benchmark: add a benchmark for read() of ReadableStreams

benchmark/webstreams/readable-read.js

@@ -0,0 +1,49 @@
+'use strict';
+const common = require('../common.js');
+const { ReadableStream } = require('node:stream/web');
+
+const bench = common.createBenchmark(main, {
+  n: [1e5],
+  type: ['normal', 'byob'],
+});
+
+async function main({ n, type }) {
+  switch (type) {
+    case 'normal': {
+      const rs = new ReadableStream({
+        pull: function(controller) {
+          controller.enqueue('a');
+        },
+      });
+      const reader = rs.getReader();
+      let x = null;
+      bench.start();
+      for (let i = 0; i < n; i++) {
+        const { value } = await reader.read();
+        x = value;
+      }
+      bench.end(n);
+      console.assert(x);
+      break;
+    }
+    case 'byob': {
+      const encode = new TextEncoder();
+      const rs = new ReadableStream({
+        type: 'bytes',
+        pull: function(controller) {
+          controller.enqueue(encode.encode('a'));
+        },
+      });
+      const reader = rs.getReader({ mode: 'byob' });
+      let x = null;
+      bench.start();
+      for (let i = 0; i < n; i++) {
+        const { value } = await reader.read(new Uint8Array(1));
+        x = value;
+      }
+      bench.end(n);
+      console.assert(x);
+      break;
+    }
+  }
+}