components/metrics/machine_id_provider.h

// Copyright 2014 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef COMPONENTS_METRICS_MACHINE_ID_PROVIDER_H_
#define COMPONENTS_METRICS_MACHINE_ID_PROVIDER_H_

#include <string>

namespace metrics {

// Provides machine characteristics used as a machine id. The implementation is
// platform specific. GetMachineId() must be called on a thread which allows
// I/O. GetMachineId() must not be called if HasId() returns false on this
// platform.
class MachineIdProvider {
 public:
  MachineIdProvider();
  MachineIdProvider(const MachineIdProvider&) = delete;
  MachineIdProvider& operator=(const MachineIdProvider&) = delete;
  virtual ~MachineIdProvider();

  // Returns true if this platform provides a non-empty GetMachineId(). This is
  // useful to avoid an async call to GetMachineId() on platforms with no
  // implementation.
  virtual bool HasId() const;

  // Get a string containing machine characteristics, to be used as a machine
  // id. The implementation is split into Windows and non-Windows. The former
  // returns the drive serial number and the latter returns the hardware
  // model name. Should not be called if HasId() returns false.
  // The return value should not be stored to disk or transmitted.
  virtual std::string GetMachineId() const;
};

}  //  namespace metrics

#endif  // COMPONENTS_METRICS_MACHINE_ID_PROVIDER_H_