RFR: 8197991: Selecting many items in a TableView is very slow

[Nir Lisker]

On Wed, 17 Nov 2021 05:34:46 GMT, Abhinay Agarwal <duke at openjdk.java.net> wrote:

> This work improves the performance of `MultipleSelectionModel`  over large data sets by caching some values and avoiding unnecessary calls to `SelectedIndicesList#size`. It further improves the performance by reducing the number of iterations required to find the index of an element in the BitSet.
> 
> The work is based on [an abandoned patch](https://github.com/openjdk/jfx/pull/127) submitted by @yososs
> 
> There are currently 2 manual tests for this fix.

modules/javafx.controls/src/main/java/com/sun/javafx/scene/control/ReadOnlyUnbackedObservableList.java line 119:

> 117:             Object obj = get(i);
> 118:             if (o.equals(obj)) return i;
> 119:         }

An alternative is

return IntStream.range(0, size())
    .filter(i -> o.equals(get(i)))
    .findFirst()
    .orElse(-1);

I don't know if it helps.

modules/javafx.controls/src/main/java/com/sun/javafx/scene/control/ReadOnlyUnbackedObservableList.java line 193:

> 191:             arr[i] = get(i);
> 192:         }
> 193:         return arr;

Have you tried `return stream().toArray();`?

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PR: https://git.openjdk.java.net/jfx/pull/673