blob: 0ebf546963ef275c6679028c71c6b4c11c99f38c [file] [log] [blame]
// Copyright 2015 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 "net/nqe/network_quality_estimator.h"
#include <algorithm>
#include <cmath>
#include <limits>
#include <utility>
#include "base/bind_helpers.h"
#include "base/location.h"
#include "base/logging.h"
#include "base/metrics/histogram.h"
#include "base/metrics/histogram_base.h"
#include "base/metrics/histogram_functions.h"
#include "base/metrics/histogram_macros.h"
#include "base/single_thread_task_runner.h"
#include "base/stl_util.h"
#include "base/strings/string_number_conversions.h"
#include "base/strings/string_piece.h"
#include "base/strings/stringprintf.h"
#include "base/task/lazy_task_runner.h"
#include "base/threading/thread_task_runner_handle.h"
#include "base/time/default_tick_clock.h"
#include "base/trace_event/trace_event.h"
#include "build/build_config.h"
#include "net/base/host_port_pair.h"
#include "net/base/load_flags.h"
#include "net/base/load_timing_info.h"
#include "net/base/network_interfaces.h"
#include "net/base/trace_constants.h"
#include "net/http/http_response_headers.h"
#include "net/http/http_response_info.h"
#include "net/http/http_status_code.h"
#include "net/nqe/network_quality_estimator_util.h"
#include "net/nqe/throughput_analyzer.h"
#include "net/nqe/weighted_observation.h"
#include "net/url_request/url_request.h"
#include "net/url_request/url_request_context.h"
#include "net/url_request/url_request_status.h"
#include "url/gurl.h"
#if defined(OS_ANDROID)
#include "net/android/cellular_signal_strength.h"
#include "net/android/network_library.h"
#endif // OS_ANDROID
namespace net {
class HostResolver;
namespace {
#if defined(OS_CHROMEOS)
// SequencedTaskRunner to get the network id. A SequencedTaskRunner is used
// rather than parallel tasks to avoid having many threads getting the network
// id concurrently.
base::LazySequencedTaskRunner g_get_network_id_task_runner =
LAZY_SEQUENCED_TASK_RUNNER_INITIALIZER(
base::TaskTraits(base::MayBlock(),
base::TaskPriority::BEST_EFFORT,
base::TaskShutdownBehavior::CONTINUE_ON_SHUTDOWN));
#endif
NetworkQualityObservationSource ProtocolSourceToObservationSource(
SocketPerformanceWatcherFactory::Protocol protocol) {
switch (protocol) {
case SocketPerformanceWatcherFactory::PROTOCOL_TCP:
return NETWORK_QUALITY_OBSERVATION_SOURCE_TCP;
case SocketPerformanceWatcherFactory::PROTOCOL_QUIC:
return NETWORK_QUALITY_OBSERVATION_SOURCE_QUIC;
}
NOTREACHED();
return NETWORK_QUALITY_OBSERVATION_SOURCE_TCP;
}
// Returns true if the scheme of the |request| is either HTTP or HTTPS.
bool RequestSchemeIsHTTPOrHTTPS(const URLRequest& request) {
return request.url().is_valid() && request.url().SchemeIsHTTPOrHTTPS();
}
nqe::internal::NetworkID DoGetCurrentNetworkID() {
// It is possible that the connection type changed between when
// GetConnectionType() was called and when the API to determine the
// network name was called. Check if that happened and retry until the
// connection type stabilizes. This is an imperfect solution but should
// capture majority of cases, and should not significantly affect estimates
// (that are approximate to begin with).
while (true) {
nqe::internal::NetworkID network_id(
NetworkChangeNotifier::GetConnectionType(), std::string(), INT32_MIN);
switch (network_id.type) {
case NetworkChangeNotifier::ConnectionType::CONNECTION_UNKNOWN:
case NetworkChangeNotifier::ConnectionType::CONNECTION_NONE:
case NetworkChangeNotifier::ConnectionType::CONNECTION_BLUETOOTH:
case NetworkChangeNotifier::ConnectionType::CONNECTION_ETHERNET:
break;
case NetworkChangeNotifier::ConnectionType::CONNECTION_WIFI:
#if defined(OS_ANDROID) || defined(OS_LINUX) || defined(OS_WIN)
network_id.id = GetWifiSSID();
#endif
break;
case NetworkChangeNotifier::ConnectionType::CONNECTION_2G:
case NetworkChangeNotifier::ConnectionType::CONNECTION_3G:
case NetworkChangeNotifier::ConnectionType::CONNECTION_4G:
#if defined(OS_ANDROID)
network_id.id = android::GetTelephonyNetworkOperator();
#endif
break;
default:
NOTREACHED() << "Unexpected connection type = " << network_id.type;
break;
}
if (network_id.type == NetworkChangeNotifier::GetConnectionType())
return network_id;
}
NOTREACHED();
}
} // namespace
NetworkQualityEstimator::NetworkQualityEstimator(
std::unique_ptr<NetworkQualityEstimatorParams> params,
NetLog* net_log)
: params_(std::move(params)),
end_to_end_rtt_observation_count_at_last_ect_computation_(0),
use_localhost_requests_(false),
disable_offline_check_(false),
tick_clock_(base::DefaultTickClock::GetInstance()),
last_connection_change_(tick_clock_->NowTicks()),
current_network_id_(nqe::internal::NetworkID(
NetworkChangeNotifier::ConnectionType::CONNECTION_UNKNOWN,
std::string(),
INT32_MIN)),
http_downstream_throughput_kbps_observations_(
params_.get(),
tick_clock_,
params_->weight_multiplier_per_second(),
params_->weight_multiplier_per_signal_strength_level()),
rtt_ms_observations_{
ObservationBuffer(
params_.get(),
tick_clock_,
params_->weight_multiplier_per_second(),
params_->weight_multiplier_per_signal_strength_level()),
ObservationBuffer(
params_.get(),
tick_clock_,
params_->weight_multiplier_per_second(),
params_->weight_multiplier_per_signal_strength_level()),
ObservationBuffer(
params_.get(),
tick_clock_,
params_->weight_multiplier_per_second(),
params_->weight_multiplier_per_signal_strength_level())},
effective_connection_type_at_last_main_frame_(
EFFECTIVE_CONNECTION_TYPE_UNKNOWN),
effective_connection_type_recomputation_interval_(
base::TimeDelta::FromSeconds(10)),
rtt_observations_size_at_last_ect_computation_(0),
throughput_observations_size_at_last_ect_computation_(0),
transport_rtt_observation_count_last_ect_computation_(0),
new_rtt_observations_since_last_ect_computation_(0),
new_throughput_observations_since_last_ect_computation_(0),
effective_connection_type_(EFFECTIVE_CONNECTION_TYPE_UNKNOWN),
cached_estimate_applied_(false),
net_log_(NetLogWithSource::Make(
net_log,
net::NetLogSourceType::NETWORK_QUALITY_ESTIMATOR)),
event_creator_(net_log_),
weak_ptr_factory_(this) {
DCHECK_EQ(nqe::internal::OBSERVATION_CATEGORY_COUNT,
base::size(rtt_ms_observations_));
network_quality_store_.reset(new nqe::internal::NetworkQualityStore());
NetworkChangeNotifier::AddConnectionTypeObserver(this);
throughput_analyzer_.reset(new nqe::internal::ThroughputAnalyzer(
this, params_.get(), base::ThreadTaskRunnerHandle::Get(),
base::Bind(&NetworkQualityEstimator::OnNewThroughputObservationAvailable,
weak_ptr_factory_.GetWeakPtr()),
tick_clock_, net_log_));
watcher_factory_.reset(new nqe::internal::SocketWatcherFactory(
base::ThreadTaskRunnerHandle::Get(),
params_->min_socket_watcher_notification_interval(),
// OnUpdatedTransportRTTAvailable() may be called via PostTask() by
// socket watchers that live on a different thread than the current thread
// (i.e., base::ThreadTaskRunnerHandle::Get()).
