OpenDHT
A lightweight C++17 Distributed Hash Table implementation.
OpenDHT provides an easy to use distributed in-memory data store.
Every node in the network can read and write values to the store.
Values are distributed over the network, with redundancy.
* Lightweight and scalable, designed for large networks and small devices
* High resilience to network disruption
* Public key cryptography layer providing optional data signature and encryption (using GnuTLS)
* IPv4 and IPv6 support
* Clean and powerful **C++17** map API
* Bindings for **C, Rust & Python 3**
* REST API with optional HTTP client+server with push notification support
## Documentation
See the wiki:
#### How-to build and install
Build instructions:
## Examples
### C++ example
The `tools` directory includes simple example programs :
* `dhtnode`, a command line tool, allowing to run a DHT node and perform operations supported by the library (get, put etc.) with text values.
* `dhtchat`, a very simple IM client working over the dht.
Example program launching a DHT node, connecting to the network and performing some basic operations:
```c++
#include
#include
int main()
{
dht::DhtRunner node;
// Launch a dht node on a new thread, using a
// generated RSA key pair, and listen on port 4222.
node.run(4222, dht::crypto::generateIdentity(), true);
// Join the network through any running node,
// here using a known bootstrap node.
node.bootstrap("bootstrap.jami.net", "4222");
// put some data on the dht
std::vector some_data(5, 10);
node.put("unique_key", some_data);
// put some data on the dht, signed with our generated private key
node.putSigned("unique_key_42", some_data);
// get data from the dht
node.get("other_unique_key", [](const std::vector>& values) {
// Callback called when values are found
for (const auto& value : values)
std::cout << "Found value: " << *value << std::endl;
return true; // return false to stop the search
});
// wait for dht threads to end
node.join();
return 0;
}
```
### Python 3 example
```python
import opendht as dht
node = dht.DhtRunner()
node.run()
# Join the network through any running node,
# here using a known bootstrap node.
node.bootstrap("bootstrap.jami.net", "4222")
# blocking call (provide callback arguments to make the call non-blocking)
node.put(dht.InfoHash.get("unique_key"), dht.Value(b'some binary data'))
results = node.get(dht.InfoHash.get("unique_key"))
for r in results:
print(r)
```
## Dependencies
- msgpack-c 1.2+, used for data serialization.
- GnuTLS 3.3+, used for cryptographic operations.
- Nettle 2.4+, a GnuTLS dependency for crypto.
- (optional) restinio used for the REST API.
- (optional) jsoncpp 1.7.4-3+, used for the REST API.
- Build tested with GCC 7+ (GNU/Linux, Windows with MinGW), Clang/LLVM (GNU/Linux, Android, macOS, iOS).
- Build tested with Microsoft Visual Studio 2017, 2019, 2022
## Contact
IRC: join us on Libera.chat at [`#opendht`](https://web.libera.chat/#opendht).
## License
Copyright (C) 2014-2022 Savoir-faire Linux Inc.
OpenDHT is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version.
This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.
See COPYING or https://www.gnu.org/licenses/gpl-3.0.en.html for the full GPLv3 license.
## Acknowledgements
This project was originally based on https://github.com/jech/dht by Juliusz Chroboczek.
It is independent from another project called OpenDHT (Sean Rhea. Ph.D. Thesis, 2005), now extinct.