org.apache.hadoop.hbase.io.encoding.HFileBlockDefaultDecodingContext.java Source code

Introduction

Here is the source code for org.apache.hadoop.hbase.io.encoding.HFileBlockDefaultDecodingContext.java

Source

/*
 * 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.io.encoding;

import java.io.ByteArrayInputStream;
import java.io.DataInputStream;
import java.io.IOException;
import java.io.InputStream;
import java.nio.ByteBuffer;

import org.apache.commons.io.IOUtils;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.hbase.io.TagCompressionContext;
import org.apache.hadoop.hbase.io.compress.Compression;
import org.apache.hadoop.hbase.io.crypto.Cipher;
import org.apache.hadoop.hbase.io.crypto.Decryptor;
import org.apache.hadoop.hbase.io.crypto.Encryption;
import org.apache.hadoop.hbase.io.hfile.HFileContext;
import org.apache.hadoop.hbase.io.util.StreamUtils;
import org.apache.hadoop.hbase.util.Bytes;

/**
 * A default implementation of {@link HFileBlockDecodingContext}. It assumes the
 * block data section is compressed as a whole.
 *
 * @see HFileBlockDefaultEncodingContext for the default compression context
 *
 */
@InterfaceAudience.Private
public class HFileBlockDefaultDecodingContext implements HFileBlockDecodingContext {
    private final HFileContext fileContext;
    private TagCompressionContext tagCompressionContext;

    public HFileBlockDefaultDecodingContext(HFileContext fileContext) {
        this.fileContext = fileContext;
    }

    @Override
    public void prepareDecoding(int onDiskSizeWithoutHeader, int uncompressedSizeWithoutHeader,
            ByteBuffer blockBufferWithoutHeader, byte[] onDiskBlock, int offset) throws IOException {
        InputStream in = new DataInputStream(
                new ByteArrayInputStream(onDiskBlock, offset, onDiskSizeWithoutHeader));

        Encryption.Context cryptoContext = fileContext.getEncryptionContext();
        if (cryptoContext != Encryption.Context.NONE) {

            Cipher cipher = cryptoContext.getCipher();
            Decryptor decryptor = cipher.getDecryptor();
            decryptor.setKey(cryptoContext.getKey());

            // Encrypted block format:
            // +--------------------------+
            // | byte iv length           |
            // +--------------------------+
            // | iv data ...              |
            // +--------------------------+
            // | encrypted block data ... |
            // +--------------------------+

            int ivLength = in.read();
            if (ivLength > 0) {
                byte[] iv = new byte[ivLength];
                IOUtils.readFully(in, iv);
                decryptor.setIv(iv);
                // All encrypted blocks will have a nonzero IV length. If we see an IV
                // length of zero, this means the encoding context had 0 bytes of
                // plaintext to encode.
                decryptor.reset();
                in = decryptor.createDecryptionStream(in);
            }
            onDiskSizeWithoutHeader -= Bytes.SIZEOF_BYTE + ivLength;
        }

        Compression.Algorithm compression = fileContext.getCompression();
        if (compression != Compression.Algorithm.NONE) {
            Compression.decompress(blockBufferWithoutHeader.array(), blockBufferWithoutHeader.arrayOffset(), in,
                    onDiskSizeWithoutHeader, uncompressedSizeWithoutHeader, compression);
        } else {
            IOUtils.readFully(in, blockBufferWithoutHeader.array(), blockBufferWithoutHeader.arrayOffset(),
                    onDiskSizeWithoutHeader);
        }
    }

    @Override
    public HFileContext getHFileContext() {
        return this.fileContext;
    }

    public TagCompressionContext getTagCompressionContext() {
        return tagCompressionContext;
    }

    public void setTagCompressionContext(TagCompressionContext tagCompressionContext) {
        this.tagCompressionContext = tagCompressionContext;
    }
}