    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one
    003 * or more contributor license agreements.  See the NOTICE file
    004 * distributed with this work for additional information
    005 * regarding copyright ownership.  The ASF licenses this file
    006 * to you under the Apache License, Version 2.0 (the
    007 * "License"); you may not use this file except in compliance
    008 * with the License.  You may obtain a copy of the License at
    009 *
    010 * http://www.apache.org/licenses/LICENSE-2.0
    011 *
    012 * Unless required by applicable law or agreed to in writing,
    013 * software distributed under the License is distributed on an
    014 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
    015 * KIND, either express or implied.  See the License for the
    016 * specific language governing permissions and limitations
    017 * under the License.
    018 */
    019package org.apache.commons.compress.archivers.tar;
    020
    021import static java.nio.charset.StandardCharsets.UTF_8;
    022
    023import java.io.File;
    024import java.io.IOException;
    025import java.io.OutputStream;
    026import java.io.StringWriter;
    027import java.math.BigDecimal;
    028import java.math.RoundingMode;
    029import java.nio.ByteBuffer;
    030import java.nio.charset.StandardCharsets;
    031import java.nio.file.LinkOption;
    032import java.nio.file.Path;
    033import java.nio.file.attribute.FileTime;
    034import java.time.Instant;
    035import java.util.Arrays;
    036import java.util.HashMap;
    037import java.util.Map;
    038
    039import org.apache.commons.compress.archivers.ArchiveOutputStream;
    040import org.apache.commons.compress.archivers.zip.ZipEncoding;
    041import org.apache.commons.compress.archivers.zip.ZipEncodingHelper;
    042import org.apache.commons.compress.utils.FixedLengthBlockOutputStream;
    043import org.apache.commons.compress.utils.TimeUtils;
    044import org.apache.commons.io.Charsets;
    045import org.apache.commons.io.output.CountingOutputStream;
    046
    047/**
    048 * The TarOutputStream writes a UNIX tar archive as an OutputStream. Methods are provided to put entries, and then write their contents by writing to this
    049 * stream using write().
    050 *
    051 * <p>
    052 * tar archives consist of a sequence of records of 512 bytes each that are grouped into blocks. Prior to Apache Commons Compress 1.14 it has been possible to
    053 * configure a record size different from 512 bytes and arbitrary block sizes. Starting with Compress 1.15 512 is the only valid option for the record size and
    054 * the block size must be a multiple of 512. Also the default block size changed from 10240 bytes prior to Compress 1.15 to 512 bytes with Compress 1.15.
    055 * </p>
    056 *
    057 * @NotThreadSafe
    058 */
    059public class TarArchiveOutputStream extends ArchiveOutputStream<TarArchiveEntry> {
    060
    061    /**
    062     * Fail if a long file name is required in the archive.
    063     */
    064    public static final int LONGFILE_ERROR = 0;
    065
    066    /**
    067     * Long paths will be truncated in the archive.
    068     */
    069    public static final int LONGFILE_TRUNCATE = 1;
    070
    071    /**
    072     * GNU tar extensions are used to store long file names in the archive.
    073     */
    074    public static final int LONGFILE_GNU = 2;
    075
    076    /**
    077     * POSIX/PAX extensions are used to store long file names in the archive.
    078     */
    079    public static final int LONGFILE_POSIX = 3;
    080
    081    /**
    082     * Fail if a big number (e.g. size &gt; 8GiB) is required in the archive.
    083     */
    084    public static final int BIGNUMBER_ERROR = 0;
    085
    086    /**
    087     * star/GNU tar/BSD tar extensions are used to store big number in the archive.
    088     */
    089    public static final int BIGNUMBER_STAR = 1;
    090
    091    /**
    092     * POSIX/PAX extensions are used to store big numbers in the archive.
