Vulkan Merkle Roots

Summary

A program to demonstrate the calculation/resolution of the roots of Merkle/hash trees of arbitrary inputs on GPUs via the Vulkan API.

Components

vkmr

This is the primary program; it reads inputs from stdin and then calculates their Merkle root, both on the CPU and on each compute-capable GPU reported by Vulkan.

strm

This helper program accepts an arbitrary number of command-line arguments and writes them to a line-separated stream in stdout.

rndm

This helper program generates a specified volume of randomly-filled input strings and writes them to a line-separated stream in stdout.

Building, Running

The Visual Studio Code project includes tasks which will build the programs; it assumes that either the Visual C++ compiler (on Windows) or Clang (elsewhere) is on the PATH.

On (Steam) Deck

To build the project on Steam Deck, I run VS Code in Flatpak. For building, and running, on Steam Deck, the project has an implicit dependency on LLVM 18, which I satisfy with the LLVM 18 extension for the flatpak Freedesktop SDK. I installed VS Code via the Discovery package manager, and the LLVM extension via the command-line:

flatpak install org.freedesktop.Sdk.Extension.llvm18

Launching VS Code

(and enabling the LLVM 18 extension)

FLATPAK_ENABLE_SDK_EXT=llvm18 flatpak run --devel com.visualstudio.code

Launching Vulkan Merkle Roots

The program, once built, also needs to run in a Flatpak container in which the LLVM16 extension is available. So, I open a shell in the VS Code sandbox:

FLATPAK_ENABLE_SDK_EXT=llvm18 flatpak run --command=sh --devel com.visualstudio.code

And, inside this shell:

cd bin
./rndm.app 1712489279 1024 127 | ./vkmr.app