// Use WeakPtr() to avoid crashes where the socket watcher is destroyed
// after |this| is destroyed.
base::Bind(&NetworkQualityEstimator::OnUpdatedTransportRTTAvailable,
weak_ptr_factory_.GetWeakPtr()),
// ShouldSocketWatcherNotifyRTT() below is called by only the socket
// watchers that live on the same thread as the current thread
// (i.e., base::ThreadTaskRunnerHandle::Get()). Also, network quality
// estimator is destroyed after network contexts and URLRequestContexts.
// It's safe to use base::Unretained() below since the socket watcher
// (owned by sockets) would be destroyed before |this|.
base::Bind(&NetworkQualityEstimator::ShouldSocketWatcherNotifyRTT,
base::Unretained(this)),
tick_clock_));
GatherEstimatesForNextConnectionType();
}
void NetworkQualityEstimator::AddDefaultEstimates() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!params_->add_default_platform_observations())
return;
if (params_->DefaultObservation(current_network_id_.type).http_rtt() !=
nqe::internal::InvalidRTT()) {
Observation rtt_observation(
params_->DefaultObservation(current_network_id_.type)
.http_rtt()
.InMilliseconds(),
tick_clock_->NowTicks(), INT32_MIN,
NETWORK_QUALITY_OBSERVATION_SOURCE_DEFAULT_HTTP_FROM_PLATFORM);
AddAndNotifyObserversOfRTT(rtt_observation);
}
if (params_->DefaultObservation(current_network_id_.type).transport_rtt() !=
nqe::internal::InvalidRTT()) {
Observation rtt_observation(
params_->DefaultObservation(current_network_id_.type)
.transport_rtt()
.InMilliseconds(),
tick_clock_->NowTicks(), INT32_MIN,
NETWORK_QUALITY_OBSERVATION_SOURCE_DEFAULT_TRANSPORT_FROM_PLATFORM);
AddAndNotifyObserversOfRTT(rtt_observation);
}
if (params_->DefaultObservation(current_network_id_.type)
.downstream_throughput_kbps() !=
nqe::internal::INVALID_RTT_THROUGHPUT) {
Observation throughput_observation(
params_->DefaultObservation(current_network_id_.type)
.downstream_throughput_kbps(),
tick_clock_->NowTicks(), INT32_MIN,
NETWORK_QUALITY_OBSERVATION_SOURCE_DEFAULT_HTTP_FROM_PLATFORM);
AddAndNotifyObserversOfThroughput(throughput_observation);
}
}
NetworkQualityEstimator::~NetworkQualityEstimator() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
NetworkChangeNotifier::RemoveConnectionTypeObserver(this);
}
void NetworkQualityEstimator::NotifyStartTransaction(
const URLRequest& request) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!RequestSchemeIsHTTPOrHTTPS(request))
return;
// Update |estimated_quality_at_last_main_frame_| if this is a main frame
// request.
// TODO(tbansal): Refactor this to a separate method.
if (request.load_flags() & LOAD_MAIN_FRAME_DEPRECATED) {
base::TimeTicks now = tick_clock_->NowTicks();
last_main_frame_request_ = now;
ComputeEffectiveConnectionType();
effective_connection_type_at_last_main_frame_ = effective_connection_type_;
estimated_quality_at_last_main_frame_ = network_quality_;
} else {
MaybeComputeEffectiveConnectionType();
}
throughput_analyzer_->NotifyStartTransaction(request);
}
bool NetworkQualityEstimator::IsHangingRequest(
base::TimeDelta observed_http_rtt) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// If there are sufficient number of end to end RTT samples available, use
// the end to end RTT estimate to determine if the request is hanging.
// If |observed_http_rtt| is within a fixed multiplier of |end_to_end_rtt_|,
// then |observed_http_rtt| is determined to be not a hanging-request RTT.
if (params_->use_end_to_end_rtt() && end_to_end_rtt_.has_value() &&
end_to_end_rtt_observation_count_at_last_ect_computation_ >=
params_->http_rtt_transport_rtt_min_count() &&
params_->hanging_request_http_rtt_upper_bound_transport_rtt_multiplier() >
0 &&
observed_http_rtt <
params_->hanging_request_http_rtt_upper_bound_transport_rtt_multiplier() *
end_to_end_rtt_.value()) {
UMA_HISTOGRAM_TIMES("NQE.RTT.NotAHangingRequest.EndToEndRTT",
observed_http_rtt);
return false;
}
DCHECK_LT(
0,
params_->hanging_request_http_rtt_upper_bound_transport_rtt_multiplier());
if (transport_rtt_observation_count_last_ect_computation_ >=
params_->http_rtt_transport_rtt_min_count() &&
(observed_http_rtt <
params_->hanging_request_http_rtt_upper_bound_transport_rtt_multiplier() *
GetTransportRTT().value_or(base::TimeDelta::FromSeconds(10)))) {
// If there are sufficient number of transport RTT samples available, use
// the transport RTT estimate to determine if the request is hanging.
UMA_HISTOGRAM_TIMES("NQE.RTT.NotAHangingRequest.TransportRTT",
observed_http_rtt);
return false;
}
DCHECK_LT(
0, params_->hanging_request_http_rtt_upper_bound_http_rtt_multiplier());
if (observed_http_rtt <
params_->hanging_request_http_rtt_upper_bound_http_rtt_multiplier() *
GetHttpRTT().value_or(base::TimeDelta::FromSeconds(10))) {
// Use the HTTP RTT estimate to determine if the request is hanging.
UMA_HISTOGRAM_TIMES("NQE.RTT.NotAHangingRequest.HttpRTT",
observed_http_rtt);
return false;
}
if (observed_http_rtt <=
params_->hanging_request_upper_bound_min_http_rtt()) {
UMA_HISTOGRAM_TIMES("NQE.RTT.NotAHangingRequest.MinHttpBound",
observed_http_rtt);
return false;
}
UMA_HISTOGRAM_TIMES("NQE.RTT.HangingRequest", observed_http_rtt);
return true;
}
void NetworkQualityEstimator::NotifyHeadersReceived(const URLRequest& request) {
TRACE_EVENT0(NetTracingCategory(),
"NetworkQualityEstimator::NotifyHeadersReceived");
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!RequestSchemeIsHTTPOrHTTPS(request) ||
!RequestProvidesRTTObservation(request)) {
return;
}
if (request.load_flags() & LOAD_MAIN_FRAME_DEPRECATED) {
ComputeEffectiveConnectionType();
RecordMetricsOnMainFrameRequest();
}
LoadTimingInfo load_timing_info;
request.GetLoadTimingInfo(&load_timing_info);
// If the load timing info is unavailable, it probably means that the request
// did not go over the network.
if (load_timing_info.send_start.is_null() ||
load_timing_info.receive_headers_end.is_null()) {
return;
}
DCHECK(!request.response_info().was_cached);
// Duration between when the resource was requested and when the response
// headers were received.
