chrome/browser/metrics/drive_metrics_provider.h

   1 // Copyright 2015 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 CHROME_BROWSER_METRICS_DRIVE_METRICS_PROVIDER_H_
   6 #define CHROME_BROWSER_METRICS_DRIVE_METRICS_PROVIDER_H_
   7
   8 #include "base/callback.h"
   9 #include "base/gtest_prod_util.h"
  10 #include "base/macros.h"
  11 #include "base/memory/weak_ptr.h"
  12 #include "base/threading/thread_checker.h"
  13 #include "components/metrics/metrics_provider.h"
  14 #include "components/metrics/proto/system_profile.pb.h"
  15
  16 namespace base {
  17 class FilePath;
  18 }
  19
  20 // Provides metrics about the local drives on a user's computer. Currently only
  21 // checks to see if they incur a seek-time penalty (e.g. if they're SSDs).
  22 //
  23 // Defers gathering metrics until after "rush hour" (startup) so as to not bog
  24 // down the FILE thread.
  25 class DriveMetricsProvider : public metrics::MetricsProvider {
  26  public:
  27   DriveMetricsProvider();
  28   ~DriveMetricsProvider() override;
  29
  30   // metrics::MetricsDataProvider:
  31   void ProvideSystemProfileMetrics(
  32       metrics::SystemProfileProto* system_profile_proto) override;
  33
  34   // Called by ChromeMetricsServiceClient to start gathering metrics.
  35   void GetDriveMetrics(const base::Closure& done);
  36
  37  private:
  38   FRIEND_TEST_ALL_PREFIXES(DriveMetricsProviderTest, HasSeekPenalty);
  39
  40   // A response to querying a drive as to whether it incurs a seek penalty.
  41   // |has_seek_penalty| is set if |success| is true.
  42   struct SeekPenaltyResponse {
  43     SeekPenaltyResponse();
  44     bool success;
  45     bool has_seek_penalty;
  46   };
  47
  48   struct DriveMetrics {
  49     SeekPenaltyResponse app_drive;
  50     SeekPenaltyResponse user_data_drive;
  51   };
  52
  53   // Determine whether the device that services |path| has a seek penalty.
  54   // Returns false if it couldn't be determined (e.g., |path| doesn't exist).
  55   static bool HasSeekPenalty(const base::FilePath& path,
  56                              bool* has_seek_penalty);
  57
  58   // Gather metrics about various drives on the FILE thread.
  59   static DriveMetrics GetDriveMetricsOnFileThread();
  60
  61   // Tries to determine whether there is a penalty for seeking on the drive that
  62   // hosts |path_service_key| (for example: the drive that holds "Local State").
  63   static void QuerySeekPenalty(int path_service_key,
  64                                SeekPenaltyResponse* response);
  65
  66   // Called when metrics are done being gathered from the FILE thread.
  67   void GotDriveMetrics(const DriveMetrics& metrics);
  68
  69   // Fills |drive| with information from successful |response|s.
  70   void FillDriveMetrics(
  71       const SeekPenaltyResponse& response,
  72       metrics::SystemProfileProto::Hardware::Drive* drive);
  73
  74   // Information gathered about various important drives.
  75   DriveMetrics metrics_;
  76
  77   // Called when metrics are done being collected.
  78   base::Closure got_metrics_callback_;
  79
  80   base::ThreadChecker thread_checker_;
  81   base::WeakPtrFactory<DriveMetricsProvider> weak_ptr_factory_;
  82
  83   DISALLOW_COPY_AND_ASSIGN(DriveMetricsProvider);
  84 };
  85
  86 #endif  // CHROME_BROWSER_METRICS_DRIVE_METRICS_PROVIDER_H_