tab_restore_service.cc revision 3345a6884c488ff3a535c2c9acdd33d74b37e311 
1// Copyright (c) 2006-2008 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/sessions/tab_restore_service.h"
6
7#include <algorithm>
8#include <iterator>
9#include <map>
10
11#include "base/callback.h"
12#include "base/scoped_vector.h"
13#include "base/stl_util-inl.h"
14#include "chrome/browser/browser_list.h"
15#include "chrome/browser/browser_window.h"
16#include "chrome/browser/profile.h"
17#include "chrome/browser/sessions/session_service.h"
18#include "chrome/browser/sessions/session_command.h"
19#include "chrome/browser/sessions/session_types.h"
20#include "chrome/browser/sessions/tab_restore_service_observer.h"
21#include "chrome/browser/tab_contents/navigation_controller.h"
22#include "chrome/browser/tab_contents/navigation_entry.h"
23#include "chrome/browser/tab_contents/tab_contents.h"
24#include "chrome/browser/tabs/tab_strip_model.h"
25#include "chrome/common/extensions/extension.h"
26
27using base::Time;
28
29// TimeFactory-----------------------------------------------------------------
30
31TabRestoreService::TimeFactory::~TimeFactory() {}
32
33// Entry ----------------------------------------------------------------------
34
35// ID of the next Entry.
36static SessionID::id_type next_entry_id = 1;
37
38TabRestoreService::Entry::Entry()
39    : id(next_entry_id++),
40      type(TAB),
41      from_last_session(false) {}
42
43TabRestoreService::Entry::Entry(Type type)
44    : id(next_entry_id++),
45      type(type),
46      from_last_session(false) {}
47
48TabRestoreService::Entry::~Entry() {}
49
50// TabRestoreService ----------------------------------------------------------
51
52// static
53const size_t TabRestoreService::kMaxEntries = 10;
54
55// Identifier for commands written to file.
56// The ordering in the file is as follows:
57// . When the user closes a tab a command of type
58//   kCommandSelectedNavigationInTab is written identifying the tab and
59//   the selected index, then a kCommandPinnedState command if the tab was
60//   pinned and kCommandSetExtensionAppID if the tab has an app id. This is
61//   followed by any number of kCommandUpdateTabNavigation commands (1 per
62//   navigation entry).
63// . When the user closes a window a kCommandSelectedNavigationInTab command
64//   is written out and followed by n tab closed sequences (as previoulsy
65//   described).
66// . When the user restores an entry a command of type kCommandRestoredEntry
67//   is written.
68static const SessionCommand::id_type kCommandUpdateTabNavigation = 1;
69static const SessionCommand::id_type kCommandRestoredEntry = 2;
70static const SessionCommand::id_type kCommandWindow = 3;
71static const SessionCommand::id_type kCommandSelectedNavigationInTab = 4;
72static const SessionCommand::id_type kCommandPinnedState = 5;
73static const SessionCommand::id_type kCommandSetExtensionAppID = 6;
74
75// Number of entries (not commands) before we clobber the file and write
76// everything.
77static const int kEntriesPerReset = 40;
78
79namespace {
80
81// Payload structures.
82
83typedef int32 RestoredEntryPayload;
84
85// Payload used for the start of a window close. This is the old struct that is
86// used for backwards compat when it comes to reading the session files. This
87// struct must be POD, because we memset the contents.
88struct WindowPayload {
89  SessionID::id_type window_id;
90  int32 selected_tab_index;
91  int32 num_tabs;
92};
93
94// Payload used for the start of a tab close. This is the old struct that is
95// used for backwards compat when it comes to reading the session files.
96struct SelectedNavigationInTabPayload {
97  SessionID::id_type id;
98  int32 index;
99};
100
101// Payload used for the start of a window close.  This struct must be POD,
102// because we memset the contents.
103struct WindowPayload2 : WindowPayload {
104  int64 timestamp;
105};
106
107// Payload used for the start of a tab close.
108struct SelectedNavigationInTabPayload2 : SelectedNavigationInTabPayload {
109  int64 timestamp;
110};
111
112// Only written if the tab is pinned.
113typedef bool PinnedStatePayload;
114
115typedef std::map<SessionID::id_type, TabRestoreService::Entry*> IDToEntry;
116
117// If |id_to_entry| contains an entry for |id| the corresponding entry is
118// deleted and removed from both |id_to_entry| and |entries|. This is used
119// when creating entries from the backend file.
120void RemoveEntryByID(SessionID::id_type id,
121                     IDToEntry* id_to_entry,
122                     std::vector<TabRestoreService::Entry*>* entries) {
123  // Look for the entry in the map. If it is present, erase it from both
124  // collections and return.
125  IDToEntry::iterator i = id_to_entry->find(id);
126  if (i != id_to_entry->end()) {
127    entries->erase(std::find(entries->begin(), entries->end(), i->second));
128    delete i->second;
129    id_to_entry->erase(i);
130    return;
131  }
132
133  // Otherwise, loop over all items in the map and see if any of the Windows
134  // have Tabs with the |id|.
