history_service.cc revision 5d1f7b1de12d16ceb2c938c56701a3e8bfa558f7 
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// The history system runs on a background thread so that potentially slow
6// database operations don't delay the browser. This backend processing is
7// represented by HistoryBackend. The HistoryService's job is to dispatch to
8// that thread.
9//
10// Main thread                       History thread
11// -----------                       --------------
12// HistoryService <----------------> HistoryBackend
13//                                   -> HistoryDatabase
14//                                      -> SQLite connection to History
15//                                   -> ArchivedDatabase
16//                                      -> SQLite connection to Archived History
17//                                   -> ThumbnailDatabase
18//                                      -> SQLite connection to Thumbnails
19//                                         (and favicons)
20
21#include "chrome/browser/history/history_service.h"
22
23#include "base/bind_helpers.h"
24#include "base/callback.h"
25#include "base/command_line.h"
26#include "base/compiler_specific.h"
27#include "base/location.h"
28#include "base/memory/ref_counted.h"
29#include "base/message_loop/message_loop.h"
30#include "base/path_service.h"
31#include "base/prefs/pref_service.h"
32#include "base/thread_task_runner_handle.h"
33#include "base/threading/thread.h"
34#include "base/time/time.h"
35#include "chrome/browser/autocomplete/history_url_provider.h"
36#include "chrome/browser/bookmarks/bookmark_model.h"
37#include "chrome/browser/bookmarks/bookmark_model_factory.h"
38#include "chrome/browser/browser_process.h"
39#include "chrome/browser/chrome_notification_types.h"
40#include "chrome/browser/history/download_row.h"
41#include "chrome/browser/history/history_backend.h"
42#include "chrome/browser/history/history_notifications.h"
43#include "chrome/browser/history/history_types.h"
44#include "chrome/browser/history/in_memory_database.h"
45#include "chrome/browser/history/in_memory_history_backend.h"
46#include "chrome/browser/history/in_memory_url_index.h"
47#include "chrome/browser/history/top_sites.h"
48#include "chrome/browser/history/visit_database.h"
49#include "chrome/browser/history/visit_filter.h"
50#include "chrome/browser/history/web_history_service.h"
51#include "chrome/browser/history/web_history_service_factory.h"
52#include "chrome/browser/profiles/profile.h"
53#include "chrome/browser/ui/profile_error_dialog.h"
54#include "chrome/common/chrome_constants.h"
55#include "chrome/common/chrome_switches.h"
56#include "chrome/common/importer/imported_favicon_usage.h"
57#include "chrome/common/pref_names.h"
58#include "chrome/common/thumbnail_score.h"
59#include "chrome/common/url_constants.h"
60#include "components/visitedlink/browser/visitedlink_master.h"
61#include "content/public/browser/browser_thread.h"
62#include "content/public/browser/download_item.h"
63#include "content/public/browser/notification_service.h"
64#include "grit/chromium_strings.h"
65#include "grit/generated_resources.h"
66#include "sync/api/sync_error_factory.h"
67#include "third_party/skia/include/core/SkBitmap.h"
68
69using base::Time;
70using history::HistoryBackend;
71
72namespace {
73
74static const char* kHistoryThreadName = "Chrome_HistoryThread";
75
76template<typename PODType> void DerefPODType(
77    const base::Callback<void(PODType)>& callback, PODType* pod_value) {
78  callback.Run(*pod_value);
79}
80
81void RunWithFaviconResults(
82    const FaviconService::FaviconResultsCallback& callback,
83    std::vector<chrome::FaviconBitmapResult>* bitmap_results) {
84  callback.Run(*bitmap_results);
85}
86
87void RunWithFaviconResult(
88    const FaviconService::FaviconRawCallback& callback,
89    chrome::FaviconBitmapResult* bitmap_result) {
90  callback.Run(*bitmap_result);
91}
92
93// Extract history::URLRows into GURLs for VisitedLinkMaster.
94class URLIteratorFromURLRows
95    : public visitedlink::VisitedLinkMaster::URLIterator {
96 public:
97  explicit URLIteratorFromURLRows(const history::URLRows& url_rows)
98      : itr_(url_rows.begin()),
99        end_(url_rows.end()) {
100  }
101
102  virtual const GURL& NextURL() OVERRIDE {
103    return (itr_++)->url();
104  }
105
106  virtual bool HasNextURL() const OVERRIDE {
107    return itr_ != end_;
108  }
109
110 private:
111  history::URLRows::const_iterator itr_;
112  history::URLRows::const_iterator end_;
113
114  DISALLOW_COPY_AND_ASSIGN(URLIteratorFromURLRows);
115};
116
117// Callback from WebHistoryService::ExpireWebHistory().
118void ExpireWebHistoryComplete(
119    history::WebHistoryService::Request* request,
120    bool success) {
121  // Ignore the result and delete the request.
122  delete request;
123}
124
125}  // namespace
126
127// Sends messages from the backend to us on the main thread. This must be a
128// separate class from the history service so that it can hold a reference to
129// the history service (otherwise we would have to manually AddRef and
130// Release when the Backend has a reference to us).
131class HistoryService::BackendDelegate : public HistoryBackend::Delegate {
132 public:
133  BackendDelegate(
134      const base::WeakPtr<HistoryService>& history_service,
135      const scoped_refptr<base::SequencedTaskRunner>& service_task_runner,
136      Profile* profile)
137      : history_service_(history_service),
138        service_task_runner_(service_task_runner),
139        profile_(profile) {
140  }
141
142  virtual void NotifyProfileError(int backend_id,
143                                  sql::InitStatus init_status) OVERRIDE {
144    // Send to the history service on the main thread.
145    service_task_runner_->PostTask(
146        FROM_HERE,
147        base::Bind(&HistoryService::NotifyProfileError, history_service_,
148                   backend_id, init_status));
149  }
150
151  virtual void SetInMemoryBackend(int backend_id,
152      history::InMemoryHistoryBackend* backend) OVERRIDE {
153    // Send the backend to the history service on the main thread.
154    scoped_ptr<history::InMemoryHistoryBackend> in_memory_backend(backend);
155    service_task_runner_->PostTask(
156        FROM_HERE,
157        base::Bind(&HistoryService::SetInMemoryBackend, history_service_,
158                   backend_id, base::Passed(&in_memory_backend)));
159  }
160
161  virtual void BroadcastNotifications(
162      int type,
163      history::HistoryDetails* details) OVERRIDE {
164    // Send the notification on the history thread.
165    if (content::NotificationService::current()) {
166      content::Details<history::HistoryDetails> det(details);
167      content::NotificationService::current()->Notify(
168          type, content::Source<Profile>(profile_), det);
169    }
170    // Send the notification to the history service on the main thread.