    093     */
    094    public static final int BIGNUMBER_POSIX = 2;
    095    private static final int RECORD_SIZE = 512;
    096
    097    private static final ZipEncoding ASCII = ZipEncodingHelper.getZipEncoding(StandardCharsets.US_ASCII);
    098
    099    private static final int BLOCK_SIZE_UNSPECIFIED = -511;
    100    private long currSize;
    101    private String currName;
    102    private long currBytes;
    103    private final byte[] recordBuf;
    104    private int longFileMode = LONGFILE_ERROR;
    105    private int bigNumberMode = BIGNUMBER_ERROR;
    106
    107    private long recordsWritten;
    108
    109    private final int recordsPerBlock;
    110
    111    private boolean closed;
    112
    113    /**
    114     * Indicates if putArchiveEntry has been called without closeArchiveEntry
    115     */
    116
    117    private boolean haveUnclosedEntry;
    118
    119    /**
    120     * indicates if this archive is finished
    121     */
    122    private boolean finished;
    123
    124    private final FixedLengthBlockOutputStream out;
    125
    126    private final CountingOutputStream countingOut;
    127
    128    private final ZipEncoding zipEncoding;
    129
    130    /**
    131     * The provided encoding (for unit tests).
    132     */
    133    final String charsetName;
    134
    135    private boolean addPaxHeadersForNonAsciiNames;
    136
    137    /**
    138     * Constructs a new instance.
    139     *
    140     * <p>
    141     * Uses a block size of 512 bytes.
    142     * </p>
    143     *
    144     * @param os the output stream to use
    145     */
    146    public TarArchiveOutputStream(final OutputStream os) {
    147        this(os, BLOCK_SIZE_UNSPECIFIED);
    148    }
    149
    150    /**
    151     * Constructs a new instance.
    152     *
    153     * @param os        the output stream to use
    154     * @param blockSize the block size to use. Must be a multiple of 512 bytes.
    155     */
    156    public TarArchiveOutputStream(final OutputStream os, final int blockSize) {
    157        this(os, blockSize, null);
    158    }
    159
    160    /**
    161     * Constructs a new instance.
    162     *
    163     * @param os         the output stream to use
    164     * @param blockSize  the block size to use
    165     * @param recordSize the record size to use. Must be 512 bytes.
    166     * @deprecated recordSize must always be 512 bytes. An IllegalArgumentException will be thrown if any other value is used
    167     */
    168    @Deprecated
    169    public TarArchiveOutputStream(final OutputStream os, final int blockSize, final int recordSize) {
    170        this(os, blockSize, recordSize, null);
    171    }
    172
    173    /**
    174     * Constructs a new instance.
    175     *
    176     * @param os         the output stream to use
    177     * @param blockSize  the block size to use . Must be a multiple of 512 bytes.
    178     * @param recordSize the record size to use. Must be 512 bytes.
    179     * @param encoding   name of the encoding to use for file names
    180     * @since 1.4
    181     * @deprecated recordSize must always be 512 bytes. An IllegalArgumentException will be thrown if any other value is used.
    182     */
    183    @Deprecated
    184    public TarArchiveOutputStream(final OutputStream os, final int blockSize, final int recordSize, final String encoding) {
    185        this(os, blockSize, encoding);
    186        if (recordSize != RECORD_SIZE) {
    187            throw new IllegalArgumentException("Tar record size must always be 512 bytes. Attempt to set size of " + recordSize);
    188        }
    189
    190    }
    191
    192    /**
    193     * Constructs a new instance.
    194     *
    195     * @param os        the output stream to use
    196     * @param blockSize the block size to use. Must be a multiple of 512 bytes.