135  for (IDToEntry::iterator i = id_to_entry->begin(); i != id_to_entry->end();
136       ++i) {
137    if (i->second->type == TabRestoreService::WINDOW) {
138      TabRestoreService::Window* window =
139          static_cast<TabRestoreService::Window*>(i->second);
140      std::vector<TabRestoreService::Tab>::iterator j = window->tabs.begin();
141      for ( ; j != window->tabs.end(); ++j) {
142        // If the ID matches one of this window's tabs, remove it from the list.
143        if ((*j).id == id) {
144          window->tabs.erase(j);
145          return;
146        }
147      }
148    }
149  }
150}
151
152}  // namespace
153
154TabRestoreService::Tab::Tab()
155    : Entry(TAB),
156      current_navigation_index(-1),
157      browser_id(0),
158      tabstrip_index(-1),
159      pinned(false) {
160}
161
162TabRestoreService::Tab::~Tab() {
163}
164
165TabRestoreService::Window::Window() : Entry(WINDOW), selected_tab_index(-1) {
166}
167
168TabRestoreService::Window::~Window() {
169}
170
171TabRestoreService::TabRestoreService(Profile* profile,
172    TabRestoreService::TimeFactory* time_factory)
173    : BaseSessionService(BaseSessionService::TAB_RESTORE, profile,
174                         FilePath()),
175      load_state_(NOT_LOADED),
176      restoring_(false),
177      reached_max_(false),
178      entries_to_write_(0),
179      entries_written_(0),
180      time_factory_(time_factory) {
181}
182
183TabRestoreService::~TabRestoreService() {
184  if (backend())
185    Save();
186
187  FOR_EACH_OBSERVER(TabRestoreServiceObserver, observer_list_,
188                    TabRestoreServiceDestroyed(this));
189  STLDeleteElements(&entries_);
190  STLDeleteElements(&staging_entries_);
191  time_factory_ = NULL;
192}
193
194void TabRestoreService::AddObserver(TabRestoreServiceObserver* observer) {
195  observer_list_.AddObserver(observer);
196}
197
198void TabRestoreService::RemoveObserver(TabRestoreServiceObserver* observer) {
199  observer_list_.RemoveObserver(observer);
200}
201
202void TabRestoreService::CreateHistoricalTab(NavigationController* tab) {
203  if (restoring_)
204    return;
205
206  Browser* browser = Browser::GetBrowserForController(tab, NULL);
207  if (closing_browsers_.find(browser) != closing_browsers_.end())
208    return;
209
210  scoped_ptr<Tab> local_tab(new Tab());
211  PopulateTab(local_tab.get(), browser, tab);
212  if (local_tab->navigations.empty())
213    return;
214
215  AddEntry(local_tab.release(), true, true);
216}
217
218void TabRestoreService::BrowserClosing(Browser* browser) {
219  if (browser->type() != Browser::TYPE_NORMAL ||
220      browser->tab_count() == 0)
221    return;
222
223  closing_browsers_.insert(browser);
224
225  Window* window = new Window();
226  window->selected_tab_index = browser->selected_index();
227  window->timestamp = TimeNow();
228  // Don't use std::vector::resize() because it will push copies of an empty tab
229  // into the vector, which will give all tabs in a window the same ID.
230  for (int i = 0; i < browser->tab_count(); ++i) {
231    window->tabs.push_back(Tab());
232  }
233  size_t entry_index = 0;
234  for (int tab_index = 0; tab_index < browser->tab_count(); ++tab_index) {
235    PopulateTab(&(window->tabs[entry_index]),
236                browser,
237                &browser->GetTabContentsAt(tab_index)->controller());
238    if (window->tabs[entry_index].navigations.empty()) {
239      window->tabs.erase(window->tabs.begin() + entry_index);
240    } else {
241      window->tabs[entry_index].browser_id = browser->session_id().id();
242      entry_index++;
243    }
244  }
245  if (window->tabs.empty()) {
246    delete window;
247    window = NULL;
248  } else {
249    window->selected_tab_index =
250        std::min(static_cast<int>(window->tabs.size() - 1),
251                 window->selected_tab_index);
252    AddEntry(window, true, true);
253  }
254}
255
256void TabRestoreService::BrowserClosed(Browser* browser) {
257  closing_browsers_.erase(browser);
258}
259
260void TabRestoreService::ClearEntries() {
261  // Mark all the tabs as closed so that we don't attempt to restore them.
262  for (Entries::iterator i = entries_.begin(); i != entries_.end(); ++i)
263    ScheduleCommand(CreateRestoredEntryCommand((*i)->id));
264
265  entries_to_write_ = 0;
266
267  // Schedule a pending reset so that we nuke the file on next write.
268  set_pending_reset(true);
269
270  // Schedule a command, otherwise if there are no pending commands Save does
271  // nothing.
