# iroh-sync
Multi-dimensional key-value documents with an efficient synchronization protocol.
The crate operates on *Replicas*. A replica contains an unlimited number of
*Entries*. Each entry is identified by a key, its author, and the replica's
namespace. Its value is the 32-byte BLAKE3 hash of the entry's content data,
the size of this content data, and a timestamp.
The content data itself is not stored or transferred through a replica.
All entries in a replica are signed with two keypairs:
* The *Namespace* key, as a token of write capability. The public key is the *NamespaceId*, which
also serves as the unique identifier for a replica.
* The *Author* key, as a proof of authorship. Any number of authors may be created, and
their semantic meaning is application-specific. The public key of an author is the [AuthorId].
Replicas can be synchronized between peers by exchanging messages. The synchronization algorithm
is based on a technique called *range-based set reconciliation*, based on [this paper][paper] by
Aljoscha Meyer:
> Range-based set reconciliation is a simple approach to efficiently compute the union of two
sets over a network, based on recursively partitioning the sets and comparing fingerprints of
the partitions to probabilistically detect whether a partition requires further work.
The crate exposes a generic storage interface with in-memory and persistent, file-based
implementations. The latter makes use of [`redb`], an embedded key-value store, and persists
the whole store with all replicas to a single file.
[paper]: https://arxiv.org/abs/2212.13567
# License
This project is licensed under either of
* Apache License, Version 2.0, ([LICENSE-APACHE](LICENSE-APACHE) or
http://www.apache.org/licenses/LICENSE-2.0)
* MIT license ([LICENSE-MIT](LICENSE-MIT) or
http://opensource.org/licenses/MIT)
at your option.
### Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted
for inclusion in this project by you, as defined in the Apache-2.0 license,
shall be dual licensed as above, without any additional terms or conditions.