Merkle trees and build systems [LWN.net]

Merkle trees and build systems

Posted May 30, 2020 13:26 UTC (Sat) by nim-nim (subscriber, #34454)
In reply to: Merkle trees and build systems by walters
Parent article: Merkle trees and build systems

A .deb/rpm is far more than an archive of built files that could be replaced with an ostree of built files

to post comments

Merkle trees and build systems

Posted May 31, 2020 20:01 UTC (Sun) by MrWim (subscriber, #47432) [Link] (1 responses)

You're referring to maintainer scripts and the like? With apt2ostree we store both the data and the metadata in separate trees. When we come to combine them together we try to reconstruct a dpkg database that would result from all these packages being unpacked into a chroot.

I think of it being a bit like map-reduce, where you design the reduce step to be as cheap as possible, and the map can be expensive if you like because it deterministic, cacheable and parallelizable.

Merkle trees and build systems

Posted Jun 5, 2020 10:09 UTC (Fri) by nim-nim (subscriber, #34454) [Link]

apt and rpm do not deal with just a set of resulting files, they deal with composition rules, build rules, and post-install file munging, because real-life software uses things like indexes that can not be computed before the things the index indexes are actually deployed