add decode-string.ts

Author: gfx

benchmark/decode-string.ts

@@ -0,0 +1,50 @@
+/* eslint-disable no-console */
+import { utf8Encode, utf8Count, utf8Decode } from "../src/utils/utf8";
+import { utf8DecodeWasm } from "../src/wasmFunctions";
+
+// @ts-ignore
+import Benchmark from "benchmark";
+
+const textDecoder = new TextDecoder();
+
+const dataSet = [10, 100, 200, 1_000, 10_000, 100_000].map((n) => {
+  return "a".repeat(n);
+});
+
+for (const str of dataSet) {
+  const byteLength = utf8Count(str);
+  const bytes = new Uint8Array(new ArrayBuffer(byteLength));
+  utf8Encode(str, bytes, 0);
+
+  console.log(`\n## string length=${str.length} byteLength=${byteLength}\n`);
+
+  const suite = new Benchmark.Suite();
+
+  const N = Math.round(100_0000 / str.length);
+
+  // use the result to avoid void-context optimizations
+  let count = 0;
+
+  suite.add("utf8Decode", () => {
+    if (utf8Decode(bytes, 0, byteLength) !== str) {
+      throw new Error("wrong result!");
+    }
+  });
+
+  suite.add("utf8DecodeWasm", () => {
+    if (utf8DecodeWasm(bytes, 0, byteLength) !== str) {
+      throw new Error("wrong result!");
+    }
+  });
+
+  suite.add("TextDecoder", () => {
+    if (textDecoder.decode(bytes.subarray(0, byteLength)) !== str) {
+      throw new Error("wrong result!");
+    }
+  });
+  suite.on("cycle", (event: any) => {
+    console.log(String(event.target));
+  });
+
+  suite.run();
+}