# iroh-blobs

This crate provides blob and collection transfer support for iroh. It implements a simple request-response protocol based on blake3 verified streaming.

A request describes data in terms of blake3 hashes and byte ranges. It is possible to
request blobs or ranges of blobs, as well as collections.

The requester opens a quic stream to the provider and sends the request. The provider answers with the requested data, encoded as [blake3](https://github.com/BLAKE3-team/BLAKE3-specs/blob/master/blake3.pdf) verified streams, on the same quic stream.

This crate is usually used together with [iroh-net](https://crates.io/crates/iroh-net), but can also be used with normal [quinn](https://crates.io/crates/quinn) connections. Connection establishment is left up to the user or a higher level APIs such as the iroh CLI.

## Concepts

- **Blob:** a sequence of bytes of arbitrary size, without any metadata.

- **Link:** a 32 byte blake3 hash of a blob.

- **HashSeq:** a blob that contains a sequence of links. Its size is a multiple of 32.

- **Provider:** The side that provides data and answers requests. Providers wait for incoming requests from Requests.

- **Requester:** The side that asks for data. It is initiating requests to one or many providers.

## Examples

Examples that use `iroh-blobs` can be found in the `iroh` crate. the iroh crate publishes `iroh_blobs` as `iroh::bytes`.


# 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.