const base::TimeDelta observed_http_rtt =
load_timing_info.receive_headers_end - load_timing_info.send_start;
if (observed_http_rtt <= base::TimeDelta())
return;
DCHECK_GE(observed_http_rtt, base::TimeDelta());
if (IsHangingRequest(observed_http_rtt))
return;
Observation http_rtt_observation(observed_http_rtt.InMilliseconds(),
tick_clock_->NowTicks(),
current_network_id_.signal_strength,
NETWORK_QUALITY_OBSERVATION_SOURCE_HTTP);
AddAndNotifyObserversOfRTT(http_rtt_observation);
throughput_analyzer_->NotifyBytesRead(request);
}
void NetworkQualityEstimator::NotifyBytesRead(const URLRequest& request) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
throughput_analyzer_->NotifyBytesRead(request);
}
void NetworkQualityEstimator::NotifyRequestCompleted(const URLRequest& request,
int net_error) {
TRACE_EVENT0(NetTracingCategory(),
"NetworkQualityEstimator::NotifyRequestCompleted");
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!RequestSchemeIsHTTPOrHTTPS(request))
return;
throughput_analyzer_->NotifyRequestCompleted(request);
}
void NetworkQualityEstimator::NotifyURLRequestDestroyed(
const URLRequest& request) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!RequestSchemeIsHTTPOrHTTPS(request))
return;
throughput_analyzer_->NotifyRequestCompleted(request);
}
void NetworkQualityEstimator::AddRTTObserver(RTTObserver* rtt_observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
rtt_observer_list_.AddObserver(rtt_observer);
}
void NetworkQualityEstimator::RemoveRTTObserver(RTTObserver* rtt_observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
rtt_observer_list_.RemoveObserver(rtt_observer);
}
void NetworkQualityEstimator::AddThroughputObserver(
ThroughputObserver* throughput_observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
throughput_observer_list_.AddObserver(throughput_observer);
}
void NetworkQualityEstimator::RemoveThroughputObserver(
ThroughputObserver* throughput_observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
throughput_observer_list_.RemoveObserver(throughput_observer);
}
SocketPerformanceWatcherFactory*
NetworkQualityEstimator::GetSocketPerformanceWatcherFactory() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
return watcher_factory_.get();
}
void NetworkQualityEstimator::SetUseLocalHostRequestsForTesting(
bool use_localhost_requests) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
use_localhost_requests_ = use_localhost_requests;
watcher_factory_->SetUseLocalHostRequestsForTesting(use_localhost_requests_);
throughput_analyzer_->SetUseLocalHostRequestsForTesting(
use_localhost_requests_);
}
void NetworkQualityEstimator::SetUseSmallResponsesForTesting(
bool use_small_responses) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
params_->SetUseSmallResponsesForTesting(use_small_responses);
}
void NetworkQualityEstimator::DisableOfflineCheckForTesting(
bool disable_offline_check) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
disable_offline_check_ = disable_offline_check;
}
void NetworkQualityEstimator::ReportEffectiveConnectionTypeForTesting(
EffectiveConnectionType effective_connection_type) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
event_creator_.MaybeAddNetworkQualityChangedEventToNetLog(
effective_connection_type_,
params_->TypicalNetworkQuality(effective_connection_type));
for (auto& observer : effective_connection_type_observer_list_)
observer.OnEffectiveConnectionTypeChanged(effective_connection_type);
network_quality_store_->Add(current_network_id_,
nqe::internal::CachedNetworkQuality(
tick_clock_->NowTicks(), network_quality_,
effective_connection_type));
}
void NetworkQualityEstimator::ReportRTTsAndThroughputForTesting(
base::TimeDelta http_rtt,
base::TimeDelta transport_rtt,
int32_t downstream_throughput_kbps) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
for (auto& observer : rtt_and_throughput_estimates_observer_list_)
observer.OnRTTOrThroughputEstimatesComputed(http_rtt, transport_rtt,
downstream_throughput_kbps);
}
bool NetworkQualityEstimator::RequestProvidesRTTObservation(
const URLRequest& request) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
bool private_network_request = nqe::internal::IsPrivateHost(
request.context()->host_resolver(), HostPortPair::FromURL(request.url()));
return (use_localhost_requests_ || !private_network_request) &&
// Verify that response headers are received, so it can be ensured that
// response is not cached.
!request.response_info().response_time.is_null() &&
!request.was_cached() &&
request.creation_time() >= last_connection_change_ &&
request.method() == "GET";
}
void NetworkQualityEstimator::OnConnectionTypeChanged(
NetworkChangeNotifier::ConnectionType type) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_EQ(nqe::internal::OBSERVATION_CATEGORY_COUNT,
base::size(rtt_ms_observations_));
// Write the estimates of the previous network to the cache.
network_quality_store_->Add(
current_network_id_, nqe::internal::CachedNetworkQuality(
last_effective_connection_type_computation_,
network_quality_, effective_connection_type_));
// Clear the local state.
last_connection_change_ = tick_clock_->NowTicks();
http_downstream_throughput_kbps_observations_.Clear();
for (int i = 0; i < nqe::internal::OBSERVATION_CATEGORY_COUNT; ++i)
rtt_ms_observations_[i].Clear();
#if defined(OS_ANDROID)
if (params_->weight_multiplier_per_signal_strength_level() < 1.0 &&
NetworkChangeNotifier::IsConnectionCellular(current_network_id_.type)) {
bool signal_strength_available =
min_signal_strength_since_connection_change_ &&
max_signal_strength_since_connection_change_;
UMA_HISTOGRAM_BOOLEAN("NQE.CellularSignalStrength.LevelAvailable",
signal_strength_available);
if (signal_strength_available) {
UMA_HISTOGRAM_COUNTS_100(
"NQE.CellularSignalStrength.LevelDifference",
max_signal_strength_since_connection_change_.value() -
min_signal_strength_since_connection_change_.value());
}
}
#endif // OS_ANDROID
current_network_id_.signal_strength = INT32_MIN;
min_signal_strength_since_connection_change_.reset();
max_signal_strength_since_connection_change_.reset();
network_quality_ = nqe::internal::NetworkQuality();
end_to_end_rtt_ = base::nullopt;
effective_connection_type_ = EFFECTIVE_CONNECTION_TYPE_UNKNOWN;
effective_connection_type_at_last_main_frame_ =
EFFECTIVE_CONNECTION_TYPE_UNKNOWN;
rtt_observations_size_at_last_ect_computation_ = 0;
throughput_observations_size_at_last_ect_computation_ = 0;
new_rtt_observations_since_last_ect_computation_ = 0;
new_throughput_observations_since_last_ect_computation_ = 0;
transport_rtt_observation_count_last_ect_computation_ = 0;
end_to_end_rtt_observation_count_at_last_ect_computation_ = 0;
last_socket_watcher_rtt_notification_ = base::TimeTicks();
estimated_quality_at_last_main_frame_ = nqe::internal::NetworkQuality();
cached_estimate_applied_ = false;
GatherEstimatesForNextConnectionType();
throughput_analyzer_->OnConnectionTypeChanged();
}
void NetworkQualityEstimator::GatherEstimatesForNextConnectionType() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
#if defined(OS_CHROMEOS)
if (get_network_id_asynchronously_) {
// Doing PostTaskAndReplyWithResult by handle because it requires the result
// type have a default constructor and nqe::internal::NetworkID does not
// have that.
g_get_network_id_task_runner.Get()->PostTask(
FROM_HERE,
base::BindOnce(
[](scoped_refptr<base::TaskRunner> reply_task_runner,
base::OnceCallback<void(const nqe::internal::NetworkID&)>
reply_callback) {
reply_task_runner->PostTask(
FROM_HERE, base::BindOnce(std::move(reply_callback),
DoGetCurrentNetworkID()));
},
base::ThreadTaskRunnerHandle::Get(),
base::BindOnce(&NetworkQualityEstimator::
ContinueGatherEstimatesForNextConnectionType,
weak_ptr_factory_.GetWeakPtr())));
return;
}
#endif // defined(OS_CHROMEOS)
ContinueGatherEstimatesForNextConnectionType(GetCurrentNetworkID());
}
void NetworkQualityEstimator::ContinueGatherEstimatesForNextConnectionType(
const nqe::internal::NetworkID& network_id) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// Update the local state as part of preparation for the new connection.
current_network_id_ = network_id;
RecordNetworkIDAvailability();
// Read any cached estimates for the new network. If cached estimates are
// unavailable, add the default estimates.
if (!ReadCachedNetworkQualityEstimate())
AddDefaultEstimates();
ComputeEffectiveConnectionType();
}
int32_t NetworkQualityEstimator::GetCurrentSignalStrength() const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
#if defined(OS_ANDROID)
if (params_->weight_multiplier_per_signal_strength_level() >= 1.0)
return INT32_MIN;
if (!NetworkChangeNotifier::IsConnectionCellular(current_network_id_.type))
return INT32_MIN;
return android::cellular_signal_strength::GetSignalStrengthLevel().value_or(
INT32_MIN);
#endif // OS_ANDROID
return INT32_MIN;
}
void NetworkQualityEstimator::UpdateSignalStrength() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
int32_t past_signal_strength = current_network_id_.signal_strength;
int32_t new_signal_strength = GetCurrentSignalStrength();
// Check if there is no change in the signal strength.
if (past_signal_strength == new_signal_strength)
return;
// Check if the signal strength is unavailable.
if (new_signal_strength == INT32_MIN)
return;
DCHECK(new_signal_strength >= 0 && new_signal_strength <= 4);
// Record the network quality we experienced for the previous signal strength
// (for when we return to that signal strength).
network_quality_store_->Add(current_network_id_,
nqe::internal::CachedNetworkQuality(
tick_clock_->NowTicks(), network_quality_,
effective_connection_type_));
current_network_id_.signal_strength = new_signal_strength;
// Update network quality from cached value for new signal strength.
