Move prerender histograms out of prerender manager.

Add a separate histogram label for GWS based prerendering.
R=cbentzel@chromium.org, dominich@chromium.org
Review URL: http://codereview.chromium.org/7605020

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@96227 0039d316-1c4b-4281-b951-d872f2087c98

chrome/browser/prerender/prerender_histograms.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/prerender/prerender_histograms.h"
+
+#include <string>
+
+#include "base/metrics/field_trial.h"
+#include "base/metrics/histogram.h"
+#include "chrome/browser/prerender/prerender_util.h"
+
+namespace prerender {
+
+namespace {
+
+// Time window for which we will record windowed PLT's from the last
+// observed link rel=prefetch tag.
+const int kWindowDurationSeconds = 30;
+
+std::string ComposeHistogramName(const std::string& prefix_type,
+                                 const std::string& name) {
+  if (prefix_type.empty())
+    return std::string("Prerender.") + name;
+  return std::string("Prerender.") + prefix_type + std::string("_") + name;
+}
+
+std::string GetHistogramName(Origin origin, uint8 experiment_id,
+                             const std::string& name) {
+  switch (origin) {
+    case ORIGIN_OMNIBOX:
+      if (experiment_id != kNoExperiment)
+        return ComposeHistogramName("wash", name);
+      return ComposeHistogramName("omnibox", name);
+    case ORIGIN_LINK_REL_PRERENDER:
+      if (experiment_id != kNoExperiment)
+        return ComposeHistogramName("wash", name);
+      return ComposeHistogramName("", name);
+    case ORIGIN_GWS_PRERENDER:
+      if (experiment_id == kNoExperiment)
+        return ComposeHistogramName("gws", name);
+      return ComposeHistogramName("exp" + std::string(1, experiment_id + '0'),
+                                  name);
+    default:
+      NOTREACHED();
+      break;
+  };
+
+  // Dummy return value to make the compiler happy.
+  NOTREACHED();
+  return ComposeHistogramName("wash", name);
+}
+
+}  // namespace
+
+// Helper macros for experiment-based and origin-based histogram reporting.
+#define PREFIXED_HISTOGRAM(histogram) \
+  PREFIXED_HISTOGRAM_INTERNAL(GetCurrentOrigin(), GetCurrentExperimentId(), \
+                              IsOriginExperimentWash(), histogram)
+
+#define PREFIXED_HISTOGRAM_ORIGIN_EXPERIMENT(origin, experiment, histogram) \
+  PREFIXED_HISTOGRAM_INTERNAL(origin, experiment, false, histogram)
+
+#define PREFIXED_HISTOGRAM_INTERNAL(origin, experiment, wash, histogram) { \
+  static uint8 recording_experiment = kNoExperiment; \
+  if (recording_experiment == kNoExperiment && experiment != kNoExperiment) \
+    recording_experiment = experiment; \
+  if (wash) { \
+    histogram; \
+  } else if (experiment != kNoExperiment && \
+             (origin != ORIGIN_GWS_PRERENDER || \
+              experiment != recording_experiment)) { \
+  } else if (origin == ORIGIN_LINK_REL_PRERENDER) { \
+    histogram; \
+  } else if (origin == ORIGIN_OMNIBOX) { \
+    histogram; \
+  } else if (experiment != kNoExperiment) { \
+    histogram; \
+  } else { \
+    histogram; \
+  } \
+}
+
+PrerenderHistograms::PrerenderHistograms()
+    : last_experiment_id_(kNoExperiment),
+      last_origin_(ORIGIN_LINK_REL_PRERENDER),
+      origin_experiment_wash_(false) {
+}
+
+void PrerenderHistograms::RecordPrerender(Origin origin, const GURL& url) {
+  // Check if we are doing an experiment.
+  uint8 experiment = GetQueryStringBasedExperiment(url);
+
+  // We need to update last_experiment_id_, last_origin_, and
+  // origin_experiment_wash_.
+  if (!WithinWindow()) {
+    // If we are outside a window, this is a fresh start and we are fine,
+    // and there is no mix.
+    origin_experiment_wash_ = false;
+  } else {
+    // If we are inside the last window, there is a mish mash of origins
+    // and experiments if either there was a mish mash before, or the current
