chrome-devtools-frontend/front_end/panels/common/ThrottlingUtils.ts

Chrome DevTools UI

// Copyright 2026 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

import * as SDK from '../../core/sdk/sdk.js';
import * as CrUXManager from '../../models/crux-manager/crux-manager.js';

export interface ThrottlingRecommendations {
  cpuOption: SDK.CPUThrottlingManager.CPUThrottlingOption|null;
  networkConditions: SDK.NetworkManager.Conditions|null;
}

/**
 * Computes the recommended CPU and network throttling presets based on CrUX
 * field metric data.
 */
export function getThrottlingRecommendations(): ThrottlingRecommendations {
  const cruxManager = CrUXManager.CrUXManager.instance();
  const roundTripTimeMetricData = cruxManager.getSelectedFieldMetricData('round_trip_time');

  let cpuOption: SDK.CPUThrottlingManager.CPUThrottlingOption =
      SDK.CPUThrottlingManager.CalibratedMidTierMobileThrottlingOption;
  if (cpuOption.rate() === 0) {
    cpuOption = SDK.CPUThrottlingManager.MidTierThrottlingOption;
  }

  const networkConditions = getRecommendedNetworkConditions(roundTripTimeMetricData);

  return {
    cpuOption,
    networkConditions,
  };
}

/**
 * Computes the recommended network throttling preset based on CrUX RTT field
 * metric data. Returns null if no RTT data is available or no preset matches.
 */
export function getRecommendedNetworkConditions(roundTripTimeMetricData?: CrUXManager.MetricResponse):
    SDK.NetworkManager.Conditions|null {
  if (roundTripTimeMetricData?.percentiles) {
    const rtt = Number(roundTripTimeMetricData.percentiles.p75);
    return SDK.NetworkManager.getRecommendedNetworkPreset(rtt);
  }
  return null;
}