/*
* Sonatype Nexus (TM) Open Source Version
* Copyright (c) 2007-2014 Sonatype, Inc.
* All rights reserved. Includes the third-party code listed at http://links.sonatype.com/products/nexus/oss/attributions.
*
* This program and the accompanying materials are made available under the terms of the Eclipse Public License Version 1.0,
* which accompanies this distribution and is available at http://www.eclipse.org/legal/epl-v10.html.
*
* Sonatype Nexus (TM) Professional Version is available from Sonatype, Inc. "Sonatype" and "Sonatype Nexus" are trademarks
* of Sonatype, Inc. Apache Maven is a trademark of the Apache Software Foundation. M2eclipse is a trademark of the
* Eclipse Foundation. All other trademarks are the property of their respective owners.
*/
package org.sonatype.nexus.blobstore.file.internal;
import java.io.FilterInputStream;
import java.io.InputStream;
import java.security.DigestInputStream;
import java.security.MessageDigest;
import java.security.NoSuchAlgorithmException;
import org.sonatype.nexus.blobstore.file.FileOperations.StreamMetrics;
import org.sonatype.nexus.orient.Hex;
import com.google.common.base.Throwables;
import com.google.common.io.CountingInputStream;
/**
* A utility to collect metrics about the content of an input stream.
*
* @since 3.0
*/
public class MetricsInputStream
extends FilterInputStream
{
private final MessageDigest messageDigest;
private final CountingInputStream countingInputStream;
public MetricsInputStream(final InputStream input) {
this(new CountingInputStream(input), createSha1());
}
private MetricsInputStream(final CountingInputStream countingStream, final MessageDigest messageDigest) {
super(new DigestInputStream(countingStream, messageDigest));
this.messageDigest = messageDigest;
this.countingInputStream = countingStream;
}
public String getMessageDigest() {
return Hex.encode(messageDigest.digest());
}
public long getSize() {
return countingInputStream.getCount();
}
public StreamMetrics getMetrics() {
return new StreamMetrics(getSize(), getMessageDigest());
}
private static MessageDigest createSha1() {
try {
return MessageDigest.getInstance("SHA1");
}
catch (NoSuchAlgorithmException e) {
// should never happen
throw Throwables.propagate(e);
}
}
}