content/browser/appcache/appcache_group.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 "content/browser/appcache/appcache_group.h"
   6
   7 #include <algorithm>
   8
   9 #include "base/bind.h"
  10 #include "base/location.h"
  11 #include "base/logging.h"
  12 #include "base/single_thread_task_runner.h"
  13 #include "base/thread_task_runner_handle.h"
  14 #include "content/browser/appcache/appcache.h"
  15 #include "content/browser/appcache/appcache_host.h"
  16 #include "content/browser/appcache/appcache_service_impl.h"
  17 #include "content/browser/appcache/appcache_storage.h"
  18 #include "content/browser/appcache/appcache_update_job.h"
  19
  20 namespace content {
  21
  22 class AppCacheGroup;
  23
  24 // Use this helper class because we cannot make AppCacheGroup a derived class
  25 // of AppCacheHost::Observer as it would create a circular dependency between
  26 // AppCacheHost and AppCacheGroup.
  27 class AppCacheGroup::HostObserver : public AppCacheHost::Observer {
  28  public:
  29   explicit HostObserver(AppCacheGroup* group) : group_(group) {}
  30
  31   // Methods for AppCacheHost::Observer.
  32   void OnCacheSelectionComplete(AppCacheHost* host) override {}  // N/A
  33   void OnDestructionImminent(AppCacheHost* host) override {
  34     group_->HostDestructionImminent(host);
  35   }
  36  private:
  37   AppCacheGroup* group_;
  38 };
  39
  40 AppCacheGroup::AppCacheGroup(AppCacheStorage* storage,
  41                              const GURL& manifest_url,
  42                              int64 group_id)
  43     : group_id_(group_id),
  44       manifest_url_(manifest_url),
  45       update_status_(IDLE),
  46       is_obsolete_(false),
  47       is_being_deleted_(false),
  48       newest_complete_cache_(NULL),
  49       update_job_(NULL),
  50       storage_(storage),
  51       is_in_dtor_(false) {
  52   storage_->working_set()->AddGroup(this);
  53   host_observer_.reset(new HostObserver(this));
  54 }
  55
  56 AppCacheGroup::~AppCacheGroup() {
  57   DCHECK(old_caches_.empty());
  58   DCHECK(!newest_complete_cache_);
  59   DCHECK(restart_update_task_.IsCancelled());
  60   DCHECK(queued_updates_.empty());
  61
  62   is_in_dtor_ = true;
  63
  64   if (update_job_)
  65     delete update_job_;
  66   DCHECK_EQ(IDLE, update_status_);
  67
  68   storage_->working_set()->RemoveGroup(this);
  69   storage_->DeleteResponses(manifest_url_, newly_deletable_response_ids_);
  70 }
  71
  72 void AppCacheGroup::AddUpdateObserver(UpdateObserver* observer) {
  73   // If observer being added is a host that has been queued for later update,
  74   // add observer to a different observer list.
  75   AppCacheHost* host = static_cast<AppCacheHost*>(observer);
  76   if (queued_updates_.find(host) != queued_updates_.end())
  77     queued_observers_.AddObserver(observer);
  78   else
  79     observers_.AddObserver(observer);
  80 }
  81
  82 void AppCacheGroup::RemoveUpdateObserver(UpdateObserver* observer) {
  83   observers_.RemoveObserver(observer);
  84   queued_observers_.RemoveObserver(observer);
  85 }
  86
  87 void AppCacheGroup::AddCache(AppCache* complete_cache) {
  88   DCHECK(complete_cache->is_complete());
  89   complete_cache->set_owning_group(this);
  90
  91   if (!newest_complete_cache_) {
  92     newest_complete_cache_ = complete_cache;
  93     return;
  94   }
  95
  96   if (complete_cache->IsNewerThan(newest_complete_cache_)) {
  97     old_caches_.push_back(newest_complete_cache_);
  98     newest_complete_cache_ = complete_cache;
  99
 100     // Update hosts of older caches to add a reference to the newest cache.
 101     for (Caches::iterator it = old_caches_.begin();
 102          it != old_caches_.end(); ++it) {
 103       AppCache::AppCacheHosts& hosts = (*it)->associated_hosts();
 104       for (AppCache::AppCacheHosts::iterator host_it = hosts.begin();
 105            host_it != hosts.end(); ++host_it) {
 106         (*host_it)->SetSwappableCache(this);
 107       }
 108     }
 109   } else {
 110     old_caches_.push_back(complete_cache);
 111   }
 112 }
 113
 114 void AppCacheGroup::RemoveCache(AppCache* cache) {
 115   DCHECK(cache->associated_hosts().empty());
 116   if (cache == newest_complete_cache_) {
 117     AppCache* tmp_cache = newest_complete_cache_;
 118     newest_complete_cache_ = NULL;
 119     tmp_cache->set_owning_group(NULL);  // may cause this group to be deleted
 120   } else {
 121     scoped_refptr<AppCacheGroup> protect(this);
 122
 123     Caches::iterator it =
 124         std::find(old_caches_.begin(), old_caches_.end(), cache);
 125     if (it != old_caches_.end()) {
 126       AppCache* tmp_cache = *it;
 127       old_caches_.erase(it);
 128       tmp_cache->set_owning_group(NULL);  // may cause group to be released
 129     }
 130
 131     if (!is_obsolete() && old_caches_.empty() &&
 132         !newly_deletable_response_ids_.empty()) {
 133       storage_->DeleteResponses(manifest_url_, newly_deletable_response_ids_);
 134       newly_deletable_response_ids_.clear();
 135     }
 136   }
 137 }
 138
 139 void AppCacheGroup::AddNewlyDeletableResponseIds(
 140     std::vector<int64>* response_ids) {
 141   if (is_being_deleted() || (!is_obsolete() && old_caches_.empty())) {
 142     storage_->DeleteResponses(manifest_url_, *response_ids);
 143     response_ids->clear();
 144     return;
 145   }
 146
 147   if (newly_deletable_response_ids_.empty()) {
 148     newly_deletable_response_ids_.swap(*response_ids);
 149     return;
 150   }
 151   newly_deletable_response_ids_.insert(
 152       newly_deletable_response_ids_.end(),
 153       response_ids->begin(), response_ids->end());
 154   response_ids->clear();
 155 }
 156
 157 void AppCacheGroup::StartUpdateWithNewMasterEntry(
 158     AppCacheHost* host, const GURL& new_master_resource) {
 159   DCHECK(!is_obsolete() && !is_being_deleted());
 160   if (is_in_dtor_)
 161     return;
 162
 163   if (!update_job_)
 164     update_job_ = new AppCacheUpdateJob(storage_->service(), this);
 165
 166   update_job_->StartUpdate(host, new_master_resource);
 167
 168   // Run queued update immediately as an update has been started manually.
