Switch from xdelta to hdiff

- Strip out xdelta3 and associated helpers/libs
- Add hdiffz.exe and target it for patch creation
- Add reference to SharpHDiffPatch.Core and utilize it for patch application

Thanks @sheepy for finding HDiffPatch for us!
Improves patch size and increases patching speed

Patcher/PatcherUtils/Helpers/XdeltaProcessHelper.cs

@@ -1,161 +0,0 @@
-using System;
-using System.Diagnostics;
-using System.IO;
-using System.Text;
-using System.Threading;
-using PatcherUtils.Model;
-
-namespace PatcherUtils.Helpers;
-
-public class XdeltaProcessHelper
-{
-    private readonly int _timeout = (int)TimeSpan.FromMinutes(10).TotalMilliseconds;
-    private string _args;
-    private string _sourcePath;
-    private string _deltaPath;
-    private string _decodedPath;
-    private bool _isDebug;
-    
-    public XdeltaProcessHelper(string args, string sourcePath, string deltaPath, string decodedPath, bool isDebug)
-    {
-        _args = args;
-        _sourcePath = sourcePath;
-        _deltaPath = deltaPath;
-        _decodedPath = decodedPath;
-        _isDebug = isDebug;
-    }
-
-    public bool Run() => _isDebug ? RunDebug() : RunNormal();
-    
-    private bool RunNormal()
-    {
-        try
-        {
-            using var proc = new Process();
-
-            proc.StartInfo = new ProcessStartInfo
-            {
-                FileName = LazyOperations.XDelta3Path,
-                Arguments = $"{_args} \"{_sourcePath}\" \"{_deltaPath}\" \"{_decodedPath}\"",
-                CreateNoWindow = true
-            };
-
-            proc.Start();
-
-            if (!proc.WaitForExit(_timeout))
-            {
-                PatchLogger.LogError("xdelta3 process timed out");
-                PatchLogger.LogDebug($"xdelta exit code: {proc.ExitCode}");
-                return false;
-            }
-
-            PatchLogger.LogDebug($"xdelta exit code: {proc.ExitCode}");
-            return true;
-        }
-        catch (Exception ex)
-        {
-            PatchLogger.LogException(ex);
-            return false;
-        }
-    }
-
-    private bool DebugPathsCheck()
-    {
-        try
-        {
-            var stream = File.Open(_sourcePath, FileMode.Open, FileAccess.ReadWrite, FileShare.None);
-            stream.Close();
-            stream.Dispose();
-            PatchLogger.LogDebug($"File is openable: {_sourcePath}");
-        }
-        catch (Exception ex)
-        {
-            PatchLogger.LogException(ex);
-            return false;
-        }
-
-        try
-        {
-            var stream = File.Open(_deltaPath, FileMode.Open, FileAccess.ReadWrite, FileShare.None);
-            stream.Close();
-            stream.Dispose();
-            PatchLogger.LogDebug($"File is openable: {_deltaPath}");
-        }
-        catch (Exception ex)
-        {
-            PatchLogger.LogException(ex);
-            return false;
-        }
-
-        return true;
-    }
-
-    private bool RunDebug()
-    {
-        if (!DebugPathsCheck())
-        {
-            return false;
-        }
-        
-        using var proc = new Process();
-
-        proc.StartInfo = new ProcessStartInfo
-        {
-            FileName = LazyOperations.XDelta3Path,
-            Arguments = $"{_args} \"{_sourcePath}\" \"{_deltaPath}\" \"{_decodedPath}\"",
-            RedirectStandardOutput = true,
-            RedirectStandardError = true,
-            CreateNoWindow = true
-        };
-
-        var outputBuilder = new StringBuilder();
-        var errorBuilder = new StringBuilder();
-
-        using AutoResetEvent outputWaitHandle = new AutoResetEvent(false);
-        using AutoResetEvent errorWaitHandle = new AutoResetEvent(false);
-
-        proc.OutputDataReceived += (s, e) =>
-        {
-            if (e.Data == null)
-            {
-                outputWaitHandle.Set();
-            }
-            else
-            {
-                outputBuilder.AppendLine(e.Data);
-            }
-        };
-
-        proc.ErrorDataReceived += (s, e) =>
-        {
-            if (e.Data == null)
-            {
-                errorWaitHandle.Set();
-            }
-            else
-            {
-                errorBuilder.AppendLine(e.Data);
-            }
-        };
-
-        proc.Start();
-
-        proc.BeginOutputReadLine();
-        proc.BeginErrorReadLine();
-
-        if (!proc.WaitForExit(_timeout) || !outputWaitHandle.WaitOne(_timeout) || !errorWaitHandle.WaitOne(_timeout))
-        {
-            PatchLogger.LogError("xdelta3 process timed out");
-            PatchLogger.LogDebug($"xdelta exit code: {proc.ExitCode}");
-            return false;
-        }
-        
-        PatchLogger.LogDebug("__xdelta stdout__");
-        PatchLogger.LogDebug(outputBuilder.ToString());
-        PatchLogger.LogDebug("__xdelta stderr__");
-        PatchLogger.LogDebug(errorBuilder.ToString());
-        PatchLogger.LogDebug($"xdelta exit code: {proc.ExitCode}");
-
-        return true;
-    }
-}