ReadCachedNetworkQualityEstimate();
min_signal_strength_since_connection_change_ =
std::min(min_signal_strength_since_connection_change_.value_or(INT32_MAX),
current_network_id_.signal_strength);
max_signal_strength_since_connection_change_ =
std::max(max_signal_strength_since_connection_change_.value_or(INT32_MIN),
current_network_id_.signal_strength);
}
void NetworkQualityEstimator::RecordNetworkIDAvailability() const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (current_network_id_.type ==
NetworkChangeNotifier::ConnectionType::CONNECTION_WIFI ||
NetworkChangeNotifier::IsConnectionCellular(current_network_id_.type)) {
UMA_HISTOGRAM_BOOLEAN("NQE.NetworkIdAvailable",
!current_network_id_.id.empty());
}
}
void NetworkQualityEstimator::RecordMetricsOnMainFrameRequest() const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (estimated_quality_at_last_main_frame_.http_rtt() !=
nqe::internal::InvalidRTT()) {
// Add the 50th percentile value.
UMA_HISTOGRAM_TIMES("NQE.MainFrame.RTT.Percentile50",
estimated_quality_at_last_main_frame_.http_rtt());
}
UMA_HISTOGRAM_BOOLEAN("NQE.EstimateAvailable.MainFrame.RTT",
estimated_quality_at_last_main_frame_.http_rtt() !=
nqe::internal::InvalidRTT());
if (estimated_quality_at_last_main_frame_.transport_rtt() !=
nqe::internal::InvalidRTT()) {
// Add the 50th percentile value.
UMA_HISTOGRAM_TIMES("NQE.MainFrame.TransportRTT.Percentile50",
estimated_quality_at_last_main_frame_.transport_rtt());
}
UMA_HISTOGRAM_BOOLEAN("NQE.EstimateAvailable.MainFrame.TransportRTT",
estimated_quality_at_last_main_frame_.transport_rtt() !=
nqe::internal::InvalidRTT());
if (estimated_quality_at_last_main_frame_.downstream_throughput_kbps() !=
nqe::internal::INVALID_RTT_THROUGHPUT) {
// Add the 50th percentile value.
UMA_HISTOGRAM_COUNTS_1M(
"NQE.MainFrame.Kbps.Percentile50",
estimated_quality_at_last_main_frame_.downstream_throughput_kbps());
}
UMA_HISTOGRAM_BOOLEAN(
"NQE.EstimateAvailable.MainFrame.Kbps",
estimated_quality_at_last_main_frame_.downstream_throughput_kbps() !=
nqe::internal::INVALID_RTT_THROUGHPUT);
UMA_HISTOGRAM_ENUMERATION("NQE.MainFrame.EffectiveConnectionType",
effective_connection_type_at_last_main_frame_,
EFFECTIVE_CONNECTION_TYPE_LAST);
}
void NetworkQualityEstimator::ComputeEffectiveConnectionType() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
UpdateSignalStrength();
const base::TimeTicks now = tick_clock_->NowTicks();
const EffectiveConnectionType past_type = effective_connection_type_;
last_effective_connection_type_computation_ = now;
base::TimeDelta http_rtt = nqe::internal::InvalidRTT();
base::TimeDelta transport_rtt = nqe::internal::InvalidRTT();
base::TimeDelta end_to_end_rtt = nqe::internal::InvalidRTT();
int32_t downstream_throughput_kbps = nqe::internal::INVALID_RTT_THROUGHPUT;
effective_connection_type_ =
GetRecentEffectiveConnectionTypeAndNetworkQuality(
base::TimeTicks(), &http_rtt, &transport_rtt, &end_to_end_rtt,
&downstream_throughput_kbps,
&transport_rtt_observation_count_last_ect_computation_,
&end_to_end_rtt_observation_count_at_last_ect_computation_);
network_quality_ = nqe::internal::NetworkQuality(http_rtt, transport_rtt,
downstream_throughput_kbps);
net::EffectiveConnectionType signal_strength_capped_ect =
GetCappedECTBasedOnSignalStrength();
if (signal_strength_capped_ect != effective_connection_type_) {
DCHECK_LE(signal_strength_capped_ect, effective_connection_type_);
UMA_HISTOGRAM_EXACT_LINEAR(
"NQE.CellularSignalStrength.ECTReduction",
effective_connection_type_ - signal_strength_capped_ect,
static_cast<int>(EFFECTIVE_CONNECTION_TYPE_LAST));
effective_connection_type_ = signal_strength_capped_ect;
// Reset |network_quality_| based on the updated effective connection type.
network_quality_ = nqe::internal::NetworkQuality(
params_->TypicalNetworkQuality(effective_connection_type_).http_rtt(),
params_->TypicalNetworkQuality(effective_connection_type_)
.transport_rtt(),
params_->TypicalNetworkQuality(effective_connection_type_)
.downstream_throughput_kbps());
}
UMA_HISTOGRAM_ENUMERATION("NQE.EffectiveConnectionType.OnECTComputation",
effective_connection_type_,
EFFECTIVE_CONNECTION_TYPE_LAST);
if (network_quality_.http_rtt() != nqe::internal::InvalidRTT()) {
UMA_HISTOGRAM_TIMES("NQE.RTT.OnECTComputation",
network_quality_.http_rtt());
}
if (network_quality_.transport_rtt() != nqe::internal::InvalidRTT()) {
UMA_HISTOGRAM_TIMES("NQE.TransportRTT.OnECTComputation",
network_quality_.transport_rtt());
}
if (end_to_end_rtt != nqe::internal::InvalidRTT()) {
UMA_HISTOGRAM_TIMES("NQE.EndToEndRTT.OnECTComputation", end_to_end_rtt);
}
end_to_end_rtt_ = base::nullopt;
if (end_to_end_rtt != nqe::internal::InvalidRTT())
end_to_end_rtt_ = end_to_end_rtt;
if (network_quality_.downstream_throughput_kbps() !=
nqe::internal::INVALID_RTT_THROUGHPUT) {
UMA_HISTOGRAM_COUNTS_1M("NQE.Kbps.OnECTComputation",
network_quality_.downstream_throughput_kbps());
}
NotifyObserversOfRTTOrThroughputComputed();
if (past_type != effective_connection_type_)
NotifyObserversOfEffectiveConnectionTypeChanged();
event_creator_.MaybeAddNetworkQualityChangedEventToNetLog(
effective_connection_type_, network_quality_);
rtt_observations_size_at_last_ect_computation_ =
rtt_ms_observations_[nqe::internal::OBSERVATION_CATEGORY_HTTP].Size() +
rtt_ms_observations_[nqe::internal::OBSERVATION_CATEGORY_TRANSPORT]
.Size();
throughput_observations_size_at_last_ect_computation_ =
http_downstream_throughput_kbps_observations_.Size();
new_rtt_observations_since_last_ect_computation_ = 0;
new_throughput_observations_since_last_ect_computation_ = 0;
}
EffectiveConnectionType
NetworkQualityEstimator::GetCappedECTBasedOnSignalStrength() const {
if (!params_->cap_ect_based_on_signal_strength())
return effective_connection_type_;
// Check if signal strength is available.
if (current_network_id_.signal_strength == INT32_MIN)
return effective_connection_type_;
if (effective_connection_type_ == EFFECTIVE_CONNECTION_TYPE_UNKNOWN ||
effective_connection_type_ == EFFECTIVE_CONNECTION_TYPE_OFFLINE) {
return effective_connection_type_;
}
// The maximum signal strength level is 4.