171    service_task_runner_->PostTask(
172        FROM_HERE,
173        base::Bind(&HistoryService::BroadcastNotificationsHelper,
174                   history_service_, type, base::Owned(details)));
175  }
176
177  virtual void DBLoaded(int backend_id) OVERRIDE {
178    service_task_runner_->PostTask(
179        FROM_HERE,
180        base::Bind(&HistoryService::OnDBLoaded, history_service_,
181                   backend_id));
182  }
183
184  virtual void NotifyVisitDBObserversOnAddVisit(
185      const history::BriefVisitInfo& info) OVERRIDE {
186    service_task_runner_->PostTask(
187        FROM_HERE,
188        base::Bind(&HistoryService::NotifyVisitDBObserversOnAddVisit,
189                   history_service_, info));
190  }
191
192 private:
193  const base::WeakPtr<HistoryService> history_service_;
194  const scoped_refptr<base::SequencedTaskRunner> service_task_runner_;
195  Profile* const profile_;
196};
197
198// The history thread is intentionally not a BrowserThread because the
199// sync integration unit tests depend on being able to create more than one
200// history thread.
201HistoryService::HistoryService()
202    : weak_ptr_factory_(this),
203      thread_(new base::Thread(kHistoryThreadName)),
204      profile_(NULL),
205      backend_loaded_(false),
206      current_backend_id_(-1),
207      bookmark_service_(NULL),
208      no_db_(false) {
209}
210
211HistoryService::HistoryService(Profile* profile)
212    : weak_ptr_factory_(this),
213      thread_(new base::Thread(kHistoryThreadName)),
214      profile_(profile),
215      visitedlink_master_(new visitedlink::VisitedLinkMaster(
216          profile, this, true)),
217      backend_loaded_(false),
218      current_backend_id_(-1),
219      bookmark_service_(NULL),
220      no_db_(false) {
221  DCHECK(profile_);
222  registrar_.Add(this, chrome::NOTIFICATION_HISTORY_URLS_DELETED,
223                 content::Source<Profile>(profile_));
224  registrar_.Add(this, chrome::NOTIFICATION_TEMPLATE_URL_REMOVED,
225                 content::Source<Profile>(profile_));
226}
227
228HistoryService::~HistoryService() {
229  DCHECK(thread_checker_.CalledOnValidThread());
230  // Shutdown the backend. This does nothing if Cleanup was already invoked.
231  Cleanup();
232}
233
234bool HistoryService::BackendLoaded() {
235  DCHECK(thread_checker_.CalledOnValidThread());
236  // NOTE: We start the backend loading even though it completes asynchronously
237  // and thus won't affect the return value of this function.  This is because
238  // callers of this assume that if the backend isn't yet loaded it will be
239  // soon, so they will either listen for notifications or just retry this call
240  // later.  If we've purged the backend, we haven't necessarily restarted it
241  // loading by now, so we need to trigger the load in order to maintain that
242  // expectation.
243  LoadBackendIfNecessary();
244  return backend_loaded_;
245}
246
247void HistoryService::UnloadBackend() {
248  DCHECK(thread_checker_.CalledOnValidThread());
249  if (!history_backend_.get())
250    return;  // Already unloaded.
251
252  // Get rid of the in-memory backend.
253  in_memory_backend_.reset();
254
255  // Give the InMemoryURLIndex a chance to shutdown.
256  if (in_memory_url_index_)
257    in_memory_url_index_->ShutDown();
258
259  // The backend's destructor must run on the history thread since it is not
260  // threadsafe. So this thread must not be the last thread holding a reference
261  // to the backend, or a crash could happen.
262  //
263  // We have a reference to the history backend. There is also an extra
264  // reference held by our delegate installed in the backend, which
265  // HistoryBackend::Closing will release. This means if we scheduled a call
266  // to HistoryBackend::Closing and *then* released our backend reference, there
267  // will be a race between us and the backend's Closing function to see who is
268  // the last holder of a reference. If the backend thread's Closing manages to
269  // run before we release our backend refptr, the last reference will be held
270  // by this thread and the destructor will be called from here.
271  //
272  // Therefore, we create a closure to run the Closing operation first. This
273  // holds a reference to the backend. Then we release our reference, then we
274  // schedule the task to run. After the task runs, it will delete its reference
275  // from the history thread, ensuring everything works properly.
276  //
277  // TODO(ajwong): Cleanup HistoryBackend lifetime issues.
278  //     See http://crbug.com/99767.
279  history_backend_->AddRef();
280  base::Closure closing_task =
281      base::Bind(&HistoryBackend::Closing, history_backend_.get());
282  ScheduleTask(PRIORITY_NORMAL, closing_task);
283  closing_task.Reset();
284  HistoryBackend* raw_ptr = history_backend_.get();
285  history_backend_ = NULL;
286  thread_->message_loop()->ReleaseSoon(FROM_HERE, raw_ptr);
287}
288
289void HistoryService::Cleanup() {
290  DCHECK(thread_checker_.CalledOnValidThread());
291  if (!thread_) {
292    // We've already cleaned up.
293    return;
294  }
295
296  weak_ptr_factory_.InvalidateWeakPtrs();
297
298  // Unload the backend.
299  UnloadBackend();
300
301  // Delete the thread, which joins with the background thread. We defensively
302  // NULL the pointer before deleting it in case somebody tries to use it
303  // during shutdown, but this shouldn't happen.
304  base::Thread* thread = thread_;
305  thread_ = NULL;
306  delete thread;
307}
308
309void HistoryService::NotifyRenderProcessHostDestruction(const void* host) {
310  DCHECK(thread_checker_.CalledOnValidThread());
311  ScheduleAndForget(PRIORITY_NORMAL,
312                    &HistoryBackend::NotifyRenderProcessHostDestruction, host);
313}
314
315history::URLDatabase* HistoryService::InMemoryDatabase() {
316  DCHECK(thread_checker_.CalledOnValidThread());
317  // NOTE: See comments in BackendLoaded() as to why we call
318  // LoadBackendIfNecessary() here even though it won't affect the return value
319  // for this call.
