Hash and compress DAT file on import.

RomRepoMgr.Core/Workers/Compression.cs

@@ -0,0 +1,57 @@
+using System;
+using System.IO;
+using RomRepoMgr.Core.EventArgs;
+using SharpCompress.Compressors;
+using SharpCompress.Compressors.LZMA;
+
+namespace RomRepoMgr.Core.Workers
+{
+    public sealed class Compression
+    {
+        const long BUFFER_SIZE = 131072;
+
+        public event EventHandler<ProgressBoundsEventArgs> SetProgressBounds;
+        public event EventHandler<ProgressEventArgs>       SetProgress;
+
+        public void CompressFile(string source, string destination)
+        {
+            var    inFs    = new FileStream(source, FileMode.Open, FileAccess.Read);
+            var    outFs   = new FileStream(destination, FileMode.CreateNew, FileAccess.Write);
+            Stream zStream = new LZipStream(outFs, CompressionMode.Compress);
+
+            byte[] buffer = new byte[BUFFER_SIZE];
+
+            SetProgressBounds?.Invoke(this, new ProgressBoundsEventArgs
+            {
+                Minimum = 0,
+                Maximum = inFs.Length
+            });
+
+            while(inFs.Position + BUFFER_SIZE <= inFs.Length)
+            {
+                SetProgress?.Invoke(this, new ProgressEventArgs
+                {
+                    Value = inFs.Position
+                });
+
+                inFs.Read(buffer, 0, buffer.Length);
+                zStream.Write(buffer, 0, buffer.Length);
+            }
+
+            buffer = new byte[inFs.Length - inFs.Position];
+
+            SetProgressBounds?.Invoke(this, new ProgressBoundsEventArgs
+            {
+                Minimum = 0,
+                Maximum = inFs.Length
+            });
+
+            inFs.Read(buffer, 0, buffer.Length);
+            zStream.Write(buffer, 0, buffer.Length);
+
+            inFs.Close();
+            zStream.Close();
+            outFs.Dispose();
+        }
+    }
+}