Patcher/PatcherUtils/LazyOperations.cs

@@ -32,12 +32,12 @@ namespace PatcherUtils
         /// </summary>
         public static string PatcherClientPath = $"{TempDir}\\{PatcherClient}";
 
-        private static string XDelta3EXE = "xdelta3.exe";
+        private static string HDiffEXE = "hdiffz.exe";
 
         /// <summary>
-        /// The path to the xdelta3.exe flie in the <see cref="TempDir"/>
+        /// The path to the hdiffz.exe file in the <see cref="TempDir"/>
         /// </summary>
-        public static string XDelta3Path = $"{TempDir}\\{XDelta3EXE}";
+        public static string HDiffPath = $"{TempDir}\\{HDiffEXE}";
 
         /// <summary>
         /// Streams embedded resources out of the assembly
@@ -90,9 +90,9 @@ namespace PatcherUtils
                             StreamResourceOut(assembly, resource, PatcherClientPath);
                             break;
                         }
-                    case string a when a.EndsWith(XDelta3EXE):
+                    case string a when a.EndsWith(HDiffEXE):
                         {
-                            StreamResourceOut(assembly, resource, XDelta3Path);
+                            StreamResourceOut(assembly, resource, HDiffPath);
                             break;
                         }
                 }

Patcher/PatcherUtils/PatchHelper.cs

@@ -1,5 +1,6 @@
 using PatchClient.Models;
 using PatcherUtils.Model;
+using SharpHDiffPatch.Core;
 using System;
 using System.Collections.Concurrent;
 using System.Collections.Generic;
@@ -9,7 +10,6 @@ using System.Linq;
 using System.Security.Cryptography;
 using System.Threading;
 using System.Threading.Tasks;
-using PleOps.XdeltaSharp.Decoder;
 
 namespace PatcherUtils
 {
@@ -116,11 +116,11 @@ namespace PatcherUtils
 
             try
             {
-                using var inputFile = new FileStream(SourceFilePath, FileMode.Open);
-                using var patchFile = new FileStream(DeltaFilePath, FileMode.Open);
-                using var decodedFile = new FileStream(decodedPath, FileMode.Create);
-                using var decoder = new Decoder(inputFile, patchFile, decodedFile);
-                decoder.Run();
+                HDiffPatch patcher = new HDiffPatch();
+                HDiffPatch.LogVerbosity = Verbosity.Quiet;
+
+                patcher.Initialize(DeltaFilePath);
+                patcher.Patch(SourceFilePath, decodedPath, true, default, false, true);
             }
             catch (Exception ex)
             {
@@ -162,10 +162,11 @@ namespace PatcherUtils
                 PatchLogger.LogException(ex);
             }
 
+            // The parameters we use here are important to allow patch application using the SharpHDiffPatch.Core library, please don't change them
             Process.Start(new ProcessStartInfo
                 {
-                    FileName = LazyOperations.XDelta3Path,
-                    Arguments = $"-0 -e -f -S none -s \"{SourceFilePath}\" \"{TargetFilePath}\" \"{deltaPath}\"",
+                    FileName = LazyOperations.HDiffPath,
+                    Arguments = $"-s-64 -c-zstd-21-24 -d \"{SourceFilePath}\" \"{TargetFilePath}\" \"{deltaPath}\"",
                     CreateNoWindow = true
                 })
                 .WaitForExit();
@@ -302,7 +303,7 @@ namespace PatcherUtils
 
 
                 Parallel.ForEach(targetFiles,
-                    new ParallelOptions() { MaxDegreeOfParallelism = 5 }, targetFile =>
+                    new ParallelOptions() { MaxDegreeOfParallelism = 10 }, targetFile =>
                     {
                         //find a matching source file based on the relative path of the file
                         FileInfo sourceFile = sourceFiles.Find(f =>

Patcher/PatcherUtils/PatcherUtils.csproj

@@ -6,13 +6,9 @@
     <FileVersion>2.15.3</FileVersion>
   </PropertyGroup>
 
-  <ItemGroup>
-    <None Remove="Resources\xdelta3.exe" />
-  </ItemGroup>
-
   <ItemGroup>
     <EmbeddedResource Include="Resources\7z.dll" />
-    <EmbeddedResource Include="Resources\xdelta3.exe" />
+	<EmbeddedResource Include="Resources\hdiffz.exe" />
   </ItemGroup>
 
   <ItemGroup>
@@ -22,7 +18,7 @@
   </ItemGroup>
 
   <ItemGroup>
-    <PackageReference Include="PleOps.XdeltaSharp" Version="1.3.0" />
+    <PackageReference Include="SharpHDiffPatch.Core" Version="2.2.8" />
     <PackageReference Include="Squid-Box.SevenZipSharp" Version="1.6.2.24" />
   </ItemGroup>