chrome/browser/extensions/api/dial/dial_registry.cc

   1 // Copyright (c) 2012 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chrome/browser/extensions/api/dial/dial_registry.h"
   6
   7 #include "base/memory/scoped_ptr.h"
   8 #include "base/stl_util.h"
   9 #include "base/strings/string_number_conversions.h"
  10 #include "base/time/time.h"
  11 #include "base/values.h"
  12 #include "chrome/browser/browser_process.h"
  13 #include "chrome/browser/extensions/api/dial/dial_api.h"
  14 #include "chrome/browser/extensions/api/dial/dial_device_data.h"
  15 #include "chrome/browser/extensions/api/dial/dial_service.h"
  16 #include "chrome/common/extensions/api/dial.h"
  17 #include "components/net_log/chrome_net_log.h"
  18
  19 using base::Time;
  20 using base::TimeDelta;
  21 using net::NetworkChangeNotifier;
  22
  23 namespace extensions {
  24
  25 DialRegistry::DialRegistry(Observer* dial_api,
  26                            const base::TimeDelta& refresh_interval,
  27                            const base::TimeDelta& expiration,
  28                            const size_t max_devices)
  29   : num_listeners_(0),
  30     discovery_generation_(0),
  31     registry_generation_(0),
  32     last_event_discovery_generation_(0),
  33     last_event_registry_generation_(0),
  34     label_count_(0),
  35     refresh_interval_delta_(refresh_interval),
  36     expiration_delta_(expiration),
  37     max_devices_(max_devices),
  38     dial_api_(dial_api) {
  39   DCHECK(max_devices_ > 0);
  40   NetworkChangeNotifier::AddNetworkChangeObserver(this);
  41 }
  42
  43 DialRegistry::~DialRegistry() {
  44   DCHECK(thread_checker_.CalledOnValidThread());
  45   NetworkChangeNotifier::RemoveNetworkChangeObserver(this);
  46 }
  47
  48 DialService* DialRegistry::CreateDialService() {
  49   DCHECK(g_browser_process->net_log());
  50   return new DialServiceImpl(g_browser_process->net_log());
  51 }
  52
  53 void DialRegistry::ClearDialService() {
  54   dial_.reset();
  55 }
  56
  57 base::Time DialRegistry::Now() const {
  58   return Time::Now();
  59 }
  60
  61 void DialRegistry::OnListenerAdded() {
  62   DCHECK(thread_checker_.CalledOnValidThread());
  63   if (++num_listeners_ == 1) {
  64     VLOG(2) << "Listener added; starting periodic discovery.";
  65     StartPeriodicDiscovery();
  66   }
  67 }
  68
  69 void DialRegistry::OnListenerRemoved() {
  70   DCHECK(thread_checker_.CalledOnValidThread());
  71   DCHECK(num_listeners_ > 0);
  72   if (--num_listeners_ == 0) {
  73     VLOG(2) << "Listeners removed; stopping periodic discovery.";
  74     StopPeriodicDiscovery();
  75   }
  76 }
  77
  78 bool DialRegistry::ReadyToDiscover() {
  79   if (num_listeners_ == 0) {
  80     dial_api_->OnDialError(DIAL_NO_LISTENERS);
  81     return false;
  82   }
  83   if (NetworkChangeNotifier::IsOffline()) {
  84     dial_api_->OnDialError(DIAL_NETWORK_DISCONNECTED);
  85     return false;
  86   }
  87   if (NetworkChangeNotifier::IsConnectionCellular(
  88           NetworkChangeNotifier::GetConnectionType())) {
  89     dial_api_->OnDialError(DIAL_CELLULAR_NETWORK);
  90     return false;
  91   }
  92   return true;
  93 }
  94
  95 bool DialRegistry::DiscoverNow() {
  96   DCHECK(thread_checker_.CalledOnValidThread());
  97   if (!ReadyToDiscover()) {
  98     return false;
  99   }
 100   if (!dial_.get()) {
 101     dial_api_->OnDialError(DIAL_UNKNOWN);
 102     return false;
 103   }
 104
 105   if (!dial_->HasObserver(this))
 106     NOTREACHED() << "DiscoverNow() called without observing dial_";
 107   discovery_generation_++;
 108   return dial_->Discover();
 109 }
 110
 111 void DialRegistry::StartPeriodicDiscovery() {
 112   DCHECK(thread_checker_.CalledOnValidThread());
 113   if (!ReadyToDiscover() || dial_.get())
 114     return;
 115
 116   dial_.reset(CreateDialService());
 117   dial_->AddObserver(this);
 118   DoDiscovery();
 119   repeating_timer_.Start(FROM_HERE,
 120                          refresh_interval_delta_,
 121                          this,
 122                          &DialRegistry::DoDiscovery);
