Ignotus Peverell
405a4bc985
* Base MMR storage structures Implementations of the MMR append-only file structure and its remove log. The append-only file is backed by a mmap for read access. The remove log is stored in memory for quick checking and backed by a simple file to persist it. * Add PMMR backend buffer, make PMMR Backend mutable * The Backend trait now has &mut self methods, and an &mut reference in PMMR. This simplifies the implementation of all backends by not forcing them to be interior mutable. Slight drawback is that a backend can't be used directly as long as it's used by a PMMR instance. * Introduced a buffer in the PMMR persistent backend to allow reads before the underlying files are fully flushed. Implemented with a temporary VecBackend. * Implement a prune list to use with dense backends The PruneList is useful when implementing compact backends for a PMMR (for example a single large byte array or a file). As nodes get pruned and removed from the backend to free space, the backend will get more compact but positions of a node within the PMMR will not match positions in the backend storage anymore. The PruneList accounts for that mismatch and does the position translation. * PMMR store compaction Implement actual pruning of the underlying PMMR storage by flushing the remove log. This triggers a rewrite of the PMMR nodes data (hashes and sums), removing pruned nodes. The information of what has been removed is kept in a prune list and the remove log is truncated. * PMMR store pruning tests and fixes
Grin
Grin is an in-progress implementation of the MimbleWimble protocol. Many characteristics are still undefined but the following constitutes a first set of choices:
- Clean and minimal implementation, aiming to stay as such.
- Follows the MimbleWimble protocol, which provides great anonymity and scaling characteristics.
- Cuckoo Cycle proof of work (at least to start with).
- Relatively fast block time (a minute or less, possibly decreasing as networks improve).
- Fixed block reward, both over time and in blocks (fees are not additive).
- Transaction fees are based on the number of UTXO created/destroyed and total transaction size.
- Smooth curve for difficulty adjustments.
To learn more, read our introduction to MimbleWimble and Grin.
Status
Grin is still an infant, much is left to be done and contributions are welcome (see below). Check our mailing list archives for the latest status.
Contributing
To get involved, read our contributing docs.
Find us:
- Chat: Gitter.
- Mailing list: join the ~MimbleWimble team and subscribe on Launchpad.
Getting Started
To learn more about the technology, read our introduction.
To build and try out Grin, see the build docs.
Philosophy
Grin likes itself small and easy on the eyes. It wants to be inclusive and welcoming for all walks of life, without judgement. Grin is terribly ambitious, but not at the detriment of others, rather to further us all. It may have strong opinions to stay in line with its objectives, which doesn't mean disrepect of others' ideas.
We believe in pull requests, data and scientific research. We do not believe in unfounded beliefs.
Credits
Tom Elvis Jedusor for the first formulation of MimbleWimble.
Andrew Poelstra for his related work and improvements.
John Tromp for the Cuckoo Cycle proof of work.
J.K. Rowling for making it despite extraordinary adversity.
License
Apache License v2.0.