Feasability to support a different version control than git #145

Hello, at my work we use Plastic SCM (Unity Version Control) and would like to add a caching tool for msbuild. Trying out the local msbuild cache I notice that it seems to use git to build a dictionary of (file, hash of file) and I was wondering if someone could shed some light on how to go about implementing a ISourceControlFileHashProvider for Plastic instead. The git variant which runs git ls-files -z -cmos --exclude-standard seems to make a list of all the tracked files? That's probably doable with cm (the Plastic SCM command line tool) somehow, although I'm not sure it has a git hash-object.

So, dear reader, if you have any thoughts about how to best go about this, please let me know. I suppose one alternative is to just make a local git repo to make MSBuildCache think we are using git.