    197     * @param encoding  name of the encoding to use for file names
    198     * @since 1.4
    199     */
    200    public TarArchiveOutputStream(final OutputStream os, final int blockSize, final String encoding) {
    201        final int realBlockSize;
    202        if (BLOCK_SIZE_UNSPECIFIED == blockSize) {
    203            realBlockSize = RECORD_SIZE;
    204        } else {
    205            realBlockSize = blockSize;
    206        }
    207
    208        if (realBlockSize <= 0 || realBlockSize % RECORD_SIZE != 0) {
    209            throw new IllegalArgumentException("Block size must be a multiple of 512 bytes. Attempt to use set size of " + blockSize);
    210        }
    211        out = new FixedLengthBlockOutputStream(countingOut = new CountingOutputStream(os), RECORD_SIZE);
    212        this.charsetName = Charsets.toCharset(encoding).name();
    213        this.zipEncoding = ZipEncodingHelper.getZipEncoding(encoding);
    214
    215        this.recordBuf = new byte[RECORD_SIZE];
    216        this.recordsPerBlock = realBlockSize / RECORD_SIZE;
    217    }
    218
    219    /**
    220     * Constructs a new instance.
    221     *
    222     * <p>
    223     * Uses a block size of 512 bytes.
    224     * </p>
    225     *
    226     * @param os       the output stream to use
    227     * @param encoding name of the encoding to use for file names
    228     * @since 1.4
    229     */
    230    public TarArchiveOutputStream(final OutputStream os, final String encoding) {
    231        this(os, BLOCK_SIZE_UNSPECIFIED, encoding);
    232    }
    233
    234    private void addFileTimePaxHeader(final Map<String, String> paxHeaders, final String header, final FileTime value) {
    235        if (value != null) {
    236            final Instant instant = value.toInstant();
    237            final long seconds = instant.getEpochSecond();
    238            final int nanos = instant.getNano();
    239            if (nanos == 0) {
    240                paxHeaders.put(header, String.valueOf(seconds));
    241            } else {
    242                addInstantPaxHeader(paxHeaders, header, seconds, nanos);
    243            }
    244        }
    245    }
    246
    247    private void addFileTimePaxHeaderForBigNumber(final Map<String, String> paxHeaders, final String header, final FileTime value, final long maxValue) {
    248        if (value != null) {
    249            final Instant instant = value.toInstant();
    250            final long seconds = instant.getEpochSecond();
    251            final int nanos = instant.getNano();
    252            if (nanos == 0) {
    253                addPaxHeaderForBigNumber(paxHeaders, header, seconds, maxValue);
    254            } else {
    255                addInstantPaxHeader(paxHeaders, header, seconds, nanos);
    256            }
    257        }
    258    }
    259
    260    private void addInstantPaxHeader(final Map<String, String> paxHeaders, final String header, final long seconds, final int nanos) {
    261        final BigDecimal bdSeconds = BigDecimal.valueOf(seconds);
    262        final BigDecimal bdNanos = BigDecimal.valueOf(nanos).movePointLeft(9).setScale(7, RoundingMode.DOWN);
    263        final BigDecimal timestamp = bdSeconds.add(bdNanos);
    264        paxHeaders.put(header, timestamp.toPlainString());
    265    }
    266
    267    private void addPaxHeaderForBigNumber(final Map<String, String> paxHeaders, final String header, final long value, final long maxValue) {
    268        if (value < 0 || value > maxValue) {
    269            paxHeaders.put(header, String.valueOf(value));
    270        }
    271    }
    272
    273    private void addPaxHeadersForBigNumbers(final Map<String, String> paxHeaders, final TarArchiveEntry entry) {
    274        addPaxHeaderForBigNumber(paxHeaders, "size", entry.getSize(), TarConstants.MAXSIZE);
    275        addPaxHeaderForBigNumber(paxHeaders, "gid", entry.getLongGroupId(), TarConstants.MAXID);
    276        addFileTimePaxHeaderForBigNumber(paxHeaders, "mtime", entry.getLastModifiedTime(), TarConstants.MAXSIZE);
    277        addFileTimePaxHeader(paxHeaders, "atime", entry.getLastAccessTime());
    278        if (entry.getStatusChangeTime() != null) {
    279            addFileTimePaxHeader(paxHeaders, "ctime", entry.getStatusChangeTime());
    280        } else {
    281            // ctime is usually set from creation time on platforms where the real ctime is not available
    282            addFileTimePaxHeader(paxHeaders, "ctime", entry.getCreationTime());
    283        }
    284        addPaxHeaderForBigNumber(paxHeaders, "uid", entry.getLongUserId(), TarConstants.MAXID);
    285        // libarchive extensions
    286        addFileTimePaxHeader(paxHeaders, "LIBARCHIVE.creationtime", entry.getCreationTime());
    287        // star extensions by Jörg Schilling
    288        addPaxHeaderForBigNumber(paxHeaders, "SCHILY.devmajor", entry.getDevMajor(), TarConstants.MAXID);
    289        addPaxHeaderForBigNumber(paxHeaders, "SCHILY.devminor", entry.getDevMinor(), TarConstants.MAXID);
    290        // there is no PAX header for file mode
    291        failForBigNumber("mode", entry.getMode(), TarConstants.MAXID);
    292    }
    293
    294    /**
    295     * Closes the underlying OutputStream.
