001/*
002 * Licensed to the Apache Software Foundation (ASF) under one
003 * or more contributor license agreements.  See the NOTICE file
004 * distributed with this work for additional information
005 * regarding copyright ownership.  The ASF licenses this file
006 * to you under the Apache License, Version 2.0 (the
007 * "License"); you may not use this file except in compliance
008 * with the License.  You may obtain a copy of the License at
009 *
010 *     http://www.apache.org/licenses/LICENSE-2.0
011 *
012 * Unless required by applicable law or agreed to in writing, software
013 * distributed under the License is distributed on an "AS IS" BASIS,
014 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
015 * See the License for the specific language governing permissions and
016 * limitations under the License.
017 */
018package org.apache.hadoop.hbase.io.compress;
019
020import edu.umd.cs.findbugs.annotations.Nullable;
021import java.io.Closeable;
022import java.io.IOException;
023import org.apache.hadoop.hbase.nio.ByteBuff;
024import org.apache.yetus.audience.InterfaceAudience;
025
026/**
027 * Specification of a ByteBuff-based decompressor, which can be more efficient than the stream-based
028 * Decompressor.
029 */
030@InterfaceAudience.Private
031public interface ByteBuffDecompressor extends Closeable {
032
033  /**
034   * Fills the ouput buffer with uncompressed data. Always call
035   * {@link #canDecompress(ByteBuff, ByteBuff)} first to check if this decompressor can handle your
036   * input and output buffers.
037   * @return The actual number of bytes of uncompressed data.
038   */
039  int decompress(ByteBuff output, ByteBuff input, int inputLen) throws IOException;
040
041  /**
042   * Signals of these two particular {@link ByteBuff}s are compatible with this decompressor.
043   * ByteBuffs can have one or multiple backing buffers, and each of these may be stored in heap or
044   * direct memory. Different {@link ByteBuffDecompressor}s may be able to handle different
045   * combinations of these, so always check.
046   */
047  boolean canDecompress(ByteBuff output, ByteBuff input);
048
049  /**
050   * Call before every use of {@link #canDecompress(ByteBuff, ByteBuff)} and
051   * {@link #decompress(ByteBuff, ByteBuff, int)} to reinitialize the decompressor with settings
052   * from the HFileInfo. This can matter because ByteBuffDecompressors are reused many times.
053   */
054  void reinit(@Nullable Compression.HFileDecompressionContext newHFileDecompressionContext);
055
056}