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