    296     *
    297     * @throws IOException on error
    298     */
    299    @Override
    300    public void close() throws IOException {
    301        try {
    302            if (!finished) {
    303                finish();
    304            }
    305        } finally {
    306            if (!closed) {
    307                out.close();
    308                closed = true;
    309            }
    310        }
    311    }
    312
    313    /**
    314     * Closes an entry. This method MUST be called for all file entries that contain data. The reason is that we must buffer data written to the stream in order
    315     * to satisfy the buffer's record based writes. Thus, there may be data fragments still being assembled that must be written to the output stream before
    316     * this entry is closed and the next entry written.
    317     *
    318     * @throws IOException on error
    319     */
    320    @Override
    321    public void closeArchiveEntry() throws IOException {
    322        if (finished) {
    323            throw new IOException("Stream has already been finished");
    324        }
    325        if (!haveUnclosedEntry) {
    326            throw new IOException("No current entry to close");
    327        }
    328        out.flushBlock();
    329        if (currBytes < currSize) {
    330            throw new IOException(
    331                    "Entry '" + currName + "' closed at '" + currBytes + "' before the '" + currSize + "' bytes specified in the header were written");
    332        }
    333        recordsWritten += currSize / RECORD_SIZE;
    334
    335        if (0 != currSize % RECORD_SIZE) {
    336            recordsWritten++;
    337        }
    338        haveUnclosedEntry = false;
    339    }
    340
    341    @Override
    342    public TarArchiveEntry createArchiveEntry(final File inputFile, final String entryName) throws IOException {
    343        if (finished) {
    344            throw new IOException("Stream has already been finished");
    345        }
    346        return new TarArchiveEntry(inputFile, entryName);
    347    }
    348
    349    @Override
    350    public TarArchiveEntry createArchiveEntry(final Path inputPath, final String entryName, final LinkOption... options) throws IOException {
    351        if (finished) {
    352            throw new IOException("Stream has already been finished");
    353        }
    354        return new TarArchiveEntry(inputPath, entryName, options);
    355    }
    356
    357    private byte[] encodeExtendedPaxHeadersContents(final Map<String, String> headers) {
    358        final StringWriter w = new StringWriter();
    359        headers.forEach((k, v) -> {
    360            int len = k.length() + v.length() + 3 /* blank, equals and newline */
    361                    + 2 /* guess 9 < actual length < 100 */;
    362            String line = len + " " + k + "=" + v + "\n";
    363            int actualLength = line.getBytes(UTF_8).length;
    364            while (len != actualLength) {
    365                // Adjust for cases where length < 10 or > 100
    366                // or where UTF-8 encoding isn't a single octet
    367                // per character.
    368                // Must be in loop as size may go from 99 to 100 in
    369                // first pass, so we'd need a second.