 123 }
 124
 125 void DialRegistry::DoDiscovery() {
 126   DCHECK(thread_checker_.CalledOnValidThread());
 127   DCHECK(dial_.get());
 128   discovery_generation_++;
 129   VLOG(2) << "About to discover! Generation = " << discovery_generation_;
 130   dial_->Discover();
 131 }
 132
 133 void DialRegistry::StopPeriodicDiscovery() {
 134   DCHECK(thread_checker_.CalledOnValidThread());
 135   if (!dial_.get())
 136     return;
 137
 138   repeating_timer_.Stop();
 139   dial_->RemoveObserver(this);
 140   ClearDialService();
 141 }
 142
 143 bool DialRegistry::PruneExpiredDevices() {
 144   DCHECK(thread_checker_.CalledOnValidThread());
 145   bool pruned_device = false;
 146   DeviceByLabelMap::iterator i = device_by_label_map_.begin();
 147   while (i != device_by_label_map_.end()) {
 148     linked_ptr<DialDeviceData> device = i->second;
 149     if (IsDeviceExpired(*device)) {
 150       VLOG(2) << "Device " << device->label() << " expired, removing";
 151       const size_t num_erased_by_id =
 152           device_by_id_map_.erase(device->device_id());
 153       DCHECK_EQ(num_erased_by_id, 1u);
 154       device_by_label_map_.erase(i++);
 155       pruned_device = true;
 156     } else {
 157       ++i;
 158     }
 159   }
 160   return pruned_device;
 161 }
 162
 163 bool DialRegistry::IsDeviceExpired(const DialDeviceData& device) const {
 164   Time now = Now();
 165
 166   // Check against our default expiration timeout.
 167   Time default_expiration_time = device.response_time() + expiration_delta_;
 168   if (now > default_expiration_time)
 169     return true;
 170
 171   // Check against the device's cache-control header, if set.
 172   if (device.has_max_age()) {
 173     Time max_age_expiration_time =
 174       device.response_time() + TimeDelta::FromSeconds(device.max_age());
 175     if (now > max_age_expiration_time)
 176       return true;
 177   }
 178   return false;
 179 }
 180
 181 void DialRegistry::Clear() {
 182   DCHECK(thread_checker_.CalledOnValidThread());
 183   device_by_id_map_.clear();
 184   device_by_label_map_.clear();
 185   registry_generation_++;
 186 }
 187
 188 void DialRegistry::MaybeSendEvent() {
 189   DCHECK(thread_checker_.CalledOnValidThread());
 190
 191   // We need to send an event if:
 192   // (1) We haven't sent one yet in this round of discovery, or
 193   // (2) The device list changed since the last MaybeSendEvent.
 194   bool needs_event =
 195       (last_event_discovery_generation_ < discovery_generation_ ||
 196        last_event_registry_generation_ < registry_generation_);
 197   VLOG(2) << "ledg = " << last_event_discovery_generation_ << ", dg = "
 198           << discovery_generation_
 199           << ", lerg = " << last_event_registry_generation_ << ", rg = "
 200           << registry_generation_
 201           << ", needs_event = " << needs_event;
 202   if (!needs_event)
 203     return;
 204
 205   DeviceList device_list;
 206   for (DeviceByLabelMap::const_iterator i = device_by_label_map_.begin();
 207        i != device_by_label_map_.end(); i++) {
 208     device_list.push_back(*(i->second));
 209   }
 210   dial_api_->OnDialDeviceEvent(device_list);
 211
 212   // Reset watermarks.
 213   last_event_discovery_generation_ = discovery_generation_;
 214   last_event_registry_generation_ = registry_generation_;
 215 }
 216
 217 std::string DialRegistry::NextLabel() {
 218   DCHECK(thread_checker_.CalledOnValidThread());
 219   return base::IntToString(++label_count_);
 220 }
 221
 222 void DialRegistry::OnDiscoveryRequest(DialService* service) {
 223   DCHECK(thread_checker_.CalledOnValidThread());
 224   MaybeSendEvent();
 225 }
 226
 227 void DialRegistry::OnDeviceDiscovered(DialService* service,
 228                                       const DialDeviceData& device) {
 229   DCHECK(thread_checker_.CalledOnValidThread());
 230
 231   // Adds |device| to our list of devices or updates an existing device, unless
 232   // |device| is a duplicate. Returns true if the list was modified and
 233   // increments the list generation.
