Collapse a large compound node is slow

[bensonnw]

In our project, we have a compound node contains more than 17000 nodes, when collapsing it, it takes about 30 seconds. After some investigation, the API expandCollapseUtilities.removeChildren is taking most of the time, it seems like the following code inside the For loop is pretty expensive:

  ......
  var removedChild = child.remove();
  if (root._private.data.collapsedChildren == null) {
    root._private.data.collapsedChildren = removedChild;
  }
  else {
    root._private.data.collapsedChildren = root._private.data.collapsedChildren.union(removedChild);
  }

Instead of doing that, how about to move the code out of the loop and do something:

if (children.length > 0) {
  const removedChildren = children.remove();
  if (root._private.data.collapsedChildren == null) {
    root._private.data.collapsedChildren = removedChildren;
  }
  else {
    root._private.data.collapsedChildren = root._private.data.collapsedChildren.union(removedChildren);
  }
} 

This way needs much less time (drop to about 1 second) to run.

[hasanbalci]

@bensonnw Thanks for your suggestion, we will evaluate it before the next release.

[bensonnw]

@hasanbalci Thanks for quick response, would you mind to tell me when is your next release?