components/metrics/machine_id_provider.h

   1 // Copyright 2014 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #ifndef COMPONENTS_METRICS_MACHINE_ID_PROVIDER_H_
   6 #define COMPONENTS_METRICS_MACHINE_ID_PROVIDER_H_
   7
   8 #include <string>
   9
  10 #include "base/macros.h"
  11 #include "base/memory/ref_counted.h"
  12
  13 namespace metrics {
  14
  15 // Provides machine characteristics used as a machine id. The implementation is
  16 // platform specific with a default implementation that gives an empty id. The
  17 // class is ref-counted thread safe so it can be used to post to the FILE thread
  18 // and communicate back to the UI thread.
  19 // This raw machine id should not be stored or transmitted over the network.
  20 // TODO(jwd): Simplify implementation to get rid of the need for
  21 // RefCountedThreadSafe (crbug.com/354882).
  22 class MachineIdProvider : public base::RefCountedThreadSafe<MachineIdProvider> {
  23  public:
  24   // Get a string containing machine characteristics, to be used as a machine
  25   // id. The implementation is platform specific, with a default implementation
  26   // returning an empty string.
  27   // The return value should not be stored to disk or transmitted.
  28   std::string GetMachineId();
  29
  30   // Returns a pointer to a new MachineIdProvider or NULL if there is no
  31   // provider implemented on a given platform. This is done to avoid posting a
  32   // task to the FILE thread on platforms with no implementation.
  33   static MachineIdProvider* CreateInstance();
  34
  35  private:
  36   friend class base::RefCountedThreadSafe<MachineIdProvider>;
  37
  38   MachineIdProvider();
  39   virtual ~MachineIdProvider();
  40
  41   DISALLOW_COPY_AND_ASSIGN(MachineIdProvider);
  42 };
  43
  44 }  //  namespace metrics
  45
  46 #endif  // COMPONENTS_METRICS_MACHINE_ID_PROVIDER_H_