320  LoadBackendIfNecessary();
321  if (in_memory_backend_)
322    return in_memory_backend_->db();
323  return NULL;
324}
325
326bool HistoryService::GetTypedCountForURL(const GURL& url, int* typed_count) {
327  DCHECK(thread_checker_.CalledOnValidThread());
328  history::URLRow url_row;
329  if (!GetRowForURL(url, &url_row))
330    return false;
331  *typed_count = url_row.typed_count();
332  return true;
333}
334
335bool HistoryService::GetLastVisitTimeForURL(const GURL& url,
336                                            base::Time* last_visit) {
337  DCHECK(thread_checker_.CalledOnValidThread());
338  history::URLRow url_row;
339  if (!GetRowForURL(url, &url_row))
340    return false;
341  *last_visit = url_row.last_visit();
342  return true;
343}
344
345bool HistoryService::GetVisitCountForURL(const GURL& url, int* visit_count) {
346  DCHECK(thread_checker_.CalledOnValidThread());
347  history::URLRow url_row;
348  if (!GetRowForURL(url, &url_row))
349    return false;
350  *visit_count = url_row.visit_count();
351  return true;
352}
353
354history::TypedUrlSyncableService* HistoryService::GetTypedUrlSyncableService()
355    const {
356  return history_backend_->GetTypedUrlSyncableService();
357}
358
359void HistoryService::Shutdown() {
360  DCHECK(thread_checker_.CalledOnValidThread());
361  // It's possible that bookmarks haven't loaded and history is waiting for
362  // bookmarks to complete loading. In such a situation history can't shutdown
363  // (meaning if we invoked history_service_->Cleanup now, we would
364  // deadlock). To break the deadlock we tell BookmarkModel it's about to be
365  // deleted so that it can release the signal history is waiting on, allowing
366  // history to shutdown (history_service_->Cleanup to complete). In such a
367  // scenario history sees an incorrect view of bookmarks, but it's better
368  // than a deadlock.
369  BookmarkModel* bookmark_model = static_cast<BookmarkModel*>(
370      BookmarkModelFactory::GetForProfileIfExists(profile_));
371  if (bookmark_model)
372    bookmark_model->Shutdown();
373
374  Cleanup();
375}
376
377void HistoryService::SetKeywordSearchTermsForURL(const GURL& url,
378                                                 TemplateURLID keyword_id,
379                                                 const base::string16& term) {
380  DCHECK(thread_checker_.CalledOnValidThread());
381  ScheduleAndForget(PRIORITY_UI,
382                    &HistoryBackend::SetKeywordSearchTermsForURL,
383                    url, keyword_id, term);
384}
385
386void HistoryService::DeleteAllSearchTermsForKeyword(
387    TemplateURLID keyword_id) {
388  DCHECK(thread_checker_.CalledOnValidThread());
389  ScheduleAndForget(PRIORITY_UI,
390                    &HistoryBackend::DeleteAllSearchTermsForKeyword,
391                    keyword_id);
392}
393
394HistoryService::Handle HistoryService::GetMostRecentKeywordSearchTerms(
395    TemplateURLID keyword_id,
396    const base::string16& prefix,
397    int max_count,
398    CancelableRequestConsumerBase* consumer,
399    const GetMostRecentKeywordSearchTermsCallback& callback) {
400  DCHECK(thread_checker_.CalledOnValidThread());
401  return Schedule(PRIORITY_UI, &HistoryBackend::GetMostRecentKeywordSearchTerms,
402                  consumer,
403                  new history::GetMostRecentKeywordSearchTermsRequest(callback),
404                  keyword_id, prefix, max_count);
405}
406
407void HistoryService::DeleteKeywordSearchTermForURL(const GURL& url) {
408  DCHECK(thread_checker_.CalledOnValidThread());
409  ScheduleAndForget(PRIORITY_UI, &HistoryBackend::DeleteKeywordSearchTermForURL,
410                    url);
411}
412
413void HistoryService::DeleteMatchingURLsForKeyword(TemplateURLID keyword_id,
414                                                  const base::string16& term) {
415  DCHECK(thread_checker_.CalledOnValidThread());
416  ScheduleAndForget(PRIORITY_UI, &HistoryBackend::DeleteMatchingURLsForKeyword,
417                    keyword_id, term);
418}
419
420void HistoryService::URLsNoLongerBookmarked(const std::set<GURL>& urls) {
421  DCHECK(thread_checker_.CalledOnValidThread());
422  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::URLsNoLongerBookmarked,
423                    urls);
424}
425
426void HistoryService::ScheduleDBTask(history::HistoryDBTask* task,
427                                    CancelableRequestConsumerBase* consumer) {
428  DCHECK(thread_checker_.CalledOnValidThread());
429  history::HistoryDBTaskRequest* request = new history::HistoryDBTaskRequest(
430      base::Bind(&history::HistoryDBTask::DoneRunOnMainThread, task));
431  request->value = task;  // The value is the task to execute.
432  Schedule(PRIORITY_UI, &HistoryBackend::ProcessDBTask, consumer, request);
433}
434
435HistoryService::Handle HistoryService::QuerySegmentUsageSince(
436    CancelableRequestConsumerBase* consumer,
437    const Time from_time,
438    int max_result_count,
439    const SegmentQueryCallback& callback) {
440  DCHECK(thread_checker_.CalledOnValidThread());
441  return Schedule(PRIORITY_UI, &HistoryBackend::QuerySegmentUsage,
442                  consumer, new history::QuerySegmentUsageRequest(callback),
443                  from_time, max_result_count);
444}
445
446void HistoryService::FlushForTest(const base::Closure& flushed) {
447  thread_->message_loop_proxy()->PostTaskAndReply(
448      FROM_HERE, base::Bind(&base::DoNothing), flushed);
449}
450
451void HistoryService::SetOnBackendDestroyTask(const base::Closure& task) {
452  DCHECK(thread_checker_.CalledOnValidThread());
453  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::SetOnBackendDestroyTask,
454                    base::MessageLoop::current(), task);
455}
456
457void HistoryService::AddPage(const GURL& url,
458                             Time time,
459                             const void* id_scope,
460                             int32 page_id,
461                             const GURL& referrer,
462                             const history::RedirectList& redirects,
463                             content::PageTransition transition,
464                             history::VisitSource visit_source,
465                             bool did_replace_entry) {
466  DCHECK(thread_checker_.CalledOnValidThread());
467  AddPage(
468      history::HistoryAddPageArgs(url, time, id_scope, page_id, referrer,
469                                  redirects, transition, visit_source,
470                                  did_replace_entry));
471}
472
473void HistoryService::AddPage(const GURL& url,
474                             base::Time time,
475                             history::VisitSource visit_source) {
476  DCHECK(thread_checker_.CalledOnValidThread());
477  AddPage(
478      history::HistoryAddPageArgs(url, time, NULL, 0, GURL(),
479                                  history::RedirectList(),
480                                  content::PAGE_TRANSITION_LINK,
481                                  visit_source, false));
482}
483
484void HistoryService::AddPage(const history::HistoryAddPageArgs& add_page_args) {
485  DCHECK(thread_checker_.CalledOnValidThread());
486  DCHECK(thread_) << "History service being called after cleanup";
487
488  // Filter out unwanted URLs. We don't add auto-subframe URLs. They are a
489  // large part of history (think iframes for ads) and we never display them in
490  // history UI. We will still add manual subframes, which are ones the user
491  // has clicked on to get.
