slow again :(

src/server/client.zig

@@ -44,6 +44,9 @@ pub fn start(self: *Client, io: std.Io, alloc: std.mem.Allocator, queue: *std.Io
                     defer m.deinit(alloc);
                     try writeMsg(self.to_client, m);
                 },
+                .@"-err" => |s| {
+                    try writeErr(self.to_client, s);
+                },
                 else => |m| {
                     std.debug.panic("unimplemented write: {any}\n", .{m});
                 },
@@ -71,6 +74,11 @@ fn writeOk(out: *std.Io.Writer) !void {
     try out.flush();
 }
 
+fn writeErr(out: *std.Io.Writer, msg: []const u8) !void {
+    _ = try out.print("-ERR '{s}'\r\n", .{msg});
+    try out.flush();
+}
+
 fn writePong(out: *std.Io.Writer) !void {
     _ = try out.write("PONG\r\n");
     try out.flush();

src/server/main.zig

@@ -162,7 +162,23 @@ fn handleConnection(
                 try client.send(io, .pong);
             },
             .@"pub" => |pb| {
-                try server.publishMessage(io, server_allocator, &client, pb);
+                var pub_task = io.async(publishMessage, .{ server, io, server_allocator, &client, pb });
+                defer pub_task.cancel(io) catch {};
+
+                var timeout_task = io.async(std.Io.sleep, .{ io, .fromMilliseconds(200), .real });
+                defer timeout_task.cancel(io) catch {};
+
+                switch (try io.select(.{
+                    .publish = &pub_task,
+                    .timeout = &timeout_task,
+                })) {
+                    .publish => {
+                        timeout_task.cancel(io) catch {};
+                    },
+                    .timeout => {
+                        pub_task.cancel(io) catch {};
+                    },
+                }
             },
             .sub => |sub| {
                 try server.subscribe(io, server_allocator, id, sub);
@@ -196,33 +212,35 @@ fn subjectMatches(expected: []const u8, actual: []const u8) bool {
 }
 
 fn publishMessage(server: *Server, io: std.Io, alloc: std.mem.Allocator, source_client: *Client, msg: Message.Pub) !void {
-    errdefer {
+    //    errdefer {
-        if (source_client.connect) |c| {
+    //        if (source_client.connect) |c| {
-            if (c.verbose) {
+    //            if (c.verbose) {
-                source_client.send(io, .@"-err") catch {};
+    //                source_client.send(io, .{ .@"-err" = "Slow Consumer" }) catch {};
+    //            }
+    //        }
+    //    }
+    {
+        defer msg.deinit(alloc);
+        try server.subs_lock.lock(io);
+        defer server.subs_lock.unlock(io);
+        for (server.subscriptions.items) |subscription| {
+            if (subjectMatches(subscription.subject, msg.subject)) {
+                const client = server.clients.get(subscription.client_id) orelse {
+                    std.debug.print("trying to publish to a client that no longer exists: {d}\n", .{subscription.client_id});
+                    continue;
+                };
+                client.send(io, .{ .msg = .{
+                    .subject = try alloc.dupe(u8, msg.subject),
+                    .sid = try alloc.dupe(u8, subscription.sid),
+                    .reply_to = if (msg.reply_to) |r| try alloc.dupe(u8, r) else null,
+                    .payload = try alloc.dupe(u8, msg.payload),
+                } }) catch continue;
             }
         }
     }
-    defer msg.deinit(alloc);
-    try server.subs_lock.lock(io);
-    defer server.subs_lock.unlock(io);
-    for (server.subscriptions.items) |subscription| {
-        if (subjectMatches(subscription.subject, msg.subject)) {
-            const client = server.clients.get(subscription.client_id) orelse {
-                std.debug.print("trying to publish to a client that no longer exists: {d}\n", .{subscription.client_id});
-                continue;
-            };
-            client.send(io, .{ .msg = .{
-                .subject = try alloc.dupe(u8, msg.subject),
-                .sid = try alloc.dupe(u8, subscription.sid),
-                .reply_to = if (msg.reply_to) |r| try alloc.dupe(u8, r) else null,
-                .payload = try alloc.dupe(u8, msg.payload),
-            } }) catch continue;
-        }
-    }
     if (source_client.connect) |c| {
         if (c.verbose) {
-            source_client.send(io, .@"+ok") catch {};
+            try source_client.send(io, .@"+ok");
         }
     }
 }

src/server/message_parser.zig

@@ -43,7 +43,7 @@ pub const Message = union(MessageType) {
     ping,
     pong,
     @"+ok": void,
-    @"-err": void,
+    @"-err": []const u8,
     pub const ServerInfo = struct {
         /// The unique identifier of the NATS server.
         server_id: []const u8,