Function detectMachineStatsSource

src/monitoring.ts:335–357

(
  preference: 'auto' | 'host' | 'cgroup',
  fileExists: FileExists = defaultFileExists,
)

];

export function detectMachineStatsSource(
  preference: 'auto' | 'host' | 'cgroup',
  fileExists: FileExists = defaultFileExists,
): MachineStatsSource {
  if (preference === 'host') return new HostSource();

  const hasAll = (paths: string[]) => paths.every((p) => fileExists(p));
  const hasV2 = hasAll(CGROUP_V2_REQUIRED);
  const hasV1 = !hasV2 && hasAll(CGROUP_V1_REQUIRED);

  if (preference === 'cgroup') {
    if (hasV2) return new CgroupV2Source();
    if (hasV1) return new CgroupV1Source();
    throw new Error(
      'MACHINE_STATS_SOURCE=cgroup but required cgroup stat files are missing.',
    );
  }

  // 'auto'
  if (hasV2) return new CgroupV2Source();
  if (hasV1) return new CgroupV1Source();
  return new HostSource();
}

export class Monitoring extends EventEmitter {
  protected log = new Logger('hardware');