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  1. Qt
  2. QTBUG-57792

QQmlPropertyMap inserting new properties is O(N^2)

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Details

    • macOS
    • b64f8dacae36fca948933cf56498d5e4ad3e2a07 f1410debc7905e704b6ed16ae345e43765ef8ef5

    Description

      QQmlPropertyMap::insert(const QString &key, const QVariant &value) has O(N^2) complexity when inserting new properties. Feels like it should be linear or O(n log n) at least. This leads to UI freezes for a significant amount of time.

      My numbers are (i7-2760 2400 MHz):
      500 301 ms
      1000 1206 ms
      1500 2689 ms
      2000 4759 ms
      2500 7546 ms (UI is blocked for 7 secs here!)

      Upd:
      Found this one marked as done – https://bugreports.qt.io/browse/QTBUG-32720
      Looks like it's a regression

      Attachments

        1. 1.png
          9 kB
          Sam Davydov
        2. test.zip
          0.6 kB
          Sam Davydov

        Issue Links

          is duplicated by

          Bug - A problem which impairs or prevents the functions of the product. QTBUG-32720 QQmlPropertyMap bad performances at insertion

          • P4: Low - Would be nice to fix, but it's not very important.
          • Closed
          relates to

          Task - A task that needs to be done. QTBUG-90004 Investigate whether QQmlCleanup can be removed

          • P3: Somewhat important - Should be fixed, but doesn't affect the release in any way.
          • Closed
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              ulherman Ulf Hermann
              samdavydov Sam Davydov
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              Dates

                Created:
                Updated:
                Resolved:

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