/*
 *
 * 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 org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.io.Writable;

/**
 * Specifies methods needed to add elements to a Bloom filter and serialize the
 * resulting Bloom filter as a sequence of bytes.
 */
@InterfaceAudience.Private
public interface BloomFilterWriter extends BloomFilterBase {

  /** Allocate memory for the bloom filter data. */
  void allocBloom();

  /** Compact the Bloom filter before writing metadata & data to disk. */
  void compactBloom();

  /**
   * Get a writable interface into bloom filter meta data.
   *
   * @return a writable instance that can be later written to a stream
   */
  Writable getMetaWriter();

  /**
   * Get a writable interface into bloom filter data (the actual Bloom bits).
   * Not used for compound Bloom filters.
   *
   * @return a writable instance that can be later written to a stream
   */
  Writable getDataWriter();

  /**
   * Add the specified binary to the bloom filter.
   *
   * @param buf data to be added to the bloom
   * @param offset offset into the data to be added
   * @param len length of the data to be added
   */
  void add(byte[] buf, int offset, int len);

}