    370                len = actualLength;
    371                line = len + " " + k + "=" + v + "\n";
    372                actualLength = line.getBytes(UTF_8).length;
    373            }
    374            w.write(line);
    375        });
    376        return w.toString().getBytes(UTF_8);
    377    }
    378
    379    private void failForBigNumber(final String field, final long value, final long maxValue) {
    380        failForBigNumber(field, value, maxValue, "");
    381    }
    382
    383    private void failForBigNumber(final String field, final long value, final long maxValue, final String additionalMsg) {
    384        if (value < 0 || value > maxValue) {
    385            throw new IllegalArgumentException(field + " '" + value // NOSONAR
    386                    + "' is too big ( > " + maxValue + " )." + additionalMsg);
    387        }
    388    }
    389
    390    private void failForBigNumbers(final TarArchiveEntry entry) {
    391        failForBigNumber("entry size", entry.getSize(), TarConstants.MAXSIZE);
    392        failForBigNumberWithPosixMessage("group id", entry.getLongGroupId(), TarConstants.MAXID);
    393        failForBigNumber("last modification time", TimeUtils.toUnixTime(entry.getLastModifiedTime()), TarConstants.MAXSIZE);
    394        failForBigNumber("user id", entry.getLongUserId(), TarConstants.MAXID);
    395        failForBigNumber("mode", entry.getMode(), TarConstants.MAXID);
    396        failForBigNumber("major device number", entry.getDevMajor(), TarConstants.MAXID);
    397        failForBigNumber("minor device number", entry.getDevMinor(), TarConstants.MAXID);
    398    }
    399
    400    private void failForBigNumberWithPosixMessage(final String field, final long value, final long maxValue) {
    401        failForBigNumber(field, value, maxValue, " Use STAR or POSIX extensions to overcome this limit");
    402    }
    403
    404    /**
    405     * Finishes the TAR archive without closing the underlying OutputStream.
    406     *
    407     * An archive consists of a series of file entries terminated by an end-of-archive entry, which consists of two 512 blocks of zero bytes. POSIX.1 requires
    408     * two EOF records, like some other implementations.
    409     *
    410     * @throws IOException on error
    411     */
    412    @Override
    413    public void finish() throws IOException {
    414        if (finished) {
    415            throw new IOException("This archive has already been finished");
    416        }
    417
    418        if (haveUnclosedEntry) {
    419            throw new IOException("This archive contains unclosed entries.");
    420        }
    421        writeEOFRecord();
    422        writeEOFRecord();
    423        padAsNeeded();
    424        out.flush();
    425        finished = true;
    426    }
    427
    428    @Override
    429    public void flush() throws IOException {
    430        out.flush();
    431    }
    432
    433    @Override
    434    public long getBytesWritten() {
    435        return countingOut.getByteCount();
    436    }
    437
    438    @Deprecated
    439    @Override
    440    public int getCount() {
    441        return (int) getBytesWritten();
    442    }
    443
    444    /**
    445     * Gets the record size being used by this stream's TarBuffer.
    446     *
    447     * @return The TarBuffer record size.
    448     * @deprecated
    449     */
    450    @Deprecated
    451    public int getRecordSize() {
    452        return RECORD_SIZE;
    453    }
    454
    455    /**
    456     * Handles long file or link names according to the longFileMode setting.
    457     *
    458     * <p>
    459     * I.e. if the given name is too long to be written to a plain tar header then
    460     * <ul>
    461     * <li>it creates a pax header who's name is given by the paxHeaderName parameter if longFileMode is POSIX</li>
    462     * <li>it creates a GNU longlink entry who's type is given by the linkType parameter if longFileMode is GNU</li>
    463     * <li>it throws an exception if longFileMode is ERROR</li>
    464     * <li>it truncates the name if longFileMode is TRUNCATE</li>
    465     * </ul>
    466     * </p>
    467     *
    468     * @param entry         entry the name belongs to
    469     * @param name          the name to write
    470     * @param paxHeaders    current map of pax headers
    471     * @param paxHeaderName name of the pax header to write
    472     * @param linkType      type of the GNU entry to write
    473     * @param fieldName     the name of the field
    474     * @throws IllegalArgumentException if the {@link TarArchiveOutputStream#longFileMode} equals {@link TarArchiveOutputStream#LONGFILE_ERROR} and the file
    475     *                                  name is too long
    476     * @return whether a pax header has been written.
