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.
5 #ifndef CHROME_BROWSER_SYNC_GLUE_SYNCED_SESSION_TRACKER_H_
6 #define CHROME_BROWSER_SYNC_GLUE_SYNCED_SESSION_TRACKER_H_
13 #include "base/basictypes.h"
14 #include "base/memory/scoped_vector.h"
15 #include "chrome/browser/sessions/session_id.h"
16 #include "chrome/browser/sessions/session_types.h"
17 #include "chrome/browser/sync/glue/synced_session.h"
18 #include "chrome/browser/sync/glue/tab_node_pool.h"
20 namespace browser_sync {
22 // Class to manage synced sessions. The tracker will own all SyncedSession
23 // and SyncedSessionTab objects it creates, and deletes them appropriately on
25 // Note: SyncedSession objects are created for all synced sessions, including
26 // the local session (whose tag we maintain separately).
27 class SyncedSessionTracker {
29 SyncedSessionTracker();
30 ~SyncedSessionTracker();
32 // We track and distinguish the local session from foreign sessions.
33 void SetLocalSessionTag(const std::string& local_session_tag);
35 // Fill a preallocated vector with all foreign sessions we're tracking (skips
36 // the local session object). SyncedSession ownership remains within the
37 // SyncedSessionTracker.
38 // Returns true if we had foreign sessions to fill it with, false otherwise.
39 bool LookupAllForeignSessions(std::vector<const SyncedSession*>* sessions)
42 // Attempts to look up the session windows associatd with the session given
43 // by |session_tag|. Ownership Of SessionWindows stays within the
44 // SyncedSessionTracker.
45 // If lookup succeeds:
46 // - Fills windows with the SessionWindow pointers, returns true.
49 bool LookupSessionWindows(const std::string& session_tag,
50 std::vector<const SessionWindow*>* windows) const;
52 // Attempts to look up the tab associated with the given tag and tab id.
53 // Ownership of the SessionTab remains within the SyncedSessionTracker.
54 // If lookup succeeds:
55 // - Sets tab to point to the SessionTab, and returns true.
57 // - Returns false, tab is set to NULL.
58 bool LookupSessionTab(const std::string& session_tag,
59 SessionID::id_type tab_id,
60 const SessionTab** tab) const;
62 // Returns a pointer to the SyncedSession object associated with
63 // |session_tag|. If none exists, creates one. Ownership of the
64 // SyncedSession remains within the SyncedSessionTracker.
65 SyncedSession* GetSession(const std::string& session_tag);
67 // Deletes the session associated with |session_tag| if it exists.
68 // Returns true if the session existed and was deleted, false otherwise.
69 bool DeleteSession(const std::string& session_tag);
71 // Resets the tracking information for the session specified by |session_tag|.
72 // This involves clearing all the windows and tabs from the session, while
73 // keeping pointers saved in the synced_window_map_ and synced_tab_map_.
74 // Once reset, all calls to PutWindowInSession and PutTabInWindow will denote
75 // that the requested windows and tabs are owned (by setting the boolean
76 // in their SessionWindowWrapper/SessionTabWrapper to true) and add them back
77 // to their session. The next call to CleanupSession(...) will delete those
78 // windows and tabs not owned.
79 void ResetSessionTracking(const std::string& session_tag);
81 // Deletes those windows and tabs associated with |session_tag| that are no
83 // See ResetSessionTracking(...).
84 void CleanupSession(const std::string& session_tag);
86 // Adds the window with id |window_id| to the session specified by
87 // |session_tag|, and markes the window as being owned. If none existed for
88 // that session, creates one. Similarly, if the session did not exist yet,
89 // creates it. Ownership of the SessionWindow remains within the
90 // SyncedSessionTracker.
91 void PutWindowInSession(const std::string& session_tag,
92 SessionID::id_type window_id);
94 // Adds the tab with id |tab_id| to the window |window_id|, and marks it as
95 // being owned. If none existed for that session, creates one. Ownership of
96 // the SessionTab remains within the SyncedSessionTracker.
97 // Note: GetSession(..) must have already been called with |session_tag| to
98 // ensure we having mapping information for this session.
99 void PutTabInWindow(const std::string& session_tag,
100 SessionID::id_type window_id,
101 SessionID::id_type tab_id,
104 // Returns a pointer to the SessionTab object associated with |tab_id| for
105 // the session specified with |session_tag|. If none exists, creates one.
106 // Ownership of the SessionTab remains within the SyncedSessionTracker.
