Multiplayer client relay bridge and match lobby menu: WebSocket bridge, match lobby page, order relay, confirmed turns, checksums, chat, abort/resume

www/dc_plugin.js

@@ -9,6 +9,8 @@
     var httpNext = 1;
     var token = "";          // login session of the savegame service (sent with every request)
     var fetched = { state: 0 }; // download of a file from the server: 0 idle, 1 running, 2 done, 3 failed
+    var ws = {};             // socket id -> { state, queue, sock }
+    var wsNext = 1;
 
     function bytes(ptr, len) {
         return new Uint8Array(wasm_memory.buffer, ptr, len);
@@ -120,6 +122,50 @@
             bytes(ptr, r.body.length).set(r.body);
             delete http[id];
         };
+        // WebSocket for multiplayer matches. state: 0 connecting, 1 open, 2 closed, 3 failed, 4 gone
+        env.dc_ws_connect = function (up, ul) {
+            var url = str(up, ul);
+            if (url.charAt(0) === "/") {
+                var proto = window.location.protocol === "https:" ? "wss://" : "ws://";
+                url = proto + window.location.host + url;
+            }
+            var id = wsNext++;
+            var s = { state: 0, queue: [], sock: null };
+            ws[id] = s;
+            try {
+                s.sock = new WebSocket(url);
+                s.sock.onopen = function () { s.state = 1; };
+                s.sock.onmessage = function (e) {
+                    if (typeof e.data === "string" && s.queue.length < 2000) s.queue.push(e.data);
+                };
+                s.sock.onclose = function () { s.state = 2; };
+                s.sock.onerror = function () { s.state = 3; };
+            } catch (e) {
+                s.state = 3;
+            }
+            return id;
+        };
+        env.dc_ws_state = function (id) {
+            var s = ws[id];
+            return s ? s.state : 4;
+        };
+        env.dc_ws_send = function (id, pp, pl) {
+            var s = ws[id];
+            if (!s || s.state !== 1 || !s.sock) return 0;
+            try { s.sock.send(str(pp, pl)); return 1; } catch (e) { return 0; }
+        };
+        env.dc_ws_take = function (id) {
+            var s = ws[id];
+            if (!s || !s.queue.length) return -1;
+            pending = new TextEncoder().encode(s.queue.shift());
+            return pending.length;
+        };
+        env.dc_ws_close = function (id) {
+            var s = ws[id];
+            if (!s) return;
+            try { if (s.sock) s.sock.close(); } catch (e) { }
+            delete ws[id];
+        };
         env.dc_storage_get = function (kp, kl) {
             var v = null;
             try { v = window.localStorage.getItem(str(kp, kl)); } catch (e) { }