Split TabRestoreService into InMemoryTRS and PersistentTRS

chrome/browser/sessions/in_memory_tab_restore_service.h

+// Copyright (c) 2012 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#ifndef CHROME_BROWSER_SESSIONS_IN_MEMORY_TAB_RESTORE_SERVICE_H_
+#define CHROME_BROWSER_SESSIONS_IN_MEMORY_TAB_RESTORE_SERVICE_H_
+
+#include <map>
+#include <set>
+
+#include "base/gtest_prod_util.h"
+#include "base/observer_list.h"
+#include "base/time.h"
+#include "chrome/browser/profiles/profile_keyed_service.h"
+#include "chrome/browser/sessions/base_session_service.h"
+#include "chrome/browser/sessions/session_id.h"
+#include "chrome/browser/sessions/session_types.h"
+#include "chrome/browser/sessions/tab_restore_service.h"
+
+class Profile;
+class TabRestoreServiceDelegate;
+class TabRestoreServiceObserver;
+struct SessionWindow;
+
+namespace content {
+class NavigationController;
+class SessionStorageNamespace;
+class WebContents;
+}
+
+// TODO
+class InMemoryTabRestoreService : public TabRestoreService {
+ public:
+  // Creates a new TabRestoreService and provides an object that provides the
+  // current time. The TabRestoreService does not take ownership of the
+  // |time_factory_|.
+  InMemoryTabRestoreService(Profile* profile,
+                            TimeFactory* time_factory_ = NULL);
+
+  virtual ~InMemoryTabRestoreService();
+
+  // TabRestoreService:
+  virtual void AddObserver(TabRestoreServiceObserver* observer) OVERRIDE;
+  virtual void RemoveObserver(TabRestoreServiceObserver* observer) OVERRIDE;
+  virtual void CreateHistoricalTab(content::WebContents* contents,
+                                   int index) OVERRIDE;
+  virtual void BrowserClosing(TabRestoreServiceDelegate* delegate) OVERRIDE;
+  virtual void BrowserClosed(TabRestoreServiceDelegate* delegate) OVERRIDE;
+  virtual void ClearEntries() OVERRIDE;
+  virtual const Entries& entries() const OVERRIDE;
+  virtual void RestoreMostRecentEntry(
+      TabRestoreServiceDelegate* delegate) OVERRIDE;
+  virtual Tab* RemoveTabEntryById(SessionID::id_type id) OVERRIDE;
+  virtual void RestoreEntryById(TabRestoreServiceDelegate* delegate,
+                                SessionID::id_type id,
+                                WindowOpenDisposition disposition) OVERRIDE;
+  virtual void LoadTabsFromLastSession() OVERRIDE;
+  virtual bool IsLoaded() const OVERRIDE;
+  virtual void DeleteLastSession() OVERRIDE;
+  virtual void Shutdown() OVERRIDE;
+
+ protected:
+  typedef std::map<SessionID::id_type, TabRestoreService::Entry*> IDToEntry;
+
+  // Max number of entries we'll keep around.
+  enum {
+    kMaxEntries = 25,
+  };
+
+  // Returns an iterator into entries_ whose id matches |id|. If |id| identifies
+  // a Window, then its iterator position will be returned. If it identifies a
+  // tab, then the iterator position of the Window in which the Tab resides is
+  // returned.
+  Entries::iterator GetEntryIteratorById(SessionID::id_type id);
+
+  // Adds |entry| to the list of entries and takes ownership. If |prune| is true
+  // |PruneAndNotify| is invoked. If |to_front| is true the entry is added to
+  // the front, otherwise the back. Normal closes go to the front, but
+  // tab/window closes from the previous session are added to the back.
+  void AddEntry(Entry* entry, bool prune, bool to_front);
+
+  // Prunes entries_ to contain only kMaxEntries, and removes uninteresting
+  // entries.
+  void PruneEntries();
+
+  // Notifies observers the tabs have changed.