UMA_HISTOGRAM_EXACT_LINEAR("NQE.CellularSignalStrength.AtECTComputation",
current_network_id_.signal_strength, 4);
// Do not cap ECT if the signal strength is high.
if (current_network_id_.signal_strength > 2)
return effective_connection_type_;
DCHECK_LE(0, current_network_id_.signal_strength);
DCHECK_LE(NetworkChangeNotifier::CONNECTION_2G, current_network_id_.type);
DCHECK_GE(NetworkChangeNotifier::CONNECTION_4G, current_network_id_.type);
// When signal strength is 0, the device is almost offline.
if (current_network_id_.signal_strength == 0) {
switch (current_network_id_.type) {
case NetworkChangeNotifier::CONNECTION_2G:
case NetworkChangeNotifier::CONNECTION_3G:
return std::min(effective_connection_type_,
EFFECTIVE_CONNECTION_TYPE_SLOW_2G);
case NetworkChangeNotifier::CONNECTION_4G:
return std::min(effective_connection_type_,
EFFECTIVE_CONNECTION_TYPE_2G);
default:
NOTREACHED();
return effective_connection_type_;
}
}
if (current_network_id_.signal_strength == 1) {
switch (current_network_id_.type) {
case NetworkChangeNotifier::CONNECTION_2G:
return std::min(effective_connection_type_,
EFFECTIVE_CONNECTION_TYPE_SLOW_2G);
case NetworkChangeNotifier::CONNECTION_3G:
return std::min(effective_connection_type_,
EFFECTIVE_CONNECTION_TYPE_2G);
case NetworkChangeNotifier::CONNECTION_4G:
return std::min(effective_connection_type_,
EFFECTIVE_CONNECTION_TYPE_3G);
default:
NOTREACHED();
return effective_connection_type_;
}
}
if (current_network_id_.signal_strength == 2) {
switch (current_network_id_.type) {
case NetworkChangeNotifier::CONNECTION_2G:
return std::min(effective_connection_type_,
EFFECTIVE_CONNECTION_TYPE_2G);
case NetworkChangeNotifier::CONNECTION_3G:
return std::min(effective_connection_type_,
EFFECTIVE_CONNECTION_TYPE_3G);
case NetworkChangeNotifier::CONNECTION_4G:
return std::min(effective_connection_type_,
EFFECTIVE_CONNECTION_TYPE_4G);
default:
NOTREACHED();
return effective_connection_type_;
}
}
NOTREACHED();
return effective_connection_type_;
}
EffectiveConnectionType NetworkQualityEstimator::GetEffectiveConnectionType()
const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
return effective_connection_type_;
}
EffectiveConnectionType
NetworkQualityEstimator::GetRecentEffectiveConnectionType(
const base::TimeTicks& start_time) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
base::TimeDelta http_rtt = nqe::internal::InvalidRTT();
base::TimeDelta transport_rtt = nqe::internal::InvalidRTT();
base::TimeDelta end_to_end_rtt = nqe::internal::InvalidRTT();
int32_t downstream_throughput_kbps = nqe::internal::INVALID_RTT_THROUGHPUT;
return GetRecentEffectiveConnectionTypeAndNetworkQuality(
start_time, &http_rtt, &transport_rtt, &end_to_end_rtt,
&downstream_throughput_kbps, nullptr, nullptr);
}
EffectiveConnectionType
NetworkQualityEstimator::GetRecentEffectiveConnectionTypeAndNetworkQuality(
const base::TimeTicks& start_time,
base::TimeDelta* http_rtt,
base::TimeDelta* transport_rtt,
base::TimeDelta* end_to_end_rtt,
int32_t* downstream_throughput_kbps,
size_t* transport_rtt_observation_count,
size_t* end_to_end_rtt_observation_count) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
return GetRecentEffectiveConnectionTypeUsingMetrics(
start_time,
http_rtt, transport_rtt, end_to_end_rtt, downstream_throughput_kbps,
transport_rtt_observation_count, end_to_end_rtt_observation_count);
}
EffectiveConnectionType
NetworkQualityEstimator::GetRecentEffectiveConnectionTypeUsingMetrics(
const base::TimeTicks& start_time,
base::TimeDelta* http_rtt,
base::TimeDelta* transport_rtt,
base::TimeDelta* end_to_end_rtt,
int32_t* downstream_throughput_kbps,
size_t* transport_rtt_observation_count,
size_t* end_to_end_rtt_observation_count) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
*http_rtt = nqe::internal::InvalidRTT();
*transport_rtt = nqe::internal::InvalidRTT();
*end_to_end_rtt = nqe::internal::InvalidRTT();
*downstream_throughput_kbps = nqe::internal::INVALID_RTT_THROUGHPUT;
auto forced_ect =
params_->GetForcedEffectiveConnectionType(current_network_id_.type);
if (forced_ect) {
*http_rtt = params_->TypicalNetworkQuality(forced_ect.value()).http_rtt();
*transport_rtt =
params_->TypicalNetworkQuality(forced_ect.value()).transport_rtt();
*downstream_throughput_kbps =
params_->TypicalNetworkQuality(forced_ect.value())
.downstream_throughput_kbps();
return forced_ect.value();
}
// If the device is currently offline, then return
// EFFECTIVE_CONNECTION_TYPE_OFFLINE.
if (current_network_id_.type == NetworkChangeNotifier::CONNECTION_NONE &&
!disable_offline_check_) {
return EFFECTIVE_CONNECTION_TYPE_OFFLINE;
}
if (!GetRecentRTT(nqe::internal::OBSERVATION_CATEGORY_HTTP, start_time,
http_rtt, nullptr)) {
*http_rtt = nqe::internal::InvalidRTT();
}
if (!GetRecentRTT(nqe::internal::OBSERVATION_CATEGORY_TRANSPORT, start_time,
transport_rtt, transport_rtt_observation_count)) {
*transport_rtt = nqe::internal::InvalidRTT();
}
if (!GetRecentRTT(nqe::internal::OBSERVATION_CATEGORY_END_TO_END, start_time,
end_to_end_rtt, end_to_end_rtt_observation_count)) {
*end_to_end_rtt = nqe::internal::InvalidRTT();
}
// Use transport RTT to clamp the lower bound on HTTP RTT.
// To improve accuracy, the transport RTT estimate is used only when the
// transport RTT estimate was computed using at least
// |params_->http_rtt_transport_rtt_min_count()| observations.
if (*http_rtt != nqe::internal::InvalidRTT() &&
*transport_rtt != nqe::internal::InvalidRTT() &&
transport_rtt_observation_count_last_ect_computation_ >=
params_->http_rtt_transport_rtt_min_count() &&
params_->lower_bound_http_rtt_transport_rtt_multiplier() > 0) {
*http_rtt =
std::max(*http_rtt,
*transport_rtt *
params_->lower_bound_http_rtt_transport_rtt_multiplier());
}
// Put lower bound on |http_rtt| using |end_to_end_rtt|.
if (*http_rtt != nqe::internal::InvalidRTT() &&
params_->use_end_to_end_rtt() &&
*end_to_end_rtt != nqe::internal::InvalidRTT() &&
end_to_end_rtt_observation_count_at_last_ect_computation_ >=
params_->http_rtt_transport_rtt_min_count() &&
params_->lower_bound_http_rtt_transport_rtt_multiplier() > 0) {
*http_rtt =
std::max(*http_rtt,
*end_to_end_rtt *
params_->lower_bound_http_rtt_transport_rtt_multiplier());
}
// Put upper bound on |http_rtt| using |end_to_end_rtt|.