    477     */
    478    private boolean handleLongName(final TarArchiveEntry entry, final String name, final Map<String, String> paxHeaders, final String paxHeaderName,
    479            final byte linkType, final String fieldName) throws IOException {
    480        final ByteBuffer encodedName = zipEncoding.encode(name);
    481        final int len = encodedName.limit() - encodedName.position();
    482        if (len >= TarConstants.NAMELEN) {
    483
    484            if (longFileMode == LONGFILE_POSIX) {
    485                paxHeaders.put(paxHeaderName, name);
    486                return true;
    487            }
    488            if (longFileMode == LONGFILE_GNU) {
    489                // create a TarEntry for the LongLink, the contents
    490                // of which are the link's name
    491                final TarArchiveEntry longLinkEntry = new TarArchiveEntry(TarConstants.GNU_LONGLINK, linkType);
    492
    493                longLinkEntry.setSize(len + 1L); // +1 for NUL
    494                transferModTime(entry, longLinkEntry);
    495                putArchiveEntry(longLinkEntry);
    496                write(encodedName.array(), encodedName.arrayOffset(), len);
    497                write(0); // NUL terminator
    498                closeArchiveEntry();
    499            } else if (longFileMode != LONGFILE_TRUNCATE) {
    500                throw new IllegalArgumentException(fieldName + " '" + name // NOSONAR
    501                        + "' is too long ( > " + TarConstants.NAMELEN + " bytes)");
    502            }
    503        }
    504        return false;
    505    }
    506
    507    private void padAsNeeded() throws IOException {
    508        final int start = Math.toIntExact(recordsWritten % recordsPerBlock);
    509        if (start != 0) {
    510            for (int i = start; i < recordsPerBlock; i++) {
    511                writeEOFRecord();
    512            }
    513        }
    514    }
    515
    516    /**
    517     * Puts an entry on the output stream. This writes the entry's header record and positions the output stream for writing the contents of the entry. Once
    518     * this method is called, the stream is ready for calls to write() to write the entry's contents. Once the contents are written, closeArchiveEntry()
    519     * <B>MUST</B> be called to ensure that all buffered data is completely written to the output stream.
    520     *
    521     * @param archiveEntry The TarEntry to be written to the archive.
    522     * @throws IOException              on error
    523     * @throws ClassCastException       if archiveEntry is not an instance of TarArchiveEntry
    524     * @throws IllegalArgumentException if the {@link TarArchiveOutputStream#longFileMode} equals {@link TarArchiveOutputStream#LONGFILE_ERROR} and the file
    525     *                                  name is too long
    526     * @throws IllegalArgumentException if the {@link TarArchiveOutputStream#bigNumberMode} equals {@link TarArchiveOutputStream#BIGNUMBER_ERROR} and one of the
    527     *                                  numeric values exceeds the limits of a traditional tar header.