272  ScheduleCommand(CreateRestoredEntryCommand(1));
273
274  STLDeleteElements(&entries_);
275  NotifyTabsChanged();
276}
277
278const TabRestoreService::Entries& TabRestoreService::entries() const {
279  return entries_;
280}
281
282void TabRestoreService::RestoreMostRecentEntry(Browser* browser) {
283  if (entries_.empty())
284    return;
285
286  RestoreEntryById(browser, entries_.front()->id, false);
287}
288
289void TabRestoreService::RestoreEntryById(Browser* browser,
290                                         SessionID::id_type id,
291                                         bool replace_existing_tab) {
292  Entries::iterator i = GetEntryIteratorById(id);
293  if (i == entries_.end()) {
294    // Don't hoark here, we allow an invalid id.
295    return;
296  }
297
298  size_t index = 0;
299  for (Entries::iterator j = entries_.begin(); j != i && j != entries_.end();
300       ++j, ++index) {}
301  if (static_cast<int>(index) < entries_to_write_)
302    entries_to_write_--;
303
304  ScheduleCommand(CreateRestoredEntryCommand(id));
305
306  restoring_ = true;
307  Entry* entry = *i;
308
309  // If the entry's ID does not match the ID that is being restored, then the
310  // entry is a window from which a single tab will be restored.
311  bool restoring_tab_in_window = entry->id != id;
312
313  if (!restoring_tab_in_window) {
314    entries_.erase(i);
315    i = entries_.end();
316  }
317
318  // |browser| will be NULL in cases where one isn't already available (eg,
319  // when invoked on Mac OS X with no windows open). In this case, create a
320  // new browser into which we restore the tabs.
321  if (entry->type == TAB) {
322    Tab* tab = static_cast<Tab*>(entry);
323    browser = RestoreTab(*tab, browser, replace_existing_tab);
324    browser->window()->Show();
325  } else if (entry->type == WINDOW) {
326    Browser* current_browser = browser;
327    Window* window = static_cast<Window*>(entry);
328
329    // When restoring a window, either the entire window can be restored, or a
330    // single tab within it. If the entry's ID matches the one to restore, then
331    // the entire window will be restored.
332    if (!restoring_tab_in_window) {
333      browser = Browser::Create(profile());
334      for (size_t tab_i = 0; tab_i < window->tabs.size(); ++tab_i) {
335        const Tab& tab = window->tabs[tab_i];
336        TabContents* restored_tab =
337            browser->AddRestoredTab(tab.navigations, browser->tab_count(),
338                                    tab.current_navigation_index,
339                                    tab.extension_app_id,
340                                    (static_cast<int>(tab_i) ==
341                                        window->selected_tab_index),
342                                    tab.pinned, tab.from_last_session,
343                                    tab.session_storage_namespace);
344        if (restored_tab)
345          restored_tab->controller().LoadIfNecessary();
346      }
347      // All the window's tabs had the same former browser_id.
348      if (window->tabs[0].has_browser()) {
349        UpdateTabBrowserIDs(window->tabs[0].browser_id,
350                            browser->session_id().id());
351      }
352    } else {
353      // Restore a single tab from the window. Find the tab that matches the ID
354      // in the window and restore it.
355      for (std::vector<Tab>::iterator tab_i = window->tabs.begin();
356           tab_i != window->tabs.end(); ++tab_i) {
357        const Tab& tab = *tab_i;
358        if (tab.id == id) {
359          browser = RestoreTab(tab, browser, replace_existing_tab);
360          window->tabs.erase(tab_i);
361          // If restoring the tab leaves the window with nothing else, delete it
362          // as well.
363          if (!window->tabs.size()) {
364            entries_.erase(i);
365            delete entry;
366          } else {
367            // Update the browser ID of the rest of the tabs in the window so if
368            // any one is restored, it goes into the same window as the tab
369            // being restored now.
370            UpdateTabBrowserIDs(tab.browser_id,
371                                browser->session_id().id());
372            for (std::vector<Tab>::iterator tab_j = window->tabs.begin();
373                 tab_j != window->tabs.end(); ++tab_j) {
374              (*tab_j).browser_id = browser->session_id().id();
375            }
376          }
377          break;
378        }
379      }
380    }
381    browser->window()->Show();
382
383    if (replace_existing_tab && current_browser &&
384        current_browser->GetSelectedTabContents()) {
385      current_browser->CloseTab();
386    }
387  } else {
388    NOTREACHED();
389  }
390
391  if (!restoring_tab_in_window) {
392    delete entry;
393  }
394
395  restoring_ = false;
396  NotifyTabsChanged();
397}
398
399void TabRestoreService::LoadTabsFromLastSession() {
400  if (load_state_ != NOT_LOADED || reached_max_)
401    return;
402
403  load_state_ = LOADING;
404
405  if (!profile()->restored_last_session() &&
406      !profile()->DidLastSessionExitCleanly() &&
407      profile()->GetSessionService()) {
408    // The previous session crashed and wasn't restored. Load the tabs/windows
409    // that were open at the point of crash from the session service.
