Nono: don't do it at lookup, set the etag when the repo is pushed. I'm open to the idea that it's less computation to simply hash the files instead of deflate

Nono: don't do it at lookup, set the etag when the repo is pushed. I'm open to the idea that it's less computation to simply hash the files instead of deflate and decide, but my point was the hash is already calculated on the client when the changed file is added to the repo.