Run results for: Reselect defaultMemoize

Run details:

User agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/70.0.3538.110 Safari/537.36

Browser: Chrome 70

Operating system: Windows

Device Platform: Desktop

Date tested: 5 years ago

Test name	Executions per second
Original defaultMemoize	62.4 Ops/sec
Optimized defaultMemoize	73.4 Ops/sec
No memoization	99.9 Ops/sec

Script Preparation code:

function defaultEqualityCheck(a, b) {
  return a === b
}

function defaultMemoize_original(func, equalityCheck = defaultEqualityCheck) {
  let lastArgs = null
  let lastResult = null
  return (...args) => {
    if (
      lastArgs === null ||
      lastArgs.length !== args.length ||
      !args.every((value, index) => equalityCheck(value, lastArgs[index]))
    ) {
      lastResult = func(...args)
    }
    lastArgs = args
    return lastResult
  }
}

function defaultMemoize_optimized(func, equalityCheck = defaultEqualityCheck) {
  const isEqual = (value, index) => equalityCheck(value, lastArgs[index])
  let lastArgs = null
  let lastResult = null
  return (...args) => {
    if (
      lastArgs === null ||
      lastArgs.length !== args.length ||
      !args.every(isEqual)
    ) {
      lastResult = func(...args)
    }
    lastArgs = args
    return lastResult
  }
}

function combine(a, b) {
  return { combined: a + b };
}

var combine_original = defaultMemoize_original(combine);
var combine_optimized = defaultMemoize_optimized(combine);

var NUM_REPEAT = 50000;

Tests:

Original defaultMemoize
let result1 = 0; for (let i = 0; i < NUM_REPEAT; ++i) result1 += combine_original(1, 2).combined;
Optimized defaultMemoize
let result2 = 0; for (let i = 0; i < NUM_REPEAT; ++i) result2 += combine_optimized(1, 2).combined;
No memoization
let result3 = 0; for (let i = 0; i < NUM_REPEAT; ++i) result3 += combine(1, 2).combined;

Run results for: Reselect defaultMemoize

Original defaultMemoize

Optimized defaultMemoize

No memoization