This is an easy to comsume, fast library for generating Delta Patches. Note: API is folder based. All operations act on folders and effect all files inside.

Generate Hash Set:

// Generate a set of hashes for a directory.
var hashes = HashSet.Generate(Assets.MismatchFolderOriginal);

Verify:

// missingFiles: Files missing from target folder.
// hashMismatches: Files with a non-matching hash.
bool matches = HashSet.Verify(hashes, targetFolder, out var missingFiles, out var hashMismatches)

Generate:

// Create a patch that transforms one folder into another.
// Save it into `patchFolder`
var patch  = Patch.Generate(originalFolder, targetFolder, patchFolder);

Apply:

// Patches all files in folderToPatch. Patched files are moved to patchedFilesOutput.
Patch.Apply(patch, folderToPatch, patchedFilesOutput);

• Patches use VCDiff based Delta Compression using an optimized port of Google open-vcdiff.

Delta generator can also be used to remove any files outside of a provided list of files.

// Make Hashes
var hashes = HashSet.Generate(Assets.AddMissingFileFolderOriginal);

// Remove extra files.
HashSet.Cleanup(hashes, folder);

You can supply an event/function that can be used to confirm whether a file can be deleted.

Results of most operations (e.g. Patch.Generate(), HashSet.Generate()) and be saved and loaded from disk.

• RAM: Memory usage explodes relative to file size. When creating a patch for a 1.5GB file, expect 6GB+ RAM usage. Applying patches is pretty much free though.

• File Size: Max file size for individual file is 2GB.

• Folks at Google for creating open-vcdiff.
• Metric for porting open-vcdiff to .NET.
• SnowflakePowered (Ronny Chan) for optimizing the .NET port of open-vcdiff.

Additional optimisations by myself :)

• Yann Collet for creating the xxHash hashing algorithm.
• Melnik Alexander for high performance port of xxHash.

• A Product of Team Salvato.