Merge pull request #336 from Squirrel/bring-back-bsdiff

Bring back bsdiff as a fallback

src/Squirrel/ContentType.cs

@@ -10,6 +10,7 @@ public static void Merge(XmlDocument doc)
         {
             var elements = new [] {
                 Tuple.Create("Default", "diff", "application/octet" ),
+                Tuple.Create("Default", "bsdiff", "application/octet" ),
                 Tuple.Create("Default", "exe", "application/octet" ),
                 Tuple.Create("Default", "dll", "application/octet" ),
                 Tuple.Create("Default", "shasum", "text/plain" ),

src/Squirrel/DeltaPackage.cs

@@ -9,6 +9,7 @@
 using Splat;
 using DeltaCompressionDotNet.MsDelta;
 using System.ComponentModel;
+using Squirrel.Bsdiff;
 
 namespace Squirrel
 {
@@ -176,9 +177,25 @@ void createDeltaForSingleFile(FileInfo targetFile, DirectoryInfo workingDirector
             var msDelta = new MsDeltaCompression();
             try {
                 msDelta.CreateDelta(baseFileListing[relativePath], targetFile.FullName, targetFile.FullName + ".diff");
-            } catch (Win32Exception ex) {
-                this.Log().Warn("We couldn't create a delta for {0}, writing full file", targetFile.Name);
-                return;
+            } catch (Win32Exception) {
+                this.Log().Warn("We couldn't create a delta for {0}, attempting to create bsdiff", targetFile.Name);
+
+                var of = default(FileStream);
+                try {
+                    of = File.Create(targetFile.FullName + ".bsdiff");
+                    BinaryPatchUtility.Create(oldData, newData, of);
+
+                    // NB: Create a dummy corrupt .diff file so that older 
+                    // versions which don't understand bsdiff will fail out
+                    // until they get upgraded, instead of seeing the missing
+                    // file and just removing it.
+                    File.WriteAllText(targetFile.FullName + ".diff", "1");
+                } catch (Exception ex) {
+                    this.Log().WarnException(String.Format("We really couldn't create a delta for {0}", targetFile.Name), ex);
+                    return;
+                } finally {
+                    if (of != null) of.Dispose();
+                }
             }
 
             var rl = ReleaseEntry.GenerateFromFile(new MemoryStream(newData), targetFile.Name + ".shasum");
@@ -202,13 +219,20 @@ void applyDiffToFile(string deltaPath, string relativeFilePath, string workingDi
                     return;
                 }
 
-                if (relativeFilePath.EndsWith(".diff", StringComparison.InvariantCultureIgnoreCase)) {
-                    this.Log().Info("Applying Diff to {0}", relativeFilePath);
+                 if (relativeFilePath.EndsWith(".bsdiff", StringComparison.InvariantCultureIgnoreCase)) {
+                    using (var of = File.OpenWrite(tempTargetFile))
+                    using (var inf = File.OpenRead(finalTarget)) {
+                        this.Log().Info("Applying BSDiff to {0}", relativeFilePath);
+                        BinaryPatchUtility.Apply(inf, () => File.OpenRead(inputFile), of);
+                    }
+
+                    verifyPatchedFile(relativeFilePath, inputFile, tempTargetFile);
+                 } else if (relativeFilePath.EndsWith(".diff", StringComparison.InvariantCultureIgnoreCase)) {
+                    this.Log().Info("Applying MSDiff to {0}", relativeFilePath);
                     var msDelta = new MsDeltaCompression();
                     msDelta.ApplyDelta(inputFile, finalTarget, tempTargetFile);
 
                     verifyPatchedFile(relativeFilePath, inputFile, tempTargetFile);
-
                 } else {
                     using (var of = File.OpenWrite(tempTargetFile))
                     using (var inf = File.OpenRead(inputFile)) {

src/Squirrel/ReleasePackage.cs

@@ -101,15 +101,13 @@ public string CreateReleasePackage(string outputFile, string packagesRootDir = n
             // ever expect one entry here (crash hard otherwise)
             var frameworks = package.GetSupportedFrameworks();
             if (frameworks.Count() > 1) {
-
                 var platforms = frameworks
                     .Aggregate(new StringBuilder(), (sb, f) => sb.Append(f.ToString() + "; "));
 
                 throw new InvalidOperationException(String.Format(
                     "The input package file {0} targets multiple platforms - {1} - and cannot be transformed into a release package.", InputPackageFile, platforms));
 
             } else if (!frameworks.Any()) {
-
                 throw new InvalidOperationException(String.Format(
                     "The input package file {0} targets no platform and cannot be transformed into a release package.", InputPackageFile));
             }

src/Squirrel/Squirrel.csproj

@@ -87,6 +87,7 @@
     <Compile Include="..\SolutionAssemblyInfo.cs">
       <Link>Properties\SolutionAssemblyInfo.cs</Link>
     </Compile>
+    <Compile Include="BinaryPatchUtility.cs" />
     <Compile Include="ContentType.cs" />
     <Compile Include="DeltaPackage.cs" />
     <Compile Include="EnumerableExtensions.cs" />