[](https://github.com/ypo/flute/actions/workflows/rust.yml)
[](https://github.com/ypo/flute/actions/workflows/python.yml)
[](https://docs.rs/crate/flute/)
[](https://crates.io/crates/flute/)
[](https://deps.rs/repo/github/ypo/flute)
[](https://codecov.io/gh/ypo/flute)
## FLUTE - File Delivery over Unidirectional Transport
Massively scalable multicast distribution solution
The library implements a unidirectional file delivery, without the need of a return channel.
## RFC
This library implements the following RFCs
| RFC 6726 | FLUTE - File Delivery over Unidirectional Transport | <https://www.rfc-editor.org/rfc/rfc6726.html> |
| RFC 5775 | Asynchronous Layered Coding (ALC) Protocol Instantiation | <https://www.rfc-editor.org/rfc/rfc5775.html> |
| RFC 5661 | Layered Coding Transport (LCT) Building Block | <https://www.rfc-editor.org/rfc/rfc5651> |
| RFC 5052 | Forward Error Correction (FEC) Building Block | <https://www.rfc-editor.org/rfc/rfc5052> |
| RFC 5510 | Reed-Solomon Forward Error Correction (FEC) Schemes | <https://www.rfc-editor.org/rfc/rfc5510.html> |
## UDP/IP Multicast files sender
Transfer files over a UDP/IP network
```rust
use flute::sender::Sender;
use flute::sender::ObjectDesc;
use flute::sender::Cenc;
use std::net::UdpSocket;
use std::time::SystemTime;
// Create UDP Socket
let udp_socket = UdpSocket::bind("0.0.0.0:0").unwrap();
udp_socket.connect("224.0.0.1:3400").expect("Connection failed");
// Create FLUTE Sender
let tsi = 1;
let oti = Default::default();
let config = Default::default();
let mut sender = Sender::new(tsi, &oti, &config);
// Add object(s) (files) to the FLUTE sender
let obj = ObjectDesc::create_from_buffer(b"hello world", "text/plain",
&url::Url::parse("file:///hello.txt").unwrap(), 1, None, None, Cenc::Null, true, None, true).unwrap();
sender.add_object(obj);
// Always call publish after adding objects
sender.publish(SystemTime::now());
// Send FLUTE packets over UDP/IP
while let Some(pkt) = sender.read(SystemTime::now()) {
udp_socket.send(&pkt).unwrap();
std::thread::sleep(std::time::Duration::from_millis(1));
}
```
## UDP/IP Multicast files receiver
Receive files from a UDP/IP network
```rust
use flute::receiver::{writer, MultiReceiver, UDPEndpoint};
use std::net::UdpSocket;
use std::time::SystemTime;
use std::rc::Rc;
// Create UDP/IP socket to receive FLUTE pkt
let endpoint = UDPEndpoint::new(None, "224.0.0.1".to_string(), 3400);
let udp_socket = UdpSocket::bind(format!("{}:{}", endpoint.destination_group_address, endpoint.port)).expect("Fail to bind");
// Create a writer able to write received files to the filesystem
let writer = Rc::new(writer::ObjectWriterFSBuilder::new(&std::path::Path::new("./flute_dir"))
.unwrap_or_else(|_| std::process::exit(0)));
// Create a multi-receiver capable of de-multiplexing several FLUTE sessions
let mut receiver = MultiReceiver::new(writer, None, false);
// Receive pkt from UDP/IP socket and push it to the FLUTE receiver
let mut buf = [0; 2048];
loop {
let (n, _src) = udp_socket.recv_from(&mut buf).expect("Failed to receive data");
let now = SystemTime::now();
receiver.push(&endpoint, &buf[..n], now).unwrap();
receiver.cleanup(now);
}
```
## Application-Level Forward Erasure Correction (AL-FEC)
The following error recovery algorithms are supported
- [X] No-code
- [X] Reed-Solomon GF 2^8
- [X] Reed-Solomon GF 2^8 Under Specified
- [ ] Reed-Solomon GF 2^16
- [ ] Reed-Solomon GF 2^m
- [X] RaptorQ
- [X] Raptor
The `Oti` module provides an implementation of the Object Transmission Information (OTI)
used to configure Forward Error Correction (FEC) encoding in the FLUTE protocol.
```rust
use flute::sender::Oti;
use flute::sender::Sender;
// Reed Solomon 2^8 with encoding blocks composed of
// 60 source symbols and 4 repair symbols of 1424 bytes per symbol
let oti = Oti::new_reed_solomon_rs28(1424, 60, 4).unwrap();
let mut sender = Sender::new(1, &oti, &Default::default());
```
## Content Encoding (CENC)
The following schemes are supported during the transmission/reception
- [x] Null (no compression)
- [x] Deflate
- [x] Zlib
- [x] Gzip
## Files multiplex / Blocks interleave
The FLUTE Sender is able to transfer multiple files in parallel by interleaving packets from each file. For example:
**Pkt file1** -> Pkt file2 -> Pkt file3 -> **Pkt file1** -> Pkt file2 -> Pkt file3 ...
The Sender can interleave blocks within a single file.
The following example shows Encoding Symbols (ES) from different blocks (B) are interleaved. For example:
**(B 1,ES 1)**->(B 2,ES 1)->(B 3,ES 1)->**(B 1,ES 2)**->(B 2,ES 2)...
To configure the multiplexing, use the `Config` struct as follows:
```rust
use flute::sender::Sender;
use flute::sender::Config;
let config = Config {
// Transfer a maximum of 3 files in parallel
multiplex_files: 3,
// Interleave a maximum of 3 blocks within each file
interleave_blocks: 3,
..Default::default()
};
let mut sender = Sender::new(1, &Default::default(), &config);
```
# Python bindings
[](https://badge.fury.io/py/flute-alc)
## Installation
```bash
pip install flute-alc
```
## Example
Flute Sender python example
```python
from flute import sender
# Flute Sender config parameters
sender_config = sender.Config()
# Object transmission parameters (no_code => no FEC)
# encoding symbol size : 1400 bytes
# Max source block length : 64 encoding symbols
oti = sender.Oti.new_no_code(1400, 64)
# Create FLUTE Sender
flute_sender = sender.Sender(1, oti, sender_config)
# Transfer a file
flute_sender.add_file("/path/to/file", 0, "application/octet-stream", None, None)
flute_sender.publish()
while True:
alc_pkt = flute_sender.read()
if alc_pkt == None:
break
#TODO Send alc_pkt over UDP/IP
```
Flute Receiver python example
```python
from flute import receiver
# Write received objects to a destination folder
receiver_writer = receiver.FluteWriter("/path/to/dest")
# FLUTE Receiver configuration parameters
receiver_config = receiver.Config()
tsi = 1
# Creation of a FLUTE receiver
udp_endpoint = receiver.UDPEndpoint("224.0.0.1", 1234)
flute_receiver = receiver.Receiver(udp_endpoint, tsi, receiver_writer, receiver_config)
while True:
# Receive LCT/ALC packet from multicast
pkt = receive_from_udp_socket()
# Push packet to the flute receiver
flute_receiver.push(bytes(pkt))
```