openethereum/util/registrar/src/registrar.rs
2020-08-07 20:47:12 +03:00

79 lines
2.7 KiB
Rust

// Copyright 2015-2019 Parity Technologies (UK) Ltd.
// This file is part of Parity Ethereum.
// Parity Ethereum 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.
// Parity Ethereum 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.
// You should have received a copy of the GNU General Public License
// along with Parity Ethereum. If not, see <http://www.gnu.org/licenses/>.
use ethabi::{Address, Bytes};
use futures::{future, Future, IntoFuture};
use keccak_hash::keccak;
use std::sync::Arc;
use_contract!(registrar, "res/registrar.json");
// Maps a domain name to an Ethereum address
const DNS_A_RECORD: &'static str = "A";
pub type Asynchronous = Box<dyn Future<Item = Bytes, Error = String> + Send>;
pub type Synchronous = Result<Bytes, String>;
/// Registrar is dedicated interface to access the registrar contract
/// which in turn generates an address when a client requests one
pub struct Registrar {
client: Arc<dyn RegistrarClient<Call = Asynchronous>>,
}
impl Registrar {
/// Registrar constructor
pub fn new(client: Arc<dyn RegistrarClient<Call = Asynchronous>>) -> Self {
Self { client: client }
}
/// Generate an address for the given key
pub fn get_address<'a>(
&self,
key: &'a str,
) -> Box<dyn Future<Item = Address, Error = String> + Send> {
// Address of the registrar itself
let registrar_address = match self.client.registrar_address() {
Ok(a) => a,
Err(e) => return Box::new(future::err(e)),
};
let hashed_key: [u8; 32] = keccak(key).into();
let id = registrar::functions::get_address::encode_input(hashed_key, DNS_A_RECORD);
let future = self
.client
.call_contract(registrar_address, id)
.and_then(move |address| {
registrar::functions::get_address::decode_output(&address)
.map_err(|e| e.to_string())
});
Box::new(future)
}
}
/// Registrar contract interface
/// Should execute transaction using current blockchain state.
pub trait RegistrarClient: Send + Sync {
/// Specifies synchronous or asynchronous communication
type Call: IntoFuture<Item = Bytes, Error = String>;
/// Get registrar address
fn registrar_address(&self) -> Result<Address, String>;
/// Call Contract
fn call_contract(&self, address: Address, data: Bytes) -> Self::Call;
}