if (*http_rtt != nqe::internal::InvalidRTT() &&
params_->use_end_to_end_rtt() &&
*end_to_end_rtt != nqe::internal::InvalidRTT() &&
end_to_end_rtt_observation_count_at_last_ect_computation_ >=
params_->http_rtt_transport_rtt_min_count() &&
params_->upper_bound_http_rtt_endtoend_rtt_multiplier() > 0) {
*http_rtt = std::min(
*http_rtt, *end_to_end_rtt *
params_->upper_bound_http_rtt_endtoend_rtt_multiplier());
}
if (!GetRecentDownlinkThroughputKbps(start_time, downstream_throughput_kbps))
*downstream_throughput_kbps = nqe::internal::INVALID_RTT_THROUGHPUT;
if (*http_rtt == nqe::internal::InvalidRTT()) {
return EFFECTIVE_CONNECTION_TYPE_UNKNOWN;
}
if (*http_rtt == nqe::internal::InvalidRTT() &&
*transport_rtt == nqe::internal::InvalidRTT() &&
*downstream_throughput_kbps == nqe::internal::INVALID_RTT_THROUGHPUT) {
// None of the metrics are available.
return EFFECTIVE_CONNECTION_TYPE_UNKNOWN;
}
// Search from the slowest connection type to the fastest to find the
// EffectiveConnectionType that best matches the current connection's
// performance. The match is done by comparing RTT and throughput.
for (size_t i = 0; i < EFFECTIVE_CONNECTION_TYPE_LAST; ++i) {
EffectiveConnectionType type = static_cast<EffectiveConnectionType>(i);
if (i == EFFECTIVE_CONNECTION_TYPE_UNKNOWN)
continue;
const bool estimated_http_rtt_is_higher_than_threshold =
*http_rtt != nqe::internal::InvalidRTT() &&
params_->ConnectionThreshold(type).http_rtt() !=
nqe::internal::InvalidRTT() &&
*http_rtt >= params_->ConnectionThreshold(type).http_rtt();
const bool estimated_throughput_is_lower_than_threshold =
*downstream_throughput_kbps != nqe::internal::INVALID_RTT_THROUGHPUT &&
params_->ConnectionThreshold(type).downstream_throughput_kbps() !=
nqe::internal::INVALID_RTT_THROUGHPUT &&
*downstream_throughput_kbps <=
params_->ConnectionThreshold(type).downstream_throughput_kbps();
if (estimated_http_rtt_is_higher_than_threshold ||
estimated_throughput_is_lower_than_threshold) {
return type;
}
}
// Return the fastest connection type.
return static_cast<EffectiveConnectionType>(EFFECTIVE_CONNECTION_TYPE_LAST -
1);
}
void NetworkQualityEstimator::AddEffectiveConnectionTypeObserver(
EffectiveConnectionTypeObserver* observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK(observer);
effective_connection_type_observer_list_.AddObserver(observer);
// Notify the |observer| on the next message pump since |observer| may not
// be completely set up for receiving the callbacks.
base::ThreadTaskRunnerHandle::Get()->PostTask(
FROM_HERE, base::Bind(&NetworkQualityEstimator::
NotifyEffectiveConnectionTypeObserverIfPresent,
weak_ptr_factory_.GetWeakPtr(), observer));
}
void NetworkQualityEstimator::RemoveEffectiveConnectionTypeObserver(
EffectiveConnectionTypeObserver* observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
effective_connection_type_observer_list_.RemoveObserver(observer);
}
void NetworkQualityEstimator::AddRTTAndThroughputEstimatesObserver(
RTTAndThroughputEstimatesObserver* observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK(observer);
rtt_and_throughput_estimates_observer_list_.AddObserver(observer);
// Notify the |observer| on the next message pump since |observer| may not
// be completely set up for receiving the callbacks.
base::ThreadTaskRunnerHandle::Get()->PostTask(
FROM_HERE,
base::Bind(&NetworkQualityEstimator::
NotifyRTTAndThroughputEstimatesObserverIfPresent,
weak_ptr_factory_.GetWeakPtr(), observer));
}
void NetworkQualityEstimator::RemoveRTTAndThroughputEstimatesObserver(
RTTAndThroughputEstimatesObserver* observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
rtt_and_throughput_estimates_observer_list_.RemoveObserver(observer);
}
bool NetworkQualityEstimator::GetRecentRTT(
nqe::internal::ObservationCategory observation_category,
const base::TimeTicks& start_time,
base::TimeDelta* rtt,
size_t* observations_count) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
*rtt = GetRTTEstimateInternal(start_time, observation_category, 50,
observations_count);
return (*rtt != nqe::internal::InvalidRTT());
}
bool NetworkQualityEstimator::GetRecentDownlinkThroughputKbps(
const base::TimeTicks& start_time,
int32_t* kbps) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
*kbps = GetDownlinkThroughputKbpsEstimateInternal(start_time, 50);
return (*kbps != nqe::internal::INVALID_RTT_THROUGHPUT);
}
base::TimeDelta NetworkQualityEstimator::GetRTTEstimateInternal(
base::TimeTicks start_time,
nqe::internal::ObservationCategory observation_category,
int percentile,
size_t* observations_count) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_EQ(nqe::internal::OBSERVATION_CATEGORY_COUNT,
base::size(rtt_ms_observations_));
// RTT observations are sorted by duration from shortest to longest, thus
// a higher percentile RTT will have a longer RTT than a lower percentile.
switch (observation_category) {
case nqe::internal::OBSERVATION_CATEGORY_HTTP:
case nqe::internal::OBSERVATION_CATEGORY_TRANSPORT:
case nqe::internal::OBSERVATION_CATEGORY_END_TO_END:
return base::TimeDelta::FromMilliseconds(
rtt_ms_observations_[observation_category]
.GetPercentile(start_time, current_network_id_.signal_strength,
percentile, observations_count)
.value_or(nqe::internal::INVALID_RTT_THROUGHPUT));
case nqe::internal::OBSERVATION_CATEGORY_COUNT:
NOTREACHED();
return base::TimeDelta();
}
}
int32_t NetworkQualityEstimator::GetDownlinkThroughputKbpsEstimateInternal(
const base::TimeTicks& start_time,
int percentile) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// Throughput observations are sorted by kbps from slowest to fastest,
// thus a higher percentile throughput will be faster than a lower one.
return http_downstream_throughput_kbps_observations_
.GetPercentile(start_time, current_network_id_.signal_strength,
100 - percentile, nullptr)
.value_or(nqe::internal::INVALID_RTT_THROUGHPUT);
}
nqe::internal::NetworkID NetworkQualityEstimator::GetCurrentNetworkID() const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// TODO(tbansal): crbug.com/498068 Add NetworkQualityEstimatorAndroid class
// that overrides this method on the Android platform.
return DoGetCurrentNetworkID();
}
bool NetworkQualityEstimator::ReadCachedNetworkQualityEstimate() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!params_->persistent_cache_reading_enabled())
return false;
nqe::internal::CachedNetworkQuality cached_network_quality;
const bool cached_estimate_available = network_quality_store_->GetById(
current_network_id_, &cached_network_quality);
UMA_HISTOGRAM_BOOLEAN("NQE.CachedNetworkQualityAvailable",
cached_estimate_available);
if (!cached_estimate_available)
return false;
EffectiveConnectionType effective_connection_type =
cached_network_quality.effective_connection_type();
if (effective_connection_type == EFFECTIVE_CONNECTION_TYPE_UNKNOWN ||
effective_connection_type == EFFECTIVE_CONNECTION_TYPE_OFFLINE ||
effective_connection_type == EFFECTIVE_CONNECTION_TYPE_LAST) {
return false;
}
nqe::internal::NetworkQuality network_quality =
cached_network_quality.network_quality();
bool update_network_quality_store = false;
// Populate |network_quality| with synthetic RTT and throughput observations
// if they are missing.
