bench-async-counter.js

// Copyright 2013-2018 Benedikt Meurer
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     <https://www.apache.org/licenses/LICENSE-2.0>
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

async function* fibonacciSequence() {
  for (let a = 0, b = 1;; ) {
    yield a;
    const c = a + b;
    a = b;
    b = c;
  }
}

async function fibonacci(n) {
  for await (const x of fibonacciSequence()) {
    if (n-- === 0) return x;
  }
}

(async() => {
  // Warmup.
  for (let i = 0; i < 100; ++i) {
    await fibonacci(10);
  }

  const start = Date.now();
  for (let i = 0; i < 1e5; ++i) {
    await fibonacci(10);
  }
  const time = Date.now() - start;
  console.log(`${time} ms.`);
})();