org.sonatype.nexus.common.hash.Hashes.java Source code

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Here is the source code for org.sonatype.nexus.common.hash.Hashes.java

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/*
 * Sonatype Nexus (TM) Open Source Version
 * Copyright (c) 2008-present 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.common.hash;

import java.io.IOException;
import java.io.InputStream;
import java.io.OutputStream;
import java.util.Map;

import com.google.common.hash.Funnels;
import com.google.common.hash.HashCode;
import com.google.common.hash.HashFunction;
import com.google.common.hash.Hasher;
import com.google.common.hash.HashingInputStream;
import com.google.common.io.ByteStreams;

import static com.google.common.base.Preconditions.checkNotNull;

/**
 * {@link HashCode} helpers.
 *
 * @since 3.0
 */
public final class Hashes {
    private Hashes() {
        // no instance
    }

    /**
     * Computes the hash of the given stream using the given algorithm.
     */
    public static HashCode hash(final HashAlgorithm algorithm, final InputStream inputStream) throws IOException {
        checkNotNull(algorithm);
        checkNotNull(inputStream);

        try (HashingInputStream hashingStream = new HashingInputStream(algorithm.function(), inputStream)) {
            ByteStreams.copy(hashingStream, ByteStreams.nullOutputStream());
            return hashingStream.hash();
        }
    }

    /**
     * Computes the hash of the given stream using multiple algorithms in one pass.
     */
    public static Map<HashAlgorithm, HashCode> hash(final Iterable<HashAlgorithm> algorithms,
            final InputStream inputStream) throws IOException {
        checkNotNull(algorithms);
        checkNotNull(inputStream);

        try (MultiHashingInputStream hashingStream = new MultiHashingInputStream(algorithms, inputStream)) {
            ByteStreams.copy(hashingStream, ByteStreams.nullOutputStream());
            return hashingStream.hashes();
        }
    }

    /**
     * Computes the hash of the given stream using the given function.
     */
    public static HashCode hash(final HashFunction function, final InputStream input) throws IOException {
        Hasher hasher = function.newHasher();
        OutputStream output = Funnels.asOutputStream(hasher);
        ByteStreams.copy(input, output);
        return hasher.hash();
    }
}