remerkleable

Re-merkle-able: Typed mutable SSZ views over cached and immutable binary Merkle trees.

Features

• Types:

  • custom byte-vector and byte-list view for Python bytes-like behavior
  • bitfields: bitlist, bitvector
  • list, container, vector
  • union
  • basic types

• Functionality:

  • Serialize all types. Into output stream (returning the written count) and as bytes
  • Deserialize all types. From input stream (and scope) and from bytes
  • Hash-tree-root all types

  • Merkle-based data-sharing:

    • every view can be initialized/backed by a binary Merkle tree
    • complex views have backings, and can share data.
    • complex views provide a nice mutable interface, and replace their backing. And this also works for child-views through view-hooks.
    • SSZ-Partials: if a partial proof is loaded as backing, a view can be overlaid, and the partial backing works as long as no excluded branches are accessed.

  • Calculate byte lengths:

    • Type min/max byte length
    • Byte length for fixed-length types
    • Output byte length for a value, without serializing

  • Navigation: construct paths from types, and convert to generalized indices.
  • History: traverse a sequence of nodes, and get the changelog for a given subtree location.

Project Links

• Docs: https://remerkleable.readthedocs.io/
• Changelog: https://remerkleable.readthedocs.io/en/latest/changelog.html
• PyPI: https://pypi.python.org/pypi/remerkleable
• Issues: https://github.com/protolambda/remerkleable/issues

Also see

• SSZ: "SimpleSerialize", part of Ethereum Proof of Stake spec
• SSZ draft spec
• Ethereum Merkle trees information aggregate

Contact

Author: @protolambda

License

MIT, see LICENSE file.