Source code

001package org.apache.archiva.checksum;
002
003/*
004 * Licensed to the Apache Software Foundation (ASF) under one
005 * or more contributor license agreements.  See the NOTICE file
006 * distributed with this work for additional information
007 * regarding copyright ownership.  The ASF licenses this file
008 * to you under the Apache License, Version 2.0 (the
009 * "License"); you may not use this file except in compliance
010 * with the License.  You may obtain a copy of the License at
011 *
012 *   http://www.apache.org/licenses/LICENSE-2.0
013 *
014 * Unless required by applicable law or agreed to in writing,
015 * software distributed under the License is distributed on an
016 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
017 * KIND, either express or implied.  See the License for the
018 * specific language governing permissions and limitations
019 * under the License.
020 */
021
022import java.io.FileNotFoundException;
023import java.io.IOException;
024import java.nio.MappedByteBuffer;
025import java.nio.channels.FileChannel;
026import java.nio.file.Path;
027import java.nio.file.StandardOpenOption;
028import java.util.List;
029import java.util.stream.Collectors;
030
031/**
032 * Utility class that handles multiple checksums for a single file.
033 */
034public class ChecksumUtil {
035
036
037    static final int BUFFER_SIZE = 32768;
038
039    public static void update(List<Checksum> checksumList, Path file ) throws IOException {
040        long fileSize;
041        try (FileChannel channel = FileChannel.open(file, StandardOpenOption.READ )) {
042            fileSize = channel.size();
043            long pos = 0;
044            while (pos < fileSize) {
045                long bufferSize = Math.min(BUFFER_SIZE, fileSize - pos);
046                MappedByteBuffer buffer = channel.map(FileChannel.MapMode.READ_ONLY, pos, bufferSize);
047                for (Checksum checksum : checksumList) {
048                    checksum.update(buffer);
049                    buffer.rewind();
050                }
051                fileSize = channel.size();
052                pos += BUFFER_SIZE;
053            }
054            for (Checksum checksum : checksumList) {
055                checksum.finish();
056            }
057        }
058    }
059
060    public static void update(Checksum checksum, Path file)
061        throws IOException
062    {
063        long fileSize;
064        try (FileChannel channel = FileChannel.open(file, StandardOpenOption.READ )) {
065            fileSize = channel.size();
066            long pos = 0;
067            while (pos<fileSize)
068            {
069                long bufferSize = Math.min(BUFFER_SIZE, fileSize-pos);
070                MappedByteBuffer buffer = channel.map( FileChannel.MapMode.READ_ONLY, pos, bufferSize);
071                checksum.update( buffer );
072                buffer.rewind();
073                fileSize = channel.size();
074                pos += BUFFER_SIZE;
075            }
076            checksum.finish();
077        }
078    }
079
080    public static List<Checksum> initializeChecksums(Path file, List<ChecksumAlgorithm> checksumAlgorithms) throws IOException {
081        final List<Checksum> checksums = newChecksums(checksumAlgorithms);
082        update(checksums, file);
083        return checksums;
084    }
085
086    /**
087     * Returns the list of configured checksum types.
088     *
089     * @param checksumTypes The list of checksum strings
090     * @return The list of checksum objects
091     */
092    public static List<ChecksumAlgorithm> getAlgorithms(List<String> checksumTypes) {
093        return checksumTypes.stream().map(ca ->
094                ChecksumAlgorithm.valueOf(ca.toUpperCase())).collect(Collectors.toList());
095    }
096
097    public static List<Checksum> newChecksums(List<ChecksumAlgorithm> checksumAlgorithms) {
098        return checksumAlgorithms.stream().map( a -> new Checksum(a)).collect(Collectors.toList());
099    }
100
101}