benchmark: add bytes variant to webstreams async-iterator

Author: mcollina

benchmark/webstreams/readable-async-iterator.js

@@ -6,23 +6,40 @@ const {
 
 const bench = common.createBenchmark(main, {
   n: [1e5],
+  type: ['normal', 'bytes'],
 });
 
 
-async function main({ n }) {
-  const rs = new ReadableStream({
-    pull: function(controller) {
-      controller.enqueue(1);
-    },
-  });
+async function main({ n, type }) {
+  const rs = type === 'bytes' ?
+    new ReadableStream({
+      type: 'bytes',
+      pull: function(controller) {
+        controller.enqueue(new Uint8Array(1));
+      },
+    }) :
+    new ReadableStream({
+      pull: function(controller) {
+        controller.enqueue(1);
+      },
+    });
 
   let x = 0;
 
   bench.start();
-  for await (const chunk of rs) {
-    x += chunk;
-    if (x > n) {
-      break;
+  if (type === 'bytes') {
+    for await (const chunk of rs) {
+      x += chunk.byteLength;
+      if (x > n) {
+        break;
+      }
+    }
+  } else {
+    for await (const chunk of rs) {
+      x += chunk;
+      if (x > n) {
+        break;
+      }
     }
   }
   // Use x to ensure V8 does not optimize away the loop as a noop.