492  if (!CanAddURL(add_page_args.url))
493    return;
494
495  // Add link & all redirects to visited link list.
496  if (visitedlink_master_) {
497    visitedlink_master_->AddURL(add_page_args.url);
498
499    if (!add_page_args.redirects.empty()) {
500      // We should not be asked to add a page in the middle of a redirect chain.
501      DCHECK_EQ(add_page_args.url,
502                add_page_args.redirects[add_page_args.redirects.size() - 1]);
503
504      // We need the !redirects.empty() condition above since size_t is unsigned
505      // and will wrap around when we subtract one from a 0 size.
506      for (size_t i = 0; i < add_page_args.redirects.size() - 1; i++)
507        visitedlink_master_->AddURL(add_page_args.redirects[i]);
508    }
509  }
510
511  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::AddPage, add_page_args);
512}
513
514void HistoryService::AddPageNoVisitForBookmark(const GURL& url,
515                                               const base::string16& title) {
516  DCHECK(thread_checker_.CalledOnValidThread());
517  if (!CanAddURL(url))
518    return;
519
520  ScheduleAndForget(PRIORITY_NORMAL,
521                    &HistoryBackend::AddPageNoVisitForBookmark, url, title);
522}
523
524void HistoryService::SetPageTitle(const GURL& url,
525                                  const base::string16& title) {
526  DCHECK(thread_checker_.CalledOnValidThread());
527  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::SetPageTitle, url, title);
528}
529
530void HistoryService::UpdateWithPageEndTime(const void* host,
531                                           int32 page_id,
532                                           const GURL& url,
533                                           Time end_ts) {
534  DCHECK(thread_checker_.CalledOnValidThread());
535  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::UpdateWithPageEndTime,
536                    host, page_id, url, end_ts);
537}
538
539void HistoryService::AddPageWithDetails(const GURL& url,
540                                        const base::string16& title,
541                                        int visit_count,
542                                        int typed_count,
543                                        Time last_visit,
544                                        bool hidden,
545                                        history::VisitSource visit_source) {
546  DCHECK(thread_checker_.CalledOnValidThread());
547  // Filter out unwanted URLs.
548  if (!CanAddURL(url))
549    return;
550
551  // Add to the visited links system.
552  if (visitedlink_master_)
553    visitedlink_master_->AddURL(url);
554
555  history::URLRow row(url);
556  row.set_title(title);
557  row.set_visit_count(visit_count);
558  row.set_typed_count(typed_count);
559  row.set_last_visit(last_visit);
560  row.set_hidden(hidden);
561
562  history::URLRows rows;
563  rows.push_back(row);
564
565  ScheduleAndForget(PRIORITY_NORMAL,
566                    &HistoryBackend::AddPagesWithDetails, rows, visit_source);
567}
568
569void HistoryService::AddPagesWithDetails(const history::URLRows& info,
570                                         history::VisitSource visit_source) {
571  DCHECK(thread_checker_.CalledOnValidThread());
572  // Add to the visited links system.
573  if (visitedlink_master_) {
574    std::vector<GURL> urls;
575    urls.reserve(info.size());
576    for (history::URLRows::const_iterator i = info.begin(); i != info.end();
577         ++i)
578      urls.push_back(i->url());
579
580    visitedlink_master_->AddURLs(urls);
581  }
582
583  ScheduleAndForget(PRIORITY_NORMAL,
584                    &HistoryBackend::AddPagesWithDetails, info, visit_source);
585}
586
587base::CancelableTaskTracker::TaskId HistoryService::GetFavicons(
588    const std::vector<GURL>& icon_urls,
589    int icon_types,
590    int desired_size_in_dip,
591    const std::vector<ui::ScaleFactor>& desired_scale_factors,
592    const FaviconService::FaviconResultsCallback& callback,
593    base::CancelableTaskTracker* tracker) {
594  DCHECK(thread_checker_.CalledOnValidThread());
595  LoadBackendIfNecessary();
596
597  std::vector<chrome::FaviconBitmapResult>* results =
598      new std::vector<chrome::FaviconBitmapResult>();
599  return tracker->PostTaskAndReply(
600      thread_->message_loop_proxy().get(),
601      FROM_HERE,
602      base::Bind(&HistoryBackend::GetFavicons,
603                 history_backend_.get(),
604                 icon_urls,
605                 icon_types,
606                 desired_size_in_dip,
607                 desired_scale_factors,
608                 results),
609      base::Bind(&RunWithFaviconResults, callback, base::Owned(results)));
610}
611
612base::CancelableTaskTracker::TaskId HistoryService::GetFaviconsForURL(
613    const GURL& page_url,
614    int icon_types,
615    int desired_size_in_dip,
616    const std::vector<ui::ScaleFactor>& desired_scale_factors,
617    const FaviconService::FaviconResultsCallback& callback,
618    base::CancelableTaskTracker* tracker) {
619  DCHECK(thread_checker_.CalledOnValidThread());
620  LoadBackendIfNecessary();
621
622  std::vector<chrome::FaviconBitmapResult>* results =
623      new std::vector<chrome::FaviconBitmapResult>();
624  return tracker->PostTaskAndReply(
625      thread_->message_loop_proxy().get(),
626      FROM_HERE,
627      base::Bind(&HistoryBackend::GetFaviconsForURL,
628                 history_backend_.get(),
629                 page_url,
630                 icon_types,
631                 desired_size_in_dip,
632                 desired_scale_factors,
633                 results),
634      base::Bind(&RunWithFaviconResults, callback, base::Owned(results)));
635}
636
637base::CancelableTaskTracker::TaskId HistoryService::GetLargestFaviconForURL(
638    const GURL& page_url,
639    const std::vector<int>& icon_types,
640    int minimum_size_in_pixels,
641    const FaviconService::FaviconRawCallback& callback,
642    base::CancelableTaskTracker* tracker) {
643  DCHECK(thread_checker_.CalledOnValidThread());
644  LoadBackendIfNecessary();
645
646  chrome::FaviconBitmapResult* result = new chrome::FaviconBitmapResult();
647  return tracker->PostTaskAndReply(
648      thread_->message_loop_proxy().get(),
649      FROM_HERE,
650      base::Bind(&HistoryBackend::GetLargestFaviconForURL,
651                 history_backend_.get(),
652                 page_url,
653                 icon_types,
654                 minimum_size_in_pixels,
655                 result),
