Adds support for XZ compressed files.

DiscImageChef.Filters/DiscImageChef.Filters.csproj

@@ -49,6 +49,7 @@
     <Compile Include="BZip2.cs" />
     <Compile Include="PCExchange.cs" />
     <Compile Include="LZip.cs" />
+    <Compile Include="XZ.cs" />
   </ItemGroup>
   <ItemGroup>
     <EmbeddedResource Include="..\LICENSE.LGPL">

DiscImageChef.Filters/XZ.cs

@@ -5,11 +5,11 @@
 // Filename       : XZ.cs
 // Author(s)      : Natalia Portillo <claunia@claunia.com>
 //
-// Component      : Component
+// Component      : Filters.
 //
 // --[ Description ] ----------------------------------------------------------
 //
-//     Description
+//     Allow to open files that are compressed using xz.
 //
 // --[ License ] --------------------------------------------------------------
 //
@@ -29,13 +29,228 @@
 // ----------------------------------------------------------------------------
 // Copyright © 2011-2017 Natalia Portillo
 // ****************************************************************************/
+
 using System;
+using System.IO;
+using SharpCompress.Compressors.Xz;
+
 namespace DiscImageChef.Filters
 {
-    public class XZ
+    public class XZ : Filter
     {
+        Stream dataStream;
+        string basePath;
+        DateTime lastWriteTime;
+        DateTime creationTime;
+        bool opened;
+        long decompressedSize;
+        Stream innerStream;
+
         public XZ()
         {
+            Name = "XZ";
+            UUID = new Guid("FCCFB0C3-32EF-40D8-9714-2333F6AC72A9");
+        }
+
+        public override void Close()
+        {
+            if(dataStream != null)
+                dataStream.Close();
+            dataStream = null;
+            basePath = null;
+            opened = false;
+        }
+
+        public override string GetBasePath()
+        {
+            return basePath;
+        }
+
+        public override Stream GetDataForkStream()
+        {
+            return innerStream;
+        }
+
+        public override string GetPath()
+        {
+            return basePath;
+        }
+
+        public override Stream GetResourceForkStream()
+        {
+            return null;
+        }
+
+        public override bool HasResourceFork()
+        {
+            return false;
+        }
+
+        public override bool Identify(byte[] buffer)
+        {
+            return buffer[0] == 0xFD && buffer[1] == 0x37 && buffer[2] == 0x7A && buffer[3] == 0x58 && buffer[4] == 0x5A && buffer[5] == 0x00 && buffer[buffer.Length - 2] == 0x59 && buffer[buffer.Length - 1] == 0x5A;
+        }
+
+        public override bool Identify(Stream stream)
+        {
+            byte[] buffer = new byte[6];
+            byte[] footer = new byte[2];
+
+            stream.Seek(0, SeekOrigin.Begin);
+            stream.Read(buffer, 0, 6);
+            stream.Seek(-2, SeekOrigin.End);
+            stream.Read(footer, 0, 2);
+            stream.Seek(0, SeekOrigin.Begin);
+
+            return buffer[0] == 0xFD && buffer[1] == 0x37 && buffer[2] == 0x7A && buffer[3] == 0x58 && buffer[4] == 0x5A && buffer[5] == 0x00 && footer[0] == 0x59 && footer[1] == 0x5A;
+        }
+
+        public override bool Identify(string path)
+        {
+            if(File.Exists(path))
+            {
+                FileStream stream = new FileStream(path, FileMode.Open, FileAccess.Read);
+                byte[] buffer = new byte[6];
+                byte[] footer = new byte[2];
+
+                stream.Seek(0, SeekOrigin.Begin);
+                stream.Read(buffer, 0, 6);
+                stream.Seek(0, SeekOrigin.Begin);
+                stream.Seek(-2, SeekOrigin.End);
+                stream.Read(footer, 0, 2);
+                stream.Seek(0, SeekOrigin.Begin);
+
+                return buffer[0] == 0xFD && buffer[1] == 0x37 && buffer[2] == 0x7A && buffer[3] == 0x58 && buffer[4] == 0x5A && buffer[5] == 0x00 && footer[0] == 0x59 && footer[1] == 0x5A;
+            }
+
+            return false;
+        }
+
+        void GuessSize()
+        {
+            decompressedSize = 0;