+    // experiment/origin does not match the previous one.
+    if (experiment != last_experiment_id_ || origin != last_origin_)
+      origin_experiment_wash_ = true;
+  }
+
+  last_origin_ = origin;
+  last_experiment_id_ = experiment;
+
+  // If we observe multiple tags within the 30 second window, we will still
+  // reset the window to begin at the most recent occurrence, so that we will
+  // always be in a window in the 30 seconds from each occurrence.
+  last_prerender_seen_time_ = GetCurrentTimeTicks();
+}
+
+base::TimeTicks PrerenderHistograms::GetCurrentTimeTicks() const {
+  return base::TimeTicks::Now();
+}
+
+// Helper macro for histograms.
+#define RECORD_PLT(tag, perceived_page_load_time) { \
+  PREFIXED_HISTOGRAM( \
+    UMA_HISTOGRAM_CUSTOM_TIMES( \
+        base::FieldTrial::MakeName(GetDefaultHistogramName(tag), "Prefetch"), \
+        perceived_page_load_time, \
+        base::TimeDelta::FromMilliseconds(10), \
+        base::TimeDelta::FromSeconds(60), \
+        100)); \
+}
+
+void PrerenderHistograms::RecordPerceivedPageLoadTime(
+    base::TimeDelta perceived_page_load_time, bool was_prerender) const {
+  bool within_window = WithinWindow();
+  RECORD_PLT("PerceivedPLT", perceived_page_load_time);
+  if (within_window)
+    RECORD_PLT("PerceivedPLTWindowed", perceived_page_load_time);
+  if (was_prerender) {
+    RECORD_PLT("PerceivedPLTMatched", perceived_page_load_time);
+  } else {
+    if (within_window)
+      RECORD_PLT("PerceivedPLTWindowNotMatched", perceived_page_load_time);
+  }
+}
+
+bool PrerenderHistograms::WithinWindow() const {
+  if (last_prerender_seen_time_.is_null())
+    return false;
+  base::TimeDelta elapsed_time =
+      base::TimeTicks::Now() - last_prerender_seen_time_;
+  return elapsed_time <= base::TimeDelta::FromSeconds(kWindowDurationSeconds);
+}
+
+
+void PrerenderHistograms::RecordTimeUntilUsed(
+    base::TimeDelta time_until_used, base::TimeDelta max_age) const {
+  PREFIXED_HISTOGRAM(UMA_HISTOGRAM_CUSTOM_TIMES(
+      GetDefaultHistogramName("TimeUntilUsed"),
+      time_until_used,
+      base::TimeDelta::FromMilliseconds(10),
+      max_age,
+      50));
+}
+
+void PrerenderHistograms::RecordPerSessionCount(int count) const {
+  PREFIXED_HISTOGRAM(UMA_HISTOGRAM_COUNTS(
+      GetDefaultHistogramName("PrerendersPerSessionCount"), count));
+}
+
+void PrerenderHistograms::RecordTimeBetweenPrerenderRequests(
+    base::TimeDelta time) const {
+  PREFIXED_HISTOGRAM(UMA_HISTOGRAM_TIMES(
+      GetDefaultHistogramName("TimeBetweenPrerenderRequests"), time));
+}
+
+void PrerenderHistograms::RecordFinalStatus(Origin origin,
+                                            uint8 experiment_id,
+                                            FinalStatus final_status) const {
+  DCHECK(final_status != FINAL_STATUS_MAX);
+  PREFIXED_HISTOGRAM_ORIGIN_EXPERIMENT(origin, experiment_id,
+                     UMA_HISTOGRAM_ENUMERATION(
+                         GetHistogramName(origin, experiment_id, "FinalStatus"),
+                         final_status,
+                         FINAL_STATUS_MAX));
+}
+
+std::string PrerenderHistograms::GetDefaultHistogramName(
+    const std::string& name) const {
+  if (!WithinWindow())
+    return ComposeHistogramName("", name);
+  if (origin_experiment_wash_)
+    return ComposeHistogramName("wash", name);
+  return GetHistogramName(last_origin_, last_experiment_id_, name);
+}
+
+uint8 PrerenderHistograms::GetCurrentExperimentId() const {
+  if (!WithinWindow())
+    return kNoExperiment;
+  return last_experiment_id_;
+}
+
+Origin PrerenderHistograms::GetCurrentOrigin() const {
+  if (!WithinWindow())
+    return ORIGIN_LINK_REL_PRERENDER;
+  return last_origin_;
+}
+
+bool PrerenderHistograms::IsOriginExperimentWash() const {
+  if (!WithinWindow())
+    return false;
+  return origin_experiment_wash_;
+}
+
+}  // namespace prerender

