src/chrome/browser/download/download_history.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 // DownloadHistory manages persisting DownloadItems to the history service by
   6 // observing a single DownloadManager and all its DownloadItems using an
   7 // AllDownloadItemNotifier.
   8 //
   9 // DownloadHistory decides whether and when to add items to, remove items from,
  10 // and update items in the database. DownloadHistory uses DownloadHistoryData to
  11 // store per-DownloadItem data such as whether the item is persisted or being
  12 // persisted, and the last history::DownloadRow that was passed to the database.
  13 // When the DownloadManager and its delegate (ChromeDownloadManagerDelegate) are
  14 // initialized, DownloadHistory is created and queries the HistoryService. When
  15 // the HistoryService calls back from QueryDownloads() to QueryCallback(),
  16 // DownloadHistory uses DownloadManager::CreateDownloadItem() to inform
  17 // DownloadManager of these persisted DownloadItems. CreateDownloadItem()
  18 // internally calls OnDownloadCreated(), which normally adds items to the
  19 // database, so QueryCallback() uses |loading_id_| to disable adding these items
  20 // to the database.  If a download is removed via OnDownloadRemoved() while the
  21 // item is still being added to the database, DownloadHistory uses
  22 // |removed_while_adding_| to remember to remove the item when its ItemAdded()
  23 // callback is called.  All callbacks are bound with a weak pointer to
  24 // DownloadHistory to prevent use-after-free bugs.
  25 // ChromeDownloadManagerDelegate owns DownloadHistory, and deletes it in
  26 // Shutdown(), which is called by DownloadManagerImpl::Shutdown() after all
  27 // DownloadItems are destroyed.
  28
  29 #include "chrome/browser/download/download_history.h"
  30
  31 #include "base/metrics/histogram.h"
  32 #include "chrome/browser/download/download_crx_util.h"
  33 #include "chrome/browser/history/download_database.h"
  34 #include "chrome/browser/history/download_row.h"
  35 #include "chrome/browser/history/history_service.h"
  36 #include "content/public/browser/browser_thread.h"
  37 #include "content/public/browser/download_item.h"
  38 #include "content/public/browser/download_manager.h"
  39
  40 #if !defined(OS_ANDROID)
  41 #include "chrome/browser/extensions/api/downloads/downloads_api.h"
  42 #endif
  43
  44 namespace {
  45
  46 // Per-DownloadItem data. This information does not belong inside DownloadItem,
  47 // and keeping maps in DownloadHistory from DownloadItem to this information is
  48 // error-prone and complicated. Unfortunately, DownloadHistory::removing_*_ and
  49 // removed_while_adding_ cannot be moved into this class partly because
  50 // DownloadHistoryData is destroyed when DownloadItems are destroyed, and we
  51 // have no control over when DownloadItems are destroyed.
  52 class DownloadHistoryData : public base::SupportsUserData::Data {
  53  public:
  54   enum PersistenceState {
  55     NOT_PERSISTED,
  56     PERSISTING,
  57     PERSISTED,
  58   };
  59
  60   static DownloadHistoryData* Get(content::DownloadItem* item) {
  61     base::SupportsUserData::Data* data = item->GetUserData(kKey);
  62     return (data == NULL) ? NULL :
  63       static_cast<DownloadHistoryData*>(data);
  64   }
  65
  66   explicit DownloadHistoryData(content::DownloadItem* item)
  67     : state_(NOT_PERSISTED) {
  68     item->SetUserData(kKey, this);
  69   }
  70
  71   virtual ~DownloadHistoryData() {
  72   }
  73
  74   PersistenceState state() const { return state_; }
  75   void SetState(PersistenceState s) { state_ = s; }
  76
  77   // This allows DownloadHistory::OnDownloadUpdated() to see what changed in a
  78   // DownloadItem if anything, in order to prevent writing to the database
  79   // unnecessarily.  It is nullified when the item is no longer in progress in
  80   // order to save memory.
