/*
* Copyright 2010 The Apache Software Foundation
*
* Licensed to the Apache Software Foundation (ASF) under one
* or more contributor license agreements. See the NOTICE file
* distributed with this work for additional information
* regarding copyright ownership. The ASF licenses this file
* to you 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.
*/
package org.apache.hadoop.hbase.util;
import java.nio.ByteBuffer;
/**
* Defines the general behavior of a bloom filter.
*
* <p>
* The Bloom filter is a data structure that was introduced in 1970 and that
* has been adopted by the networking research community in the past decade
* thanks to the bandwidth efficiencies that it offers for the transmission of
* set membership information between networked hosts. A sender encodes the
* information into a bit vector, the Bloom filter, that is more compact than a
* conventional representation. Computation and space costs for construction
* are linear in the number of elements. The receiver uses the filter to test
* whether various elements are members of the set. Though the filter will
* occasionally return a false positive, it will never return a false negative.
* When creating the filter, the sender can choose its desired point in a
* trade-off between the false positive rate and the size.
*
* @see BloomFilterWriter for the ability to add elements to a Bloom filter
*/
public interface BloomFilter extends BloomFilterBase {
/**
* Check if the specified key is contained in the bloom filter.
*
* @param buf data to check for existence of
* @param offset offset into the data
* @param length length of the data
* @param bloom bloom filter data to search. This can be null if auto-loading
* is supported.
* @return true if matched by bloom, false if not
*/
boolean contains(byte [] buf, int offset, int length, ByteBuffer bloom);
/**
* @return true if this Bloom filter can automatically load its data
* and thus allows a null byte buffer to be passed to contains()
*/
boolean supportsAutoLoading();
}