DiffPatcher

Simple patch creator and applier aimed at applications and games.

How it works

The DiffPatchCreator allows the comparision of two folders, creating a single patch file (zip archive) to patch the old version to be equal to the new version, using delta compression, to only patch what is necessary, and not replace entire files.

DiffPatcher in turn downloads these patch files and applies them to the files in the folder it is in.

Both are currently using xdelta3.exe, for diffing and applying patches to changed files. Executables for Linux and Mac can be found in the Libs folder, but the source code has to be changed slightly for them to be used.

Versioning

Every patch gets assigned a version, or revision number that it uses to determine if there are new patches available. If there's a patch with version 3, and its local version is 2, it will download the new patch.

It doesn't matter if there are versions missing in between, it will simply download them in order.

If the local version is 0, or the version file, where the local version is stored, is deleted, the patcher downloads everything over. Due to this behavior it's a good idea to make the first "patch" a diff between an empty folder and the full application, as that will allow users to redownload everything by deleting the version file, getting a clean slate.

Patcher configuration

patch_uri

URI to the folder that contains the patch list and the patches listed in said list.

patch_list

List of patch files for the patcher to download and apply in the following format:

<version> <file_name>

Example:

1  1_full_application.zip
2  2_some_bug_fix.zip
3  3_new_feature.zip

Ignores empty lines and lines prefixed with !, ;, #, //, or --.

exe

Name of the executable file to start when the Start button is clicked after patching. If this is empty, the Start button will be disabled.

arguments

Arguments to pass to the exe that is started when the Start button is clicked.

Licenses

DiffPatcher is licensed under GPLv3. It makes use of xdelta3 and DotNetZip. The respective licenses can be found in LICENSE.md and LICENSE-3RD-PARTY.md.