/
dns.rs
56 lines (45 loc) · 1.18 KB
/
dns.rs
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use std::io;
use std::net::{SocketAddr, ToSocketAddrs};
use std::vec;
use ::futures::{Future, Poll};
use ::futures_cpupool::{CpuPool, CpuFuture, Builder};
#[derive(Clone)]
pub struct Dns {
pool: CpuPool,
}
impl Dns {
pub fn new(threads: usize) -> Dns {
Dns {
pool: Builder::new()
.name_prefix("hyper-dns")
.pool_size(threads)
.create()
}
}
pub fn resolve(&self, host: String, port: u16) -> Query {
Query(self.pool.spawn_fn(move || work(host, port)))
}
}
pub struct Query(CpuFuture<IpAddrs, io::Error>);
impl Future for Query {
type Item = IpAddrs;
type Error = io::Error;
fn poll(&mut self) -> Poll<Self::Item, Self::Error> {
self.0.poll()
}
}
pub struct IpAddrs {
iter: vec::IntoIter<SocketAddr>,
}
impl Iterator for IpAddrs {
type Item = SocketAddr;
#[inline]
fn next(&mut self) -> Option<SocketAddr> {
self.iter.next()
}
}
pub type Answer = io::Result<IpAddrs>;
fn work(hostname: String, port: u16) -> Answer {
debug!("resolve host={:?}, port={:?}", hostname, port);
(&*hostname, port).to_socket_addrs().map(|i| IpAddrs { iter: i })
}