  81   history::DownloadRow* info() { return info_.get(); }
  82   void set_info(const history::DownloadRow& i) {
  83     info_.reset(new history::DownloadRow(i));
  84   }
  85   void clear_info() {
  86     info_.reset();
  87   }
  88
  89  private:
  90   static const char kKey[];
  91
  92   PersistenceState state_;
  93   scoped_ptr<history::DownloadRow> info_;
  94
  95   DISALLOW_COPY_AND_ASSIGN(DownloadHistoryData);
  96 };
  97
  98 const char DownloadHistoryData::kKey[] =
  99   "DownloadItem DownloadHistoryData";
 100
 101 history::DownloadRow GetDownloadRow(
 102     content::DownloadItem* item) {
 103   std::string by_ext_id, by_ext_name;
 104 #if !defined(OS_ANDROID)
 105   extensions::DownloadedByExtension* by_ext =
 106       extensions::DownloadedByExtension::Get(item);
 107   if (by_ext) {
 108     by_ext_id = by_ext->id();
 109     by_ext_name = by_ext->name();
 110   }
 111 #endif
 112
 113   return history::DownloadRow(
 114       item->GetFullPath(),
 115       item->GetTargetFilePath(),
 116       item->GetUrlChain(),
 117       item->GetReferrerUrl(),
 118       item->GetStartTime(),
 119       item->GetEndTime(),
 120       item->GetETag(),
 121       item->GetLastModifiedTime(),
 122       item->GetReceivedBytes(),
 123       item->GetTotalBytes(),
 124       item->GetState(),
 125       item->GetDangerType(),
 126       item->GetLastReason(),
 127       item->GetId(),
 128       item->GetOpened(),
 129       by_ext_id,
 130       by_ext_name);
 131 }
 132
 133 bool ShouldUpdateHistory(const history::DownloadRow* previous,
 134                          const history::DownloadRow& current) {
 135   // Ignore url, referrer, start_time, id, which don't change.
 136   return ((previous == NULL) ||
 137           (previous->current_path != current.current_path) ||
 138           (previous->target_path != current.target_path) ||
 139           (previous->end_time != current.end_time) ||
 140           (previous->received_bytes != current.received_bytes) ||
 141           (previous->total_bytes != current.total_bytes) ||
 142           (previous->etag != current.etag) ||
 143           (previous->last_modified != current.last_modified) ||
 144           (previous->state != current.state) ||
 145           (previous->danger_type != current.danger_type) ||
 146           (previous->interrupt_reason != current.interrupt_reason) ||
 147           (previous->opened != current.opened) ||
 148           (previous->by_ext_id != current.by_ext_id) ||
 149           (previous->by_ext_name != current.by_ext_name));
 150 }
 151
 152 typedef std::vector<history::DownloadRow> InfoVector;
 153
 154 }  // anonymous namespace
 155
 156 DownloadHistory::HistoryAdapter::HistoryAdapter(HistoryService* history)
 157   : history_(history) {
 158 }
 159 DownloadHistory::HistoryAdapter::~HistoryAdapter() {}
 160
 161 void DownloadHistory::HistoryAdapter::QueryDownloads(
 162     const HistoryService::DownloadQueryCallback& callback) {
 163   history_->QueryDownloads(callback);
 164 }
 165
 166 void DownloadHistory::HistoryAdapter::CreateDownload(
 167     const history::DownloadRow& info,
 168     const HistoryService::DownloadCreateCallback& callback) {
 169   history_->CreateDownload(info, callback);
 170 }
 171
 172 void DownloadHistory::HistoryAdapter::UpdateDownload(
 173     const history::DownloadRow& data) {
 174   history_->UpdateDownload(data);
 175 }
 176
 177 void DownloadHistory::HistoryAdapter::RemoveDownloads(
 178     const std::set<uint32>& ids) {
 179   history_->RemoveDownloads(ids);
 180 }
 181
 182
 183 DownloadHistory::Observer::Observer() {}
 184 DownloadHistory::Observer::~Observer() {}
 185
 186 bool DownloadHistory::IsPersisted(content::DownloadItem* item) {
 187   DownloadHistoryData* data = DownloadHistoryData::Get(item);
 188   return data && (data->state() == DownloadHistoryData::PERSISTED);
 189 }
 190
 191 DownloadHistory::DownloadHistory(content::DownloadManager* manager,
 192                                  scoped_ptr<HistoryAdapter> history)
 193   : notifier_(manager, this),
 194     history_(history.Pass()),
 195     loading_id_(content::DownloadItem::kInvalidId),
 196     history_size_(0),
 197     weak_ptr_factory_(this) {
 198   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 199   content::DownloadManager::DownloadVector items;
 200   notifier_.GetManager()->GetAllDownloads(&items);
 201   for (content::DownloadManager::DownloadVector::const_iterator
 202        it = items.begin(); it != items.end(); ++it) {
 203     OnDownloadCreated(notifier_.GetManager(), *it);
 204   }
 205   history_->QueryDownloads(base::Bind(
 206       &DownloadHistory::QueryCallback, weak_ptr_factory_.GetWeakPtr()));
 207 }
 208
 209 DownloadHistory::~DownloadHistory() {
 210   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 211   FOR_EACH_OBSERVER(Observer, observers_, OnDownloadHistoryDestroyed());
 212   observers_.Clear();
 213 }
 214
 215 void DownloadHistory::AddObserver(DownloadHistory::Observer* observer) {
 216   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 217   observers_.AddObserver(observer);
 218 }
 219
 220 void DownloadHistory::RemoveObserver(DownloadHistory::Observer* observer) {
 221   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 222   observers_.RemoveObserver(observer);
 223 }
 224
 225 void DownloadHistory::QueryCallback(scoped_ptr<InfoVector> infos) {
 226   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 227   // ManagerGoingDown() may have happened before the history loaded.
