blob: 3e928670d34dd9568d7a77cf20b834bc6c33b131 [file] [log] [blame]
// Copyright 2016 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 "chromeos/components/tether/hotspot_usage_duration_tracker.h"
#include "base/metrics/histogram_macros.h"
#include "base/time/clock.h"
#include "chromeos/components/proximity_auth/logging/logging.h"
namespace chromeos {
namespace tether {
namespace {
// Minimum value for the usage duration metric.
const int64_t kMinDurationSeconds = 1;
// Maximum value for the usage duration metric.
const int64_t kMaxDurationHours = 5;
// Number of buckets in the metric.
const int kNumMetricsBuckets = 100;
} // namespace
HotspotUsageDurationTracker::HotspotUsageDurationTracker(
ActiveHost* active_host,
base::Clock* clock)
: active_host_(active_host), clock_(clock) {
active_host_->AddObserver(this);
}
HotspotUsageDurationTracker::~HotspotUsageDurationTracker() {
active_host_->RemoveObserver(this);
}
void HotspotUsageDurationTracker::OnActiveHostChanged(
const ActiveHost::ActiveHostChangeInfo& change_info) {
// Handle the case that a session is being tracked but the active host's
// status changes unexpectedly.
HandleUnexpectedCurrentSession(change_info.new_status);
switch (change_info.new_status) {
case ActiveHost::ActiveHostStatus::CONNECTED:
last_connection_start_ = clock_->Now();
break;
case ActiveHost::ActiveHostStatus::DISCONNECTED: {
// If |last_connection_start_| has not been set, there was no active
// connection before this status change; thus, there is nothing to do.
if (last_connection_start_.is_null())
break;
base::TimeDelta duration = clock_->Now() - last_connection_start_;
// Reset |last_connection_start_|; it will be set again the next time that
// a connection is established.
last_connection_start_ = base::Time();
PA_LOG(INFO) << "Connection to hotspot has ended. Duration was "
<< duration.InSeconds() << " second(s).";
UMA_HISTOGRAM_CUSTOM_TIMES(
"InstantTethering.HotspotUsageDuration", duration,
base::TimeDelta::FromSeconds(kMinDurationSeconds) /* min */,
base::TimeDelta::FromHours(kMaxDurationHours) /* max */,
kNumMetricsBuckets /* bucket_count */);
break;
}
default:
break;
}
}
void HotspotUsageDurationTracker::HandleUnexpectedCurrentSession(
const ActiveHost::ActiveHostStatus& active_host_status) {
// If there is no start timestamp, no session is being tracked.
if (last_connection_start_.is_null())
return;
// It is expected that when a current session ends, the active host's status
// will change to DISCONNECTED.
if (active_host_status == ActiveHost::ActiveHostStatus::DISCONNECTED)
return;
base::TimeDelta previous_duration = clock_->Now() - last_connection_start_;
PA_LOG(ERROR) << "Active host status changed to "
<< ActiveHost::StatusToString(active_host_status) << ", but a "
<< "session was already being tracked ("
<< previous_duration.InSeconds() << " second(s)). "
<< "Not recording any metrics for this session since this "
<< "situation was reached in error.";
// Delete the erroneously started session.
last_connection_start_ = base::Time();
}
} // namespace tether
} // namespace chromeos