/** Clears the cache making this operator stateless on window boundary */
public void clearCache() {
if (cumulative) {
for (Map.Entry<K, SumEntry> e : sums.entrySet()) {
SumEntry val = e.getValue();
val.changed = false;
}
} else {
sums.clear();
}
}
/** For each tuple (a key value pair) Adds the values for each key. */
@Override
public void process(KeyValPair<K, V> tuple) {
K key = tuple.getKey();
if (!doprocessKey(key)) {
return;
}
SumEntry val = sums.get(key);
if (val == null) {
val = new SumEntry(new MutableDouble(tuple.getValue().doubleValue()), true);
} else {
val.sum.add(tuple.getValue().doubleValue());
val.changed = true;
}
sums.put(cloneKey(key), val);
}