410    profile()->GetSessionService()->GetLastSession(
411        &load_consumer_,
412        NewCallback(this, &TabRestoreService::OnGotPreviousSession));
413  } else {
414    load_state_ |= LOADED_LAST_SESSION;
415  }
416
417  // Request the tabs closed in the last session. If the last session crashed,
418  // this won't contain the tabs/window that were open at the point of the
419  // crash (the call to GetLastSession above requests those).
420  ScheduleGetLastSessionCommands(
421      new InternalGetCommandsRequest(
422          NewCallback(this, &TabRestoreService::OnGotLastSessionCommands)),
423      &load_consumer_);
424}
425
426void TabRestoreService::Save() {
427  int to_write_count = std::min(entries_to_write_,
428                                static_cast<int>(entries_.size()));
429  entries_to_write_ = 0;
430  if (entries_written_ + to_write_count > kEntriesPerReset) {
431    to_write_count = entries_.size();
432    set_pending_reset(true);
433  }
434  if (to_write_count) {
435    // Write the to_write_count most recently added entries out. The most
436    // recently added entry is at the front, so we use a reverse iterator to
437    // write in the order the entries were added.
438    Entries::reverse_iterator i = entries_.rbegin();
439    DCHECK(static_cast<size_t>(to_write_count) <= entries_.size());
440    std::advance(i, entries_.size() - static_cast<int>(to_write_count));
441    for (; i != entries_.rend(); ++i) {
442      Entry* entry = *i;
443      if (entry->type == TAB) {
444        Tab* tab = static_cast<Tab*>(entry);
445        int selected_index = GetSelectedNavigationIndexToPersist(*tab);
446        if (selected_index != -1)
447          ScheduleCommandsForTab(*tab, selected_index);
448      } else {
449        ScheduleCommandsForWindow(*static_cast<Window*>(entry));
450      }
451      entries_written_++;
452    }
453  }
454  if (pending_reset())
455    entries_written_ = 0;
456  BaseSessionService::Save();
457}
458
459void TabRestoreService::PopulateTab(Tab* tab,
460                                    Browser* browser,
461                                    NavigationController* controller) {
462  const int pending_index = controller->pending_entry_index();
463  int entry_count = controller->entry_count();
464  if (entry_count == 0 && pending_index == 0)
465    entry_count++;
466  tab->navigations.resize(static_cast<int>(entry_count));
467  for (int i = 0; i < entry_count; ++i) {
468    NavigationEntry* entry = (i == pending_index) ?
469        controller->pending_entry() : controller->GetEntryAtIndex(i);
470    tab->navigations[i].SetFromNavigationEntry(*entry);
471  }
472  tab->timestamp = TimeNow();
473  tab->current_navigation_index = controller->GetCurrentEntryIndex();
474  if (tab->current_navigation_index == -1 && entry_count > 0)
475    tab->current_navigation_index = 0;
476
477  Extension* extension = controller->tab_contents()->extension_app();
478  if (extension)
479    tab->extension_app_id = extension->id();
480
481  tab->session_storage_namespace = controller->session_storage_namespace();
482
483  // Browser may be NULL during unit tests.
484  if (browser) {
485    tab->browser_id = browser->session_id().id();
486    tab->tabstrip_index =
487        browser->tabstrip_model()->GetIndexOfController(controller);
488    tab->pinned = browser->tabstrip_model()->IsTabPinned(tab->tabstrip_index);
489  }
490}
491
492void TabRestoreService::NotifyTabsChanged() {
493  FOR_EACH_OBSERVER(TabRestoreServiceObserver, observer_list_,
494                    TabRestoreServiceChanged(this));
495}
496
497void TabRestoreService::AddEntry(Entry* entry, bool notify, bool to_front) {
498  if (to_front)
499    entries_.push_front(entry);
500  else
501    entries_.push_back(entry);
502  if (notify)
503    PruneAndNotify();
504  // Start the save timer, when it fires we'll generate the commands.
505  StartSaveTimer();
506  entries_to_write_++;
507}
508
509void TabRestoreService::PruneAndNotify() {
510  while (entries_.size() > kMaxEntries) {
511    delete entries_.back();
512    entries_.pop_back();
513    reached_max_ = true;
514  }
515
516  NotifyTabsChanged();
517}
518
519TabRestoreService::Entries::iterator TabRestoreService::GetEntryIteratorById(
520    SessionID::id_type id) {
521  for (Entries::iterator i = entries_.begin(); i != entries_.end(); ++i) {
522    if ((*i)->id == id)
523      return i;
524
525    // For Window entries, see if the ID matches a tab. If so, report the window
526    // as the Entry.