656      base::Bind(&RunWithFaviconResult, callback, base::Owned(result)));
657}
658
659base::CancelableTaskTracker::TaskId HistoryService::GetFaviconForID(
660    chrome::FaviconID favicon_id,
661    int desired_size_in_dip,
662    ui::ScaleFactor desired_scale_factor,
663    const FaviconService::FaviconResultsCallback& callback,
664    base::CancelableTaskTracker* tracker) {
665  DCHECK(thread_checker_.CalledOnValidThread());
666  LoadBackendIfNecessary();
667
668  std::vector<chrome::FaviconBitmapResult>* results =
669      new std::vector<chrome::FaviconBitmapResult>();
670  return tracker->PostTaskAndReply(
671      thread_->message_loop_proxy().get(),
672      FROM_HERE,
673      base::Bind(&HistoryBackend::GetFaviconForID,
674                 history_backend_.get(),
675                 favicon_id,
676                 desired_size_in_dip,
677                 desired_scale_factor,
678                 results),
679      base::Bind(&RunWithFaviconResults, callback, base::Owned(results)));
680}
681
682base::CancelableTaskTracker::TaskId
683HistoryService::UpdateFaviconMappingsAndFetch(
684    const GURL& page_url,
685    const std::vector<GURL>& icon_urls,
686    int icon_types,
687    int desired_size_in_dip,
688    const std::vector<ui::ScaleFactor>& desired_scale_factors,
689    const FaviconService::FaviconResultsCallback& callback,
690    base::CancelableTaskTracker* tracker) {
691  DCHECK(thread_checker_.CalledOnValidThread());
692  LoadBackendIfNecessary();
693
694  std::vector<chrome::FaviconBitmapResult>* results =
695      new std::vector<chrome::FaviconBitmapResult>();
696  return tracker->PostTaskAndReply(
697      thread_->message_loop_proxy().get(),
698      FROM_HERE,
699      base::Bind(&HistoryBackend::UpdateFaviconMappingsAndFetch,
700                 history_backend_.get(),
701                 page_url,
702                 icon_urls,
703                 icon_types,
704                 desired_size_in_dip,
705                 desired_scale_factors,
706                 results),
707      base::Bind(&RunWithFaviconResults, callback, base::Owned(results)));
708}
709
710void HistoryService::MergeFavicon(
711    const GURL& page_url,
712    const GURL& icon_url,
713    chrome::IconType icon_type,
714    scoped_refptr<base::RefCountedMemory> bitmap_data,
715    const gfx::Size& pixel_size) {
716  DCHECK(thread_checker_.CalledOnValidThread());
717  if (!CanAddURL(page_url))
718    return;
719
720  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::MergeFavicon, page_url,
721                    icon_url, icon_type, bitmap_data, pixel_size);
722}
723
724void HistoryService::SetFavicons(
725    const GURL& page_url,
726    chrome::IconType icon_type,
727    const std::vector<chrome::FaviconBitmapData>& favicon_bitmap_data) {
728  DCHECK(thread_checker_.CalledOnValidThread());
729  if (!CanAddURL(page_url))
730    return;
731
732  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::SetFavicons, page_url,
733      icon_type, favicon_bitmap_data);
734}
735
736void HistoryService::SetFaviconsOutOfDateForPage(const GURL& page_url) {
737  DCHECK(thread_checker_.CalledOnValidThread());
738  ScheduleAndForget(PRIORITY_NORMAL,
739                    &HistoryBackend::SetFaviconsOutOfDateForPage, page_url);
740}
741
742void HistoryService::CloneFavicons(const GURL& old_page_url,
743                                   const GURL& new_page_url) {
744  DCHECK(thread_checker_.CalledOnValidThread());
745  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::CloneFavicons,
746                    old_page_url, new_page_url);
747}
748
749void HistoryService::SetImportedFavicons(
750    const std::vector<ImportedFaviconUsage>& favicon_usage) {
751  DCHECK(thread_checker_.CalledOnValidThread());
752  ScheduleAndForget(PRIORITY_NORMAL,
753                    &HistoryBackend::SetImportedFavicons, favicon_usage);
754}
755
756HistoryService::Handle HistoryService::QueryURL(
757    const GURL& url,
758    bool want_visits,
759    CancelableRequestConsumerBase* consumer,
760    const QueryURLCallback& callback) {
761  DCHECK(thread_checker_.CalledOnValidThread());
762  return Schedule(PRIORITY_UI, &HistoryBackend::QueryURL, consumer,
763                  new history::QueryURLRequest(callback), url, want_visits);
764}
765
766// Downloads -------------------------------------------------------------------
767
768// Handle creation of a download by creating an entry in the history service's
769// 'downloads' table.
770void HistoryService::CreateDownload(
771    const history::DownloadRow& create_info,
772    const HistoryService::DownloadCreateCallback& callback) {
773  DCHECK(thread_) << "History service being called after cleanup";
774  DCHECK(thread_checker_.CalledOnValidThread());
775  LoadBackendIfNecessary();
776  bool* success = new bool(false);
777  thread_->message_loop_proxy()->PostTaskAndReply(
778      FROM_HERE,
779      base::Bind(&HistoryBackend::CreateDownload,
780                 history_backend_.get(),
781                 create_info,
782                 success),
783      base::Bind(&DerefPODType<bool>, callback, base::Owned(success)));
784}
785
786void HistoryService::GetNextDownloadId(
787    const content::DownloadIdCallback& callback) {
788  DCHECK(thread_) << "History service being called after cleanup";
789  DCHECK(thread_checker_.CalledOnValidThread());
790  LoadBackendIfNecessary();
791  uint32* next_id = new uint32(content::DownloadItem::kInvalidId);
792  thread_->message_loop_proxy()->PostTaskAndReply(
793      FROM_HERE,
794      base::Bind(&HistoryBackend::GetNextDownloadId,
795                 history_backend_.get(),
796                 next_id),
797      base::Bind(&DerefPODType<uint32>, callback, base::Owned(next_id)));
798}
799
800// Handle queries for a list of all downloads in the history database's
801// 'downloads' table.
802void HistoryService::QueryDownloads(
803    const DownloadQueryCallback& callback) {
804  DCHECK(thread_) << "History service being called after cleanup";
805  DCHECK(thread_checker_.CalledOnValidThread());
806  LoadBackendIfNecessary();
807  std::vector<history::DownloadRow>* rows =
808    new std::vector<history::DownloadRow>();
809  scoped_ptr<std::vector<history::DownloadRow> > scoped_rows(rows);
810  // Beware! The first Bind() does not simply |scoped_rows.get()| because
811  // base::Passed(&scoped_rows) nullifies |scoped_rows|, and compilers do not
812  // guarantee that the first Bind's arguments are evaluated before the second
813  // Bind's arguments.
