| package com.gemstone.gemfire.internal.redis.executor.hll; |
| |
| /* |
| * Copyright (C) 2011 Clearspring Technologies, Inc. |
| * |
| * Licensed under the Apache License, Version 2.0 (the "License"); |
| * you may not use this file except in compliance with the License. |
| * You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, software |
| * distributed under the License is distributed on an "AS IS" BASIS, |
| * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| * See the License for the specific language governing permissions and |
| * limitations under the License. |
| */ |
| |
| |
| import java.io.IOException; |
| |
| |
| public interface ICardinality { |
| |
| /** |
| * @param o stream element |
| * @return false if the value returned by cardinality() is unaffected by the appearance of o in the stream. |
| */ |
| boolean offer(Object o); |
| |
| /** |
| * Offer the value as a hashed long value |
| * |
| * @param hashedLong - the hash of the item to offer to the estimator |
| * @return false if the value returned by cardinality() is unaffected by the appearance of hashedLong in the stream |
| */ |
| boolean offerHashed(long hashedLong); |
| |
| /** |
| * Offer the value as a hashed long value |
| * |
| * @param hashedInt - the hash of the item to offer to the estimator |
| * @return false if the value returned by cardinality() is unaffected by the appearance of hashedInt in the stream |
| */ |
| boolean offerHashed(int hashedInt); |
| |
| /** |
| * @return the number of unique elements in the stream or an estimate thereof |
| */ |
| long cardinality(); |
| |
| /** |
| * @return size in bytes needed for serialization |
| */ |
| int sizeof(); |
| |
| /** |
| * @return byte[] |
| * @throws IOException |
| */ |
| byte[] getBytes() throws IOException; |
| |
| /** |
| * Merges estimators to produce a new estimator for the combined streams |
| * of this estimator and those passed as arguments. |
| * <p/> |
| * Nor this estimator nor the one passed as parameters are modified. |
| * |
| * @param estimators Zero or more compatible estimators |
| * @throws CardinalityMergeException If at least one of the estimators is not compatible with this one |
| */ |
| ICardinality merge(ICardinality... estimators) throws CardinalityMergeException; |
| } |