 169   if (!restart_update_task_.IsCancelled()) {
 170     restart_update_task_.Cancel();
 171     RunQueuedUpdates();
 172   }
 173 }
 174
 175 void AppCacheGroup::CancelUpdate() {
 176   if (update_job_) {
 177     delete update_job_;
 178     DCHECK(!update_job_);
 179     DCHECK_EQ(IDLE, update_status_);
 180   }
 181 }
 182
 183 void AppCacheGroup::QueueUpdate(AppCacheHost* host,
 184                                 const GURL& new_master_resource) {
 185   DCHECK(update_job_ && host && !new_master_resource.is_empty());
 186   queued_updates_.insert(QueuedUpdates::value_type(host, new_master_resource));
 187
 188   // Need to know when host is destroyed.
 189   host->AddObserver(host_observer_.get());
 190
 191   // If host is already observing for updates, move host to queued observers
 192   // list so that host is not notified when the current update completes.
 193   if (FindObserver(host, observers_)) {
 194     observers_.RemoveObserver(host);
 195     queued_observers_.AddObserver(host);
 196   }
 197 }
 198
 199 void AppCacheGroup::RunQueuedUpdates() {
 200   if (!restart_update_task_.IsCancelled())
 201     restart_update_task_.Cancel();
 202
 203   if (queued_updates_.empty())
 204     return;
 205
 206   QueuedUpdates updates_to_run;
 207   queued_updates_.swap(updates_to_run);
 208   DCHECK(queued_updates_.empty());
 209
 210   for (QueuedUpdates::iterator it = updates_to_run.begin();
 211        it != updates_to_run.end(); ++it) {
 212     AppCacheHost* host = it->first;
 213     host->RemoveObserver(host_observer_.get());
 214     if (FindObserver(host, queued_observers_)) {
 215       queued_observers_.RemoveObserver(host);
 216       observers_.AddObserver(host);
 217     }
 218
 219     if (!is_obsolete() && !is_being_deleted())
 220       StartUpdateWithNewMasterEntry(host, it->second);
 221   }
 222 }
 223
 224 // static
 225 bool AppCacheGroup::FindObserver(
 226     const UpdateObserver* find_me,
 227     const base::ObserverList<UpdateObserver>& observer_list) {
 228   return observer_list.HasObserver(find_me);
 229 }
 230
 231 void AppCacheGroup::ScheduleUpdateRestart(int delay_ms) {
 232   DCHECK(restart_update_task_.IsCancelled());
 233   restart_update_task_.Reset(
 234       base::Bind(&AppCacheGroup::RunQueuedUpdates, this));
 235   base::ThreadTaskRunnerHandle::Get()->PostDelayedTask(
 236       FROM_HERE, restart_update_task_.callback(),
 237       base::TimeDelta::FromMilliseconds(delay_ms));
 238 }
 239
 240 void AppCacheGroup::HostDestructionImminent(AppCacheHost* host) {
 241   queued_updates_.erase(host);
 242   if (queued_updates_.empty() && !restart_update_task_.IsCancelled())
 243     restart_update_task_.Cancel();
 244 }
 245
 246 void AppCacheGroup::SetUpdateAppCacheStatus(UpdateAppCacheStatus status) {
 247   if (status == update_status_)
 248     return;
 249
 250   update_status_ = status;
 251
 252   if (status != IDLE) {
 253     DCHECK(update_job_);
 254   } else {
 255     update_job_ = NULL;
 256
 257     // Observers may release us in these callbacks, so we protect against
 258     // deletion by adding an extra ref in this scope (but only if we're not
 259     // in our destructor).
 260     scoped_refptr<AppCacheGroup> protect(is_in_dtor_ ? NULL : this);
 261     FOR_EACH_OBSERVER(UpdateObserver, observers_, OnUpdateComplete(this));
 262     if (!queued_updates_.empty())
 263       ScheduleUpdateRestart(kUpdateRestartDelayMs);
 264   }
 265 }
 266
 267 }  // namespace content