    001/*
    002 *  Licensed to the Apache Software Foundation (ASF) under one or more
    003 *  contributor license agreements.  See the NOTICE file distributed with
    004 *  this work for additional information regarding copyright ownership.
    005 *  The ASF licenses this file to You under the Apache License, Version 2.0
    006 *  (the "License"); you may not use this file except in compliance with
    007 *  the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 *  Unless required by applicable law or agreed to in writing, software
    012 *  distributed under the License is distributed on an "AS IS" BASIS,
    013 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 *  See the License for the specific language governing permissions and
    015 *  limitations under the License.
    016 */
    017package org.apache.commons.compress.archivers.zip;
    018
    019import static org.apache.commons.compress.archivers.zip.ZipConstants.WORD;
    020
    021import java.io.Serializable;
    022
    023import org.apache.commons.compress.utils.ByteUtils;
    024
    025/**
    026 * Utility class that represents a four byte integer with conversion
    027 * rules for the little endian byte order of ZIP files.
    028 * @Immutable
    029 */
    030public final class ZipLong implements Cloneable, Serializable {
    031    private static final long serialVersionUID = 1L;
    032
    033    /** Central File Header Signature */
    034    public static final ZipLong CFH_SIG = new ZipLong(0X02014B50L);
    035
    036    /** Local File Header Signature */
    037    public static final ZipLong LFH_SIG = new ZipLong(0X04034B50L);
    038
    039    /**
    040     * Data Descriptor signature.
    041     *
    042     * <p>Actually, PKWARE uses this as marker for split/spanned
    043     * archives and other archivers have started to use it as Data
    044     * Descriptor signature (as well).</p>
    045     * @since 1.1
    046     */
    047    public static final ZipLong DD_SIG = new ZipLong(0X08074B50L);
    048
    049    /**
    050     * Value stored in size and similar fields if ZIP64 extensions are
    051     * used.
    052     * @since 1.3
    053     */
    054    static final ZipLong ZIP64_MAGIC = new ZipLong(ZipConstants.ZIP64_MAGIC);
    055
    056    /**
    057     * Marks ZIP archives that were supposed to be split or spanned
    058     * but only needed a single segment in then end (so are actually
    059     * neither split nor spanned).
    060     *
    061     * <p>This is the "PK00" prefix found in some archives.</p>
    062     * @since 1.5
    063     */
    064    public static final ZipLong SINGLE_SEGMENT_SPLIT_MARKER =
    065        new ZipLong(0X30304B50L);
    066
    067    /**
    068     * Archive extra data record signature.
    069     * @since 1.5
    070     */
    071    public static final ZipLong AED_SIG = new ZipLong(0X08064B50L);
    072
    073    /**
    074     * Gets value as four bytes in big endian byte order.
    075     * @param value the value to convert
    076     * @return value as four bytes in big endian byte order
    077     */
    078    public static byte[] getBytes(final long value) {
    079        final byte[] result = new byte[WORD];
    080        putLong(value, result, 0);
    081        return result;
    082    }
    083
    084    /**
    085     * Helper method to get the value as a Java long from a four-byte array
    086     * @param bytes the array of bytes
    087     * @return the corresponding Java long value
    088     */
    089    public static long getValue(final byte[] bytes) {
    090        return getValue(bytes, 0);
    091    }
    092
    093    /**
    094     * Helper method to get the value as a Java long from four bytes starting at given array offset
    095     * @param bytes the array of bytes
    096     * @param offset the offset to start
    097     * @return the corresponding Java long value
    098     */
    099    public static long getValue(final byte[] bytes, final int offset) {
    100        return ByteUtils.fromLittleEndian(bytes, offset, 4);
    101    }
    102
    103    /**
    104     * put the value as four bytes in big endian byte order.
    105     * @param value the Java long to convert to bytes
    106     * @param buf the output buffer
    107     * @param  offset
    108     *         The offset within the output buffer of the first byte to be written.
    109     *         must be non-negative and no larger than {@code buf.length-4}
    110     */
    111
    112    public static void putLong(final long value, final byte[] buf, final int offset) {
    113        ByteUtils.toLittleEndian(buf, value, offset, 4);
    114    }
    115
    116    private final long value;
    117
    118    /**
    119     * Create instance from bytes.
    120     * @param bytes the bytes to store as a ZipLong
    121     */
    122    public ZipLong(final byte[] bytes) {
    123        this(bytes, 0);
    124    }
    125
    126    /**
    127     * Create instance from the four bytes starting at offset.
    128     * @param bytes the bytes to store as a ZipLong
    129     * @param offset the offset to start
    130     */
    131    public ZipLong(final byte[] bytes, final int offset) {
    132        value = ZipLong.getValue(bytes, offset);
    133    }
    134
    135    /**
    136     * create instance from a java int.
    137     * @param value the int to store as a ZipLong
    138     * @since 1.15
    139     */
    140    public ZipLong(final int value) {
    141        this.value = value;
    142    }
    143
    144    /**
    145     * Create instance from a number.
    146     * @param value the long to store as a ZipLong
    147     */
    148    public ZipLong(final long value) {
    149        this.value = value;
    150    }
    151
    152    @Override
    153    public Object clone() {
    154        try {
    155            return super.clone();
    156        } catch (final CloneNotSupportedException cnfe) {
    157            // impossible
    158            throw new UnsupportedOperationException(cnfe); //NOSONAR
    159        }
    160    }
    161
    162    /**
    163     * Override to make two instances with same value equal.
    164     * @param o an object to compare
    165     * @return true if the objects are equal
    166     */
    167    @Override
    168    public boolean equals(final Object o) {
    169        if (!(o instanceof ZipLong)) {
    170            return false;
    171        }
    172        return value == ((ZipLong) o).getValue();
    173    }
    174
    175    /**
    176     * Gets value as four bytes in big endian byte order.
    177     * @return value as four bytes in big endian order
    178     */
    179    public byte[] getBytes() {
    180        return ZipLong.getBytes(value);
    181    }
    182
    183    /**
    184     * Gets value as a (signed) java int
    185     * @return value as int
    186     * @since 1.15
    187     */
    188    public int getIntValue() { return (int) value;}
    189
    190    /**
    191     * Gets value as Java long.
    192     * @return value as a long
    193     */
    194    public long getValue() {
    195        return value;
    196    }
    197
    198    /**
    199     * Override to make two instances with same value equal.
    200     * @return the value stored in the ZipLong
    201     */
    202    @Override
    203    public int hashCode() {
    204        return (int) value;
    205    }
    206
    207    public void putLong(final byte[] buf, final int offset) {
    208        putLong(value, buf, offset);
    209    }
    210
    211    @Override
    212    public String toString() {
    213        return "ZipLong value: " + value;
    214    }
    215}