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// 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_field_trial.h"
#include "base/command_line.h"
#include "base/logging.h"
#include "base/metrics/field_trial.h"
#include "base/metrics/histogram.h"
#include "chrome/browser/metrics/metrics_service.h"
#include "chrome/browser/prefs/pref_service.h"
#include "chrome/browser/prerender/prerender_manager.h"
#include "chrome/browser/profiles/profile.h"
#include "chrome/common/chrome_switches.h"
#include "chrome/common/chrome_version_info.h"
#include "content/browser/renderer_host/resource_dispatcher_host.h"
namespace prerender {
namespace {
const char kPrerenderFromOmniboxTrialName[] = "PrerenderFromOmnibox";
void SetupPrefetchFieldTrial() {
chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
if (channel == chrome::VersionInfo::CHANNEL_STABLE ||
channel == chrome::VersionInfo::CHANNEL_BETA) {
return;
}
const base::FieldTrial::Probability divisor = 1000;
const base::FieldTrial::Probability prefetch_probability = 500;
scoped_refptr<base::FieldTrial> trial(
new base::FieldTrial("Prefetch", divisor,
"ContentPrefetchPrefetchOff", 2012, 6, 30));
const int kPrefetchOnGroup = trial->AppendGroup("ContentPrefetchPrefetchOn",
prefetch_probability);
ResourceDispatcherHost::set_is_prefetch_enabled(
trial->group() == kPrefetchOnGroup);
}
void SetupPrerenderFieldTrial() {
base::FieldTrial::Probability divisor = 1000;
base::FieldTrial::Probability exp1_probability = 200;
base::FieldTrial::Probability control1_probability = 200;
base::FieldTrial::Probability no_use1_probability = 100;
base::FieldTrial::Probability exp2_probability = 200;
base::FieldTrial::Probability control2_probability = 200;
base::FieldTrial::Probability no_use2_probability = 100;
chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
if (channel == chrome::VersionInfo::CHANNEL_STABLE ||
channel == chrome::VersionInfo::CHANNEL_BETA) {
exp1_probability = 495;
control1_probability = 5;
no_use1_probability = 0;
exp2_probability = 495;
control2_probability = 5;
no_use2_probability = 0;
}
CHECK_EQ(divisor, exp1_probability + control1_probability +
no_use1_probability + exp2_probability +
control2_probability + no_use2_probability);
scoped_refptr<base::FieldTrial> trial(
new base::FieldTrial("Prerender", divisor,
"ContentPrefetchPrerender1", 2012, 6, 30));
const int kPrerenderExperiment1Group = trial->kDefaultGroupNumber;
const int kPrerenderControl1Group =
trial->AppendGroup("ContentPrefetchPrerenderControl1",
control1_probability);
const int kPrerenderNoUse1Group =
trial->AppendGroup("ContentPrefetchPrerenderNoUse1",
no_use1_probability);
const int kPrerenderExperiment2Group =
trial->AppendGroup("ContentPrefetchPrerender2",
exp2_probability);
const int kPrerenderControl2Group =
trial->AppendGroup("ContentPrefetchPrerenderControl2",
control2_probability);
const int kPrerenderNoUse2Group =
trial->AppendGroup("ContentPrefetchPrerenderNoUse2",
no_use2_probability);
const int trial_group = trial->group();
if (trial_group == kPrerenderExperiment1Group ||
trial_group == kPrerenderExperiment2Group) {
PrerenderManager::SetMode(
PrerenderManager::PRERENDER_MODE_EXPERIMENT_PRERENDER_GROUP);
} else if (trial_group == kPrerenderControl1Group ||
trial_group == kPrerenderControl2Group) {
PrerenderManager::SetMode(
PrerenderManager::PRERENDER_MODE_EXPERIMENT_CONTROL_GROUP);
} else if (trial_group == kPrerenderNoUse1Group ||
trial_group == kPrerenderNoUse2Group) {
PrerenderManager::SetMode(
PrerenderManager::PRERENDER_MODE_EXPERIMENT_NO_USE_GROUP);
} else {
NOTREACHED();
}
}
} // end namespace
void ConfigurePrerenderFromOmnibox();
void ConfigurePrefetchAndPrerender(const CommandLine& command_line) {
enum PrerenderOption {
PRERENDER_OPTION_AUTO,
PRERENDER_OPTION_DISABLED,
PRERENDER_OPTION_ENABLED,
PRERENDER_OPTION_PREFETCH_ONLY,
};
PrerenderOption prerender_option = PRERENDER_OPTION_AUTO;
if (command_line.HasSwitch(switches::kPrerenderMode)) {
const std::string switch_value =
command_line.GetSwitchValueASCII(switches::kPrerenderMode);
if (switch_value == switches::kPrerenderModeSwitchValueAuto) {
prerender_option = PRERENDER_OPTION_AUTO;
} else if (switch_value == switches::kPrerenderModeSwitchValueDisabled) {
prerender_option = PRERENDER_OPTION_DISABLED;
} else if (switch_value.empty() ||
switch_value == switches::kPrerenderModeSwitchValueEnabled) {
// The empty string means the option was provided with no value, and that
// means enable.
