001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with this
004 * work for additional information regarding copyright ownership. The ASF
005 * licenses this file to you under the Apache License, Version 2.0 (the
006 * "License"); you may not use this file except in compliance with the License.
007 * You may obtain a copy of the License at
008 *
009 * http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
013 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
014 * License for the specific language governing permissions and limitations
015 * under the License.
016 */
017package org.apache.hadoop.hbase.io.encoding;
018
019import java.io.DataInputStream;
020import java.io.IOException;
021import java.io.InputStream;
022import org.apache.commons.io.IOUtils;
023import org.apache.hadoop.hbase.io.ByteBuffInputStream;
024import org.apache.hadoop.hbase.io.TagCompressionContext;
025import org.apache.hadoop.hbase.io.compress.Compression;
026import org.apache.hadoop.hbase.io.crypto.Cipher;
027import org.apache.hadoop.hbase.io.crypto.Decryptor;
028import org.apache.hadoop.hbase.io.crypto.Encryption;
029import org.apache.hadoop.hbase.io.hfile.HFileContext;
030import org.apache.hadoop.hbase.io.util.BlockIOUtils;
031import org.apache.hadoop.hbase.nio.ByteBuff;
032import org.apache.hadoop.hbase.util.Bytes;
033import org.apache.yetus.audience.InterfaceAudience;
034
035/**
036 * A default implementation of {@link HFileBlockDecodingContext}. It assumes the
037 * block data section is compressed as a whole.
038 *
039 * @see HFileBlockDefaultEncodingContext for the default compression context
040 *
041 */
042@InterfaceAudience.Private
043public class HFileBlockDefaultDecodingContext implements HFileBlockDecodingContext {
044  private final HFileContext fileContext;
045  private TagCompressionContext tagCompressionContext;
046
047  public HFileBlockDefaultDecodingContext(HFileContext fileContext) {
048    this.fileContext = fileContext;
049  }
050
051  @Override
052  public void prepareDecoding(int onDiskSizeWithoutHeader, int uncompressedSizeWithoutHeader,
053      ByteBuff blockBufferWithoutHeader, ByteBuff onDiskBlock) throws IOException {
054    final ByteBuffInputStream byteBuffInputStream = new ByteBuffInputStream(onDiskBlock);
055    InputStream dataInputStream = new DataInputStream(byteBuffInputStream);
056
057    try {
058      Encryption.Context cryptoContext = fileContext.getEncryptionContext();
059      if (cryptoContext != Encryption.Context.NONE) {
060
061        Cipher cipher = cryptoContext.getCipher();
062        Decryptor decryptor = cipher.getDecryptor();
063        decryptor.setKey(cryptoContext.getKey());
064
065        // Encrypted block format:
066        // +--------------------------+
067        // | byte iv length           |
068        // +--------------------------+
069        // | iv data ...              |
070        // +--------------------------+
071        // | encrypted block data ... |
072        // +--------------------------+
073
074        int ivLength = dataInputStream.read();
075        if (ivLength > 0) {
076          byte[] iv = new byte[ivLength];
077          IOUtils.readFully(dataInputStream, iv);
078          decryptor.setIv(iv);
079          // All encrypted blocks will have a nonzero IV length. If we see an IV
080          // length of zero, this means the encoding context had 0 bytes of
081          // plaintext to encode.
082          decryptor.reset();
083          dataInputStream = decryptor.createDecryptionStream(dataInputStream);
084        }
085        onDiskSizeWithoutHeader -= Bytes.SIZEOF_BYTE + ivLength;
086      }
087
088      Compression.Algorithm compression = fileContext.getCompression();
089      if (compression != Compression.Algorithm.NONE) {
090        Compression.decompress(blockBufferWithoutHeader, dataInputStream,
091          uncompressedSizeWithoutHeader, compression);
092      } else {
093        BlockIOUtils.readFullyWithHeapBuffer(dataInputStream, blockBufferWithoutHeader,
094          onDiskSizeWithoutHeader);
095      }
096    } finally {
097      byteBuffInputStream.close();
098      dataInputStream.close();
099    }
100  }
101
102  @Override
103  public HFileContext getHFileContext() {
104    return this.fileContext;
105  }
106
107  public TagCompressionContext getTagCompressionContext() {
108    return tagCompressionContext;
109  }
110
111  public void setTagCompressionContext(TagCompressionContext tagCompressionContext) {
112    this.tagCompressionContext = tagCompressionContext;
113  }
114}