814  thread_->message_loop_proxy()->PostTaskAndReply(
815      FROM_HERE,
816      base::Bind(&HistoryBackend::QueryDownloads, history_backend_.get(), rows),
817      base::Bind(callback, base::Passed(&scoped_rows)));
818}
819
820// Handle updates for a particular download. This is a 'fire and forget'
821// operation, so we don't need to be called back.
822void HistoryService::UpdateDownload(const history::DownloadRow& data) {
823  DCHECK(thread_checker_.CalledOnValidThread());
824  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::UpdateDownload, data);
825}
826
827void HistoryService::RemoveDownloads(const std::set<uint32>& ids) {
828  DCHECK(thread_checker_.CalledOnValidThread());
829  ScheduleAndForget(PRIORITY_NORMAL,
830                    &HistoryBackend::RemoveDownloads, ids);
831}
832
833HistoryService::Handle HistoryService::QueryHistory(
834    const base::string16& text_query,
835    const history::QueryOptions& options,
836    CancelableRequestConsumerBase* consumer,
837    const QueryHistoryCallback& callback) {
838  DCHECK(thread_checker_.CalledOnValidThread());
839  return Schedule(PRIORITY_UI, &HistoryBackend::QueryHistory, consumer,
840                  new history::QueryHistoryRequest(callback),
841                  text_query, options);
842}
843
844HistoryService::Handle HistoryService::QueryRedirectsFrom(
845    const GURL& from_url,
846    CancelableRequestConsumerBase* consumer,
847    const QueryRedirectsCallback& callback) {
848  DCHECK(thread_checker_.CalledOnValidThread());
849  return Schedule(PRIORITY_UI, &HistoryBackend::QueryRedirectsFrom, consumer,
850      new history::QueryRedirectsRequest(callback), from_url);
851}
852
853HistoryService::Handle HistoryService::QueryRedirectsTo(
854    const GURL& to_url,
855    CancelableRequestConsumerBase* consumer,
856    const QueryRedirectsCallback& callback) {
857  DCHECK(thread_checker_.CalledOnValidThread());
858  return Schedule(PRIORITY_NORMAL, &HistoryBackend::QueryRedirectsTo, consumer,
859      new history::QueryRedirectsRequest(callback), to_url);
860}
861
862HistoryService::Handle HistoryService::GetVisibleVisitCountToHost(
863    const GURL& url,
864    CancelableRequestConsumerBase* consumer,
865    const GetVisibleVisitCountToHostCallback& callback) {
866  DCHECK(thread_checker_.CalledOnValidThread());
867  return Schedule(PRIORITY_UI, &HistoryBackend::GetVisibleVisitCountToHost,
868      consumer, new history::GetVisibleVisitCountToHostRequest(callback), url);
869}
870
871HistoryService::Handle HistoryService::QueryTopURLsAndRedirects(
872    int result_count,
873    CancelableRequestConsumerBase* consumer,
874    const QueryTopURLsAndRedirectsCallback& callback) {
875  DCHECK(thread_checker_.CalledOnValidThread());
876  return Schedule(PRIORITY_NORMAL, &HistoryBackend::QueryTopURLsAndRedirects,
877      consumer, new history::QueryTopURLsAndRedirectsRequest(callback),
878      result_count);
879}
880
881HistoryService::Handle HistoryService::QueryMostVisitedURLs(
882    int result_count,
883    int days_back,
884    CancelableRequestConsumerBase* consumer,
885    const QueryMostVisitedURLsCallback& callback) {
886  DCHECK(thread_checker_.CalledOnValidThread());
887  return Schedule(PRIORITY_NORMAL, &HistoryBackend::QueryMostVisitedURLs,
888                  consumer,
889                  new history::QueryMostVisitedURLsRequest(callback),
890                  result_count, days_back);
891}
892
893HistoryService::Handle HistoryService::QueryFilteredURLs(
894    int result_count,
895    const history::VisitFilter& filter,
896    bool extended_info,
897    CancelableRequestConsumerBase* consumer,
898    const QueryFilteredURLsCallback& callback) {
899  DCHECK(thread_checker_.CalledOnValidThread());
900  return Schedule(PRIORITY_NORMAL,
901                  &HistoryBackend::QueryFilteredURLs,
902                  consumer,
903                  new history::QueryFilteredURLsRequest(callback),
904                  result_count, filter, extended_info);
905}
906
907void HistoryService::Observe(int type,
908                             const content::NotificationSource& source,
909                             const content::NotificationDetails& details) {
910  DCHECK(thread_checker_.CalledOnValidThread());
911  if (!thread_)
912    return;
913
914  switch (type) {
915    case chrome::NOTIFICATION_HISTORY_URLS_DELETED: {
916      // Update the visited link system for deleted URLs. We will update the
917      // visited link system for added URLs as soon as we get the add
918      // notification (we don't have to wait for the backend, which allows us to
919      // be faster to update the state).
920      //
921      // For deleted URLs, we don't typically know what will be deleted since
922      // delete notifications are by time. We would also like to be more
923      // respectful of privacy and never tell the user something is gone when it
924      // isn't. Therefore, we update the delete URLs after the fact.
925      if (visitedlink_master_) {
926        content::Details<history::URLsDeletedDetails> deleted_details(details);
927
928        if (deleted_details->all_history) {
929          visitedlink_master_->DeleteAllURLs();
930        } else {
931          URLIteratorFromURLRows iterator(deleted_details->rows);
932          visitedlink_master_->DeleteURLs(&iterator);
933        }
934      }
935      break;
936    }
937
938    case chrome::NOTIFICATION_TEMPLATE_URL_REMOVED:
939      DeleteAllSearchTermsForKeyword(
940          *(content::Details<TemplateURLID>(details).ptr()));
941      break;
942
943    default:
944      NOTREACHED();
945  }
946}
947
948void HistoryService::RebuildTable(
949    const scoped_refptr<URLEnumerator>& enumerator) {
950  DCHECK(thread_checker_.CalledOnValidThread());
951  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::IterateURLs, enumerator);
952}
953
954bool HistoryService::Init(const base::FilePath& history_dir,
955                          BookmarkService* bookmark_service,
956                          bool no_db) {
957  DCHECK(thread_checker_.CalledOnValidThread());
958  if (!thread_->Start()) {
959    Cleanup();
960    return false;
961  }
962
963  history_dir_ = history_dir;
964  bookmark_service_ = bookmark_service;
965  no_db_ = no_db;
966
967  if (profile_) {
968    std::string languages =
969        profile_->GetPrefs()->GetString(prefs::kAcceptLanguages);
970    in_memory_url_index_.reset(
971        new history::InMemoryURLIndex(profile_, history_dir_, languages));
972    in_memory_url_index_->Init();
973  }
974
975  // Create the history backend.
