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}