/**
* 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.fs;
import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;
import org.apache.hadoop.fs.Options.ChecksumOpt;
import org.apache.hadoop.io.MD5Hash;
import org.apache.hadoop.io.WritableUtils;
import org.apache.hadoop.util.DataChecksum;
import org.xml.sax.Attributes;
import org.xml.sax.SAXException;
import org.znerd.xmlenc.XMLOutputter;
import org.apache.hadoop.fs.MD5MD5CRC32CastagnoliFileChecksum;
import org.apache.hadoop.fs.MD5MD5CRC32GzipFileChecksum;
/** MD5 of MD5 of CRC32. */
@InterfaceAudience.LimitedPrivate({"HDFS"})
@InterfaceStability.Unstable
public class MD5MD5CRC32FileChecksum extends FileChecksum {
public static final int LENGTH = MD5Hash.MD5_LEN
+ (Integer.SIZE + Long.SIZE)/Byte.SIZE;
private int bytesPerCRC;
private long crcPerBlock;
private MD5Hash md5;
/** Same as this(0, 0, null) */
public MD5MD5CRC32FileChecksum() {
this(0, 0, null);
}
/** Create a MD5FileChecksum */
public MD5MD5CRC32FileChecksum(int bytesPerCRC, long crcPerBlock, MD5Hash md5) {
this.bytesPerCRC = bytesPerCRC;
this.crcPerBlock = crcPerBlock;
this.md5 = md5;
}
@Override
public String getAlgorithmName() {
return "MD5-of-" + crcPerBlock + "MD5-of-" + bytesPerCRC +
getCrcType().name();
}
public static DataChecksum.Type getCrcTypeFromAlgorithmName(String algorithm)
throws IOException {
if (algorithm.endsWith(DataChecksum.Type.CRC32.name())) {
return DataChecksum.Type.CRC32;
} else if (algorithm.endsWith(DataChecksum.Type.CRC32C.name())) {
return DataChecksum.Type.CRC32C;
}
throw new IOException("Unknown checksum type in " + algorithm);
}
@Override
public int getLength() {return LENGTH;}
@Override
public byte[] getBytes() {
return WritableUtils.toByteArray(this);
}
/** returns the CRC type */
public DataChecksum.Type getCrcType() {
// default to the one that is understood by all releases.
return DataChecksum.Type.CRC32;
}
public ChecksumOpt getChecksumOpt() {
return new ChecksumOpt(getCrcType(), bytesPerCRC);
}
@Override
public void readFields(DataInput in) throws IOException {
bytesPerCRC = in.readInt();
crcPerBlock = in.readLong();
md5 = MD5Hash.read(in);
}
@Override
public void write(DataOutput out) throws IOException {
out.writeInt(bytesPerCRC);
out.writeLong(crcPerBlock);
md5.write(out);
}
/** Write that object to xml output. */
public static void write(XMLOutputter xml, MD5MD5CRC32FileChecksum that
) throws IOException {
xml.startTag(MD5MD5CRC32FileChecksum.class.getName());
if (that != null) {
xml.attribute("bytesPerCRC", "" + that.bytesPerCRC);
xml.attribute("crcPerBlock", "" + that.crcPerBlock);
xml.attribute("crcType", ""+ that.getCrcType().name());
xml.attribute("md5", "" + that.md5);
}
xml.endTag();
}
/** Return the object represented in the attributes. */
public static MD5MD5CRC32FileChecksum valueOf(Attributes attrs
) throws SAXException {
final String bytesPerCRC = attrs.getValue("bytesPerCRC");
final String crcPerBlock = attrs.getValue("crcPerBlock");
final String md5 = attrs.getValue("md5");
String crcType = attrs.getValue("crcType");
DataChecksum.Type finalCrcType;
if (bytesPerCRC == null || crcPerBlock == null || md5 == null) {
return null;
}
try {
// old versions don't support crcType.
if (crcType == null || crcType == "") {
finalCrcType = DataChecksum.Type.CRC32;
} else {
finalCrcType = DataChecksum.Type.valueOf(crcType);
}
switch (finalCrcType) {
case CRC32:
return new MD5MD5CRC32GzipFileChecksum(
Integer.valueOf(bytesPerCRC),
Integer.valueOf(crcPerBlock),
new MD5Hash(md5));
case CRC32C:
return new MD5MD5CRC32CastagnoliFileChecksum(
Integer.valueOf(bytesPerCRC),
Integer.valueOf(crcPerBlock),
new MD5Hash(md5));
default:
// we should never get here since finalCrcType will
// hold a valid type or we should have got an exception.
return null;
}
} catch (Exception e) {
throw new SAXException("Invalid attributes: bytesPerCRC=" + bytesPerCRC
+ ", crcPerBlock=" + crcPerBlock + ", crcType=" + crcType
+ ", md5=" + md5, e);
}
}
@Override
public String toString() {
return getAlgorithmName() + ":" + md5;
}
}