001    /*
002     * Copyright 2010 The Apache Software Foundation.
003     * 
004     * Licensed under the Apache License, Version 2.0 (the "License");
005     * you may not use this file except in compliance with the License.
006     * You may obtain a copy of the License at
007     * 
008     *      http://www.apache.org/licenses/LICENSE-2.0
009     * 
010     * Unless required by applicable law or agreed to in writing, software
011     * distributed under the License is distributed on an "AS IS" BASIS,
012     * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
013     * See the License for the specific language governing permissions and
014     * limitations under the License.
015     */
016    package org.vafer.jdeb.producers;
017    
018    import java.io.File;
019    import java.io.FileInputStream;
020    import java.io.IOException;
021    import java.io.InputStream;
022    import java.io.PushbackInputStream;
023    import java.util.zip.GZIPInputStream;
024    
025    import org.apache.tools.bzip2.CBZip2InputStream;
026    import org.apache.tools.tar.TarEntry;
027    import org.apache.tools.tar.TarInputStream;
028    import org.vafer.jdeb.DataConsumer;
029    import org.vafer.jdeb.DataProducer;
030    import org.vafer.jdeb.mapping.Mapper;
031    
032    /**
033     * Providing data from an archive keeping permissions and ownerships.
034     * 
035     * @author Torsten Curdt <tcurdt@vafer.org>
036     */
037    public final class DataProducerArchive extends AbstractDataProducer implements DataProducer {
038    
039        private final File archive;
040        
041        public DataProducerArchive( final File pArchive, final String[] pIncludes, final String[] pExcludes, final Mapper[] pMappers ) {
042            super(pIncludes, pExcludes, pMappers);
043            archive = pArchive;
044        }
045            
046        public void produce( final DataConsumer pReceiver ) throws IOException {
047    
048            TarInputStream archiveInputStream = null;
049            try {
050                archiveInputStream = new TarInputStream(getCompressedInputStream(new FileInputStream(archive)));
051    
052                while(true) {
053                    
054                    TarEntry entry = archiveInputStream.getNextEntry();
055    
056                    if (entry == null) {
057                        break;
058                    }
059    
060                    if (!isIncluded(entry.getName())) {
061                        continue;                   
062                    }               
063    
064                    entry = map(entry);
065                    
066                    if (entry.isDirectory()) {
067                        pReceiver.onEachDir(entry.getName(), entry.getLinkName(), entry.getUserName(), entry.getUserId(), entry.getGroupName(), entry.getGroupId(), entry.getMode(), entry.getSize());
068                        continue;
069                    }
070                    pReceiver.onEachFile(archiveInputStream, entry.getName(), entry.getLinkName(), entry.getUserName(), entry.getUserId(), entry.getGroupName(), entry.getGroupId(), entry.getMode(), entry.getSize());                      
071                }
072    
073            } finally {
074                if (archiveInputStream != null) {
075                    archiveInputStream.close();
076                }
077            }       
078        }
079    
080    
081        /**
082         * TODO: replace by commons compress
083         * 
084         * Guess the compression used by looking at the first bytes of the stream.
085         */
086        private InputStream getCompressedInputStream(InputStream in) throws IOException {
087            
088            PushbackInputStream pin = new PushbackInputStream(in, 2);
089            byte[] header = new byte[2];
090            if (pin.read(header) != header.length) {
091                throw new IOException("Could not read header");
092            }
093    
094            if (header[0] == (byte) 0x1f && header[1] == (byte) 0x8b) {
095                pin.unread(header);
096                return new GZIPInputStream(pin);
097            } else if (header[0] == 'B' && header[1] == 'Z') {
098                return new CBZip2InputStream(pin);
099            } else {
100                throw new IOException("Unsupported archive format : " + archive);
101            }
102        }
103        
104    }