feat(runtime/worker): Structured cloning worker message passing (#9323)

This commit upgrade "Worker.postMessage()" implementation to use 
structured clone algorithm instead of non-spec compliant JSON serialization.

2 files changed, 81 insertions, 124 deletions

diff --git a/runtime/js/11_workers.js b/runtime/js/11_workers.js
index 508dd46d4..dca83c818 100644
--- a/runtime/js/11_workers.js
+++ b/runtime/js/11_workers.js
@@ -39,26 +39,8 @@
     return core.opAsync("op_host_get_message", id);
   }
 
-  const encoder = new TextEncoder();
   const decoder = new TextDecoder();
 
-  function encodeMessage(data) {
-    const dataJson = JSON.stringify(data);
-    return encoder.encode(dataJson);
-  }
-
-  function decodeMessage(dataIntArray) {
-    // Temporary solution until structured clone arrives in v8.
-    // Current clone is made by parsing json to byte array and from byte array back to json.
-    // In that case "undefined" transforms to empty byte array, but empty byte array does not transform back to undefined.
-    // Thats why this special is statement is needed.
-    if (dataIntArray.length == 0) {
-      return undefined;
-    }
-    const dataJson = decoder.decode(dataIntArray);
-    return JSON.parse(dataJson);
-  }
-
   /**
    * @param {string} permission
    * @return {boolean}
@@ -211,18 +193,7 @@
       this.#poll();
     }
 
-    #handleMessage = (msgData) => {
-      let data;
-      try {
-        data = decodeMessage(new Uint8Array(msgData));
-      } catch (e) {
-        const msgErrorEvent = new MessageEvent("messageerror", {
-          cancelable: false,
-          data,
-        });
-        return;
-      }
-
+    #handleMessage = (data) => {
       const msgEvent = new MessageEvent("message", {
         cancelable: false,
         data,
@@ -253,56 +224,44 @@
 
     #poll = async () => {
       while (!this.#terminated) {
-        const event = await hostGetMessage(this.#id);
+        const [type, data] = await hostGetMessage(this.#id);
 
         // If terminate was called then we ignore all messages
         if (this.#terminated) {
           return;
         }
 
-        const type = event.type;
-
-        if (type === "terminalError") {
-          this.#terminated = true;
-          if (!this.#handleError(event.error)) {
-            if (globalThis instanceof Window) {
-              throw new Error("Unhandled error event reached main worker.");
-            } else {
-              core.opSync(
-                "op_host_unhandled_error",
-                event.error.message,
-              );
-            }
+        switch (type) {
+          case 0: { // Message
+            const msg = core.deserialize(data);
+            this.#handleMessage(msg);
+            break;
           }
-          continue;
-        }
-
-        if (type === "msg") {
-          this.#handleMessage(event.data);
-          continue;
-        }
-
-        if (type === "error") {
-          if (!this.#handleError(event.error)) {
-            if (globalThis instanceof Window) {
-              throw new Error("Unhandled error event reached main worker.");
-            } else {
-              core.opSync(
-                "op_host_unhandled_error",
-                event.error.message,
-              );
+          case 1: { // TerminalError
+            this.#terminated = true;
+          } /* falls through */
+          case 2: { // Error
+            if (!this.#handleError(data)) {
+              if (globalThis instanceof Window) {
+                throw new Error("Unhandled error event reached main worker.");
+              } else {
+                core.opSync(
+                  "op_worker_unhandled_error",
+                  data.message,
+                );
+              }
             }
+            break;
+          }
+          case 3: { // Close
+            log(`Host got "close" message from worker: ${this.#name}`);
+            this.#terminated = true;
+            return;
+          }
+          default: {
+            throw new Error(`Unknown worker event: "${type}"`);
           }
-          continue;
-        }
-
-        if (type === "close") {
-          log(`Host got "close" message from worker: ${this.#name}`);
-          this.#terminated = true;
-          return;
         }
-
-        throw new Error(`Unknown worker event: "${type}"`);
       }
     };
 
