Stream MSCab extraction output.

OpenRA.Mods.Common/FileFormats/MSCabCompression.cs

@@ -87,23 +87,22 @@ namespace OpenRA.Mods.Common.FileFormats
 				files[i] = new CabFile(stream);
 		}
 
-		public byte[] ExtractFile(string filename, Action<int> onProgress = null)
+		public void ExtractFile(string filename, Stream output, Action<int> onProgress = null)
 		{
 			var file = files.FirstOrDefault(f => f.FileName == filename);
 			if (file == null)
-				return null;
+				throw new FileNotFoundException(filename);
 
 			var folder = folders[file.FolderIndex];
 			stream.Seek(folder.BlockOffset, SeekOrigin.Begin);
 
-			using (var outputStream = new MemoryStream())
-			{
 			var inflater = new Inflater(true);
 			var buffer = new byte[4096];
+			var decompressedBytes = 0;
 			for (var i = 0; i < folder.BlockCount; i++)
 			{
 				if (onProgress != null)
-						onProgress((int)(100 * outputStream.Position / file.DecompressedLength));
+					onProgress((int)(100 * output.Position / file.DecompressedLength));
 
 				// Ignore checksums
 				stream.Position += 4;
@@ -115,15 +114,18 @@ namespace OpenRA.Mods.Common.FileFormats
 				{
 					int n;
 					while ((n = inflaterStream.Read(buffer, 0, buffer.Length)) > 0)
-							outputStream.Write(buffer, 0, n);
+					{
+						var offset = Math.Max(0, file.DecompressedOffset - decompressedBytes);
+						var count = Math.Min(n - offset, file.DecompressedLength - decompressedBytes);
+						if (offset < n)
+							output.Write(buffer, (int)offset, (int)count);
+
+						decompressedBytes += n;
+					}
 				}
 
 				inflater.Reset();
 			}
-
-				outputStream.Seek(file.DecompressedOffset, SeekOrigin.Begin);
-				return outputStream.ReadBytes((int)file.DecompressedLength);
-			}
 		}
 
 		public IEnumerable<string> Contents { get { return files.Select(f => f.FileName); } }

OpenRA.Mods.Common/Widgets/Logic/Installation/InstallFromDiscLogic.cs

@@ -304,12 +304,10 @@ namespace OpenRA.Mods.Common.Widgets.Logic
 					Directory.CreateDirectory(Path.GetDirectoryName(targetPath));
 					using (var target = File.OpenWrite(targetPath))
 					{
-						// This is a bit dumb memory-wise, but we load the whole thing when running the game anyway
 						Log.Write("install", "Extracting {0} -> {1}".F(sourcePath, targetPath));
-
 						var displayFilename = Path.GetFileName(Path.GetFileName(targetPath));
 						Action<int> onProgress = percent => updateMessage("Extracting {0} ({1}%)".F(displayFilename, percent));
-						target.Write(reader.ExtractFile(node.Value.Value, onProgress));
+						reader.ExtractFile(node.Value.Value, target, onProgress);
 					}
 				}
 			}