TVL tracking on XRPL with only on-chain calls

This repo is a proof of concept for platforms like DeFiLlama to fetch XRPL TVL without relying on a third-party indexing API.

Different versions of a script

The repository contains 2 versions of the script. They are mostly identical and are here just for easier understanding what's going on.

1. index.js - the main "production" script that is going to be plugged into DeFiLlama adapter. Mostle the same as index_verbose but with removed debugging addons and comments.
2. index_verbose.js - the Proof-of-Concept script that gets TVL and prints it in the terminal, also has additional stuff like: JSDoc typings, basic test for verifying calculation logic, performance measurements. Run with npm run start:verbose.

Error handling

The errors that might be thrown in this script are caught in the top-most caller. This is because there is not much point in handling individual hiccups in the middle of execution, if something went wrong - it is better to retry the whole process.

It is, of course, possible to attach retry logic to individual requests, but that complicates code quite a bit. Given that errors are not that common (at least in my testing) it is easier to re-run the whole thing if that happens.

Performance

Rought estimates on the performance of this script. Ran with dedicated rippled node (expect public to be much slower due to throttling).

Remote rippled node

Discovery phase:
Duration - ~20 minutes
Memory Usage (in MB):

Low { rss: 47.25, heapTotal: 10.84, heapUsed: 7.81, external: 0.64 }
High { rss: 129.31, heapTotal: 30.59, heapUsed: 22.97, external: 1.98 }

Getting pool reserves:
Duration - 23 seconds
Memory Usage (in MB):

Low { rss: 47.25, heapTotal: 10.84, heapUsed: 7.81, external: 0.64 }
High { rss: 175.39, heapTotal: 79.34, heapUsed: 47.51, external: 2.19 }

Calculating TVL:
Duration - 6 milliseconds
Memory Usage (in MB):

Low { rss: 47.25, heapTotal: 10.84, heapUsed: 7.81, external: 0.64 }
High { rss: 175.39, heapTotal: 79.34, heapUsed: 47.51, external: 2.19 }