[NoStatePrefetch] Add performance histograms.

chrome/browser/prerender/prerender_histograms.cc

 // Copyright (c) 2012 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/format_macros.h"
 #include "base/logging.h"
 #include "base/metrics/histogram.h"
 #include "base/metrics/histogram_macros.h"
 #include "base/strings/stringprintf.h"
 #include "chrome/browser/prerender/prerender_manager.h"
 #include "chrome/browser/prerender/prerender_util.h"
+#include "net/http/http_cache.h"
 
 namespace prerender {
 
 namespace {
 
 // This enum is used to define the buckets for the
 // "Prerender.NoStatePrefetchResourceCount" histogram family.
 // Hence, existing enumerated constants should never be deleted or reordered,
 // and new constants should only be appended at the end of the enumeration.
 enum NoStatePrefetchResponseType {
   NO_STORE = 1 << 0,
   REDIRECT = 1 << 1,
   MAIN_RESOURCE = 1 << 2,
   NO_STATE_PREFETCH_RESPONSE_TYPE_COUNT = 1 << 3
 };
 
 int GetResourceType(bool is_main_resource, bool is_redirect, bool is_no_store) {
   return (is_no_store * NO_STORE) + (is_redirect * REDIRECT) +
          (is_main_resource * MAIN_RESOURCE);
 }
 
 // Similar to UMA_HISTOGRAM_ENUMERATION but allows a dynamic histogram name.
 // Records a sample such as 0 <= sample < bucket_count, in a histogram with
 // |bucket_count| buckets of width 1 each.
-void RecordHistogramEnum(std::string histogram_name,
+void RecordHistogramEnum(const std::string& histogram_name,
                          base::HistogramBase::Sample sample,
                          base::HistogramBase::Sample bucket_count) {
   DCHECK_LT(sample, bucket_count);
   base::HistogramBase* histogram_pointer = base::LinearHistogram::FactoryGet(
       histogram_name, 1, bucket_count, bucket_count + 1,
       base::HistogramBase::kUmaTargetedHistogramFlag);
   histogram_pointer->Add(sample);
 }
 
+// Similar to UMA_HISTOGRAM_CUSTOM_TIMES but allows a dynamic histogram name.
+void RecordHistogramTime(const std::string& histogram_name,
+                         base::TimeDelta time_min,
+                         base::TimeDelta time_max,
+                         base::TimeDelta sample,
+                         base::HistogramBase::Sample bucket_count) {
+  base::HistogramBase* histogram_pointer = base::Histogram::FactoryTimeGet(
+      histogram_name, time_min, time_max, bucket_count,
+      base::HistogramBase::kUmaTargetedHistogramFlag);
+  histogram_pointer->AddTime(sample);
+}
+
 // Time window for which we will record windowed PLTs from the last observed
 // link rel=prefetch tag. This is not intended to be the same as the prerender
 // ttl, it's just intended to be a window during which a prerender has likely
 // affected performance.
 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;
@@ skipping 372 matching lines @@
   DCHECK(thread_checker_.CalledOnValidThread());
 
   const int kMaxRedirectCount = 10;
   std::string histogram_base_name = base::StringPrintf(
       "NoStatePrefetch%sResourceRedirects", is_main_resource ? "Main" : "Sub");
   std::string histogram_name =
       GetHistogramName(origin, IsOriginWash(), histogram_base_name);
   RecordHistogramEnum(histogram_name, redirect_count, kMaxRedirectCount);
 }
 
+void PrerenderHistograms::RecordFirstContentfulPaint(
+    Origin origin,
+    bool is_no_store,
+    base::TimeDelta time,
+    base::TimeDelta prefetch_age) {
+  DCHECK(thread_checker_.CalledOnValidThread());
+
+  if (!prefetch_age.is_zero()) {
+    DCHECK_NE(origin, ORIGIN_NONE);
+    RecordHistogramTime(GetHistogramName(origin, IsOriginWash(),
+                                         "Prerender.NoStatePrefetchAge"),
+                        base::TimeDelta::FromMilliseconds(10),
+                        base::TimeDelta::FromMinutes(30), prefetch_age, 50);
+  }
+
+  RecordHistogramTime(GetFirstContentfulPaintHistogrameName(
+                          origin, IsOriginWash(), is_no_store, prefetch_age),
+                      base::TimeDelta::FromMilliseconds(10),
+                      base::TimeDelta::FromMinutes(2), time, 50);
+}
+
 bool PrerenderHistograms::IsOriginWash() const {
   if (!WithinWindow())
     return false;
   return origin_wash_;
 }
 
+// static
+std::string PrerenderHistograms::GetFirstContentfulPaintHistogrameName(
+    Origin origin,
+    bool is_wash,
+    bool is_no_store,
+    base::TimeDelta prefetch_age) {
+  std::string histogram_base_name;
+  if (prefetch_age.is_zero()) {
+    histogram_base_name = "NoStatePrefetchTTFCP.Reference";
+  } else {
+    histogram_base_name = prefetch_age < base::TimeDelta::FromMinutes(
+                                             net::HttpCache::kPrefetchReuseMins)
+                              ? "NoStatePrefetchTTFCP.Warm"
+                              : "NoStatePrefetchTTFCP.Cold";
+  }
+
+  histogram_base_name += is_no_store ? ".NoStore" : ".Cacheable";
+  return GetHistogramName(origin, is_wash, histogram_base_name);
+}
+
 }  // namespace prerender