zstd IIS Compression Scheme Plugin

Build

git clone https://github.com/kimboslice99/zstd-IIS.git
cd zstd-IIS
git submodule init
git submodule update
pushd zstd\build\cmake
cmake .
msbuild zstd.sln -target:libzstd_static:Rebuild /p:Configuration=Release
popd
cd src
msbuild zstdIIS.vcxproj /p:Configuration=Release;Platform=x64

Setup

compression levels in zstd can be negative, but we cant specify a negative here, so up to 100 is a negative range and over 100 is a positive range.

fastest	middle	slowest
5 4 3 2	1 0 101	120 121 122

From zstd manual

value 0 means default, which is controlled by ZSTD_CLEVEL_DEFAULT.
Default level is ZSTD_CLEVEL_DEFAULT==3

<httpCompression>
    ...
    <scheme name="zstd" dll="%ProgramFiles%\path\to\zstd.dll" dynamicCompressionLevel="104" staticCompressionLevel="107" />
    ...
</httpCompression>

Thanks to @saucecontrol for Brotli-IIS being a great starting point at getting this done