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use super::subscriber::*;
use super::pubsub_core::*;
use super::publisher_sink::*;
use futures::*;
use std::sync::*;
use std::collections::{HashMap, VecDeque};
pub struct SinglePublisher<Message> {
core: Arc<Mutex<PubCore<Message>>>
}
impl<Message> SinglePublisher<Message> {
pub fn new(buffer_size: usize) -> SinglePublisher<Message> {
let core = PubCore {
next_subscriber_id: 0,
publisher_count: 1,
subscribers: HashMap::new(),
max_queue_size: buffer_size
};
SinglePublisher {
core: Arc::new(Mutex::new(core))
}
}
pub fn count_subscribers(&self) -> usize {
self.core.lock().unwrap().subscribers.len()
}
pub fn republish(&self) -> Self {
self.core.lock().unwrap().publisher_count += 1;
SinglePublisher {
core: Arc::clone(&self.core)
}
}
}
impl<Message> PublisherSink<Message> for SinglePublisher<Message> {
fn subscribe(&mut self) -> Subscriber<Message> {
let subscriber_id = {
let mut core = self.core.lock().unwrap();
let id = core.next_subscriber_id;
core.next_subscriber_id += 1;
id
};
let sub_core = SubCore {
id: subscriber_id,
published: true,
waiting: VecDeque::new(),
notify_waiting: vec![],
notify_ready: vec![],
notify_complete: vec![]
};
let sub_core = Arc::new(Mutex::new(sub_core));
let pub_core = Arc::downgrade(&self.core);
{
let mut core = self.core.lock().unwrap();
core.subscribers.insert(subscriber_id, Arc::clone(&sub_core));
}
Subscriber::new(pub_core, sub_core)
}
}
impl<Message> Drop for SinglePublisher<Message> {
fn drop(&mut self) {
let to_notify = {
let mut pub_core = self.core.lock().unwrap();
pub_core.publisher_count -= 1;
if pub_core.publisher_count == 0 {
let mut to_notify = vec![];
for subscriber in pub_core.subscribers.values() {
let mut subscriber = subscriber.lock().unwrap();
subscriber.published = false;
subscriber.notify_ready = vec![];
to_notify.extend(subscriber.notify_waiting.drain(..));
}
to_notify
} else {
vec![]
}
};
to_notify.into_iter().for_each(|notify| notify.notify());
}
}
impl<Message> Sink for SinglePublisher<Message> {
type SinkItem = Message;
type SinkError = ();
fn start_send(&mut self, item: Message) -> StartSend<Message, ()> {
let notify = { self.core.lock().unwrap().publish_single(item) };
match notify {
PublishSingleOutcome::Published(notify) => {
notify.into_iter().for_each(|notify| notify.notify());
Ok(AsyncSink::Ready)
},
PublishSingleOutcome::NotPublished(item) => {
Ok(AsyncSink::NotReady(item))
}
}
}
fn poll_complete(&mut self) -> Poll<(), ()> {
if self.core.lock().unwrap().complete() {
Ok(Async::Ready(()))
} else {
Ok(Async::NotReady)
}
}
}