f0bdf3 /tests/auto | |
parent | fdbf7cdd09fb5d32d74908a22bbc4459ed2b5517 (diff) |
QVarLengthArray: Reduce memory allocations in emplace()
Currently, we allocate memory for elements one by one which can get
pretty slow when adding many elements.
[ChangeLog][QtCore][QVarLengthArray] Reduced number of memory
allocations in emplace() by allocating more memory at once.
Fixes: QTBUG-97489
Pick-to: 6.2
Change-Id: Idfb5b5946b047d5215c8ed00770574249f9f5d40
Reviewed-by: Andrei Golubev <andrei.golubev@qt.io>
Reviewed-by: Allan Sandfeld Jensen <allan.jensen@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>
Diffstat (limited to 'tests/auto')
-rw-r--r-- | tests/auto/corelib/tools/qvarlengtharray/tst_qvarlengtharray.cpp | 27 |
1 files changed, 27 insertions, 0 deletions
diff --git a/tests/auto/corelib/tools/qvarlengtharray/tst_qvarlengtharray.cpp b/tests/auto/corelib/tools/qvarlengtharray/tst_qvarlengtharray.cpp index 6e95577655..1d30ca3d03 100644 --- a/tests/auto/corelib/tools/qvarlengtharray/tst_qvarlengtharray.cpp +++ b/tests/auto/corelib/tools/qvarlengtharray/tst_qvarlengtharray.cpp @@ -180,6 +180,33 @@ void tst_QVarLengthArray::emplace() QCOMPARE(&r, &strings.back()); QCOMPARE(strings.size(), 3); QCOMPARE(strings.back(), QString(42, u'y')); + + // test growing from empty arrays + QVarLengthArray<QString> emptyArrDefaultPrealloc; + QCOMPARE(emptyArrDefaultPrealloc.size(), 0); + emptyArrDefaultPrealloc.emplace_back(); + QCOMPARE(emptyArrDefaultPrealloc.size(), 1); + emptyArrDefaultPrealloc.resize(1024); + QCOMPARE(emptyArrDefaultPrealloc.size(), 1024); + emptyArrDefaultPrealloc.resize(0); + QCOMPARE(emptyArrDefaultPrealloc.size(), 0); + emptyArrDefaultPrealloc.squeeze(); + QCOMPARE(emptyArrDefaultPrealloc.size(), 0); + emptyArrDefaultPrealloc.emplace_back(); + QCOMPARE(emptyArrDefaultPrealloc.size(), 1); + + QVarLengthArray<QString, 1> emptyArrSmallPrealloc; + QCOMPARE(emptyArrSmallPrealloc.size(), 0); + emptyArrSmallPrealloc.emplace_back(); + QCOMPARE(emptyArrSmallPrealloc.size(), 1); + emptyArrSmallPrealloc.resize(1024); + QCOMPARE(emptyArrSmallPrealloc.size(), 1024); + emptyArrSmallPrealloc.resize(0); + QCOMPARE(emptyArrSmallPrealloc.size(), 0); + emptyArrSmallPrealloc.squeeze(); + QCOMPARE(emptyArrSmallPrealloc.size(), 0); + emptyArrSmallPrealloc.emplace_back(); + QCOMPARE(emptyArrSmallPrealloc.size(), 1); } } |