976  LoadBackendIfNecessary();
977
978  if (visitedlink_master_) {
979    bool result = visitedlink_master_->Init();
980    DCHECK(result);
981  }
982
983  return true;
984}
985
986void HistoryService::ScheduleAutocomplete(HistoryURLProvider* provider,
987                                          HistoryURLProviderParams* params) {
988  DCHECK(thread_checker_.CalledOnValidThread());
989  ScheduleAndForget(PRIORITY_UI, &HistoryBackend::ScheduleAutocomplete,
990                    scoped_refptr<HistoryURLProvider>(provider), params);
991}
992
993void HistoryService::ScheduleTask(SchedulePriority priority,
994                                  const base::Closure& task) {
995  DCHECK(thread_checker_.CalledOnValidThread());
996  CHECK(thread_);
997  CHECK(thread_->message_loop());
998  // TODO(brettw): Do prioritization.
999  thread_->message_loop()->PostTask(FROM_HERE, task);
1000}
1001
1002// static
1003bool HistoryService::CanAddURL(const GURL& url) {
1004  if (!url.is_valid())
1005    return false;
1006
1007  // TODO: We should allow kChromeUIScheme URLs if they have been explicitly
1008  // typed.  Right now, however, these are marked as typed even when triggered
1009  // by a shortcut or menu action.
1010  if (url.SchemeIs(content::kJavaScriptScheme) ||
1011      url.SchemeIs(content::kChromeDevToolsScheme) ||
1012      url.SchemeIs(content::kChromeUIScheme) ||
1013      url.SchemeIs(content::kViewSourceScheme) ||
1014      url.SchemeIs(chrome::kChromeNativeScheme) ||
1015      url.SchemeIs(chrome::kChromeSearchScheme) ||
1016      url.SchemeIs(chrome::kDomDistillerScheme))
1017    return false;
1018
1019  // Allow all about: and chrome: URLs except about:blank, since the user may
1020  // like to see "chrome://memory/", etc. in their history and autocomplete.
1021  if (url == GURL(content::kAboutBlankURL))
1022    return false;
1023
1024  return true;
1025}
1026
1027base::WeakPtr<HistoryService> HistoryService::AsWeakPtr() {
1028  DCHECK(thread_checker_.CalledOnValidThread());
1029  return weak_ptr_factory_.GetWeakPtr();
1030}
1031
1032syncer::SyncMergeResult HistoryService::MergeDataAndStartSyncing(
1033    syncer::ModelType type,
1034    const syncer::SyncDataList& initial_sync_data,
1035    scoped_ptr<syncer::SyncChangeProcessor> sync_processor,
1036    scoped_ptr<syncer::SyncErrorFactory> error_handler) {
1037  DCHECK(thread_checker_.CalledOnValidThread());
1038  DCHECK_EQ(type, syncer::HISTORY_DELETE_DIRECTIVES);
1039  delete_directive_handler_.Start(this, initial_sync_data,
1040                                  sync_processor.Pass());
1041  return syncer::SyncMergeResult(type);
1042}
1043
1044void HistoryService::StopSyncing(syncer::ModelType type) {
1045  DCHECK(thread_checker_.CalledOnValidThread());
1046  DCHECK_EQ(type, syncer::HISTORY_DELETE_DIRECTIVES);
1047  delete_directive_handler_.Stop();
1048}
1049
1050syncer::SyncDataList HistoryService::GetAllSyncData(
1051    syncer::ModelType type) const {
1052  DCHECK(thread_checker_.CalledOnValidThread());
1053  DCHECK_EQ(type, syncer::HISTORY_DELETE_DIRECTIVES);
1054  // TODO(akalin): Keep track of existing delete directives.
1055  return syncer::SyncDataList();
1056}
1057
1058syncer::SyncError HistoryService::ProcessSyncChanges(
1059    const tracked_objects::Location& from_here,
1060    const syncer::SyncChangeList& change_list) {
1061  delete_directive_handler_.ProcessSyncChanges(this, change_list);
1062  return syncer::SyncError();
1063}
1064
1065syncer::SyncError HistoryService::ProcessLocalDeleteDirective(
1066    const sync_pb::HistoryDeleteDirectiveSpecifics& delete_directive) {
1067  DCHECK(thread_checker_.CalledOnValidThread());
1068  return delete_directive_handler_.ProcessLocalDeleteDirective(
1069      delete_directive);
1070}
1071
1072void HistoryService::SetInMemoryBackend(
1073    int backend_id, scoped_ptr<history::InMemoryHistoryBackend> mem_backend) {
1074  DCHECK(thread_checker_.CalledOnValidThread());
1075  if (!history_backend_.get() || current_backend_id_ != backend_id) {
1076    DVLOG(1) << "Message from obsolete backend";
1077    // mem_backend is deleted.
1078    return;
1079  }
1080  DCHECK(!in_memory_backend_) << "Setting mem DB twice";
1081  in_memory_backend_.reset(mem_backend.release());
1082
1083  // The database requires additional initialization once we own it.
1084  in_memory_backend_->AttachToHistoryService(profile_);
1085}
1086
1087void HistoryService::NotifyProfileError(int backend_id,
1088                                        sql::InitStatus init_status) {
1089  DCHECK(thread_checker_.CalledOnValidThread());
1090  if (!history_backend_.get() || current_backend_id_ != backend_id) {
1091    DVLOG(1) << "Message from obsolete backend";
1092    return;
1093  }
1094  ShowProfileErrorDialog(
1095      PROFILE_ERROR_HISTORY,
1096      (init_status == sql::INIT_FAILURE) ?
1097      IDS_COULDNT_OPEN_PROFILE_ERROR : IDS_PROFILE_TOO_NEW_ERROR);
1098}
1099
1100void HistoryService::DeleteURL(const GURL& url) {
1101  DCHECK(thread_checker_.CalledOnValidThread());
1102  // We will update the visited links when we observe the delete notifications.
1103  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::DeleteURL, url);
1104}
1105
1106void HistoryService::DeleteURLsForTest(const std::vector<GURL>& urls) {
1107  DCHECK(thread_checker_.CalledOnValidThread());
1108  // We will update the visited links when we observe the delete
1109  // notifications.
