/** {@inheritDoc} */
public void clear() {
map.clear();
if (parent != null) {
int curRange = range();
parent.updateParentRange(-curRange);
}
range = 0;
}
/** {@inheritDoc} */
public Set<V> remove(Object key) {
Set<V> v = map.remove(key);
if (v != null) range -= v.size();
if (parent != null) {
parent.updateParentRange(-(v.size()));
}
return v;
}
/** {@inheritDoc} */
public boolean remove(K key, V value) {
Set<V> values = map.get(key);
boolean removed = values.remove(value);
if (removed) {
range--;
if (parent != null) {
parent.updateParentRange(-1);
}
}
// if this was the last value mapping for this key, remove the
// key altogether
if (values.size() == 0) map.remove(key);
return removed;
}
/** {@inheritDoc} */
public boolean put(K key, V value) {
Set<V> values = map.get(key);
if (values == null) {
values = new HashSet<V>();
map.put(key, values);
}
boolean added = values.add(value);
if (added) {
range++;
if (parent != null) {
parent.updateParentRange(1);
}
}
return added;
}
/** Recursively updates the range value for the the super-map of this sub-map if it exists. */
private void updateParentRange(int valueDifference) {
range += valueDifference;
if (parent != null) {
parent.updateParentRange(valueDifference);
}
}