1/*
2 * Copyright (c) 2013, 2015, Oracle and/or its affiliates. All rights reserved.
3 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
4 *
5 * This code is free software; you can redistribute it and/or modify it
6 * under the terms of the GNU General Public License version 2 only, as
7 * published by the Free Software Foundation.  Oracle designates this
8 * particular file as subject to the "Classpath" exception as provided
9 * by Oracle in the LICENSE file that accompanied this code.
10 *
11 * This code is distributed in the hope that it will be useful, but WITHOUT
12 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
13 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
14 * version 2 for more details (a copy is included in the LICENSE file that
15 * accompanied this code).
16 *
17 * You should have received a copy of the GNU General Public License version
18 * 2 along with this work; if not, write to the Free Software Foundation,
19 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
20 *
21 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
22 * or visit www.oracle.com if you need additional information or have any
23 * questions.
24 */
25
26package java.util.zip;
27
28import java.nio.file.attribute.FileTime;
29import java.util.Date;
30import java.util.concurrent.TimeUnit;
31
32class ZipUtils {
33
34    // used to adjust values between Windows and java epoch
35    private static final long WINDOWS_EPOCH_IN_MICROSECONDS = -11644473600000000L;
36
37    /**
38     * Converts Windows time (in microseconds, UTC/GMT) time to FileTime.
39     */
40    public static final FileTime winTimeToFileTime(long wtime) {
41        return FileTime.from(wtime / 10 + WINDOWS_EPOCH_IN_MICROSECONDS,
42                             TimeUnit.MICROSECONDS);
43    }
44
45    /**
46     * Converts FileTime to Windows time.
47     */
48    public static final long fileTimeToWinTime(FileTime ftime) {
49        return (ftime.to(TimeUnit.MICROSECONDS) - WINDOWS_EPOCH_IN_MICROSECONDS) * 10;
50    }
51
52    /**
53     * Converts "standard Unix time"(in seconds, UTC/GMT) to FileTime
54     */
55    public static final FileTime unixTimeToFileTime(long utime) {
56        return FileTime.from(utime, TimeUnit.SECONDS);
57    }
58
59    /**
60     * Converts FileTime to "standard Unix time".
61     */
62    public static final long fileTimeToUnixTime(FileTime ftime) {
63        return ftime.to(TimeUnit.SECONDS);
64    }
65
66    /**
67     * Converts DOS time to Java time (number of milliseconds since epoch).
68     */
69    private static long dosToJavaTime(long dtime) {
70        @SuppressWarnings("deprecation") // Use of date constructor.
71        Date d = new Date((int)(((dtime >> 25) & 0x7f) + 80),
72                          (int)(((dtime >> 21) & 0x0f) - 1),
73                          (int)((dtime >> 16) & 0x1f),
74                          (int)((dtime >> 11) & 0x1f),
75                          (int)((dtime >> 5) & 0x3f),
76                          (int)((dtime << 1) & 0x3e));
77        return d.getTime();
78    }
79
80    /**
81     * Converts extended DOS time to Java time, where up to 1999 milliseconds
82     * might be encoded into the upper half of the returned long.
83     *
84     * @param xdostime the extended DOS time value
85     * @return milliseconds since epoch
86     */
87    public static long extendedDosToJavaTime(long xdostime) {
88        long time = dosToJavaTime(xdostime);
89        return time + (xdostime >> 32);
90    }
91
92    /**
93     * Converts Java time to DOS time.
94     */
95    @SuppressWarnings("deprecation") // Use of date methods
96    private static long javaToDosTime(long time) {
97        Date d = new Date(time);
98        int year = d.getYear() + 1900;
99        if (year < 1980) {
100            return ZipEntry.DOSTIME_BEFORE_1980;
101        }
102        // Android-changed: backport of JDK-8130914 fix
103        return ((year - 1980) << 25 | (d.getMonth() + 1) << 21 |
104                d.getDate() << 16 | d.getHours() << 11 | d.getMinutes() << 5 |
105                d.getSeconds() >> 1) & 0xffffffffL;
106    }
107
108    /**
109     * Converts Java time to DOS time, encoding any milliseconds lost
110     * in the conversion into the upper half of the returned long.
111     *
112     * @param time milliseconds since epoch
113     * @return DOS time with 2s remainder encoded into upper half
114     */
115    public static long javaToExtendedDosTime(long time) {
116        if (time < 0) {
117            return ZipEntry.DOSTIME_BEFORE_1980;
118        }
119        long dostime = javaToDosTime(time);
120        return (dostime != ZipEntry.DOSTIME_BEFORE_1980)
121                ? dostime + ((time % 2000) << 32)
122                : ZipEntry.DOSTIME_BEFORE_1980;
123    }
124
125    /**
126     * Fetches unsigned 16-bit value from byte array at specified offset.
127     * The bytes are assumed to be in Intel (little-endian) byte order.
128     */
129    public static final int get16(byte b[], int off) {
130        return Byte.toUnsignedInt(b[off]) | (Byte.toUnsignedInt(b[off+1]) << 8);
131    }
132
133    /**
134     * Fetches unsigned 32-bit value from byte array at specified offset.
135     * The bytes are assumed to be in Intel (little-endian) byte order.
136     */
137    public static final long get32(byte b[], int off) {
138        return (get16(b, off) | ((long)get16(b, off+2) << 16)) & 0xffffffffL;
139    }
140
141    /**
142     * Fetches signed 64-bit value from byte array at specified offset.
143     * The bytes are assumed to be in Intel (little-endian) byte order.
144     */
145    public static final long get64(byte b[], int off) {
146        return get32(b, off) | (get32(b, off+4) << 32);
147    }
148}
149