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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one or more
3    *  contributor license agreements.  See the NOTICE file distributed with
4    *  this work for additional information regarding copyright ownership.
5    *  The ASF licenses this file to You under the Apache License, Version 2.0
6    *  (the "License"); you may not use this file except in compliance with
7    *  the License.  You may obtain a copy of the License at
8    *
9    *      http://www.apache.org/licenses/LICENSE-2.0
10   *
11   *  Unless required by applicable law or agreed to in writing, software
12   *  distributed under the License is distributed on an "AS IS" BASIS,
13   *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
14   *  See the License for the specific language governing permissions and
15   *  limitations under the License.
16   */
17  package org.apache.commons.compress.archivers.zip;
18  
19  import static org.apache.commons.compress.archivers.zip.ZipConstants.WORD;
20  
21  import java.io.Serializable;
22  
23  import org.apache.commons.compress.utils.ByteUtils;
24  
25  /**
26   * Utility class that represents a four byte integer with conversion rules for the little-endian byte order of ZIP files.
27   *
28   * @Immutable
29   */
30  public final class ZipLong implements Cloneable, Serializable {
31      private static final long serialVersionUID = 1L;
32  
33      /** Central File Header Signature */
34      public static final ZipLong CFH_SIG = new ZipLong(0X02014B50L);
35  
36      /** Local File Header Signature */
37      public static final ZipLong LFH_SIG = new ZipLong(0X04034B50L);
38  
39      /**
40       * Data Descriptor signature.
41       *
42       * <p>
43       * Actually, PKWARE uses this as marker for split/spanned archives and other archivers have started to use it as Data Descriptor signature (as well).
44       * </p>
45       *
46       * @since 1.1
47       */
48      public static final ZipLong DD_SIG = new ZipLong(0X08074B50L);
49  
50      /**
51       * Value stored in size and similar fields if ZIP64 extensions are used.
52       *
53       * @since 1.3
54       */
55      static final ZipLong ZIP64_MAGIC = new ZipLong(ZipConstants.ZIP64_MAGIC);
56  
57      /**
58       * Marks ZIP archives that were supposed to be split or spanned but only needed a single segment in then end (so are actually neither split nor spanned).
59       *
60       * <p>
61       * This is the "PK00" prefix found in some archives.
62       * </p>
63       *
64       * @since 1.5
65       */
66      public static final ZipLong SINGLE_SEGMENT_SPLIT_MARKER = new ZipLong(0X30304B50L);
67  
68      /**
69       * Archive extra data record signature.
70       *
71       * @since 1.5
72       */
73      public static final ZipLong AED_SIG = new ZipLong(0X08064B50L);
74  
75      /**
76       * Gets value as four bytes in big-endian byte order.
77       *
78       * @param value the value to convert
79       * @return value as four bytes in big-endian byte order
80       */
81      public static byte[] getBytes(final long value) {
82          final byte[] result = new byte[WORD];
83          putLong(value, result, 0);
84          return result;
85      }
86  
87      /**
88       * Helper method to get the value as a Java long from a four-byte array
89       *
90       * @param bytes the array of bytes
91       * @return the corresponding Java long value
92       */
93      public static long getValue(final byte[] bytes) {
94          return getValue(bytes, 0);
95      }
96  
97      /**
98       * Helper method to get the value as a Java long from four bytes starting at given array offset
99       *
100      * @param bytes  the array of bytes
101      * @param offset the offset to start
102      * @return the corresponding Java long value
103      */
104     public static long getValue(final byte[] bytes, final int offset) {
105         return ByteUtils.fromLittleEndian(bytes, offset, 4);
106     }
107 
108     /**
109      * put the value as four bytes in big-endian byte order.
110      *
111      * @param value  the Java long to convert to bytes
112      * @param buf    the output buffer
113      * @param offset The offset within the output buffer of the first byte to be written. must be non-negative and no larger than {@code buf.length-4}
114      */
115 
116     public static void putLong(final long value, final byte[] buf, final int offset) {
117         ByteUtils.toLittleEndian(buf, value, offset, 4);
118     }
119 
120     private final long value;
121 
122     /**
123      * Constructs a new instance from bytes.
124      *
125      * @param bytes the bytes to store as a ZipLong
126      */
127     public ZipLong(final byte[] bytes) {
128         this(bytes, 0);
129     }
130 
131     /**
132      * Creates instance from the four bytes starting at offset.
133      *
134      * @param bytes  the bytes to store as a ZipLong
135      * @param offset the offset to start
136      */
137     public ZipLong(final byte[] bytes, final int offset) {
138         value = ZipLong.getValue(bytes, offset);
139     }
140 
141     /**
142      * create instance from a Java int.
143      *
144      * @param value the int to store as a ZipLong
145      * @since 1.15
146      */
147     public ZipLong(final int value) {
148         this.value = value;
149     }
150 
151     /**
152      * Creates instance from a number.
153      *
154      * @param value the long to store as a ZipLong
155      */
156     public ZipLong(final long value) {
157         this.value = value;
158     }
159 
160     @Override
161     public Object clone() {
162         try {
163             return super.clone();
164         } catch (final CloneNotSupportedException cnfe) {
165             // impossible
166             throw new UnsupportedOperationException(cnfe); // NOSONAR
167         }
168     }
169 
170     /**
171      * Override to make two instances with same value equal.
172      *
173      * @param o an object to compare
174      * @return true if the objects are equal
175      */
176     @Override
177     public boolean equals(final Object o) {
178         if (!(o instanceof ZipLong)) {
179             return false;
180         }
181         return value == ((ZipLong) o).getValue();
182     }
183 
184     /**
185      * Gets value as four bytes in big-endian byte order.
186      *
187      * @return value as four bytes in big-endian order
188      */
189     public byte[] getBytes() {
190         return ZipLong.getBytes(value);
191     }
192 
193     /**
194      * Gets value as a (signed) Java int
195      *
196      * @return value as int
197      * @since 1.15
198      */
199     public int getIntValue() {
200         return (int) value;
201     }
202 
203     /**
204      * Gets value as Java long.
205      *
206      * @return value as a long
207      */
208     public long getValue() {
209         return value;
210     }
211 
212     /**
213      * Override to make two instances with same value equal.
214      *
215      * @return the value stored in the ZipLong
216      */
217     @Override
218     public int hashCode() {
219         return (int) value;
220     }
221 
222     public void putLong(final byte[] buf, final int offset) {
223         putLong(value, buf, offset);
224     }
225 
226     @Override
227     public String toString() {
228         return "ZipLong value: " + value;
229     }
230 }