import * as Logging from "~/common/logging";

// Source
// https://github.com/Data-Wrangling-with-JavaScript/nodejs-memory-test/blob/master/index.js
// Small program to test the maximum amount of allocations in multiple blocks.
// This script searches for the largest allocation amount.
//

//
// Allocate a certain size to test if it can be done.
//
function alloc(size) {
  const numbers = size / 8;
  const arr = [];
  arr.length = numbers; // Simulate allocation of 'size' bytes.
  for (let i = 0; i < numbers; i++) {
    arr[i] = i;
  }
  return arr;
}

//
// Keep allocations referenced so they aren't garbage collected.
//
const allocations = [];

//
// Allocate successively larger sizes, doubling each time until we hit the limit.
//
function allocToMax() {
  Logging.log("[ starting memory burn  ]");

  const field = "heapUsed";
  const mu = process.memoryUsage();
  Logging.log(mu);
  const gbStart = mu[field] / 1024 / 1024 / 1024;
  Logging.log(`[ memory burn           ] ${Math.round(gbStart * 100) / 100} GB`);

  let allocationStep = 100 * 1024;

  while (true) {
    // Allocate memory.
    const allocation = alloc(allocationStep);

    // Allocate and keep a reference so the allocated memory isn't garbage collected.
    allocations.push(allocation);

    // Check how much memory is now allocated.
    const mu = process.memoryUsage();
    const mbNow = mu[field] / 1024 / 1024 / 1024;
    //Logging.log(`Total allocated       ${Math.round(mbNow * 100) / 100} GB`);
    Logging.log(`[ allocated since start ] ${Math.round((mbNow - gbStart) * 100) / 100} GB`);

    // Infinite loop, never get here.
  }

  // Infinite loop, never get here.
}

allocToMax();