Extract out FileTypes namespace

SabreTools.FileTypes/Aaru/ChecksumHeader.cs

@@ -0,0 +1,41 @@
+using System.IO;
+using System.Text;
+
+using SabreTools.Core;
+
+namespace SabreTools.FileTypes.Aaru
+{
+    /// <summary>
+    /// Checksum block, contains a checksum of all user data sectors
+    /// (except for optical discs that is 2352 bytes raw sector if available
+    /// </summary>
+    /// <see cref="https://github.com/aaru-dps/Aaru/blob/master/Aaru.Images/AaruFormat/Structs.cs" />
+    public class ChecksumHeader
+    {
+        /// <summary>Identifier, <see cref="BlockType.ChecksumBlock" /></summary>
+        public AaruBlockType identifier;
+        /// <summary>Length in bytes of the block</summary>
+        public uint length;
+        /// <summary>How many checksums follow</summary>
+        public byte entries;
+
+        /// <summary>
+        /// Read a stream as an ChecksumHeader
+        /// </summary>
+        /// <param name="stream">ChecksumHeader as a stream</param>
+        /// <returns>Populated ChecksumHeader, null on failure</returns>
+        public static ChecksumHeader Deserialize(Stream stream)
+        {
+            ChecksumHeader checksumHeader = new ChecksumHeader();
+
+            using (BinaryReader br = new BinaryReader(stream, Encoding.Default, true))
+            {
+                checksumHeader.identifier = (AaruBlockType)br.ReadUInt32();
+                checksumHeader.length = br.ReadUInt32();
+                checksumHeader.entries = br.ReadByte();
+            }
+
+            return checksumHeader;
+        }
+    }
+}