chrome/browser/prerender/prerender_histograms.h

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_PRERENDER_PRERENDER_HISTOGRAMS_H_
+#define CHROME_BROWSER_PRERENDER_PRERENDER_HISTOGRAMS_H_
+#pragma once
+
+#include <string>
+
+#include "base/time.h"
+#include "chrome/browser/prerender/prerender_final_status.h"
+#include "chrome/browser/prerender/prerender_origin.h"
+#include "googleurl/src/gurl.h"
+
+namespace prerender {
+
+// PrerenderHistograms is responsible for recording all prerender specific
+// histograms for PrerenderManager.  It keeps track of the type of prerender
+// currently underway (based on the PrerenderOrigin of the most recent
+// prerenders, and any experiments detected).
+// PrerenderHistograms does not necessarily record all histograms related to
+// prerendering, only the ones in the context of PrerenderManager.
+class PrerenderHistograms {
+ public:
+  // Owned by a PrerenderManager object for the lifetime of the
+  // PrerenderManager.
+  PrerenderHistograms();
+
+  // Records the perceived page load time for a page - effectively the time from
+  // when the user navigates to a page to when it finishes loading.  The actual
+  // load may have started prior to navigation due to prerender hints.
+  void RecordPerceivedPageLoadTime(base::TimeDelta perceived_page_load_time,
+                                   bool was_prerender) const;
+
+  // Records the time from when a page starts prerendering to when the user
+  // navigates to it. This must be called on the UI thread.
+  void RecordTimeUntilUsed(base::TimeDelta time_until_used,
+                           base::TimeDelta max_age) const;
+
+  // Record a PerSessionCount data point.
+  void RecordPerSessionCount(int count) const;
+
+  // Record time between two prerender requests.
+  void RecordTimeBetweenPrerenderRequests(base::TimeDelta time) const;
+
+  // Record a final status of a prerendered page in a histogram.
+  void RecordFinalStatus(Origin origin,
+                         uint8 experiment_id,
+                         FinalStatus final_status) const;
+
+
+  // To be called when a new prerender is added.
+  void RecordPrerender(Origin origin, const GURL& url);
+
+ private:
+  base::TimeTicks GetCurrentTimeTicks() const;
+
+  // Returns whether the PrerenderManager is currently within the prerender
+  // window - effectively, up to 30 seconds after a prerender tag has been
+  // observed.
+  bool WithinWindow() const;
+
+  // Returns the histogram name for the current window.
+  std::string GetDefaultHistogramName(const std::string& name) const;
+  // Returns the current experiment.
+  uint8 GetCurrentExperimentId() const;
+  // Returns the current origin.
+  Origin GetCurrentOrigin() const;
+  // Returns whether or not there is currently an origin/experiment wash.
+  bool IsOriginExperimentWash() const;
+
+  // An integer indicating a Prerendering Experiment being currently conducted.
+  // (The last experiment ID seen).
+  uint8 last_experiment_id_;
+
+  // Origin of the last prerender seen.
+  Origin last_origin_;
+
+  // A boolean indicating that we have recently encountered a combination of
+  // different experiments and origins, making an attribution of PPLT's to
+  // experiments / origins impossible.
+  bool origin_experiment_wash_;
+
+  // The time when we last saw a prerender request coming from a renderer.
+  // This is used to record perceived PLT's for a certain amount of time
+  // from the point that we last saw a <link rel=prerender> tag.
+  base::TimeTicks last_prerender_seen_time_;
+
+  DISALLOW_COPY_AND_ASSIGN(PrerenderHistograms);
+};
+
+}  // namespace prerender
+
+#endif  // CHROME_BROWSER_PRERENDER_PRERENDER_HISTOGRAMS_H_

chrome/browser/prerender/prerender_manager.h

@@ -8,6 +8,7 @@
 
 #include <list>
 #include <map>
+#include <string>
 #include <vector>
 
 #include "base/hash_tables.h"
@@ -20,6 +21,7 @@
 #include "base/timer.h"
 #include "chrome/browser/prerender/prerender_config.h"
 #include "chrome/browser/prerender/prerender_contents.h"
+#include "chrome/browser/prerender/prerender_final_status.h"
 #include "chrome/browser/prerender/prerender_origin.h"
 #include "googleurl/src/gurl.h"
 