1110  ScheduleAndForget(PRIORITY_NORMAL, &HistoryBackend::DeleteURLs, urls);
1111}
1112
1113void HistoryService::ExpireHistoryBetween(
1114    const std::set<GURL>& restrict_urls,
1115    Time begin_time,
1116    Time end_time,
1117    const base::Closure& callback,
1118    base::CancelableTaskTracker* tracker) {
1119  DCHECK(thread_);
1120  DCHECK(thread_checker_.CalledOnValidThread());
1121  DCHECK(history_backend_.get());
1122  tracker->PostTaskAndReply(thread_->message_loop_proxy().get(),
1123                            FROM_HERE,
1124                            base::Bind(&HistoryBackend::ExpireHistoryBetween,
1125                                       history_backend_,
1126                                       restrict_urls,
1127                                       begin_time,
1128                                       end_time),
1129                            callback);
1130}
1131
1132void HistoryService::ExpireHistory(
1133    const std::vector<history::ExpireHistoryArgs>& expire_list,
1134    const base::Closure& callback,
1135    base::CancelableTaskTracker* tracker) {
1136  DCHECK(thread_);
1137  DCHECK(thread_checker_.CalledOnValidThread());
1138  DCHECK(history_backend_.get());
1139  tracker->PostTaskAndReply(
1140      thread_->message_loop_proxy().get(),
1141      FROM_HERE,
1142      base::Bind(&HistoryBackend::ExpireHistory, history_backend_, expire_list),
1143      callback);
1144}
1145
1146void HistoryService::ExpireLocalAndRemoteHistoryBetween(
1147    const std::set<GURL>& restrict_urls,
1148    Time begin_time,
1149    Time end_time,
1150    const base::Closure& callback,
1151    base::CancelableTaskTracker* tracker) {
1152  // TODO(dubroy): This should be factored out into a separate class that
1153  // dispatches deletions to the proper places.
1154
1155  history::WebHistoryService* web_history =
1156      WebHistoryServiceFactory::GetForProfile(profile_);
1157  if (web_history) {
1158    // TODO(dubroy): This API does not yet support deletion of specific URLs.
1159    DCHECK(restrict_urls.empty());
1160
1161    delete_directive_handler_.CreateDeleteDirectives(
1162        std::set<int64>(), begin_time, end_time);
1163
1164    // Attempt online deletion from the history server, but ignore the result.
1165    // Deletion directives ensure that the results will eventually be deleted.
1166    // Pass ownership of the request to the callback.
1167    scoped_ptr<history::WebHistoryService::Request> request =
1168        web_history->ExpireHistoryBetween(
1169            restrict_urls, begin_time, end_time,
1170            base::Bind(&ExpireWebHistoryComplete));
1171
1172    // The request will be freed when the callback is called.
1173    CHECK(request.release());
1174  }
1175  ExpireHistoryBetween(restrict_urls, begin_time, end_time, callback, tracker);
1176}
1177
1178void HistoryService::BroadcastNotificationsHelper(
1179    int type,
1180    history::HistoryDetails* details) {
1181  DCHECK(thread_checker_.CalledOnValidThread());
1182  // TODO(evanm): this is currently necessitated by generate_profile, which
1183  // runs without a browser process. generate_profile should really create
1184  // a browser process, at which point this check can then be nuked.
1185  if (!g_browser_process)
1186    return;
1187
1188  if (!thread_)
1189    return;
1190
1191  // The source of all of our notifications is the profile. Note that this
1192  // pointer is NULL in unit tests.
1193  content::Source<Profile> source(profile_);
1194
1195  // The details object just contains the pointer to the object that the
1196  // backend has allocated for us. The receiver of the notification will cast
1197  // this to the proper type.
1198  content::Details<history::HistoryDetails> det(details);
1199
1200  content::NotificationService::current()->Notify(type, source, det);
1201}
1202
1203void HistoryService::LoadBackendIfNecessary() {
1204  DCHECK(thread_checker_.CalledOnValidThread());
1205  if (!thread_ || history_backend_.get())
1206    return;  // Failed to init, or already started loading.
1207
1208  ++current_backend_id_;
1209  scoped_refptr<HistoryBackend> backend(
1210      new HistoryBackend(history_dir_,
1211                         current_backend_id_,
1212                         new BackendDelegate(
1213                             weak_ptr_factory_.GetWeakPtr(),
1214                             base::ThreadTaskRunnerHandle::Get(),
1215                             profile_),
1216                         bookmark_service_));
1217  history_backend_.swap(backend);
1218
1219  // There may not be a profile when unit testing.
1220  std::string languages;
1221  if (profile_) {
1222    PrefService* prefs = profile_->GetPrefs();
1223    languages = prefs->GetString(prefs::kAcceptLanguages);
1224  }
1225  ScheduleAndForget(PRIORITY_UI, &HistoryBackend::Init, languages, no_db_);
1226}
1227
1228void HistoryService::OnDBLoaded(int backend_id) {
1229  DCHECK(thread_checker_.CalledOnValidThread());
1230  if (!history_backend_.get() || current_backend_id_ != backend_id) {
1231    DVLOG(1) << "Message from obsolete backend";
1232    return;
1233  }
1234  backend_loaded_ = true;
1235  content::NotificationService::current()->Notify(
1236      chrome::NOTIFICATION_HISTORY_LOADED,
1237      content::Source<Profile>(profile_),
1238      content::Details<HistoryService>(this));
1239}
1240
1241bool HistoryService::GetRowForURL(const GURL& url, history::URLRow* url_row) {
1242  DCHECK(thread_checker_.CalledOnValidThread());
1243  history::URLDatabase* db = InMemoryDatabase();
1244  return db && (db->GetRowForURL(url, url_row) != 0);
1245}
1246
1247void HistoryService::AddVisitDatabaseObserver(
1248    history::VisitDatabaseObserver* observer) {
1249  DCHECK(thread_checker_.CalledOnValidThread());
1250  visit_database_observers_.AddObserver(observer);
1251}
1252
1253void HistoryService::RemoveVisitDatabaseObserver(
1254    history::VisitDatabaseObserver* observer) {
1255  DCHECK(thread_checker_.CalledOnValidThread());
1256  visit_database_observers_.RemoveObserver(observer);
1257}
1258
1259void HistoryService::NotifyVisitDBObserversOnAddVisit(
1260    const history::BriefVisitInfo& info) {
1261  DCHECK(thread_checker_.CalledOnValidThread());
1262  FOR_EACH_OBSERVER(history::VisitDatabaseObserver, visit_database_observers_,
1263                    OnAddVisit(info));
1264}
1265