SlowAbstractSetRemoveAll

Reports calls to java.util.Set.removeAll() with a java.util.List argument.

Such a call can be slow when the size of the argument is greater than or equal to the size of the set, and the set is a subclass of java.util.AbstractSet. In this case, List.contains() is called for each element in the set, which will perform a linear search.

Example:

public void check(String... ss) {
    // possible O(n^2) complexity
    mySet.removeAll(List.of(ss));
  }

After the quick fix is applied:

public void check(String... ss) {
    // O(n) complexity
    List.of(ss).forEach(mySet::remove);
  }

New in 2020.3