/** Adds a new entry. */
public final void add(long timestamp, long value) {
final long now = getNow();
removeOldBuckets(now);
Bucket bucket;
if (buckets.isEmpty() || (bucket = buckets.getFirst()).deadline < timestamp) {
// Create new bucket.
bucket = new Bucket(now + bucketSizeMillis);
buckets.addFirst(bucket);
}
bucket.elements++;
currentCount++;
bucket.sum += value;
currentSum += value;
}
