From 0352f64c0fa5365c02934078916626b1fb5c7cf5 Mon Sep 17 00:00:00 2001
From: TQ Hirsch <thequux@thequux.com>
Date: Thu, 11 May 2023 12:45:47 +0200
Subject: [PATCH] Renamed connection to arbiter, which should be clearer

---
 d3270d/src/{connection.rs => arbiter.rs} | 81 +++++++++++++++++-------
 d3270d/src/main.rs                       |  4 +-
 2 files changed, 61 insertions(+), 24 deletions(-)
 rename d3270d/src/{connection.rs => arbiter.rs} (85%)

diff --git a/d3270d/src/connection.rs b/d3270d/src/arbiter.rs
similarity index 85%
rename from d3270d/src/connection.rs
rename to d3270d/src/arbiter.rs
index de3a659..0e0c932 100644
--- a/d3270d/src/connection.rs
+++ b/d3270d/src/arbiter.rs
@@ -19,18 +19,7 @@ use tokio::sync::{broadcast, mpsc, oneshot};
 use tokio_stream::wrappers::{errors::BroadcastStreamRecvError, BroadcastStream};
 use tracing::{error, info, warn};
 
-pub struct B3270 {
-    tracker: Tracker,                            //
-    child: Child,                                //
-    comm: mpsc::Receiver<B3270Request>,          //
-    ind_chan: broadcast::Sender<Indication>,     //
-    child_reader: Lines<BufReader<ChildStdout>>, //
-
-    write_buf: VecDeque<u8>,
-    action_response_map: HashMap<String, oneshot::Sender<RunResult>>, //
-}
-
-pub enum B3270Request {
+enum B3270Request {
     Action(Vec<Action>, oneshot::Sender<RunResult>),
     Resync(oneshot::Sender<(Vec<Indication>, broadcast::Receiver<Indication>)>),
 }
@@ -47,17 +36,35 @@ enum HandleReceiveState {
         oneshot::Receiver<(Vec<Indication>, broadcast::Receiver<Indication>)>,
     ),
 }
-pub struct Handle {
+pub struct ArbiterHandle {
     sender: mpsc::Sender<B3270Request>,
     receiver: Option<HandleReceiveState>,
 }
 
-impl Stream for Handle {
+impl ArbiterHandle {
+    pub async fn send_action(
+        &self,
+        action: Action,
+    ) -> anyhow::Result<oneshot::Receiver<RunResult>> {
+        self.send_actions(vec![action]).await
+    }
+    pub async fn send_actions(
+        &self,
+        actions: Vec<Action>,
+    ) -> anyhow::Result<oneshot::Receiver<RunResult>> {
+        let (os_snd, os_rcv) = oneshot::channel();
+        self.sender
+            .send(B3270Request::Action(actions, os_snd))
+            .await
+            .map_err(|_| anyhow!("Failed to send action to arbiter"))?;
+        Ok(os_rcv)
+    }
+}
+
+impl Stream for ArbiterHandle {
     type Item = Indication;
 
     fn poll_next(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Option<Self::Item>> {
-        // iter tracks whether any progress has been made
-
         loop {
             match self.receiver.take() {
                 Some(HandleReceiveState::TryRestart(mut fut, receiver)) => {
@@ -118,7 +125,10 @@ impl Stream for Handle {
                         warn!("Failed to receive from b3270 server");
                         return Poll::Ready(None);
                     }
-                    Poll::Pending => return Poll::Pending,
+                    Poll::Pending => {
+                        self.receiver = Some(HandleReceiveState::Steady(rcvr));
+                        return Poll::Pending;
+                    }
                 },
 
                 None => {
@@ -129,13 +139,40 @@ impl Stream for Handle {
     }
 }
 
+#[derive(Clone)]
+pub struct B3270HandleRequester(mpsc::Sender<B3270Request>);
+
+impl B3270HandleRequester {
+    pub async fn connect(&self) -> anyhow::Result<ArbiterHandle> {
+        let (conn_send, conn_rcv) = oneshot::channel();
+        self.0
+            .send(B3270Request::Resync(conn_send))
+            .await
+            .map_err(|_| anyhow!("Failed to send request to arbiter"))?;
+
+        let (indications, rcvr) = conn_rcv.await?;
+        Ok(ArbiterHandle {
+            sender: self.0.clone(),
+            receiver: Some(HandleReceiveState::Resume(indications.into_iter(), rcvr)),
+        })
+    }
+}
+
+pub struct B3270 {
+    tracker: Tracker,
+    child: Child,
+    comm: mpsc::Receiver<B3270Request>,
+    ind_chan: broadcast::Sender<Indication>,
+    child_reader: Lines<BufReader<ChildStdout>>,
+
+    write_buf: VecDeque<u8>,
+    action_response_map: HashMap<String, oneshot::Sender<RunResult>>,
+}
+
 impl B3270 {
     pub fn spawn(
         mut child: Child,
-    ) -> (
-        tokio::task::JoinHandle<anyhow::Error>,
-        mpsc::Sender<B3270Request>,
-    ) {
+    ) -> (tokio::task::JoinHandle<anyhow::Error>, B3270HandleRequester) {
         let (subproc_snd, subproc_rcv) = mpsc::channel(10);
         let child_reader = child
             .stdout
@@ -153,7 +190,7 @@ impl B3270 {
             write_buf: VecDeque::new(),
             action_response_map: Default::default(),
         };
-        (tokio::task::spawn(proc), subproc_snd)
+        (tokio::task::spawn(proc), B3270HandleRequester(subproc_snd))
     }
 }
 
diff --git a/d3270d/src/main.rs b/d3270d/src/main.rs
index 90e515f..5a9d55d 100644
--- a/d3270d/src/main.rs
+++ b/d3270d/src/main.rs
@@ -46,10 +46,10 @@ async fn main() -> anyhow::Result<()> {
         .stdout(Stdio::piped())
         .spawn()?;
 
-    let (_server, _server_req) = connection::B3270::spawn(subproc);
+    let (_server, _server_req) = arbiter::B3270::spawn(subproc);
     // TODO: make connection before starting listeners
 
     Ok(())
 }
 
-pub mod connection;
+pub mod arbiter;