@@ -42,6 +44,7 @@ struct hash<TabContents*> {
 namespace prerender {
 
 class PrerenderCondition;
+class PrerenderHistograms;
 class PrerenderHistory;
 class PrerenderTracker;
 
@@ -324,26 +327,6 @@ class PrerenderManager : public base::SupportsWeakPtr<PrerenderManager>,
   // Used both on destruction, and when clearing the browing history.
   void DestroyAllContents(FinalStatus final_status);
 
-  // Records the time from when a page starts prerendering to when the user
-  // navigates to it. This must be called on the UI thread.
-  void RecordTimeUntilUsed(base::TimeDelta time_until_used);
-
-  // Composes a histogram name based on a histogram type.
-  std::string ComposeHistogramName(const std::string& prefix_type,
-                                   const std::string& name) const;
-
-  // Returns the histogram name for a given origin and experiment.
-  std::string GetHistogramName(Origin origin, uint8 experiment_id,
-                               const std::string& name) const;
-  // Returns the histogram name for the current window.
-  std::string GetDefaultHistogramName(const std::string& name) const;
-  // Returns the current experiment.
-  uint8 GetCurrentExperimentId() const;
-  // Returns the current origin.
-  Origin GetCurrentOrigin() const;
-  // Returns whether or not there is currently an origin/experiment wash.
-  bool IsOriginExperimentWash() const;
-
   // The configuration.
   Config config_;
 
@@ -383,23 +366,6 @@ class PrerenderManager : public base::SupportsWeakPtr<PrerenderManager>,
 
   static PrerenderManagerMode mode_;
 
-  // An integer indicating a Prerendering Experiment being currently conducted.
-  // (The last experiment ID seen).
-  uint8 last_experiment_id_;
-
-  // Origin of the last prerender seen.
-  Origin last_origin_;
-
-  // A boolean indicating that we have recently encountered a combination of
-  // different experiments and origins, making an attribution of PPLT's to
-  // experiments / origins impossible.
-  bool origin_experiment_wash_;
-
-  // The time when we last saw a prerender request coming from a renderer.
-  // This is used to record perceived PLT's for a certain amount of time
-  // from the point that we last saw a <link rel=prerender> tag.
-  base::TimeTicks last_prerender_seen_time_;
-
   // A count of how many prerenders we do per session. Initialized to 0 then
   // incremented and emitted to a histogram on each successful prerender.
   static int prerenders_per_session_count_;
@@ -422,6 +388,8 @@ class PrerenderManager : public base::SupportsWeakPtr<PrerenderManager>,
 
   std::list<const PrerenderCondition*> prerender_conditions_;
 
+  scoped_ptr<PrerenderHistograms> histograms_;
+
   DISALLOW_COPY_AND_ASSIGN(PrerenderManager);
 };
 

chrome/browser/prerender/prerender_origin.cc

@@ -14,11 +14,11 @@ namespace {
 const char* kOriginNames[] = {
   "Link Rel Prerender",
   "Omnibox",
+  "GWS Prerender",
   "Max"
 };
 COMPILE_ASSERT(arraysize(kOriginNames) == ORIGIN_MAX + 1,
                PrerenderOrigin_name_count_mismatch);
-
 }
 
 const char* NameFromOrigin(Origin origin) {

chrome/browser/prerender/prerender_origin.h

@@ -12,6 +12,7 @@ namespace prerender {
 enum Origin {
   ORIGIN_LINK_REL_PRERENDER = 0,
   ORIGIN_OMNIBOX = 1,
+  ORIGIN_GWS_PRERENDER = 2,
   ORIGIN_MAX
 };
 

chrome/chrome_browser.gypi

@@ -1767,6 +1767,8 @@
         'browser/prerender/prerender_field_trial.h',
         'browser/prerender/prerender_final_status.cc',
         'browser/prerender/prerender_final_status.h',
+        'browser/prerender/prerender_histograms.cc',
+        'browser/prerender/prerender_histograms.h',
         'browser/prerender/prerender_history.cc',
         'browser/prerender/prerender_history.h',
         'browser/prerender/prerender_manager.cc',