default-stats-capture.ts

/**
 * @license
 * Copyright Google LLC All Rights Reserved.
 *
 * Use of this source code is governed by an MIT-style license that can be
 * found in the LICENSE file at https://angular.io/license
 */

import { Observable } from 'rxjs';
import { map, reduce } from 'rxjs/operators';
import { AggregatedProcessStats, Capture, MetricGroup } from './interfaces';
import { cumulativeMovingAverage, max } from './utils';

export const defaultStatsCapture: Capture = (
  stats: Observable<AggregatedProcessStats>,
): Observable<MetricGroup> => {
  type Accumulator = {
    elapsed: number;
    avgProcesses: number;
    peakProcesses: number;
    avgCpu: number;
    peakCpu: number;
    avgMemory: number;
    peakMemory: number;
  };
  const seed: Accumulator = {
    elapsed: 0,
    avgProcesses: 0,
    peakProcesses: 0,
    avgCpu: 0,
    peakCpu: 0,
    avgMemory: 0,
    peakMemory: 0,
  };

  return stats.pipe(
    reduce<AggregatedProcessStats, Accumulator>(
      (acc, val, idx) => ({
        elapsed: val.elapsed,
        avgProcesses: cumulativeMovingAverage(acc.avgProcesses, val.processes, idx),
        peakProcesses: max(acc.peakProcesses, val.processes),
        avgCpu: cumulativeMovingAverage(acc.avgCpu, val.cpu, idx),
        peakCpu: max(acc.peakCpu, val.cpu),
        avgMemory: cumulativeMovingAverage(acc.avgMemory, val.memory, idx),
        peakMemory: max(acc.peakMemory, val.memory),
      }),
      seed,
    ),
    map((metrics) => ({
      name: 'Process Stats',
      metrics: [
        { name: 'Elapsed Time', unit: 'ms', value: metrics.elapsed },
        { name: 'Average Process usage', unit: 'process(es)', value: metrics.avgProcesses },
        { name: 'Peak Process usage', unit: 'process(es)', value: metrics.peakProcesses },
        { name: 'Average CPU usage', unit: '%', value: metrics.avgCpu },
        { name: 'Peak CPU usage', unit: '%', value: metrics.peakCpu },
        { name: 'Average Memory usage', unit: 'MB', value: metrics.avgMemory * 1e-6 },
        { name: 'Peak Memory usage', unit: 'MB', value: metrics.peakMemory * 1e-6 },
      ],
    })),
  );
};