From 57c2e75a592cc344d38508ec85a20c058a8d946a Mon Sep 17 00:00:00 2001
From: Paul Chote <paul@chote.net>
Date: Sun, 1 Dec 2013 14:35:13 +1300
Subject: [PATCH] Add a Pak parser for Dune II archives.

---
 CHANGELOG                                    |  2 +-
 OpenRA.FileFormats/FileSystem/FileSystem.cs  |  4 +
 OpenRA.FileFormats/Filesystem/Pak.cs         | 97 ++++++++++++++++++++
 OpenRA.FileFormats/OpenRA.FileFormats.csproj |  1 +
 4 files changed, 103 insertions(+), 1 deletion(-)
 create mode 100644 OpenRA.FileFormats/Filesystem/Pak.cs

diff --git a/CHANGELOG b/CHANGELOG
index 7d92929a72..7d6b8c7976 100644
--- a/CHANGELOG
+++ b/CHANGELOG
@@ -90,7 +90,7 @@ NEW:
 		Overhauled sprite loading code.
 		Improved error message when loading corrupted sprites.
 		Rewritten shp(ts) parser makes more efficient use of texture space.
-		Added support for the dune 2 shp format.
+		Added support for the dune 2 shp and pak formats.
 	Build system and packages:
 		Added GeoIP to Makefile so it is installed properly.
 		Added desktop shortcut creation support to the Makefile and Windows installer.
diff --git a/OpenRA.FileFormats/FileSystem/FileSystem.cs b/OpenRA.FileFormats/FileSystem/FileSystem.cs
index 84f3f4c654..c4dd0f8b13 100644
--- a/OpenRA.FileFormats/FileSystem/FileSystem.cs
+++ b/OpenRA.FileFormats/FileSystem/FileSystem.cs
@@ -57,6 +57,8 @@ namespace OpenRA.FileFormats
 				throw new NotImplementedException("Creating .RS archives is unsupported");
 			else if (filename.EndsWith(".Z", StringComparison.InvariantCultureIgnoreCase))
 				throw new NotImplementedException("Creating .Z archives is unsupported");
+			else if (filename.EndsWith(".PAK", StringComparison.InvariantCultureIgnoreCase))
+				throw new NotImplementedException("Creating .PAK archives is unsupported");
 			else
 				return new Folder(filename, order, content);
 		}
@@ -77,6 +79,8 @@ namespace OpenRA.FileFormats
 				return new D2kSoundResources(filename, order);
 			else if (filename.EndsWith(".Z", StringComparison.InvariantCultureIgnoreCase))
 				return new InstallShieldPackage(filename, order);
+			else if (filename.EndsWith(".PAK", StringComparison.InvariantCultureIgnoreCase))
+				return new PakFile(filename, order);
 			else
 				return new Folder(filename, order);
 		}
diff --git a/OpenRA.FileFormats/Filesystem/Pak.cs b/OpenRA.FileFormats/Filesystem/Pak.cs
new file mode 100644
index 0000000000..4247c37c35
--- /dev/null
+++ b/OpenRA.FileFormats/Filesystem/Pak.cs
@@ -0,0 +1,97 @@
+#region Copyright & License Information
+/*
+ * Copyright 2007-2013 The OpenRA Developers (see AUTHORS)
+ * This file is part of OpenRA, which is free software. It is made
+ * available to you under the terms of the GNU General Public License
+ * as published by the Free Software Foundation. For more information,
+ * see COPYING.
+ */
+#endregion
+
+using System;
+using System.Collections.Generic;
+using System.IO;
+
+namespace OpenRA.FileFormats
+{
+	struct Entry
+	{
+		public uint Offset;
+		public uint Length;
+		public string Filename;
+	}
+
+	public class PakFile : IFolder
+	{
+		string filename;
+		int priority;
+		Dictionary<string, Entry> index;
+		Stream stream;
+
+		public PakFile(string filename, int priority)
+		{
+			this.filename = filename;
+			this.priority = priority;
+			index = new Dictionary<string, Entry>();
+			stream = FileSystem.Open(filename);
+
+			index = new Dictionary<string, Entry>();
+			var offset = stream.ReadUInt32();
+			while (offset != 0)
+			{
+				var file = stream.ReadASCIIZ();
+				var next = stream.ReadUInt32();
+				var length = (next == 0 ? (uint)stream.Length : next) - offset;
+
+				// Ignore duplicate files
+				if (index.ContainsKey(file))
+					continue;
+
+				index.Add(file, new Entry { Offset = offset, Length = length, Filename = file });
+				offset = next;
+			}
+		}
+
+		public Stream GetContent(string filename)
+		{
+			Entry entry;
+			if (!index.TryGetValue(filename, out entry))
+				return null;
+
+			stream.Seek(entry.Offset, SeekOrigin.Begin);
+			var data = new byte[entry.Length];
+			stream.Read(data, 0, (int)entry.Length);
+			return new MemoryStream(data);
+		}
+
+		public IEnumerable<uint> ClassicHashes()
+		{
+			foreach (var filename in index.Keys)
+				yield return PackageEntry.HashFilename(filename, PackageHashType.Classic);
+		}
+
+		public IEnumerable<uint> CrcHashes()
+		{
+			yield break;
+		}
+
+		public IEnumerable<string> AllFileNames()
+		{
+			foreach (var filename in index.Keys)
+				yield return filename;
+		}
+
+		public bool Exists(string filename)
+		{
+			return index.ContainsKey(filename);
+		}
+
+		public void Write(Dictionary<string, byte[]> contents)
+		{
+			throw new NotImplementedException("Cannot save Pak archives.");
+		}
+
+		public int Priority { get { return 1000 + priority; } }
+		public string Name { get { return filename; } }
+	}
+}
diff --git a/OpenRA.FileFormats/OpenRA.FileFormats.csproj b/OpenRA.FileFormats/OpenRA.FileFormats.csproj
index e867a1dc03..1f838e1a46 100644
--- a/OpenRA.FileFormats/OpenRA.FileFormats.csproj
+++ b/OpenRA.FileFormats/OpenRA.FileFormats.csproj
@@ -153,6 +153,7 @@
     <Compile Include="Graphics\TmpRAReader.cs" />
     <Compile Include="Graphics\TmpTDReader.cs" />
     <Compile Include="Graphics\ShpD2Reader.cs" />
+    <Compile Include="FileSystem\Pak.cs" />
   </ItemGroup>
   <ItemGroup>
     <BootstrapperPackage Include="Microsoft.Net.Client.3.5">