Comment by twoodfin
1 day ago
What made git special & powerful from the start was its data model: Like the network databases of old, but embedded in a Merkle tree for independent evolution and verifiability.
Scaling that data model beyond projects the size of the Linux kernel was not critical for the original implementation. I do wonder if there are fundamental limits to scaling the model for use cases beyond “source code management for modest-sized, long-lived projects”.
Most of the problems mentioned in the article are not problems with using a content-addressed tree like git or even with using precisely git’s schema. The problems are with git’s protocol and GitHub’s implementation thereof.
Consider vcpkg. It’s entirely reasonable to download a tree named by its hash to represent a locked package. Git knows how to store exactly this, but git does not know how to transfer it efficiently.
> Git knows how to store [a hash-addressed tree], but git does not know how to transfer it efficiently.
Naïvely, I’d expect shallow clones to be this, so I was quite surprised by a mention of GitHub asking people not to use them. Perhaps Git tries too hard to make a good packfile?..
Meanwhile, what Nixpkgs does (and why “release tarballs” were mentioned as a potential culprit in the discussion linked from TFA) is request a gzipped tarball of a particular commit’s files from a GitHub-specific endpoint over HTTP rather than use the Git protocol. So that’s already more or less what you want, except even the tarball is 46 MB at this point :( Either way, I don’t think the current problems with Nixpkgs actually support TFA’s thesis.