Class CgroupV2Source

src/monitoring.ts:90–176

}

export class CgroupV2Source implements MachineStatsSource {
  public readonly name = 'cgroup-v2';
  protected log = new Logger('hardware');
  protected lastSample: Sample | null = null;
  protected loggedFailure: Set<string> = new Set();

  protected now: () => number;
  protected readFile: ReadFileFn;

  constructor(opts: CgroupSourceOpts = {}) {
    this.now = opts.now ?? Date.now;
    this.readFile = opts.readFile ?? defaultReadFile;
  }

  public async read(): Promise<IResourceLoad> {
    const [cpu, memory] = await Promise.all([
      this.readCpu(),
      this.readMemory(),
    ]);
    return { cpu, memory };
  }

  protected async readCpu(): Promise<number | null> {
    let usageContent: string;
    let maxContent: string;
    try {
      [usageContent, maxContent] = await Promise.all([
        readWithTimeout('/sys/fs/cgroup/cpu.stat', this.readFile),
        readWithTimeout('/sys/fs/cgroup/cpu.max', this.readFile),
      ]);
    } catch (err) {
      this.logOnce('cpu-read', err);
      return null;
    }

    const usageUsec = parseCpuStatUsageUsec(usageContent);
    const cores = parseCpuMax(maxContent);
    if (usageUsec === null || cores === null || cores <= 0) {
      this.logOnce('cpu-parse', new Error('cgroup v2 cpu parse failed'));
      return null;
    }

    const timestamp = this.now();
    const previous = this.lastSample;
    this.lastSample = { timestamp, usageUsec };

    if (!previous) return null;

    const dWallMs = timestamp - previous.timestamp;
    if (dWallMs <= 0) return null;
    const dUsageUsec = usageUsec - previous.usageUsec;
    if (dUsageUsec < 0) return null;

    return dUsageUsec / (dWallMs * cores * 1000);
  }

  protected async readMemory(): Promise<number | null> {
    let currentContent: string;