This package contains a single function, generate_checksum, which takes a file and returns a promise which resolves to the sha256 checksum of this file.
This has been tested using an Intel Pentium N4200 1.1Ghz and this is faster than the Web Crypto digest by around 1 second per 60 Mb of file.
This has also been compared against the javascript function in the MVC app and this function is around 1 second faster per 80Mb file.
Because gcc, which Rust relies on, is at such a low version on Centos 7 with no easy way to upgrade it, it is difficult to build this project on Centos. The alternatives are to use the Dockerfile in this repo to run a Docker container, or install another Linux distro.
Install rust
curl --proto '=https' --tlsv1.2 -sSf https://sh.rustup.rs | shInstall wasm-pack
curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | shBuild
wasm-pack buildBuild the Docker image:
sudo docker build . --tag checksumcalculator
Start a container:
sudo docker run -a stdin -a stdout -v $PWD:/usr/src/checksumcalc -t -i checksumcalculator:latest /bin/bash
This starts an interactive bash shell on the container. The -v command mounts
this project folder to the /usr/src/checksumcalc directory in the container,
so that you can edit the code and build the npm package without having to
rebuild the container.
From the bash shell, you can run wasm-pack build to build the package.
Once you've run wasm-pack build (whether locally or in the Docker container),
your code will be packaged in the pkg directory.
To use this package for local development in the MVC site, update package.json in the MVC code and change the checksum-calculator line to:
"@nationalarchives/checksum-calculator": "file:../tdr-prototype-wasm-checksum/pkg"
Update the file path if necessary, so that it points to the pkg directory in
this project.
Run npm install in the MVC codebase, then rebuild the frontend code.
wasm-pack login
wasm-pack publish