if (network_quality.http_rtt().InMilliseconds() ==
nqe::internal::INVALID_RTT_THROUGHPUT) {
network_quality.set_http_rtt(
params_->TypicalNetworkQuality(effective_connection_type).http_rtt());
update_network_quality_store = true;
}
if (network_quality.transport_rtt().InMilliseconds() ==
nqe::internal::INVALID_RTT_THROUGHPUT) {
network_quality.set_transport_rtt(
params_->TypicalNetworkQuality(effective_connection_type)
.transport_rtt());
update_network_quality_store = true;
}
if (network_quality.downstream_throughput_kbps() ==
nqe::internal::INVALID_RTT_THROUGHPUT) {
network_quality.set_downstream_throughput_kbps(
params_->TypicalNetworkQuality(effective_connection_type)
.downstream_throughput_kbps());
update_network_quality_store = true;
}
if (update_network_quality_store) {
network_quality_store_->Add(current_network_id_,
nqe::internal::CachedNetworkQuality(
tick_clock_->NowTicks(), network_quality,
effective_connection_type));
}
Observation http_rtt_observation(
network_quality.http_rtt().InMilliseconds(), tick_clock_->NowTicks(),
INT32_MIN, NETWORK_QUALITY_OBSERVATION_SOURCE_HTTP_CACHED_ESTIMATE);
AddAndNotifyObserversOfRTT(http_rtt_observation);
Observation transport_rtt_observation(
network_quality.transport_rtt().InMilliseconds(), tick_clock_->NowTicks(),
INT32_MIN, NETWORK_QUALITY_OBSERVATION_SOURCE_TRANSPORT_CACHED_ESTIMATE);
AddAndNotifyObserversOfRTT(transport_rtt_observation);
Observation througphput_observation(
network_quality.downstream_throughput_kbps(), tick_clock_->NowTicks(),
INT32_MIN, NETWORK_QUALITY_OBSERVATION_SOURCE_HTTP_CACHED_ESTIMATE);
AddAndNotifyObserversOfThroughput(througphput_observation);
ComputeEffectiveConnectionType();
return true;
}
void NetworkQualityEstimator::SetTickClockForTesting(
const base::TickClock* tick_clock) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
tick_clock_ = tick_clock;
for (int i = 0; i < nqe::internal::OBSERVATION_CATEGORY_COUNT; ++i)
rtt_ms_observations_[i].SetTickClockForTesting(tick_clock_);
http_downstream_throughput_kbps_observations_.SetTickClockForTesting(
tick_clock_);
throughput_analyzer_->SetTickClockForTesting(tick_clock_);
watcher_factory_->SetTickClockForTesting(tick_clock_);
}
void NetworkQualityEstimator::OnUpdatedTransportRTTAvailable(
SocketPerformanceWatcherFactory::Protocol protocol,
const base::TimeDelta& rtt,
const base::Optional<nqe::internal::IPHash>& host) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_LT(nqe::internal::INVALID_RTT_THROUGHPUT, rtt.InMilliseconds());
Observation observation(rtt.InMilliseconds(), tick_clock_->NowTicks(),
current_network_id_.signal_strength,
ProtocolSourceToObservationSource(protocol), host);
AddAndNotifyObserversOfRTT(observation);
}
void NetworkQualityEstimator::AddAndNotifyObserversOfRTT(
const Observation& observation) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_NE(nqe::internal::InvalidRTT(),
base::TimeDelta::FromMilliseconds(observation.value()));
DCHECK_GT(NETWORK_QUALITY_OBSERVATION_SOURCE_MAX, observation.source());
if (!ShouldAddObservation(observation))
return;
MaybeUpdateCachedEstimateApplied(
observation,
&rtt_ms_observations_[nqe::internal::OBSERVATION_CATEGORY_HTTP]);
MaybeUpdateCachedEstimateApplied(
observation,
&rtt_ms_observations_[nqe::internal::OBSERVATION_CATEGORY_TRANSPORT]);
++new_rtt_observations_since_last_ect_computation_;
std::vector<nqe::internal::ObservationCategory> observation_categories =
observation.GetObservationCategories();
for (nqe::internal::ObservationCategory observation_category :
observation_categories) {
rtt_ms_observations_[observation_category].AddObservation(observation);
}
if (observation.source() == NETWORK_QUALITY_OBSERVATION_SOURCE_TCP ||
observation.source() == NETWORK_QUALITY_OBSERVATION_SOURCE_QUIC) {
last_socket_watcher_rtt_notification_ = tick_clock_->NowTicks();
}
UMA_HISTOGRAM_ENUMERATION("NQE.RTT.ObservationSource", observation.source(),
NETWORK_QUALITY_OBSERVATION_SOURCE_MAX);
base::HistogramBase* raw_observation_histogram = base::Histogram::FactoryGet(
std::string("NQE.RTT.RawObservation.") +
nqe::internal::GetNameForObservationSource(observation.source()),
1, 10 * 1000, 50, base::HistogramBase::kUmaTargetedHistogramFlag);
if (raw_observation_histogram)
raw_observation_histogram->Add(observation.value());
// Maybe recompute the effective connection type since a new RTT observation
// is available.
MaybeComputeEffectiveConnectionType();
for (auto& observer : rtt_observer_list_) {
observer.OnRTTObservation(observation.value(), observation.timestamp(),
observation.source());
}
}
void NetworkQualityEstimator::AddAndNotifyObserversOfThroughput(
const Observation& observation) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_NE(nqe::internal::INVALID_RTT_THROUGHPUT, observation.value());
DCHECK_GT(NETWORK_QUALITY_OBSERVATION_SOURCE_MAX, observation.source());
DCHECK_EQ(1u, observation.GetObservationCategories().size());
DCHECK_EQ(nqe::internal::OBSERVATION_CATEGORY_HTTP,
observation.GetObservationCategories().front());
if (!ShouldAddObservation(observation))
return;
MaybeUpdateCachedEstimateApplied(
observation, &http_downstream_throughput_kbps_observations_);
++new_throughput_observations_since_last_ect_computation_;
http_downstream_throughput_kbps_observations_.AddObservation(observation);
UMA_HISTOGRAM_ENUMERATION("NQE.Kbps.ObservationSource", observation.source(),
NETWORK_QUALITY_OBSERVATION_SOURCE_MAX);
base::HistogramBase* raw_observation_histogram = base::Histogram::FactoryGet(
std::string("NQE.Kbps.RawObservation.") +
nqe::internal::GetNameForObservationSource(observation.source()),
1, 10 * 1000, 50, base::HistogramBase::kUmaTargetedHistogramFlag);
if (raw_observation_histogram)
raw_observation_histogram->Add(observation.value());
// Maybe recompute the effective connection type since a new throughput
// observation is available.
MaybeComputeEffectiveConnectionType();
for (auto& observer : throughput_observer_list_) {
observer.OnThroughputObservation(
observation.value(), observation.timestamp(), observation.source());
}
}
void NetworkQualityEstimator::OnNewThroughputObservationAvailable(
int32_t downstream_kbps) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (downstream_kbps <= 0)
return;
DCHECK_NE(nqe::internal::INVALID_RTT_THROUGHPUT, downstream_kbps);
Observation throughput_observation(downstream_kbps, tick_clock_->NowTicks(),
current_network_id_.signal_strength,
NETWORK_QUALITY_OBSERVATION_SOURCE_HTTP);
AddAndNotifyObserversOfThroughput(throughput_observation);
}
bool NetworkQualityEstimator::ShouldComputeEffectiveConnectionType() const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_EQ(nqe::internal::OBSERVATION_CATEGORY_COUNT,
base::size(rtt_ms_observations_));
const base::TimeTicks now = tick_clock_->NowTicks();
// Recompute effective connection type only if
// |effective_connection_type_recomputation_interval_| has passed since it was
// last computed or a connection change event was observed since the last
// computation. Strict inequalities are used to ensure that effective
// connection type is recomputed on connection change events even if the clock
// has not updated.
if (now - last_effective_connection_type_computation_ >=
effective_connection_type_recomputation_interval_) {
return true;
}
if (last_connection_change_ >= last_effective_connection_type_computation_) {
return true;
}
// Recompute the effective connection type if the previously computed
// effective connection type was unknown.
if (effective_connection_type_ == EFFECTIVE_CONNECTION_TYPE_UNKNOWN) {
return true;
}
// Recompute the effective connection type if the number of samples
// available now are 50% more than the number of samples that were
// available when the effective connection type was last computed.