527    if ((*i)->type == WINDOW) {
528      std::vector<Tab>& tabs = static_cast<Window*>(*i)->tabs;
529      for (std::vector<Tab>::iterator j = tabs.begin();
530           j != tabs.end(); ++j) {
531        if ((*j).id == id) {
532          return i;
533        }
534      }
535    }
536  }
537  return entries_.end();
538}
539
540void TabRestoreService::ScheduleCommandsForWindow(const Window& window) {
541  DCHECK(!window.tabs.empty());
542  int selected_tab = window.selected_tab_index;
543  int valid_tab_count = 0;
544  int real_selected_tab = selected_tab;
545  for (size_t i = 0; i < window.tabs.size(); ++i) {
546    if (GetSelectedNavigationIndexToPersist(window.tabs[i]) != -1) {
547      valid_tab_count++;
548    } else if (static_cast<int>(i) < selected_tab) {
549      real_selected_tab--;
550    }
551  }
552  if (valid_tab_count == 0)
553    return;  // No tabs to persist.
554
555  ScheduleCommand(
556      CreateWindowCommand(window.id,
557                          std::min(real_selected_tab, valid_tab_count - 1),
558                          valid_tab_count,
559                          window.timestamp));
560
561  for (size_t i = 0; i < window.tabs.size(); ++i) {
562    int selected_index = GetSelectedNavigationIndexToPersist(window.tabs[i]);
563    if (selected_index != -1)
564      ScheduleCommandsForTab(window.tabs[i], selected_index);
565  }
566}
567
568void TabRestoreService::ScheduleCommandsForTab(const Tab& tab,
569                                               int selected_index) {
570  const std::vector<TabNavigation>& navigations = tab.navigations;
571  int max_index = static_cast<int>(navigations.size());
572
573  // Determine the first navigation we'll persist.
574  int valid_count_before_selected = 0;
575  int first_index_to_persist = selected_index;
576  for (int i = selected_index - 1; i >= 0 &&
577       valid_count_before_selected < max_persist_navigation_count; --i) {
578    if (ShouldTrackEntry(navigations[i])) {
579      first_index_to_persist = i;
580      valid_count_before_selected++;
581    }
582  }
583
584  // Write the command that identifies the selected tab.
585  ScheduleCommand(
586      CreateSelectedNavigationInTabCommand(tab.id,
587                                           valid_count_before_selected,
588                                           tab.timestamp));
589
590  if (tab.pinned) {
591    PinnedStatePayload payload = true;
592    SessionCommand* command =
593        new SessionCommand(kCommandPinnedState, sizeof(payload));
594    memcpy(command->contents(), &payload, sizeof(payload));
595    ScheduleCommand(command);
596  }
597
598  if (!tab.extension_app_id.empty()) {
599    ScheduleCommand(
600        CreateSetTabExtensionAppIDCommand(kCommandSetExtensionAppID, tab.id,
601                                          tab.extension_app_id));
602  }
603
604  // Then write the navigations.
605  for (int i = first_index_to_persist, wrote_count = 0;
606       i < max_index && wrote_count < 2 * max_persist_navigation_count; ++i) {
607    if (ShouldTrackEntry(navigations[i])) {
608      // Creating a NavigationEntry isn't the most efficient way to go about
609      // this, but it simplifies the code and makes it less error prone as we
610      // add new data to NavigationEntry.
611      scoped_ptr<NavigationEntry> entry(
612          navigations[i].ToNavigationEntry(wrote_count, profile()));
613      ScheduleCommand(
614          CreateUpdateTabNavigationCommand(kCommandUpdateTabNavigation, tab.id,
615                                           wrote_count++, *entry));
616    }
617  }
618}
619
620SessionCommand* TabRestoreService::CreateWindowCommand(SessionID::id_type id,
621                                                       int selected_tab_index,
622                                                       int num_tabs,
623                                                       Time timestamp) {
624  WindowPayload2 payload;
625  // |timestamp| is aligned on a 16 byte boundary, leaving 4 bytes of
626  // uninitialized memory in the struct.
627  memset(&payload, 0, sizeof(payload));
628  payload.window_id = id;
629  payload.selected_tab_index = selected_tab_index;
630  payload.num_tabs = num_tabs;
631  payload.timestamp = timestamp.ToInternalValue();
632
633  SessionCommand* command =
634      new SessionCommand(kCommandWindow, sizeof(payload));
635  memcpy(command->contents(), &payload, sizeof(payload));
636  return command;
637}
638
639SessionCommand* TabRestoreService::CreateSelectedNavigationInTabCommand(
640    SessionID::id_type tab_id,
641    int32 index,
642    Time timestamp) {
643  SelectedNavigationInTabPayload2 payload;
644  payload.id = tab_id;
645  payload.index = index;
646  payload.timestamp = timestamp.ToInternalValue();
647  SessionCommand* command =
648      new SessionCommand(kCommandSelectedNavigationInTab, sizeof(payload));
649  memcpy(command->contents(), &payload, sizeof(payload));
650  return command;
651}
652
653SessionCommand* TabRestoreService::CreateRestoredEntryCommand(
654    SessionID::id_type entry_id) {
655  RestoredEntryPayload payload = entry_id;
656  SessionCommand* command =
657      new SessionCommand(kCommandRestoredEntry, sizeof(payload));
658  memcpy(command->contents(), &payload, sizeof(payload));
659  return command;
660}
661
662int TabRestoreService::GetSelectedNavigationIndexToPersist(const Tab& tab) {
663  const std::vector<TabNavigation>& navigations = tab.navigations;
664  int selected_index = tab.current_navigation_index;
665  int max_index = static_cast<int>(navigations.size());
666
667  // Find the first navigation to persist. We won't persist the selected
668  // navigation if ShouldTrackEntry returns false.
