@shopify/react-server/build/cjs/metrics/metrics.js

Utilities for React server-side rendering

'use strict';

Object.defineProperty(exports, '__esModule', { value: true });

var compose = require('koa-compose');

function _interopDefaultLegacy (e) { return e && typeof e === 'object' && 'default' in e ? e : { 'default': e }; }

var compose__default = /*#__PURE__*/_interopDefaultLegacy(compose);

const MILLIS_PER_SECOND = 1000;
const NANOS_PER_MILLIS = 1e6;
const START_TIME_STATE_KEY = Symbol('startTime');
async function startRequestTiming(ctx, next) {
  ctx.state[START_TIME_STATE_KEY] = process.hrtime();
  await next();
}
async function middleware(ctx, next) {
  try {
    await next();
  } finally {
    const [seconds, nanoseconds] = process.hrtime(ctx.state[START_TIME_STATE_KEY]);
    const ms = seconds * MILLIS_PER_SECOND + nanoseconds / NANOS_PER_MILLIS;
    const requestTime = Math.round(ms);
    const uiMetrics = `ui;request_time=${requestTime}`;
    ctx.set('Server-Timing', uiMetrics);
  }
}
const metricsMiddleware = compose__default["default"]([startRequestTiming, middleware]);

exports.metricsMiddleware = metricsMiddleware;