prerender_option = PRERENDER_OPTION_ENABLED;
} else if (switch_value ==
switches::kPrerenderModeSwitchValuePrefetchOnly) {
prerender_option = PRERENDER_OPTION_PREFETCH_ONLY;
} else {
prerender_option = PRERENDER_OPTION_DISABLED;
LOG(ERROR) << "Invalid --prerender option received on command line: "
<< switch_value;
LOG(ERROR) << "Disabling prerendering!";
}
}
switch (prerender_option) {
case PRERENDER_OPTION_AUTO:
SetupPrefetchFieldTrial();
SetupPrerenderFieldTrial();
break;
case PRERENDER_OPTION_DISABLED:
ResourceDispatcherHost::set_is_prefetch_enabled(false);
PrerenderManager::SetMode(PrerenderManager::PRERENDER_MODE_DISABLED);
break;
case PRERENDER_OPTION_ENABLED:
ResourceDispatcherHost::set_is_prefetch_enabled(true);
PrerenderManager::SetMode(PrerenderManager::PRERENDER_MODE_ENABLED);
break;
case PRERENDER_OPTION_PREFETCH_ONLY:
ResourceDispatcherHost::set_is_prefetch_enabled(true);
PrerenderManager::SetMode(PrerenderManager::PRERENDER_MODE_DISABLED);
break;
default:
NOTREACHED();
}
UMA_HISTOGRAM_ENUMERATION("Prerender.Sessions",
PrerenderManager::GetMode(),
PrerenderManager::PRERENDER_MODE_MAX);
ConfigurePrerenderFromOmnibox();
}
void ConfigurePrerenderFromOmnibox() {
// Field trial to see if we're enabled.
const base::FieldTrial::Probability kDivisor = 100;
base::FieldTrial::Probability kEnabledProbability = 90;
chrome::VersionInfo::Channel channel = chrome::VersionInfo::GetChannel();
if (channel == chrome::VersionInfo::CHANNEL_STABLE ||
channel == chrome::VersionInfo::CHANNEL_BETA) {
kEnabledProbability = 99;
}
scoped_refptr<base::FieldTrial> enabled_trial(
new base::FieldTrial(kPrerenderFromOmniboxTrialName, kDivisor,
"OmniboxPrerenderDisabled", 2012, 8, 30));
enabled_trial->AppendGroup("OmniboxPrerenderEnabled", kEnabledProbability);
}
bool IsOmniboxEnabled(Profile* profile) {
if (!profile || profile->IsOffTheRecord())
return false;
if (!PrerenderManager::IsPrerenderingPossible())
return false;
// Override any field trial groups if the user has set a command line flag.
if (CommandLine::ForCurrentProcess()->HasSwitch(
switches::kPrerenderFromOmnibox)) {
const std::string switch_value =
CommandLine::ForCurrentProcess()->GetSwitchValueASCII(
switches::kPrerenderFromOmnibox);
if (switch_value == switches::kPrerenderFromOmniboxSwitchValueEnabled)
return true;
if (switch_value == switches::kPrerenderFromOmniboxSwitchValueDisabled)
return false;
DCHECK(switch_value == switches::kPrerenderFromOmniboxSwitchValueAuto);
}
const int group =
base::FieldTrialList::FindValue(kPrerenderFromOmniboxTrialName);
return group != base::FieldTrial::kNotFinalized &&
group != base::FieldTrial::kDefaultGroupNumber;
}
} // namespace prerender
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