From 07e2085190e30010ad595369a07842413bacd3d1 Mon Sep 17 00:00:00 2001
From: Aria <me@aria.rip>
Date: Sun, 15 Oct 2023 01:07:02 +0100
Subject: track path through network for broadcast

---
 broadcast/src/handler.rs | 25 +++++++++++++++++++------
 broadcast/src/msg.rs     |  1 +
 2 files changed, 20 insertions(+), 6 deletions(-)

(limited to 'broadcast')

diff --git a/broadcast/src/handler.rs b/broadcast/src/handler.rs
index b55cd9b..b38e2b7 100644
--- a/broadcast/src/handler.rs
+++ b/broadcast/src/handler.rs
@@ -6,7 +6,6 @@ use smol::{
 };
 use std::{
     collections::{HashMap, HashSet},
-    iter,
     sync::Arc,
     time::Duration,
 };
@@ -52,9 +51,10 @@ impl Handler for BroadcastHandler {
                 BroadcastBody::Broadcast {
                     msg_id: Some(msg_id),
                     message,
+                    path,
                 } => {
                     future::zip(
-                        self.receive_broadcast(&header.src, message),
+                        self.receive_broadcast(&header.src, path, message),
                         self.send_broadcast_ok(&header.src, msg_id),
                     )
                     .await;
@@ -62,8 +62,9 @@ impl Handler for BroadcastHandler {
                 BroadcastBody::Broadcast {
                     msg_id: None,
                     message,
+                    path,
                 } => {
-                    self.receive_broadcast(&header.src, message).await;
+                    self.receive_broadcast(&header.src, path, message).await;
                 }
 
                 BroadcastBody::Topology { msg_id, topology } => {
@@ -126,18 +127,29 @@ impl BroadcastHandler {
     }
 
     /// Receive a given message, and broadcast it onwards if it is new
-    async fn receive_broadcast(self: &Arc<Self>, src: &str, message: BroadcastTarget) {
+    async fn receive_broadcast(
+        self: &Arc<Self>,
+        src: &str,
+        previous_path: Option<Vec<String>>,
+        message: BroadcastTarget,
+    ) {
         let new = self.seen.write().await.insert(message);
         if !new {
             return;
         }
 
         // Race all send futures
-        let path = iter::once(src);
+        let mut previous_path = previous_path.unwrap_or_else(|| vec![]);
+        previous_path.push(src.to_string());
         let mut tasks = self.attempted_broadcasts.lock().await;
-        for target in self.topology.targets(&self.node_id, path).await {
+        for target in self
+            .topology
+            .targets(&self.node_id, previous_path.iter().map(String::as_str))
+            .await
+        {
             let msg_id = gen_msg_id();
             let this = self.clone();
+            let path = previous_path.clone();
             tasks.insert(
                 msg_id,
                 smol::spawn(async move {
@@ -148,6 +160,7 @@ impl BroadcastHandler {
                                 &BroadcastBody::Broadcast {
                                     msg_id: Some(msg_id),
                                     message,
+                                    path: Some(path.clone()),
                                 },
                             )
                             .await;
diff --git a/broadcast/src/msg.rs b/broadcast/src/msg.rs
index 81abb2d..c252394 100644
--- a/broadcast/src/msg.rs
+++ b/broadcast/src/msg.rs
@@ -11,6 +11,7 @@ pub enum BroadcastBody {
     Broadcast {
         msg_id: Option<MessageID>,
         message: BroadcastTarget,
+        path: Option<Vec<String>>,
     },
 
     #[serde(rename = "broadcast_ok")]
-- 
cgit v1.2.3