Looking for detailed documentation around zInfo

[aochagavia]

I'm interested in writing an independent implementation of SOCI in Rust, specifically meant to create SOCI Indexes. The TOC part seems easy to do (it looks somewhat similar to the eStargz TOC), but the specific details on zInfo aren't covered by the docs. Here are some examples:

• The docs mention that zInfo is stored in binary format, instead of as human-readable JSON, but they don't specify which binary format is used. Judging from the source code, it looks like the binary format uses FlatBuffers. Maybe it'd be useful to document this explicitly.
• The docs describe checkpoints / compression info, but don't explain how it is calculated. Is it tightly coupled to this snapshotter's implementation of gzip?

[aochagavia]

In case anyone stumbles upon this in the future, I discovered a Rust crate that implements the ztoc index: ztoc-rs. It looks like it's being used by replit in production, which is nice.

[austinvazquez]

Hi, @aochagavia thanks for the interest in SOCI. I drafted #1125 to capture some of the feedback you provided to improve the documentation here.