 228   if (!notifier_.GetManager())
 229     return;
 230   for (InfoVector::const_iterator it = infos->begin();
 231        it != infos->end(); ++it) {
 232     loading_id_ = it->id;
 233     content::DownloadItem* item = notifier_.GetManager()->CreateDownloadItem(
 234         loading_id_,
 235         it->current_path,
 236         it->target_path,
 237         it->url_chain,
 238         it->referrer_url,
 239         it->start_time,
 240         it->end_time,
 241         it->etag,
 242         it->last_modified,
 243         it->received_bytes,
 244         it->total_bytes,
 245         it->state,
 246         it->danger_type,
 247         it->interrupt_reason,
 248         it->opened);
 249 #if !defined(OS_ANDROID)
 250     if (!it->by_ext_id.empty() && !it->by_ext_name.empty()) {
 251       new extensions::DownloadedByExtension(
 252           item, it->by_ext_id, it->by_ext_name);
 253       item->UpdateObservers();
 254     }
 255 #endif
 256     DCHECK_EQ(DownloadHistoryData::Get(item)->state(),
 257               DownloadHistoryData::PERSISTED);
 258     ++history_size_;
 259   }
 260   notifier_.GetManager()->CheckForHistoryFilesRemoval();
 261 }
 262
 263 void DownloadHistory::MaybeAddToHistory(content::DownloadItem* item) {
 264   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 265
 266   uint32 download_id = item->GetId();
 267   DownloadHistoryData* data = DownloadHistoryData::Get(item);
 268   bool removing = removing_ids_.find(download_id) != removing_ids_.end();
 269
 270   // TODO(benjhayden): Remove IsTemporary().
 271   if (download_crx_util::IsExtensionDownload(*item) ||
 272       item->IsTemporary() ||
 273       (data->state() != DownloadHistoryData::NOT_PERSISTED) ||
 274       removing)
 275     return;
 276
 277   data->SetState(DownloadHistoryData::PERSISTING);
 278   if (data->info() == NULL) {
 279     // Keep the info here regardless of whether the item is in progress so that,
 280     // when ItemAdded() calls OnDownloadUpdated(), it can decide whether to
 281     // Update the db and/or clear the info.
 282     data->set_info(GetDownloadRow(item));
 283   }
 284
 285   history_->CreateDownload(*data->info(), base::Bind(
 286       &DownloadHistory::ItemAdded, weak_ptr_factory_.GetWeakPtr(),
 287       download_id));
 288   FOR_EACH_OBSERVER(Observer, observers_, OnDownloadStored(
 289       item, *data->info()));
 290 }
 291
 292 void DownloadHistory::ItemAdded(uint32 download_id, bool success) {
 293   if (removed_while_adding_.find(download_id) !=
 294       removed_while_adding_.end()) {
 295     removed_while_adding_.erase(download_id);
 296     if (success)
 297       ScheduleRemoveDownload(download_id);
 298     return;
 299   }
 300
 301   if (!notifier_.GetManager())
 302     return;
 303
 304   content::DownloadItem* item = notifier_.GetManager()->GetDownload(
 305       download_id);
 306   if (!item) {
 307     // This item will have called OnDownloadDestroyed().  If the item should
 308     // have been removed from history, then it would have also called
 309     // OnDownloadRemoved(), which would have put |download_id| in
 310     // removed_while_adding_, handled above.
 311     return;
 312   }
 313
 314   DownloadHistoryData* data = DownloadHistoryData::Get(item);
 315
 316   // The sql INSERT statement failed. Avoid an infinite loop: don't
 317   // automatically retry. Retry adding the next time the item is updated by
 318   // resetting the state to NOT_PERSISTED.
 319   if (!success) {
 320     DVLOG(20) << __FUNCTION__ << " INSERT failed id=" << download_id;
 321     data->SetState(DownloadHistoryData::NOT_PERSISTED);
 322     return;
 323   }
 324   data->SetState(DownloadHistoryData::PERSISTED);
 325
 326   UMA_HISTOGRAM_CUSTOM_COUNTS("Download.HistorySize2",
 327                               history_size_,
 328                               0/*min*/,
 329                               (1 << 23)/*max*/,
 330                               (1 << 7)/*num_buckets*/);
 331   ++history_size_;
 332
 333   // In case the item changed or became temporary while it was being added.