+  void NotifyTabsChanged();
+
+  // Converts a SessionWindow into a Window, returning true on success. We use 0
+  // as the timestamp here since we do not know when the window/tab was closed.
+  bool ConvertSessionWindowToWindow(
+      SessionWindow* session_window,
+      Window* window);
+
+  // Calls either ValidateTab or ValidateWindow as appropriate.
+  static bool ValidateEntry(Entry* entry);
+
+  // Methods than can be overridden by subclasses to add some behavior (e.g.
+  // persistence).
+  virtual void OnClearEntries() {}
+  virtual void OnRestoreEntryById(SessionID::id_type id,
+                                  Entries::const_iterator entry_iterator) {}
+  virtual void OnAddEntry() {}
+
+ private:
+  friend class TabRestoreServiceTest;
+  FRIEND_TEST_ALL_PREFIXES(TabRestoreServiceTest, PruneEntries);
+  FRIEND_TEST_ALL_PREFIXES(TabRestoreServiceTest, PruneIsCalled);
+
+  // Populates the tab's navigations from the NavigationController, and its
+  // browser_id and pinned state from the browser.
+  void PopulateTab(Tab* tab,
+                   int index,
+                   TabRestoreServiceDelegate* delegate,
+                   content::NavigationController* controller);
+
+  // This is a helper function for RestoreEntryById() for restoring a single
+  // tab. If |delegate| is NULL, this creates a new window for the entry. This
+  // returns the TabRestoreServiceDelegate into which the tab was restored.
+  // |disposition| will be respected, but if it is UNKNOWN then the tab's
+  // original attributes will be respected instead.
+  TabRestoreServiceDelegate* RestoreTab(const Tab& tab,
+                                        TabRestoreServiceDelegate* delegate,
+                                        WindowOpenDisposition disposition);
+
+  // Returns true if |tab| has more than one navigation. If |tab| has more
+  // than one navigation |tab->current_navigation_index| is constrained based
+  // on the number of navigations.
+  static bool ValidateTab(Tab* tab);
+
+  // Validates all the tabs in a window, plus the window's active tab index.
+  static bool ValidateWindow(Window* window);
+
+  // Returns true if |tab| is one we care about restoring.
+  static bool IsTabInteresting(const Tab* tab);
+
+  // Checks whether |window| is interesting --- if it only contains a single,
+  // uninteresting tab, it's not interesting.
+  static bool IsWindowInteresting(const Window* window);
+
+  // Validates and checks |entry| for interesting.
+  static bool FilterEntry(Entry* entry);
+
+  // Finds tab entries with the old browser_id and sets it to the new one.
+  void UpdateTabBrowserIDs(SessionID::id_type old_id,
+                           SessionID::id_type new_id);
+
+  // Invoked when previous tabs or session is loaded. If both have finished
+  // loading the entries in staging_entries_ are added to entries_ and
+  // observers are notified.
+  void LoadStateChanged();
+
+  // Gets the current time. This uses the time_factory_ if there is one.
+  base::Time TimeNow() const;
+
+  Profile* const profile_;
+
+  // Set of entries. They are ordered from most to least recent.
+  Entries entries_;
+
+  // Are we restoring a tab? If this is true we ignore requests to create a
+  // historical tab.
+  bool restoring_;
+
+  ObserverList<TabRestoreServiceObserver> observer_list_;
+
+  // Set of delegates that we've received a BrowserClosing method for but no
+  // corresponding BrowserClosed. We cache the set of delegates closing to
+  // avoid creating historical tabs for them.
+  std::set<TabRestoreServiceDelegate*> closing_delegates_;
+
+  // Used when loading open tabs/session when recovering from a crash.
+  CancelableRequestConsumer crash_consumer_;
+
+  TimeFactory* time_factory_;
+
+  DISALLOW_COPY_AND_ASSIGN(InMemoryTabRestoreService);
+};
+
+#endif  // CHROME_BROWSER_SESSIONS_IN_MEMORY_TAB_RESTORE_SERVICE_H_