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