 334   // Don't just update all of the item's observers because we're the only
 335   // observer that can also see data->state(), which is the only thing that
 336   // ItemAdded() changed.
 337   OnDownloadUpdated(notifier_.GetManager(), item);
 338 }
 339
 340 void DownloadHistory::OnDownloadCreated(
 341     content::DownloadManager* manager, content::DownloadItem* item) {
 342   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 343
 344   // All downloads should pass through OnDownloadCreated exactly once.
 345   CHECK(!DownloadHistoryData::Get(item));
 346   DownloadHistoryData* data = new DownloadHistoryData(item);
 347   if (item->GetId() == loading_id_) {
 348     data->SetState(DownloadHistoryData::PERSISTED);
 349     loading_id_ = content::DownloadItem::kInvalidId;
 350   }
 351   if (item->GetState() == content::DownloadItem::IN_PROGRESS) {
 352     data->set_info(GetDownloadRow(item));
 353   }
 354   MaybeAddToHistory(item);
 355 }
 356
 357 void DownloadHistory::OnDownloadUpdated(
 358     content::DownloadManager* manager, content::DownloadItem* item) {
 359   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 360
 361   DownloadHistoryData* data = DownloadHistoryData::Get(item);
 362   if (data->state() == DownloadHistoryData::NOT_PERSISTED) {
 363     MaybeAddToHistory(item);
 364     return;
 365   }
 366   if (item->IsTemporary()) {
 367     OnDownloadRemoved(notifier_.GetManager(), item);
 368     return;
 369   }
 370
 371   history::DownloadRow current_info(GetDownloadRow(item));
 372   bool should_update = ShouldUpdateHistory(data->info(), current_info);
 373   UMA_HISTOGRAM_ENUMERATION("Download.HistoryPropagatedUpdate",
 374                             should_update, 2);
 375   if (should_update) {
 376     history_->UpdateDownload(current_info);
 377     FOR_EACH_OBSERVER(Observer, observers_, OnDownloadStored(
 378         item, current_info));
 379   }
 380   if (item->GetState() == content::DownloadItem::IN_PROGRESS) {
 381     data->set_info(current_info);
 382   } else {
 383     data->clear_info();
 384   }
 385 }
 386
 387 void DownloadHistory::OnDownloadOpened(
 388     content::DownloadManager* manager, content::DownloadItem* item) {
 389   OnDownloadUpdated(manager, item);
 390 }
 391
 392 void DownloadHistory::OnDownloadRemoved(
 393     content::DownloadManager* manager, content::DownloadItem* item) {
 394   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 395
 396   DownloadHistoryData* data = DownloadHistoryData::Get(item);
 397   if (data->state() != DownloadHistoryData::PERSISTED) {
 398     if (data->state() == DownloadHistoryData::PERSISTING) {
 399       // ScheduleRemoveDownload will be called when history_ calls ItemAdded().
 400       removed_while_adding_.insert(item->GetId());
 401     }
 402     return;
 403   }
 404   ScheduleRemoveDownload(item->GetId());
 405   // This is important: another OnDownloadRemoved() handler could do something
 406   // that synchronously fires an OnDownloadUpdated().
 407   data->SetState(DownloadHistoryData::NOT_PERSISTED);
 408   // ItemAdded increments history_size_ only if the item wasn't
 409   // removed_while_adding_, so the next line does not belong in
 410   // ScheduleRemoveDownload().
 411   --history_size_;
 412 }
 413
 414 void DownloadHistory::ScheduleRemoveDownload(uint32 download_id) {
 415   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 416
 417   // For database efficiency, batch removals together if they happen all at
 418   // once.
 419   if (removing_ids_.empty()) {
 420     content::BrowserThread::PostTask(content::BrowserThread::UI, FROM_HERE,
 421         base::Bind(&DownloadHistory::RemoveDownloadsBatch,
 422                    weak_ptr_factory_.GetWeakPtr()));
 423   }
 424   removing_ids_.insert(download_id);
 425 }
 426
 427 void DownloadHistory::RemoveDownloadsBatch() {
 428   DCHECK(content::BrowserThread::CurrentlyOn(content::BrowserThread::UI));
 429   IdSet remove_ids;
 430   removing_ids_.swap(remove_ids);
 431   history_->RemoveDownloads(remove_ids);
 432   FOR_EACH_OBSERVER(Observer, observers_, OnDownloadsRemoved(remove_ids));
 433 }