benchmark: add text-encoder benchmark

benchmark/util/text-encoder.js

@@ -0,0 +1,32 @@
+'use strict';
+
+const common = require('../common.js');
+
+const BASE = 'string\ud801';
+
+const bench = common.createBenchmark(main, {
+  len: [256, 1024, 1024 * 32],
+  n: [1e4],
+  op: ['encode', 'encodeInto']
+});
+
+function main({ n, op, len }) {
+  const encoder = new TextEncoder();
+  const input = BASE.repeat(len);
+  const subarray = new Uint8Array(len);
+
+  bench.start();
+  switch (op) {
+    case 'encode': {
+      for (let i = 0; i < n; i++)
+        encoder.encode(input);
+      break;
+    }
+    case 'encodeInto': {
+      for (let i = 0; i < n; i++)
+        encoder.encodeInto(input, subarray);
+      break;
+    }
+  }
+  bench.end(n);
+}