if (rtt_observations_size_at_last_ect_computation_ * 1.5 <
(rtt_ms_observations_[nqe::internal::OBSERVATION_CATEGORY_HTTP].Size() +
rtt_ms_observations_[nqe::internal::OBSERVATION_CATEGORY_TRANSPORT]
.Size())) {
return true;
}
if (throughput_observations_size_at_last_ect_computation_ * 1.5 <
http_downstream_throughput_kbps_observations_.Size()) {
return true;
}
if ((new_rtt_observations_since_last_ect_computation_ +
new_throughput_observations_since_last_ect_computation_) >=
params_->count_new_observations_received_compute_ect()) {
return true;
}
return false;
}
void NetworkQualityEstimator::MaybeComputeEffectiveConnectionType() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!ShouldComputeEffectiveConnectionType())
return;
ComputeEffectiveConnectionType();
}
void NetworkQualityEstimator::
NotifyObserversOfEffectiveConnectionTypeChanged() {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_NE(EFFECTIVE_CONNECTION_TYPE_LAST, effective_connection_type_);
// TODO(tbansal): Add hysteresis in the notification.
for (auto& observer : effective_connection_type_observer_list_)
observer.OnEffectiveConnectionTypeChanged(effective_connection_type_);
// Add the estimates of the current network to the cache store.
network_quality_store_->Add(current_network_id_,
nqe::internal::CachedNetworkQuality(
tick_clock_->NowTicks(), network_quality_,
effective_connection_type_));
}
void NetworkQualityEstimator::NotifyObserversOfRTTOrThroughputComputed() const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
// TODO(tbansal): Add hysteresis in the notification.
for (auto& observer : rtt_and_throughput_estimates_observer_list_) {
observer.OnRTTOrThroughputEstimatesComputed(
network_quality_.http_rtt(), network_quality_.transport_rtt(),
network_quality_.downstream_throughput_kbps());
}
}
void NetworkQualityEstimator::NotifyEffectiveConnectionTypeObserverIfPresent(
EffectiveConnectionTypeObserver* observer) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!effective_connection_type_observer_list_.HasObserver(observer))
return;
if (effective_connection_type_ == EFFECTIVE_CONNECTION_TYPE_UNKNOWN)
return;
observer->OnEffectiveConnectionTypeChanged(effective_connection_type_);
}
void NetworkQualityEstimator::NotifyRTTAndThroughputEstimatesObserverIfPresent(
RTTAndThroughputEstimatesObserver* observer) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (!rtt_and_throughput_estimates_observer_list_.HasObserver(observer))
return;
observer->OnRTTOrThroughputEstimatesComputed(
network_quality_.http_rtt(), network_quality_.transport_rtt(),
network_quality_.downstream_throughput_kbps());
}
void NetworkQualityEstimator::AddNetworkQualitiesCacheObserver(
nqe::internal::NetworkQualityStore::NetworkQualitiesCacheObserver*
observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
network_quality_store_->AddNetworkQualitiesCacheObserver(observer);
}
void NetworkQualityEstimator::RemoveNetworkQualitiesCacheObserver(
nqe::internal::NetworkQualityStore::NetworkQualitiesCacheObserver*
observer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
network_quality_store_->RemoveNetworkQualitiesCacheObserver(observer);
}
void NetworkQualityEstimator::OnPrefsRead(
const std::map<nqe::internal::NetworkID,
nqe::internal::CachedNetworkQuality> read_prefs) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
UMA_HISTOGRAM_COUNTS_1M("NQE.Prefs.ReadSize", read_prefs.size());
for (auto& it : read_prefs) {
EffectiveConnectionType effective_connection_type =
it.second.effective_connection_type();
if (effective_connection_type == EFFECTIVE_CONNECTION_TYPE_UNKNOWN ||
effective_connection_type == EFFECTIVE_CONNECTION_TYPE_OFFLINE) {
continue;
}
// RTT and throughput values are not set in the prefs.
DCHECK_EQ(nqe::internal::InvalidRTT(),
it.second.network_quality().http_rtt());
DCHECK_EQ(nqe::internal::InvalidRTT(),
it.second.network_quality().transport_rtt());
DCHECK_EQ(nqe::internal::INVALID_RTT_THROUGHPUT,
it.second.network_quality().downstream_throughput_kbps());
nqe::internal::CachedNetworkQuality cached_network_quality(
tick_clock_->NowTicks(),
params_->TypicalNetworkQuality(effective_connection_type),
effective_connection_type);
network_quality_store_->Add(it.first, cached_network_quality);
}
ReadCachedNetworkQualityEstimate();
}
#if defined(OS_CHROMEOS)
void NetworkQualityEstimator::EnableGetNetworkIdAsynchronously() {
get_network_id_asynchronously_ = true;
}
#endif // defined(OS_CHROMEOS)
base::Optional<base::TimeDelta> NetworkQualityEstimator::GetHttpRTT() const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (network_quality_.http_rtt() == nqe::internal::InvalidRTT())
return base::Optional<base::TimeDelta>();
return network_quality_.http_rtt();
}
base::Optional<base::TimeDelta> NetworkQualityEstimator::GetTransportRTT()
const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (network_quality_.transport_rtt() == nqe::internal::InvalidRTT())
return base::Optional<base::TimeDelta>();
return network_quality_.transport_rtt();
}
base::Optional<int32_t> NetworkQualityEstimator::GetDownstreamThroughputKbps()
const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (network_quality_.downstream_throughput_kbps() ==
nqe::internal::INVALID_RTT_THROUGHPUT) {
return base::Optional<int32_t>();
}
return network_quality_.downstream_throughput_kbps();
}
void NetworkQualityEstimator::MaybeUpdateCachedEstimateApplied(
const Observation& observation,
ObservationBuffer* buffer) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (observation.source() !=
NETWORK_QUALITY_OBSERVATION_SOURCE_HTTP_CACHED_ESTIMATE &&
observation.source() !=
NETWORK_QUALITY_OBSERVATION_SOURCE_TRANSPORT_CACHED_ESTIMATE) {
return;
}
cached_estimate_applied_ = true;
bool deleted_observation_sources[NETWORK_QUALITY_OBSERVATION_SOURCE_MAX] = {
false};
deleted_observation_sources
[NETWORK_QUALITY_OBSERVATION_SOURCE_DEFAULT_HTTP_FROM_PLATFORM] = true;
deleted_observation_sources
[NETWORK_QUALITY_OBSERVATION_SOURCE_DEFAULT_TRANSPORT_FROM_PLATFORM] =
true;
buffer->RemoveObservationsWithSource(deleted_observation_sources);
}
bool NetworkQualityEstimator::ShouldAddObservation(
const Observation& observation) const {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
if (cached_estimate_applied_ &&
(observation.source() ==
NETWORK_QUALITY_OBSERVATION_SOURCE_DEFAULT_HTTP_FROM_PLATFORM ||
observation.source() ==
NETWORK_QUALITY_OBSERVATION_SOURCE_DEFAULT_TRANSPORT_FROM_PLATFORM)) {
return false;
}
return true;
}
bool NetworkQualityEstimator::ShouldSocketWatcherNotifyRTT(
base::TimeTicks now) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
return (now - last_socket_watcher_rtt_notification_ >=
params_->socket_watchers_min_notification_interval());
}
void NetworkQualityEstimator::SimulateNetworkQualityChangeForTesting(
net::EffectiveConnectionType type) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
params_->SetForcedEffectiveConnectionTypeForTesting(type);
ComputeEffectiveConnectionType();
}
void NetworkQualityEstimator::RecordSpdyPingLatency(
const HostPortPair& host_port_pair,
base::TimeDelta rtt) {
DCHECK_CALLED_ON_VALID_SEQUENCE(sequence_checker_);
DCHECK_LT(nqe::internal::INVALID_RTT_THROUGHPUT, rtt.InMilliseconds());
Observation observation(rtt.InMilliseconds(), tick_clock_->NowTicks(),
current_network_id_.signal_strength,
NETWORK_QUALITY_OBSERVATION_SOURCE_H2_PINGS);
AddAndNotifyObserversOfRTT(observation);
}
} // namespace net