This month in RsNano 10/2022

Welcome to the second issue of This month in RsNano! RsNano is a Rust port of the original nano-node. This is a monthly summary of its progress and community. Want to get involved? We love contributions.

Roughly 25% is ported

This month we had:

  • 160 commits
  • 13,866 lines inserted
  • 15,171 lines deleted

This changed the current line count (excluding comments and blank lines) to:

  • C++: 100,185 lines
  • Rust: 33,633 lines

The ported status increased by 1.5 percentage points to 25%. This is less than in the previous months and is due to the fact that most of this months work went into rewriting the LMDB data stores with the Rust crate lmdb-rkv, which decreased the Rust line count.

Database layer fully ported

We reached a milestone: All LMDB data stores are now fully ported to Rust! And it gets even better. The data stores were still dependent on callbacks to C++ for using the LMDB C library. So after the last data store was ported, all data stores were rewritten with the Rust crate lmdb-rkv. This means that now the data stores are Rust only. It is now possible to write tools that work with the ledger in pure Rust.

First community contribution

This month we had our very first community contribution. Fiono was one of the first members in our Discord and we met in person at the London Meetup this year. He had said several times that he would like to help, but that he didn’t know Rust yet. But now he has picked up Rust and translated his first class! He ported the class rep_weights in this commit. Thanks a lot for your help Fiono!

Also many thanks to Gr0vity, who once again ran his test tools against RsNano. It reached up to 1100 CPS on his very fast local setup. He said that RsNano worked just like the current develop branch of Nano, but was roughly 20% slower. That is because the glue layer between Rust and C++ drains perfomance a bit. That’s ok, because that glue layer will eventually be removed. If you don’t know Gr0vity’s awesome test tools yet then check out nano-local on github.

Removed C Libraries

All cryptography, hashing and random number generation is now handled in Rust. Therefore the following C/C++ libraries could be removed from the repository:

  • blake2: The hashing algorithm used by Nano
  • Argon2: Another hashing algorithm used by Nano
  • CryptoPP: A crypto library for C++
  • LMDB: Lightning Memory-Mapped Database
  • RocksDb: RocksDb will not be supported by RsNano


Up until now the Rust code was similarly organised as the original Nano code. This has changed now. I took some time to reorganize the Rust modules to better adhere to screaming architecure . Eventually the RsNano crate will be split up into reusable sub crates, so that the community can develop new Nano related Rust projects.

Next steps

  • Port the ledger class, which is responsible for ensuring consistency of the ledger. It is a very big class and will take some time.
  • Create a YouTube video for new contributors that shows how to port code in RsNano.

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