669  while (selected_index >= 0 &&
670         !ShouldTrackEntry(navigations[selected_index])) {
671    selected_index--;
672  }
673
674  if (selected_index != -1)
675    return selected_index;
676
677  // Couldn't find a navigation to persist going back, go forward.
678  selected_index = tab.current_navigation_index + 1;
679  while (selected_index < max_index &&
680         !ShouldTrackEntry(navigations[selected_index])) {
681    selected_index++;
682  }
683
684  return (selected_index == max_index) ? -1 : selected_index;
685}
686
687void TabRestoreService::OnGotLastSessionCommands(
688    Handle handle,
689    scoped_refptr<InternalGetCommandsRequest> request) {
690  std::vector<Entry*> entries;
691  CreateEntriesFromCommands(request, &entries);
692  // Closed tabs always go to the end.
693  staging_entries_.insert(staging_entries_.end(), entries.begin(),
694                          entries.end());
695  load_state_ |= LOADED_LAST_TABS;
696  LoadStateChanged();
697}
698
699void TabRestoreService::CreateEntriesFromCommands(
700    scoped_refptr<InternalGetCommandsRequest> request,
701    std::vector<Entry*>* loaded_entries) {
702  if (request->canceled() || entries_.size() == kMaxEntries)
703    return;
704
705  std::vector<SessionCommand*>& commands = request->commands;
706  // Iterate through the commands populating entries and id_to_entry.
707  ScopedVector<Entry> entries;
708  IDToEntry id_to_entry;
709  // If non-null we're processing the navigations of this tab.
710  Tab* current_tab = NULL;
711  // If non-null we're processing the tabs of this window.
712  Window* current_window = NULL;
713  // If > 0, we've gotten a window command but not all the tabs yet.
714  int pending_window_tabs = 0;
715  for (std::vector<SessionCommand*>::const_iterator i = commands.begin();
716       i != commands.end(); ++i) {
717    const SessionCommand& command = *(*i);
718    switch (command.id()) {
719      case kCommandRestoredEntry: {
720        if (pending_window_tabs > 0) {
721          // Should never receive a restored command while waiting for all the
722          // tabs in a window.
723          return;
724        }
725
726        current_tab = NULL;
727        current_window = NULL;
728
729        RestoredEntryPayload payload;
730        if (!command.GetPayload(&payload, sizeof(payload)))
731          return;
732        RemoveEntryByID(payload, &id_to_entry, &(entries.get()));
733        break;
734      }
735
736      case kCommandWindow: {
737        WindowPayload2 payload;
738        if (pending_window_tabs > 0) {
739          // Should never receive a window command while waiting for all the
740          // tabs in a window.
741          return;
742        }
743
744        // Try the new payload first
745        if (!command.GetPayload(&payload, sizeof(payload))) {
746          // then the old payload
747          WindowPayload old_payload;
748          if (!command.GetPayload(&old_payload, sizeof(old_payload)))
749            return;
750
751          // Copy the old payload data to the new payload.
752          payload.window_id = old_payload.window_id;
753          payload.selected_tab_index = old_payload.selected_tab_index;
754          payload.num_tabs = old_payload.num_tabs;
755          // Since we don't have a time use time 0 which is used to mark as an
756          // unknown timestamp.
757          payload.timestamp = 0;
758        }
759
760        pending_window_tabs = payload.num_tabs;
761        if (pending_window_tabs <= 0) {
762          // Should always have at least 1 tab. Likely indicates corruption.
763          return;
764        }
765
766        RemoveEntryByID(payload.window_id, &id_to_entry, &(entries.get()));
767
768        current_window = new Window();
769        current_window->selected_tab_index = payload.selected_tab_index;
770        current_window->timestamp = Time::FromInternalValue(payload.timestamp);
771        entries->push_back(current_window);
772        id_to_entry[payload.window_id] = current_window;
773        break;
774      }
775
776      case kCommandSelectedNavigationInTab: {
777        SelectedNavigationInTabPayload2 payload;
778        if (!command.GetPayload(&payload, sizeof(payload))) {
779          SelectedNavigationInTabPayload old_payload;
780          if (!command.GetPayload(&old_payload, sizeof(old_payload)))
781            return;
782          payload.id = old_payload.id;
783          payload.index = old_payload.index;
784          // Since we don't have a time use time 0 which is used to mark as an
785          // unknown timestamp.
786          payload.timestamp = 0;
787        }
788
789        if (pending_window_tabs > 0) {
790          if (!current_window) {
791            // We should have created a window already.
