Add device status reports to policy requests.

chrome/browser/policy/device_status_reporter.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/policy/device_status_reporter.h"
+
+#include "base/bind.h"
+#include "base/callback.h"
+#include "base/message_loop.h"
+#include "base/task.h"
+#include "chrome/browser/idle.h"
+#include "chrome/browser/policy/proto/device_management_backend.pb.h"
+#include "chrome/browser/prefs/pref_service.h"
+#include "chrome/browser/prefs/scoped_user_pref_update.h"
+
+namespace em = enterprise_management;
+
+namespace {
+  // How many seconds of inactivity triggers the idle state.
+  const unsigned int kIdleStateThresholdSeconds = 300;

[Mattias Nissler (ping if slow), 2011/11/25 14:15:19]

no indentation

[Patrick Dubroy, 2011/11/29 18:01:46]

Done.

+
+  // How often, in seconds, to poll to see if the user is idle.
+  const unsigned int kDefaultPollIntervalSeconds = 30;
+
+  // Stores the baseline timestamp, to which the active periods are relative.
+  const char* const kPrefBaselineTime = "device_status.baseline_timestamp";
+
+  // Stores a list of timestamps representing device active periods.
+  const char* const kPrefDeviceActivePeriods = "device_status.active_periods";
+}
+
+namespace policy {
+
+DeviceStatusReporter::DeviceStatusReporter(PrefService* local_state)
+    : poll_interval_seconds_(kDefaultPollIntervalSeconds),
+      local_state_(local_state),
+      last_idle_check_(base::Time::Now()),
+      last_idle_state_(IDLE_STATE_UNKNOWN) {
+  local_state_->RegisterInt64Pref(kPrefBaselineTime,
+                                  base::Time::Now().ToTimeT());
+  local_state_->RegisterListPref(kPrefDeviceActivePeriods, new ListValue);
+  CheckIdleState();
+}
+
+void DeviceStatusReporter::CheckIdleState() {
+  CalculateIdleState(kIdleStateThresholdSeconds,
+      base::Bind(&DeviceStatusReporter::IdleStateCallback,
+                 base::Unretained(this)));
+}
+
+int DeviceStatusReporter::ToInternalTime(const base::Time& time) {
+  base::Time baseline = base::Time::FromTimeT(
+      local_state_->GetInt64(kPrefBaselineTime));
+  return (int)(time - baseline).InSeconds();
+}
+
+base::Time DeviceStatusReporter::FromInternalTime(int internal_time) {
+  base::Time baseline = base::Time::FromTimeT(
+      local_state_->GetInt64(kPrefBaselineTime));
+  return baseline + base::TimeDelta::FromSeconds(internal_time);
+}
+
+void DeviceStatusReporter::AddActivePeriod(base::Time start, base::Time end) {
+  // Maintain the list of active periods in a local_state pref.
+  ListPrefUpdate update(local_state_, kPrefDeviceActivePeriods);
+  ListValue* active_periods = update.Get();
+
+  int start_offset = ToInternalTime(start);
+  int end_offset = ToInternalTime(end);
+
+  int list_size = active_periods->GetSize();
+  DCHECK(list_size % 2 == 0);
+
+  // Check if this period can be combined with the previous one.
+  if (list_size > 0 && last_idle_state_ == IDLE_STATE_ACTIVE) {
+    int last_period_end;
+    if (active_periods->GetInteger(list_size - 1, &last_period_end) &&
+        last_period_end == start_offset) {
+      active_periods->Set(list_size - 1,
+                          Value::CreateIntegerValue(end_offset));
+      return;
+    }
+  }
+  // Add a new period to the list.
+  active_periods->Append(Value::CreateIntegerValue(start_offset));
+  active_periods->Append(Value::CreateIntegerValue(end_offset));

[Mattias Nissler (ping if slow), 2011/11/25 14:15:19]

we should probably limit the maximum number of entries we're willing to put into
the list.

+}
+
+void DeviceStatusReporter::IdleStateCallback(IdleState state) {
+  base::Time now = base::Time::Now();
+
+  if (state == IDLE_STATE_ACTIVE) {
+    base::Time period_start = last_idle_check_;
+
+    // If it's been too long since the last report, assume that the system was
+    // in standby, and only count a single interval of activity.
+    if ((now - period_start).InSeconds() >= (2 * poll_interval_seconds_)) {
+      period_start =
+          now - base::TimeDelta::FromSeconds(poll_interval_seconds_);
+    }
+
+    AddActivePeriod(period_start, now);
+  }
+  last_idle_check_ = now;
+  last_idle_state_ = state;
+
+  MessageLoop::current()->PostDelayedTask(

[Mattias Nissler (ping if slow), 2011/11/25 14:15:19]

You might want to use base/timer.h instead, which gives you periodic callbacks
without having to worry about MessageLoops and stuff.

[Patrick Dubroy, 2011/11/29 18:01:46]

Done.

+      FROM_HERE,
+      base::Bind(&DeviceStatusReporter::CheckIdleState,
+                 base::Unretained(this)),
+      poll_interval_seconds_ * 1000);
+}
+
+void DeviceStatusReporter::GetStatus(em::DeviceStatusReportRequest* request) {
+  const ListValue* active_periods =
+      local_state_->GetList(kPrefDeviceActivePeriods);
+  em::TimePeriod* time_period;
+
+  DCHECK(active_periods->GetSize() % 2 == 0);
+
+  int period_count = active_periods->GetSize() / 2;
+  for (int i = 0; i < period_count; i++) {
+    int start, end;
+
+    if (!active_periods->GetInteger(2 * i, &start) ||
+        !active_periods->GetInteger(2 * i + 1, &end) ||
+        end <= start) {
+      // Something is amiss -- move to the next pair.

[Mattias Nissler (ping if slow), 2011/11/25 14:15:19]

If this happens, we might as well clear the list to get to a known good state?

[Patrick Dubroy, 2011/11/29 18:01:46]

Done.

+      NOTREACHED();
+      continue;
+    }
+    time_period = request->add_active_time();
+    time_period->set_start_timestamp(FromInternalTime(start).ToTimeT());
+    time_period->set_end_timestamp(FromInternalTime(end).ToTimeT());
+  }
+  // TODO(dubroy): This should probably happen elsewhere, after we know that
+  // the status was successfully sent.
+  ListPrefUpdate update(local_state_, kPrefDeviceActivePeriods);
+  update.Get()->Clear();
+}
+
+}  // namespace policy