• Forked from jaimehgb/RaiBlocksWebAssemblyPoW

nanocurrency-wasm-pow

Overview

This repo contains a simple Nano Currency PoW implementation compiled to WebAssembly to boost its performance on browsers. It uses emscripten under the hood.

Compiling to WebAssembly, the result is around 10 times faster than a pure JS PoW implementation (e.g.: RaiBlocksJS).

This basically makes possible to generate proofs of work on modern browsers in a reasonable time (see below).

Average time it takes to compute in a Ryzen 7 3700x:

• Send/change blocks: average of <25 seconds
• Open/receive blocks: average of <2.5 seconds

Usage

To get the proof of work you can simply add the nano-pow/index.js to your source code and do:

    <script src="/nano-pow/index.js"></script>
    <script>
      test();

      async function test() {
        const start = Date.now();
        const hash =
          "BD9F737DDECB0A34DFBA0EDF7017ACB0EF0AA04A6F7A73A406191EF80BB20000";

        const proofOfWork = await NanoPow.getProofOfWorkMultiThreaded(
          {
            hash,
            threshold: NanoPow.THRESHOLD__OPEN_RECEIVE,
          }
          // , { workers: 5 } // optionally limit the number of workers, default is number of threads-1
        );

        const end = Date.now();
        const time = (end - start) / 1000;

        console.log({ hash, time, proofOfWork });
      }
    </script>

See the files in the examples directory for a full overview.

Available proof Of Work thresholds

  NanoPow.THRESHOLD__SEND_CHANGE,  // "fffffff800000000"
  NanoPow.THRESHOLD__OPEN_RECEIVE, // "fffffe0000000000"

If a new threshold is needed in a new version, it can be passed to the function getProofOfWorkMultiThreaded as a simple hex string.

Compiling from source

All the PoW work takes place at nano-pow.cpp. There is the main loop which calculates the PoW and a function which can be called from JS and runs the loop (the iterations function).

To compile it to Web Assembly you need to install emscripten and add it to your path:

• https://emscripten.org/docs/getting_started/downloads.html

With that done, at the repo directory run:

$ ./compile.sh

It will output 2 files: nano-pow.js and nano-pow.wasm. To get directions on how to use these files, check the JS files in the nano-pow directory.

Additional help

There are more docs about the emscripten itself here.

Compatibility

This implementation has just been tested in Chrome (Windows 64bit), Firefox (Windows 64bit) and Chrome (Android) but should also work in all the devices supporting WASM.