@@ -317,7 +276,8 @@
         return;
       }
 
-      hostPostMessage(this.#id, encodeMessage(message));
+      const bufferMsg = core.serialize(message);
+      hostPostMessage(this.#id, bufferMsg);
     }
 
     terminate() {
diff --git a/runtime/js/99_main.js b/runtime/js/99_main.js
index d2926bb1f..082c83593 100644
--- a/runtime/js/99_main.js
+++ b/runtime/js/99_main.js
@@ -67,7 +67,7 @@ delete Object.prototype.__proto__;
     }
 
     isClosing = true;
-    opCloseWorker();
+    core.opSync("op_worker_close");
   }
 
   // TODO(bartlomieju): remove these functions
@@ -76,68 +76,64 @@ delete Object.prototype.__proto__;
   const onerror = () => {};
 
   function postMessage(data) {
-    const dataJson = JSON.stringify(data);
-    const dataIntArray = encoder.encode(dataJson);
-    opPostMessage(dataIntArray);
+    const dataIntArray = core.serialize(data);
+    core.opSync("op_worker_post_message", null, dataIntArray);
   }
 
   let isClosing = false;
-  async function workerMessageRecvCallback(data) {
-    const msgEvent = new MessageEvent("message", {
-      cancelable: false,
-      data,
-    });
-
-    try {
-      if (globalThis["onmessage"]) {
-        const result = globalThis.onmessage(msgEvent);
-        if (result && "then" in result) {
-          await result;
-        }
-      }
-      globalThis.dispatchEvent(msgEvent);
-    } catch (e) {
-      let handled = false;
-
-      const errorEvent = new ErrorEvent("error", {
-        cancelable: true,
-        message: e.message,
-        lineno: e.lineNumber ? e.lineNumber + 1 : undefined,
-        colno: e.columnNumber ? e.columnNumber + 1 : undefined,
-        filename: e.fileName,
-        error: null,
+  async function pollForMessages() {
+    while (!isClosing) {
+      const bufferMsg = await core.opAsync("op_worker_get_message");
+      const data = core.deserialize(bufferMsg);
+
+      const msgEvent = new MessageEvent("message", {
+        cancelable: false,
+        data,
       });
 
-      if (globalThis["onerror"]) {
-        const ret = globalThis.onerror(
-          e.message,
-          e.fileName,
-          e.lineNumber,
-          e.columnNumber,
-          e,
-        );
-        handled = ret === true;
-      }
+      try {
+        if (globalThis.onmessage) {
+          await globalThis.onmessage(msgEvent);
+        }
+        globalThis.dispatchEvent(msgEvent);
+      } catch (e) {
+        let handled = false;
+
+        const errorEvent = new ErrorEvent("error", {
+          cancelable: true,
+          message: e.message,
+          lineno: e.lineNumber ? e.lineNumber + 1 : undefined,
+          colno: e.columnNumber ? e.columnNumber + 1 : undefined,
+          filename: e.fileName,
+          error: null,
+        });
+
+        if (globalThis["onerror"]) {
+          const ret = globalThis.onerror(
+            e.message,
+            e.fileName,
+            e.lineNumber,
+            e.columnNumber,
+            e,
+          );
+          handled = ret === true;
+        }
 
-      globalThis.dispatchEvent(errorEvent);
-      if (errorEvent.defaultPrevented) {
-        handled = true;
-      }
+        globalThis.dispatchEvent(errorEvent);
+        if (errorEvent.defaultPrevented) {
+          handled = true;
+        }
 
-      if (!handled) {
-        throw e;
+        if (!handled) {
+          core.opSync(
+            "op_worker_unhandled_error",
+            e.message,
+          );
+        }
       }
     }
   }
 
-  function opPostMessage(data) {
-    core.opSync("op_worker_post_message", null, data);
-  }
-
-  function opCloseWorker() {
-    core.opSync("op_worker_close");
-  }
-
   function opMainModule() {
     return core.opSync("op_main_module");
   }
@@ -395,7 +391,6 @@ delete Object.prototype.__proto__;
     // TODO(bartlomieju): should be readonly?
     close: util.nonEnumerable(workerClose),
     postMessage: util.writable(postMessage),
-    workerMessageRecvCallback: util.nonEnumerable(workerMessageRecvCallback),
   };
 
   let hasBootstrapped = false;
@@ -506,6 +501,8 @@ delete Object.prototype.__proto__;
     location.setLocationHref(locationHref);
     registerErrors();
 
+    pollForMessages();
+
     const internalSymbol = Symbol("Deno.internal");
 
     const finalDenoNs = {