792            NOTREACHED();
793            return;
794          }
795          current_window->tabs.resize(current_window->tabs.size() + 1);
796          current_tab = &(current_window->tabs.back());
797          if (--pending_window_tabs == 0)
798            current_window = NULL;
799        } else {
800          RemoveEntryByID(payload.id, &id_to_entry, &(entries.get()));
801          current_tab = new Tab();
802          id_to_entry[payload.id] = current_tab;
803          current_tab->timestamp = Time::FromInternalValue(payload.timestamp);
804          entries->push_back(current_tab);
805        }
806        current_tab->current_navigation_index = payload.index;
807        break;
808      }
809
810      case kCommandUpdateTabNavigation: {
811        if (!current_tab) {
812          // Should be in a tab when we get this.
813          return;
814        }
815        current_tab->navigations.resize(current_tab->navigations.size() + 1);
816        SessionID::id_type tab_id;
817        if (!RestoreUpdateTabNavigationCommand(
818            command, &current_tab->navigations.back(), &tab_id)) {
819          return;
820        }
821        break;
822      }
823
824      case kCommandPinnedState: {
825        if (!current_tab) {
826          // Should be in a tab when we get this.
827          return;
828        }
829        // NOTE: payload doesn't matter. kCommandPinnedState is only written if
830        // tab is pinned.
831        current_tab->pinned = true;
832        break;
833      }
834
835      case kCommandSetExtensionAppID: {
836        if (!current_tab) {
837          // Should be in a tab when we get this.
838          return;
839        }
840        SessionID::id_type tab_id;
841        std::string extension_app_id;
842        if (!RestoreSetTabExtensionAppIDCommand(command, &tab_id,
843                                                &extension_app_id)) {
844          return;
845        }
846        current_tab->extension_app_id.swap(extension_app_id);
847        break;
848      }
849
850      default:
851        // Unknown type, usually indicates corruption of file. Ignore it.
852        return;
853    }
854  }
855
856  // If there was corruption some of the entries won't be valid. Prune any
857  // entries with no navigations.
858  ValidateAndDeleteEmptyEntries(&(entries.get()));
859
860  loaded_entries->swap(entries.get());
861}
862
863Browser* TabRestoreService::RestoreTab(const Tab& tab,
864                                       Browser* browser,
865                                       bool replace_existing_tab) {
866  // |browser| will be NULL in cases where one isn't already available (eg,
867  // when invoked on Mac OS X with no windows open). In this case, create a
868  // new browser into which we restore the tabs.
869  if (replace_existing_tab && browser) {
870    browser->ReplaceRestoredTab(tab.navigations,
871                                tab.current_navigation_index,
872                                tab.from_last_session,
873                                tab.extension_app_id,
874                                tab.session_storage_namespace);
875  } else {
876    if (tab.has_browser())
877      browser = BrowserList::FindBrowserWithID(tab.browser_id);
878
879    int tab_index = -1;
880    if (browser) {
881      tab_index = tab.tabstrip_index;
882    } else {
883      browser = Browser::Create(profile());
884      if (tab.has_browser()) {
885        UpdateTabBrowserIDs(tab.browser_id, browser->session_id().id());
886      }
887    }
888
889    if (tab_index < 0 || tab_index > browser->tab_count()) {
890      tab_index = browser->tab_count();
891    }
892
893    browser->AddRestoredTab(tab.navigations,
894                            tab_index,
895                            tab.current_navigation_index,
896                            tab.extension_app_id,
897                            true, tab.pinned, tab.from_last_session,
898                            tab.session_storage_namespace);
899  }
900  return browser;
901}
902
903
904bool TabRestoreService::ValidateTab(Tab* tab) {
905  if (tab->navigations.empty())
906    return false;
907
908  tab->current_navigation_index =
909      std::max(0, std::min(tab->current_navigation_index,
910                           static_cast<int>(tab->navigations.size()) - 1));
911  return true;
912}
913
914void TabRestoreService::ValidateAndDeleteEmptyEntries(
915    std::vector<Entry*>* entries) {
916  std::vector<Entry*> valid_entries;
917  std::vector<Entry*> invalid_entries;
918
919  size_t max_valid = kMaxEntries - entries_.size();
920  // Iterate from the back so that we keep the most recently closed entries.
921  for (std::vector<Entry*>::reverse_iterator i = entries->rbegin();
922       i != entries->rend(); ++i) {
923    bool valid_entry = false;
924    if (valid_entries.size() != max_valid) {
925      if ((*i)->type == TAB) {
926        Tab* tab = static_cast<Tab*>(*i);
927        if (ValidateTab(tab))
928          valid_entry = true;
929      } else {
930        Window* window = static_cast<Window*>(*i);
931        for (std::vector<Tab>::iterator tab_i = window->tabs.begin();
932             tab_i != window->tabs.end();) {
933          if (!ValidateTab(&(*tab_i)))
934            tab_i = window->tabs.erase(tab_i);
935          else
936            ++tab_i;
937        }
938        if (!window->tabs.empty()) {
939          window->selected_tab_index =
940              std::max(0, std::min(window->selected_tab_index,
941                                   static_cast<int>(window->tabs.size() - 1)));
942          valid_entry = true;
943        }
944      }
945    }
946    if (valid_entry)
947      valid_entries.push_back(*i);
948    else
949      invalid_entries.push_back(*i);
950  }
951  // NOTE: at this point the entries are ordered with newest at the front.
