msg: fix len for msg.Buffer and encode msg size as binary header

Signed-off-by: Francis Bouvier <francis@lightpanda.io>

src/handler.zig

@@ -19,6 +19,7 @@
 const std = @import("std");
 
 const ws = @import("websocket");
+const Msg = @import("msg.zig").Msg;
 
 const log = std.log.scoped(.handler);
 
@@ -45,7 +46,7 @@ pub const Stream = struct {
     }
 
     fn closeCDP(self: *const Stream) void {
-        const close_msg: []const u8 = "5:close";
+        const close_msg: []const u8 = .{ 5, 0 } ++ "close";
         self.recv(close_msg) catch |err| {
             log.err("stream close error: {any}", .{err});
         };
@@ -82,8 +83,10 @@ pub const Handler = struct {
         self.stream.closeCDP();
     }
 
-    pub fn clientMessage(self: *Handler, alloc: std.mem.Allocator, data: []const u8) !void {
-        const msg = try std.fmt.allocPrint(alloc, "{d}:{s}", .{ data.len, data });
-        try self.stream.recv(msg);
+    pub fn clientMessage(self: *Handler, data: []const u8) !void {
+        var header: [2]u8 = undefined;
+        Msg.setSize(data.len, &header);
+        try self.stream.recv(&header);
+        try self.stream.recv(data);
     }
 };