+            // Seek to footer backwards size field 
+            dataStream.Seek(-8, SeekOrigin.End);
+            byte[] tmp = new byte[4];
+            dataStream.Read(tmp, 0, 4);
+            uint backwardSize = (BitConverter.ToUInt32(tmp, 0) + 1) * 4;
+            // Seek to first indexed record
+            dataStream.Seek(-12 - (backwardSize - 2), SeekOrigin.End);
+
+            // Skip compressed size
+            tmp = new byte[backwardSize - 2];
+            dataStream.Read(tmp, 0, tmp.Length);
+            ulong number = 0;
+            int ignore = Decode(tmp, tmp.Length, ref number);
+
+            // Get compressed size
+            dataStream.Seek(-12 - (backwardSize - 2 - ignore), SeekOrigin.End);
+            tmp = new byte[backwardSize - 2 - ignore];
+            dataStream.Read(tmp, 0, tmp.Length);
+            Decode(tmp, tmp.Length, ref number);
+            decompressedSize = (long)number;
+
+            dataStream.Seek(0, SeekOrigin.Begin);
+        }
+
+        int Decode(byte[] buf, int size_max, ref ulong num)
+        {
+            if(size_max == 0)
+                return 0;
+
+            if(size_max > 9)
+                size_max = 9;
+
+            num = (ulong)(buf[0] & 0x7F);
+            int i = 0;
+
+            while((buf[i++] & 0x80) == 0x80)
+            {
+                if(i >= size_max || buf[i] == 0x00)
+                    return 0;
+
+                num |= (ulong)(buf[i] & 0x7F) << (i * 7);
+            }
+
+            return i;
+        }
+
+        public override void Open(byte[] buffer)
+        {
+            dataStream = new MemoryStream(buffer);
+            basePath = null;
+            creationTime = DateTime.UtcNow;
+            lastWriteTime = creationTime;
+            GuessSize();
+            innerStream = new ForcedSeekStream<XZStream>(decompressedSize, dataStream);
+            opened = true;
+        }
+
+        public override void Open(Stream stream)
+        {
+            dataStream = stream;
+            basePath = null;
+            creationTime = DateTime.UtcNow;
+            lastWriteTime = creationTime;
+            GuessSize();
+            innerStream = new ForcedSeekStream<XZStream>(decompressedSize, dataStream);
+            opened = true;
+        }
+
+        public override void Open(string path)
+        {
+            dataStream = new FileStream(path, FileMode.Open, FileAccess.Read);
+            basePath = Path.GetFullPath(path);
+
+            DateTime start = DateTime.UtcNow;
+            DateTime end = DateTime.UtcNow;
+
+            FileInfo fi = new FileInfo(path);
+            creationTime = fi.CreationTimeUtc;
+            lastWriteTime = fi.LastWriteTimeUtc;
+            GuessSize();
+            innerStream = new ForcedSeekStream<XZStream>(decompressedSize, dataStream);
+            opened = true;
+        }
+
+        public override DateTime GetCreationTime()
+        {
+            return creationTime;
+        }
+
+        public override long GetDataForkLength()
+        {
+            return decompressedSize;
+        }
+
+        public override DateTime GetLastWriteTime()
+        {
+            return lastWriteTime;
+        }
+
+        public override long GetLength()
+        {
+            return decompressedSize;
+        }
+
+        public override long GetResourceForkLength()
+        {
+            return 0;
+        }
+
+        public override string GetFilename()
+        {
+            return basePath != null ? Path.GetFileName(basePath) : null;
+        }
+
+        public override string GetParentFolder()
+        {
+            return Path.GetDirectoryName(basePath);
+        }
+
+        public override bool IsOpened()
+        {
+            return opened;
         }
     }
 }

README.md

@@ -172,6 +172,7 @@ Supported filters
 * GZip
 * LZip
 * MacBinary I, II, III
+* XZ
 
 Changelog
 =========

TODO

@@ -62,5 +62,4 @@ CHD plugin:
 
 Filters:
 --- Add support for 7Z archives
---- Add support for XZ compressed files
 --- Add support for ZIP archives