nstdlib-nightly/lib/internal/perf/utils.mjs

Node.js standard library converted to runtime-agnostic ES modules.

// Source: https://github.com/nodejs/node/blob/65eff1eb/lib/internal/perf/utils.js

import {
  constants as __constants__,
  milestones,
  now,
} from "nstdlib/stub/binding/performance";

const {
  NODE_PERFORMANCE_MILESTONE_TIME_ORIGIN,
  NODE_PERFORMANCE_MILESTONE_TIME_ORIGIN_TIMESTAMP,
} = __constants__;

function getTimeOrigin() {
  // Do not cache this to prevent it from being serialized into the
  // snapshot.
  return milestones[NODE_PERFORMANCE_MILESTONE_TIME_ORIGIN] / 1e6;
}

// Returns the milestone relative to the process start time in milliseconds.
function getMilestoneTimestamp(milestoneIdx) {
  const ns = milestones[milestoneIdx];
  if (ns === -1) return ns;
  return ns / 1e6 - getTimeOrigin();
}

function getTimeOriginTimestamp() {
  return milestones[NODE_PERFORMANCE_MILESTONE_TIME_ORIGIN_TIMESTAMP] / 1e3;
}

export { now };
export { getMilestoneTimestamp };
export { getTimeOriginTimestamp };