    528     */
    529    @Override
    530    public void putArchiveEntry(final TarArchiveEntry archiveEntry) throws IOException {
    531        if (finished) {
    532            throw new IOException("Stream has already been finished");
    533        }
    534        if (archiveEntry.isGlobalPaxHeader()) {
    535            final byte[] data = encodeExtendedPaxHeadersContents(archiveEntry.getExtraPaxHeaders());
    536            archiveEntry.setSize(data.length);
    537            archiveEntry.writeEntryHeader(recordBuf, zipEncoding, bigNumberMode == BIGNUMBER_STAR);
    538            writeRecord(recordBuf);
    539            currSize = archiveEntry.getSize();
    540            currBytes = 0;
    541            this.haveUnclosedEntry = true;
    542            write(data);
    543            closeArchiveEntry();
    544        } else {
    545            final Map<String, String> paxHeaders = new HashMap<>();
    546            final String entryName = archiveEntry.getName();
    547            final boolean paxHeaderContainsPath = handleLongName(archiveEntry, entryName, paxHeaders, "path", TarConstants.LF_GNUTYPE_LONGNAME, "file name");
    548            final String linkName = archiveEntry.getLinkName();
    549            final boolean paxHeaderContainsLinkPath = linkName != null && !linkName.isEmpty()
    550                    && handleLongName(archiveEntry, linkName, paxHeaders, "linkpath", TarConstants.LF_GNUTYPE_LONGLINK, "link name");
    551
    552            if (bigNumberMode == BIGNUMBER_POSIX) {
    553                addPaxHeadersForBigNumbers(paxHeaders, archiveEntry);
    554            } else if (bigNumberMode != BIGNUMBER_STAR) {
    555                failForBigNumbers(archiveEntry);
    556            }
    557
    558            if (addPaxHeadersForNonAsciiNames && !paxHeaderContainsPath && !ASCII.canEncode(entryName)) {
    559                paxHeaders.put("path", entryName);
    560            }
    561
    562            if (addPaxHeadersForNonAsciiNames && !paxHeaderContainsLinkPath && (archiveEntry.isLink() || archiveEntry.isSymbolicLink())
    563                    && !ASCII.canEncode(linkName)) {
    564                paxHeaders.put("linkpath", linkName);
    565            }
    566            paxHeaders.putAll(archiveEntry.getExtraPaxHeaders());
    567
    568            if (!paxHeaders.isEmpty()) {
    569                writePaxHeaders(archiveEntry, entryName, paxHeaders);
    570            }
    571
    572            archiveEntry.writeEntryHeader(recordBuf, zipEncoding, bigNumberMode == BIGNUMBER_STAR);
    573            writeRecord(recordBuf);
    574
    575            currBytes = 0;
    576
    577            if (archiveEntry.isDirectory()) {
    578                currSize = 0;
    579            } else {
    580                currSize = archiveEntry.getSize();
    581            }
    582            currName = entryName;
    583            haveUnclosedEntry = true;
    584        }
    585    }
    586
    587    /**
    588     * Sets whether to add a PAX extension header for non-ASCII file names.
    589     *
    590     * @param b whether to add a PAX extension header for non-ASCII file names.
    591     * @since 1.4
    592     */
    593    public void setAddPaxHeadersForNonAsciiNames(final boolean b) {
    594        addPaxHeadersForNonAsciiNames = b;
    595    }
    596
    597    /**
    598     * Sets the big number mode. This can be BIGNUMBER_ERROR(0), BIGNUMBER_STAR(1) or BIGNUMBER_POSIX(2). This specifies the treatment of big files (sizes &gt;
    599     * TarConstants.MAXSIZE) and other numeric values too big to fit into a traditional tar header. Default is BIGNUMBER_ERROR.
    600     *
    601     * @param bigNumberMode the mode to use
    602     * @since 1.4
    603     */
    604    public void setBigNumberMode(final int bigNumberMode) {
    605        this.bigNumberMode = bigNumberMode;
    606    }
    607
    608    /**
    609     * Sets the long file mode. This can be LONGFILE_ERROR(0), LONGFILE_TRUNCATE(1), LONGFILE_GNU(2) or LONGFILE_POSIX(3). This specifies the treatment of long
    610     * file names (names &gt;= TarConstants.NAMELEN). Default is LONGFILE_ERROR.
    611     *
    612     * @param longFileMode the mode to use
    613     */
    614    public void setLongFileMode(final int longFileMode) {
    615        this.longFileMode = longFileMode;
    616    }
    617
    618    /**
    619     * Tests whether the character could lead to problems when used inside a TarArchiveEntry name for a PAX header.
    620     *
    621     * @return true if the character could lead to problems when used inside a TarArchiveEntry name for a PAX header.