952  entries->swap(valid_entries);
953
954  // Delete the remaining entries.
955  STLDeleteElements(&invalid_entries);
956}
957
958void TabRestoreService::UpdateTabBrowserIDs(SessionID::id_type old_id,
959                                            SessionID::id_type new_id) {
960  for (Entries::iterator i = entries_.begin(); i != entries_.end(); ++i) {
961    Entry* entry = *i;
962    if (entry->type == TAB) {
963      Tab* tab = static_cast<Tab*>(entry);
964      if (tab->browser_id == old_id)
965        tab->browser_id = new_id;
966    }
967  }
968}
969
970void TabRestoreService::OnGotPreviousSession(
971    Handle handle,
972    std::vector<SessionWindow*>* windows) {
973  std::vector<Entry*> entries;
974  CreateEntriesFromWindows(windows, &entries);
975  // Previous session tabs go first.
976  staging_entries_.insert(staging_entries_.begin(), entries.begin(),
977                          entries.end());
978  load_state_ |= LOADED_LAST_SESSION;
979  LoadStateChanged();
980}
981
982void TabRestoreService::CreateEntriesFromWindows(
983    std::vector<SessionWindow*>* windows,
984    std::vector<Entry*>* entries) {
985  for (size_t i = 0; i < windows->size(); ++i) {
986    scoped_ptr<Window> window(new Window());
987    if (ConvertSessionWindowToWindow((*windows)[i], window.get()))
988      entries->push_back(window.release());
989  }
990}
991
992bool TabRestoreService::ConvertSessionWindowToWindow(
993    SessionWindow* session_window,
994    Window* window) {
995  for (size_t i = 0; i < session_window->tabs.size(); ++i) {
996    if (!session_window->tabs[i]->navigations.empty()) {
997      window->tabs.resize(window->tabs.size() + 1);
998      Tab& tab = window->tabs.back();
999      tab.pinned = session_window->tabs[i]->pinned;
1000      tab.navigations.swap(session_window->tabs[i]->navigations);
1001      tab.current_navigation_index =
1002          session_window->tabs[i]->current_navigation_index;
1003      tab.extension_app_id = session_window->tabs[i]->extension_app_id;
1004      tab.timestamp = Time();
1005    }
1006  }
1007  if (window->tabs.empty())
1008    return false;
1009
1010  window->selected_tab_index =
1011      std::min(session_window->selected_tab_index,
1012               static_cast<int>(window->tabs.size() - 1));
1013  window->timestamp = Time();
1014  return true;
1015}
1016
1017void TabRestoreService::LoadStateChanged() {
1018  if ((load_state_ & (LOADED_LAST_TABS | LOADED_LAST_SESSION)) !=
1019      (LOADED_LAST_TABS | LOADED_LAST_SESSION)) {
1020    // Still waiting on previous session or previous tabs.
1021    return;
1022  }
1023
1024  // We're done loading.
1025  load_state_ ^= LOADING;
1026
1027  if (staging_entries_.empty() || reached_max_) {
1028    STLDeleteElements(&staging_entries_);
1029    return;
1030  }
1031
1032  if (staging_entries_.size() + entries_.size() > kMaxEntries) {
1033    // If we add all the staged entries we'll end up with more than
1034    // kMaxEntries. Delete entries such that we only end up with
1035    // at most kMaxEntries.
1036    DCHECK(entries_.size() < kMaxEntries);
1037    STLDeleteContainerPointers(
1038        staging_entries_.begin() + (kMaxEntries - entries_.size()),
1039        staging_entries_.end());
1040    staging_entries_.erase(
1041        staging_entries_.begin() + (kMaxEntries - entries_.size()),
1042        staging_entries_.end());
1043  }
1044
1045  // And add them.
1046  for (size_t i = 0; i < staging_entries_.size(); ++i) {
1047    staging_entries_[i]->from_last_session = true;
1048    AddEntry(staging_entries_[i], false, false);
1049  }
1050
1051  // AddEntry takes ownership of the entry, need to clear out entries so that
1052  // it doesn't delete them.
1053  staging_entries_.clear();
1054
1055  // Make it so we rewrite all the tabs. We need to do this otherwise we won't
1056  // correctly write out the entries when Save is invoked (Save starts from
1057  // the front, not the end and we just added the entries to the end).
1058  entries_to_write_ = staging_entries_.size();
1059
1060  PruneAndNotify();
1061}
1062
1063Time TabRestoreService::TimeNow() const {
1064  return time_factory_ ? time_factory_->TimeNow() : Time::Now();
1065}
1066