 234   linked_ptr<DialDeviceData> device_data(new DialDeviceData(device));
 235   DCHECK(!device_data->device_id().empty());
 236   DCHECK(device_data->label().empty());
 237
 238   bool did_modify_list = false;
 239   DeviceByIdMap::iterator lookup_result =
 240       device_by_id_map_.find(device_data->device_id());
 241
 242   if (lookup_result != device_by_id_map_.end()) {
 243     VLOG(2) << "Found device " << device_data->device_id() << ", merging";
 244
 245     // Already have previous response.  Merge in data from this response and
 246     // track if there were any API visible changes.
 247     did_modify_list = lookup_result->second->UpdateFrom(*device_data);
 248   } else {
 249     did_modify_list = MaybeAddDevice(device_data);
 250   }
 251
 252   if (did_modify_list)
 253     registry_generation_++;
 254
 255   VLOG(2) << "did_modify_list = " << did_modify_list
 256           << ", generation = " << registry_generation_;
 257 }
 258
 259 bool DialRegistry::MaybeAddDevice(
 260     const linked_ptr<DialDeviceData>& device_data) {
 261   DCHECK(thread_checker_.CalledOnValidThread());
 262   if (device_by_id_map_.size() == max_devices_) {
 263     VLOG(1) << "Maximum registry size reached.  Cannot add device.";
 264     return false;
 265   }
 266   device_data->set_label(NextLabel());
 267   device_by_id_map_[device_data->device_id()] = device_data;
 268   device_by_label_map_[device_data->label()] = device_data;
 269   VLOG(2) << "Added device, id = " << device_data->device_id()
 270           << ", label = " << device_data->label();
 271   return true;
 272 }
 273
 274 void DialRegistry::OnDiscoveryFinished(DialService* service) {
 275   DCHECK(thread_checker_.CalledOnValidThread());
 276   if (PruneExpiredDevices())
 277     registry_generation_++;
 278   MaybeSendEvent();
 279 }
 280
 281 void DialRegistry::OnError(DialService* service,
 282                            const DialService::DialServiceErrorCode& code) {
 283   DCHECK(thread_checker_.CalledOnValidThread());
 284   switch (code) {
 285     case DialService::DIAL_SERVICE_SOCKET_ERROR:
 286       dial_api_->OnDialError(DIAL_SOCKET_ERROR);
 287       break;
 288     case DialService::DIAL_SERVICE_NO_INTERFACES:
 289       dial_api_->OnDialError(DIAL_NO_INTERFACES);
 290       break;
 291     default:
 292       NOTREACHED();
 293       dial_api_->OnDialError(DIAL_UNKNOWN);
 294       break;
 295   }
 296 }
 297
 298 void DialRegistry::OnNetworkChanged(
 299     NetworkChangeNotifier::ConnectionType type) {
 300   switch (type) {
 301     case NetworkChangeNotifier::CONNECTION_NONE:
 302       if (dial_.get()) {
 303         VLOG(2) << "Lost connection, shutting down discovery and clearing"
 304                 << " list.";
 305         dial_api_->OnDialError(DIAL_NETWORK_DISCONNECTED);
 306
 307         StopPeriodicDiscovery();
 308         // TODO(justinlin): As an optimization, we can probably keep our device
 309         // list around and restore it if we reconnected to the exact same
 310         // network.
 311         Clear();
 312         MaybeSendEvent();
 313       }
 314       break;
 315     case NetworkChangeNotifier::CONNECTION_2G:
 316     case NetworkChangeNotifier::CONNECTION_3G:
 317     case NetworkChangeNotifier::CONNECTION_4G:
 318     case NetworkChangeNotifier::CONNECTION_ETHERNET:
 319     case NetworkChangeNotifier::CONNECTION_WIFI:
 320     case NetworkChangeNotifier::CONNECTION_UNKNOWN:
 321     case NetworkChangeNotifier::CONNECTION_BLUETOOTH:
 322       if (!dial_.get()) {
 323         VLOG(2) << "Connection detected, restarting discovery.";
 324         StartPeriodicDiscovery();
 325       }
 326       break;
 327   }
 328 }
 329
 330 }  // namespace extensions