chrome/browser/prerender/prerender_histograms.h

   1 // Copyright (c) 2012 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_PRERENDER_PRERENDER_HISTOGRAMS_H_
   6 #define CHROME_BROWSER_PRERENDER_PRERENDER_HISTOGRAMS_H_
   7
   8 #include <string>
   9
  10 #include "base/time/time.h"
  11 #include "chrome/browser/prerender/prerender_contents.h"
  12 #include "chrome/browser/prerender/prerender_events.h"
  13 #include "chrome/browser/prerender/prerender_final_status.h"
  14 #include "chrome/browser/prerender/prerender_local_predictor.h"
  15 #include "chrome/browser/prerender/prerender_origin.h"
  16 #include "url/gurl.h"
  17
  18 namespace prerender {
  19
  20 // PrerenderHistograms is responsible for recording all prerender specific
  21 // histograms for PrerenderManager.  It keeps track of the type of prerender
  22 // currently underway (based on the PrerenderOrigin of the most recent
  23 // prerenders, and any experiments detected).
  24 // PrerenderHistograms does not necessarily record all histograms related to
  25 // prerendering, only the ones in the context of PrerenderManager.
  26 class PrerenderHistograms {
  27  public:
  28   // Owned by a PrerenderManager object for the lifetime of the
  29   // PrerenderManager.
  30   PrerenderHistograms();
  31
  32   // Records the perceived page load time for a page - effectively the time from
  33   // when the user navigates to a page to when it finishes loading.  The actual
  34   // load may have started prior to navigation due to prerender hints.
  35   void RecordPerceivedPageLoadTime(Origin origin,
  36                                    base::TimeDelta perceived_page_load_time,
  37                                    bool was_prerender,
  38                                    bool was_complete_prerender,
  39                                    const GURL& url);
  40
  41   // Records, in a histogram, the percentage of the page load time that had
  42   // elapsed by the time it is swapped in.  Values outside of [0, 1.0] are
  43   // invalid and ignored.
  44   void RecordPercentLoadDoneAtSwapin(Origin origin, double fraction) const;
  45
  46   // Records the actual pageload time of a prerender that has not been swapped
  47   // in yet, but finished loading.
  48   void RecordPageLoadTimeNotSwappedIn(Origin origin,
  49                                       base::TimeDelta page_load_time,
  50                                       const GURL& url) const;
  51
  52   // Records the time from when a page starts prerendering to when the user
  53   // navigates to it. This must be called on the UI thread.
  54   void RecordTimeUntilUsed(Origin origin,
  55                            base::TimeDelta time_until_used) const;
  56
  57   // Record a PerSessionCount data point.
  58   void RecordPerSessionCount(Origin origin, int count) const;
  59
  60   // Record time between two prerender requests.
  61   void RecordTimeBetweenPrerenderRequests(Origin origin,
  62                                           base::TimeDelta time) const;
  63
  64   // Record a final status of a prerendered page in a histogram.
  65   void RecordFinalStatus(Origin origin,
  66                          uint8 experiment_id,
  67                          PrerenderContents::MatchCompleteStatus mc_status,
  68                          FinalStatus final_status) const;
  69
  70   // To be called when a new prerender is added.
  71   void RecordPrerender(Origin origin, const GURL& url);
  72
  73   // To be called when a new prerender is started.
  74   void RecordPrerenderStarted(Origin origin) const;
  75
  76   // To be called when we know how many prerenders are running after starting
  77   // a prerender.
  78   void RecordConcurrency(size_t prerender_count) const;
  79
  80   // Called when we swap in a prerender.
  81   void RecordUsedPrerender(Origin origin) const;
  82
  83   // Record the time since a page was recently visited.
  84   void RecordTimeSinceLastRecentVisit(Origin origin,
  85                                       base::TimeDelta time) const;
  86
  87   // Records a prerender event.
  88   void RecordEvent(Origin origin, uint8 experiment_id, PrerenderEvent event)
  89       const;
  90
  91   // Record a prerender cookie status bitmap. Must be in the range
  92   // [0, PrerenderContents::kNumCookieStatuses).
  93   void RecordCookieStatus(Origin origin,
  94                           uint8 experiment_id,
  95                           int cookie_status) const;
  96
  97  private:
  98   base::TimeTicks GetCurrentTimeTicks() const;
  99
 100   // Returns the time elapsed since the last prerender happened.
 101   base::TimeDelta GetTimeSinceLastPrerender() const;
 102
 103   // Returns whether the PrerenderManager is currently within the prerender
 104   // window - effectively, up to 30 seconds after a prerender tag has been
 105   // observed.
 106   bool WithinWindow() const;
 107
 108   // Returns the current experiment.
 109   uint8 GetCurrentExperimentId() const;
 110
 111   // Returns whether or not there is currently an origin/experiment wash.
 112   bool IsOriginExperimentWash() const;
 113
 114   // An integer indicating a Prerendering Experiment being currently conducted.
 115   // (The last experiment ID seen).
 116   uint8 last_experiment_id_;
 117
 118   // Origin of the last prerender seen.
 119   Origin last_origin_;
 120
 121   // A boolean indicating that we have recently encountered a combination of
 122   // different experiments and origins, making an attribution of PPLT's to
 123   // experiments / origins impossible.
 124   bool origin_experiment_wash_;
 125
 126   // The time when we last saw a prerender request coming from a renderer.
 127   // This is used to record perceived PLT's for a certain amount of time
 128   // from the point that we last saw a <link rel=prerender> tag.
 129   base::TimeTicks last_prerender_seen_time_;
 130
 131   // Indicates whether we have recorded page load events after the most
 132   // recent prerender.  These must be initialized to true, so that we don't
 133   // start recording events before the first prerender occurs.
 134   bool seen_any_pageload_;
 135   bool seen_pageload_started_after_prerender_;
 136
 137   DISALLOW_COPY_AND_ASSIGN(PrerenderHistograms);
 138 };
 139
 140 }  // namespace prerender
 141
 142 #endif  // CHROME_BROWSER_PRERENDER_PRERENDER_HISTOGRAMS_H_