aboutsummaryrefslogtreecommitdiffstatshomepage
path: root/OpenSim/Region/CoreModules/World/Archiver/TarArchiveWriter.cs
blob: f8e649ec8175cb3d5f6c905521306e6732bbb3e1 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
/*
 * Copyright (c) Contributors, http://opensimulator.org/
 * See CONTRIBUTORS.TXT for a full list of copyright holders.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the OpenSim Project nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE DEVELOPERS ``AS IS'' AND ANY
 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE CONTRIBUTORS BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;

namespace OpenSim.Region.CoreModules.World.Archiver
{
    /// <summary>
    /// Temporary code to produce a tar archive in tar v7 format
    /// </summary>
    public class TarArchiveWriter
    {
        //private static readonly ILog m_log = LogManager.GetLogger(MethodBase.GetCurrentMethod().DeclaringType);

        protected Dictionary<string, byte[]> m_files = new Dictionary<string, byte[]>();

        protected static ASCIIEncoding m_asciiEncoding = new ASCIIEncoding();

        /// <summary>
        /// Add a directory to the tar archive.  We can only handle one path level right now!
        /// </summary>
        /// <param name="dirName"></param>
        public void AddDir(string dirName)
        {
            // Directories are signalled by a final /
            if (!dirName.EndsWith("/"))
                dirName += "/";

            AddFile(dirName, new byte[0]);
        }

        /// <summary>
        /// Add a file to the tar archive
        /// </summary>
        /// <param name="filePath"></param>
        /// <param name="data"></param>
        public void AddFile(string filePath, string data)
        {
            AddFile(filePath, m_asciiEncoding.GetBytes(data));
        }

        /// <summary>
        /// Add a file to the tar archive
        /// </summary>
        /// <param name="filePath"></param>
        /// <param name="data"></param>
        public void AddFile(string filePath, byte[] data)
        {
            m_files[filePath] = data;
        }

        /// <summary>
        /// Write the raw tar archive data to a stream.  The stream will be closed on completion.
        /// </summary>
        /// <param name="s">Stream to which to write the data</param>
        /// <returns></returns>
        public void WriteTar(Stream s)
        {
            BinaryWriter bw = new BinaryWriter(s);

            foreach (string filePath in m_files.Keys)
            {
                byte[] header = new byte[512];
                byte[] data = m_files[filePath];

                // file path field (100)
                byte[] nameBytes = m_asciiEncoding.GetBytes(filePath);
                int nameSize = (nameBytes.Length >= 100) ? 100 : nameBytes.Length;
                Array.Copy(nameBytes, header, nameSize);

                // file mode (8)
                byte[] modeBytes = m_asciiEncoding.GetBytes("0000777");
                Array.Copy(modeBytes, 0, header, 100, 7);

                // owner user id (8)
                byte[] ownerIdBytes = m_asciiEncoding.GetBytes("0000764");
                Array.Copy(ownerIdBytes, 0, header, 108, 7);

                // group user id (8)
                byte[] groupIdBytes = m_asciiEncoding.GetBytes("0000764");
                Array.Copy(groupIdBytes, 0, header, 116, 7);

                // file size in bytes (12)
                int fileSize = data.Length;
                //m_log.DebugFormat("[TAR ARCHIVE WRITER]: File size of {0} is {1}", filePath, fileSize);

                byte[] fileSizeBytes = ConvertDecimalToPaddedOctalBytes(fileSize, 11);

                Array.Copy(fileSizeBytes, 0, header, 124, 11);

                // last modification time (12)
                byte[] lastModTimeBytes = m_asciiEncoding.GetBytes("11017037332");
                Array.Copy(lastModTimeBytes, 0, header, 136, 11);

                // link indicator (1)
                //header[156] = m_asciiEncoding.GetBytes("0")[0];
                if (filePath.EndsWith("/"))
                {
                    header[156] = m_asciiEncoding.GetBytes("5")[0];
                }
                else
                {
                    header[156] = 0;
                }

                Array.Copy(m_asciiEncoding.GetBytes("0000000"), 0, header, 329, 7);
                Array.Copy(m_asciiEncoding.GetBytes("0000000"), 0, header, 337, 7);

                // check sum for header block (8) [calculated last]
                Array.Copy(m_asciiEncoding.GetBytes("        "), 0, header, 148, 8);

                int checksum = 0;
                foreach (byte b in header)
                {
                    checksum += b;
                }

                //m_log.DebugFormat("[TAR ARCHIVE WRITER]: Decimal header checksum is {0}", checksum);

                byte[] checkSumBytes = ConvertDecimalToPaddedOctalBytes(checksum, 6);

                Array.Copy(checkSumBytes, 0, header, 148, 6);

                header[154] = 0;

                // Write out header
                bw.Write(header);

                // Write out data
                bw.Write(data);

                if (data.Length % 512 != 0)
                {
                    int paddingRequired = 512 - (data.Length % 512);

                    //m_log.DebugFormat("[TAR ARCHIVE WRITER]: Padding data with {0} bytes", paddingRequired);

                    byte[] padding = new byte[paddingRequired];
                    bw.Write(padding);
                }
            }

            //m_log.Debug("[TAR ARCHIVE WRITER]: Writing final consecutive 0 blocks");
            
            // Write two consecutive 0 blocks to end the archive
            byte[] finalZeroPadding = new byte[1024];
            bw.Write(finalZeroPadding);

            bw.Flush();
            bw.Close();
        }

        public static byte[] ConvertDecimalToPaddedOctalBytes(int d, int padding)
        {
            string oString = "";

            while (d > 0)
            {
                oString = Convert.ToString((byte)'0' + d & 7) + oString;
                d >>= 3;
            }

            while (oString.Length < padding)
            {
                oString = "0" + oString;
            }

            byte[] oBytes = m_asciiEncoding.GetBytes(oString);

            return oBytes;
        }
    }
}