Automatically fills a Lancache with games from Battle.net, so that subsequent downloads for the same content will be served from the Lancache, improving speeds and reducing load on your internet connection.

Inspired by the lancache-autofill project for Steam games.

• Downloads specific games by product ID
• High-performance! Downloads are significantly faster than using Battle.net, and can easily reach 10gbit/s or more!
• Game install writes no data to disk, so there is no need to have enough free space available. This also means no unnecessary wear-and-tear to SSDs!
• Multi-platform support (Windows, Linux, MacOS, Arm64)
• No installation required! A completely self-contained, portable application.

• Initial Setup
• Getting Started
• Frequently Asked Questions
• Detailed Command Usage
• Updating
• Need Help?

1. Download the latest version for your OS from the Releases page.
2. Unzip to a directory of your choice
3. (Linux / OSX Only) Give the downloaded executable permissions to be run with chmod +x .\BattleNetPrefill
4. (Windows Only - Optional) Configure your terminal to use Unicode, for much nicer looking UI output.
   • 
   • As the default console in Windows does not support UTF8, Windows Terminal should be installed from the App Store, or Chocolatey.
   • Unicode on Windows is not enabled by default, however running the following will enable it if it hasn't already been enabled.
   • if(!(Test-Path $profile) -or !(gc $profile).Contains("OutputEncoding")) { ac $profile "[console]::InputEncoding = [console]::OutputEncoding = [System.Text.UTF8Encoding]::new()"; & $profile; }

Prior to prefilling for the first time, you will have to decide which games should be prefilled.
A table of all currently downloadable games can be listed with the following command

.\BattleNetPrefill.exe list-products

This table will show a list of available games, and their corresponding product code.
These product codes will be used in subsequent commands, in order to specify which games to prefill.

Now that we've decided on some games that we'd like to prefill, we can move onto running the prefill.

One or more games can be downloaded by specifying as many product codes as desired, in this example we will be prefilling 3 total games

.\BattleNetPrefill.exe prefill --products s1 d3 zeus

Alternatively, optional flags can be used to bulk preload products, without having to specify each product code individually. This can be useful when you are interested in installing most of the available games, as specifiying the individual product codes is not required.

.\BattleNetPrefill.exe prefill --all
.\BattleNetPrefill.exe prefill --blizzard 
.\BattleNetPrefill.exe prefill --activision 

During this initial run, it is likely that the Lancache is empty, so download speeds should be expected to be around your internet line speed (in the below example, a 300megabit connection was used).
Once the prefill has completed, the Lancache should be fully ready to serve clients cached data.

Updating any previously prefilled games can be done by simply re-running the prefill command, with the same games specified as before.

BattleNetPrefill keeps track of which version of each game was previously prefilled, and will only re-download if there is a newer version of the game available.
Any games that are currently up to date, will simply be skipped.

However, if there is a newer version of a game that is available, then BattleNetPrefill will re-download the game.
Due to how Lancache works, this subsequent run should complete much faster than the initial prefill (example below used a 10gbit connection). Any data that was previously downloaded, will be retrieved from the Lancache, while any new data from the update will be retrieved from the internet.

You certainly can! All you need to do is download BattleNetPrefill onto the server, and run it as you reguarly would!

If everything works as expected, you should see a message saying it found the server at 127.0.0.1

Running from a Docker container on the Lancache server is also supported! You should instead see a message saying the server was found at 172.17.0.1

Running on the Lancache server itself can give you some advantages over running BattleNetPrefill on a client machine, primarily the speed at which you can prefill apps.
Since there is no network transfer happening, the prefill should only be limited by disk I/O and CPU throughput.
For example, using a SK hynix Gold P31 2TB NVME and running prefill --force on previously cached game yields the following performance

Displays a table of all currently supported Activision and Blizzard games. Only currently supports retail products, and does not include any PTR or beta products.

These product IDs can then be used with the prefill command to specify which games to be prefilled.

Fills a Lancache by downloading the exact same files from Blizzard's CDN as the official Battle.Net client. Expected initial download speeds should be the speed of your internet connection.

Subsequent runs of this command should be hitting the Lancache, and as such should be dramatically faster than the initial run.

If a list of products is supplied, only these products will be downloaded. This parameter is ideally used when only interested in a small number of games.

Downloads multiple products, useful for prefilling a completely empty cache. Can be combined with --products.

By default, BattleNetPrefill will cache copies of certain files on disk, in order to dramatically speed up future runs (in some cases 3X faster).
These cache files will be stored in the /Cache directory in the same directory as BattleNetPrefill. However, in some scenarios this disk cache can potentially take up a non-trivial amount of storage (~1gb), which may not be ideal for all use cases.

By running with the additional flag --nocache, BattleNetPrefill will no longer cache any files locally, at the expense of slower runtime.

By default, BattleNetPrefill will keep track of the most recently prefilled product, and will only attempt to prefill if there it determines there a newer version available for download. This default behavior will work best for most use cases, as no time will be wasted re-downloading files that have been previously prefilled.

Running with the flag --force will override this behavior, and instead will always run the prefill, re-downloading all files for the specified product. This flag may be useful for diagnostics, or benchmarking network performance.

Deletes temporary cache files stored in the /Cache directory.
These files are cached in order to dramatically speed up future prefill runs (in some cases 3X faster), however in some cases this disk cache can potentially take up a non-trivial amount of storage (~1gb).

These cache files will also build up over time, as newer versions of games are released, leaving unused cache data behind that will never be used again.

In the case that you would like to save disk space without having to constantly clear the cache, running prefill with the --nocache flag specified will prevent the cache files from being written in the first place.

Skips the prompt asking to clear the cache, and immediately begins clearing the cache.

BattleNetPrefill will automatically check for updates, and notify you when an update is available :

To update:

1. Download the latest version for your OS from the Releases page.
2. Unzip to the directory where BattleNetPrefill is currently installed, overwriting the previous executable.
3. Thats it! You're all up to date!

If you are running into any issues, feel free to open up a Github issue on this repository.

You can also find us at the LanCache.NET Discord, in the #battlenet-prefill channel.

• Developer's guide

• https://wowdev.wiki/TACT
• https://github.com/d07RiV/blizzget/wiki

• https://github.com/Marlamin/BuildBackup
• https://github.com/WoW-Tools/CASCExplorer
• https://github.com/d07RiV/blizzget