    622     */
    623    private boolean shouldBeReplaced(final char c) {
    624        return c == 0 // would be read as Trailing null
    625                || c == '/' // when used as last character TAE will consider the PAX header a directory
    626                || c == '\\'; // same as '/' as slashes get "normalized" on Windows
    627    }
    628
    629    private String stripTo7Bits(final String name) {
    630        final int length = name.length();
    631        final StringBuilder result = new StringBuilder(length);
    632        for (int i = 0; i < length; i++) {
    633            final char stripped = (char) (name.charAt(i) & 0x7F);
    634            if (shouldBeReplaced(stripped)) {
    635                result.append("_");
    636            } else {
    637                result.append(stripped);
    638            }
    639        }
    640        return result.toString();
    641    }
    642
    643    private void transferModTime(final TarArchiveEntry from, final TarArchiveEntry to) {
    644        long fromModTimeSeconds = TimeUtils.toUnixTime(from.getLastModifiedTime());
    645        if (fromModTimeSeconds < 0 || fromModTimeSeconds > TarConstants.MAXSIZE) {
    646            fromModTimeSeconds = 0;
    647        }
    648        to.setLastModifiedTime(TimeUtils.unixTimeToFileTime(fromModTimeSeconds));
    649    }
    650
    651    /**
    652     * Writes bytes to the current tar archive entry. This method is aware of the current entry and will throw an exception if you attempt to write bytes past
    653     * the length specified for the current entry.
    654     *
    655     * @param wBuf       The buffer to write to the archive.
    656     * @param wOffset    The offset in the buffer from which to get bytes.
    657     * @param numToWrite The number of bytes to write.
    658     * @throws IOException on error
    659     */
    660    @Override
    661    public void write(final byte[] wBuf, final int wOffset, final int numToWrite) throws IOException {
    662        if (!haveUnclosedEntry) {
    663            throw new IllegalStateException("No current tar entry");
    664        }
    665        if (currBytes + numToWrite > currSize) {
    666            throw new IOException(
    667                    "Request to write '" + numToWrite + "' bytes exceeds size in header of '" + currSize + "' bytes for entry '" + currName + "'");
    668        }
    669        out.write(wBuf, wOffset, numToWrite);
    670        currBytes += numToWrite;
    671    }
    672
    673    /**
    674     * Writes an EOF (end of archive) record to the tar archive. An EOF record consists of a record of all zeros.
    675     */
    676    private void writeEOFRecord() throws IOException {
    677        Arrays.fill(recordBuf, (byte) 0);
    678        writeRecord(recordBuf);
    679    }
    680
    681    /**
    682     * Writes a PAX extended header with the given map as contents.
    683     *
    684     * @since 1.4
    685     */
    686    void writePaxHeaders(final TarArchiveEntry entry, final String entryName, final Map<String, String> headers) throws IOException {
    687        String name = "./PaxHeaders.X/" + stripTo7Bits(entryName);
    688        if (name.length() >= TarConstants.NAMELEN) {
    689            name = name.substring(0, TarConstants.NAMELEN - 1);
    690        }
    691        final TarArchiveEntry pex = new TarArchiveEntry(name, TarConstants.LF_PAX_EXTENDED_HEADER_LC);
    692        transferModTime(entry, pex);
    693
    694        final byte[] data = encodeExtendedPaxHeadersContents(headers);
    695        pex.setSize(data.length);
    696        putArchiveEntry(pex);
    697        write(data);
    698        closeArchiveEntry();
    699    }
    700
    701    /**
    702     * Writes an archive record to the archive.
    703     *
    704     * @param record The record data to write to the archive.
    705     * @throws IOException on error
    706     */
    707    private void writeRecord(final byte[] record) throws IOException {
    708        if (record.length != RECORD_SIZE) {
    709            throw new IOException("Record to write has length '" + record.length + "' which is not the record size of '" + RECORD_SIZE + "'");
    710        }
    711
    712        out.write(record);
    713        recordsWritten++;
    714    }
    715}