From ab4a8a31ec6825f865c40baa611b26e10a0b32c8 Mon Sep 17 00:00:00 2001
From: Rory& <root@rory.gay>
Date: Fri, 27 Feb 2026 15:39:55 +0100
Subject: [PATCH] IPC: unix socket reinit + backlog system

---
 src/util/util/Event.ts | 74 ++++++++++++++++++++++++++++++------------
 1 file changed, 53 insertions(+), 21 deletions(-)

diff --git a/src/util/util/Event.ts b/src/util/util/Event.ts
index 08507dc76..2e6cf8206 100644
--- a/src/util/util/Event.ts
+++ b/src/util/util/Event.ts
@@ -333,6 +333,10 @@ class UnixSocketWriter {
     socketPath: string;
     clients: { [key: string]: Socket } = {};
     watcher?: FSWatcher;
+    backlog: Event[] = [];
+    broadcastLock: Promise<void> = Promise.resolve();
+    replayLock: Promise<void> = Promise.resolve();
+    isInitializing = true;
 
     constructor(socketPath: string) {
         this.socketPath = socketPath;
@@ -442,6 +446,8 @@ class UnixSocketWriter {
         } catch (err) {
             console.error("[Events] Unix socket writer failed to read directory:", err);
         }
+
+        this.isInitializing = false;
     }
 
     async emit(event: Event) {
@@ -450,33 +456,59 @@ class UnixSocketWriter {
         // check if there are any listeners
         const clientCount = Object.entries(this.clients).length;
         if (clientCount === 0) {
-            console.warn("[Events] Unix socket writer has no connected clients to emit to");
+            console.warn("[Events] Unix socket writer has no connected clients to emit to, backlog size:", this.backlog.length + 1);
+            this.backlog.push(event);
+            if (!this.isInitializing) {
+                this.isInitializing = true;
+                console.log("[Events] Re-initializing unix socket writer due to new event with no listeners");
+                await this.close();
+                await this.init();
+            }
             return;
         }
 
-        const tsw = Stopwatch.startNew();
-        const payloadBuf = Buffer.from(JSON.stringify({ id: (event.guild_id || event.channel_id || event.user_id) as string, event }));
-        const lenBuf = Buffer.alloc(4);
-        lenBuf.writeUInt32BE(payloadBuf.length, 0);
-        const framed = Buffer.concat([lenBuf, payloadBuf]);
+        await this.replayLock;
+        await (this.replayLock = Promise.resolve().then(async () => {
+            if (this.backlog.length > 0) {
+                console.log(`[Events] Replaying ${this.backlog.length} backlog events`);
+                for (const backlogEvent of this.backlog) {
+                    await this.broadcast(backlogEvent);
+                }
+                this.backlog = [];
+            }
+        }));
 
-        for (const [socketPath, socket] of Object.entries(this.clients)) {
-            if (socket.destroyed) {
-                console.log("[Events] Unix socket writer found destroyed socket, removing:", socketPath);
-                delete this.clients[socketPath];
-                continue;
+        await this.broadcast(event);
+    }
+
+    private async broadcast(event: Event) {
+        await this.broadcastLock;
+        return await (this.broadcastLock = new Promise((res) => {
+            const tsw = Stopwatch.startNew();
+            const payloadBuf = Buffer.from(JSON.stringify({ id: (event.guild_id || event.channel_id || event.user_id) as string, event }));
+            const lenBuf = Buffer.alloc(4);
+            lenBuf.writeUInt32BE(payloadBuf.length, 0);
+            const framed = Buffer.concat([lenBuf, payloadBuf]);
+
+            for (const [socketPath, socket] of Object.entries(this.clients)) {
+                if (socket.destroyed) {
+                    console.log("[Events] Unix socket writer found destroyed socket, removing:", socketPath);
+                    delete this.clients[socketPath];
+                    continue;
+                }
+
+                try {
+                    socket.write(framed);
+                } catch (e) {
+                    console.error("[Events] Unix socket writer failed to write to socket", socketPath, ":", e);
+                }
             }
 
-            try {
-                socket.write(framed);
-            } catch (e) {
-                console.error("[Events] Unix socket writer failed to write to socket", socketPath, ":", e);
-            }
-        }
-
-        if (tsw.elapsed().totalMilliseconds > 5)
-            // else it's too noisy
-            console.log(`[Events] Unix socket writer emitted to ${Object.entries(this.clients).length} sockets in ${tsw.elapsed().totalMilliseconds}ms`);
+            if (tsw.elapsed().totalMilliseconds > 5)
+                // else it's too noisy
+                console.log(`[Events] Unix socket writer emitted to ${Object.entries(this.clients).length} sockets in ${tsw.elapsed().totalMilliseconds}ms`);
+            res();
+        }));
     }
 
     async close() {