107 // |tab_node_id| must be a valid node id for the node backing this tab.
108 SessionTab* GetTab(const std::string& session_tag,
109 SessionID::id_type tab_id,
112 // Fills |tab_node_ids| with the tab node ids (see GetTab) for all the tabs*
113 // associated with the session having tag |session_tag|.
114 // Returns false if we don't have any record of the session. If no tabs were
115 // found as part of the session, the return value will be true but
116 // |tab_node_ids| will be empty.
118 // * - note that this only returns the ids we're aware of; it's possible we
119 // don't have the latest tab state from a foreign session and it's also
120 // possible we just haven't updated the tab_node_id for a tab yet, so the
121 // result list should not be treated as authoritative.
122 bool LookupTabNodeIds(const std::string& session_tag,
123 std::set<int>* tab_node_ids);
125 // Free the memory for all dynamically allocated objects and clear the
126 // tracking structures.
130 return synced_tab_map_.empty() && synced_session_map_.empty();
133 // Includes both foreign sessions and the local session.
134 size_t num_synced_sessions() const {
135 return synced_session_map_.size();
138 // Returns the number of tabs associated with the specified session tag.
139 size_t num_synced_tabs(const std::string& session_tag) const {
140 SyncedTabMap::const_iterator iter = synced_tab_map_.find(session_tag);
141 if (iter != synced_tab_map_.end()) {
142 return iter->second.size();
148 // Datatypes for accessing session data. Neither of the *Wrappers actually
149 // have ownership of the Windows/Tabs, they just provide id-based access to
150 // them. The ownership remains within its containing session (for windows and
151 // mapped tabs, unmapped tabs are owned by the unmapped_tabs_ container).
152 // Note, we pair pointers with bools so that we can track what is owned and
153 // what can be deleted (see ResetSessionTracking(..) and CleanupSession(..)
155 // The wrappers also serve as a convenient place to augment state stored in
156 // SessionTab for sync purposes, such as |tab_node_id|.
157 // IsOwned is used as a wrapper constructor parameter for readability.
162 struct SessionTabWrapper {
163 SessionTabWrapper() : tab_ptr(NULL),
165 tab_node_id(TabNodePool::kInvalidTabNodeID) {}
166 SessionTabWrapper(SessionTab* tab_ptr, OwnedState owned, int tab_node_id)
168 owned(owned == IS_OWNED),
169 tab_node_id(tab_node_id) {}
172 // This is used as part of a mark-and-sweep approach to garbage
173 // collection for closed tabs that are no longer "in use", or "owned".
174 // ResetSessionTracking will clear |owned| bits, and if it is not claimed
175 // by a window by the time CleanupSession is called it will be deleted.
178 // This lets us identify the sync node that is "backing" this tab in the
179 // sync model, whether it is part of a local or foreign session. The
180 // "tab node id" is described in session_specifics.proto.
183 typedef std::map<SessionID::id_type, SessionTabWrapper> IDToSessionTabMap;
184 typedef std::map<std::string, IDToSessionTabMap> SyncedTabMap;
186 struct SessionWindowWrapper {
187 SessionWindowWrapper() : window_ptr(NULL), owned(false) {}
188 SessionWindowWrapper(SessionWindow* window_ptr, OwnedState owned)
189 : window_ptr(window_ptr),
190 owned(owned == IS_OWNED) {}
191 SessionWindow* window_ptr;
194 typedef std::map<SessionID::id_type, SessionWindowWrapper>
195 IDToSessionWindowMap;
196 typedef std::map<std::string, IDToSessionWindowMap> SyncedWindowMap;
198 typedef std::map<std::string, SyncedSession*> SyncedSessionMap;
200 // Helper methods for deleting SessionWindows and SessionTabs without owners.
201 bool DeleteOldSessionWindowIfNecessary(SessionWindowWrapper window_wrapper);
202 bool DeleteOldSessionTabIfNecessary(SessionTabWrapper tab_wrapper);
204 // Implementation for GetTab(...) above, permits invalid tab_node_id.
205 SessionTab* GetTabImpl(const std::string& session_tag,
206 SessionID::id_type tab_id,
209 // Per client mapping of tab id's to their SessionTab objects.
211 // Value: Tab id to SessionTabWrapper map.
212 SyncedTabMap synced_tab_map_;
214 // Per client mapping of the window id's to their SessionWindow objects.
216 // Value: Window id to SessionWindowWrapper map.
217 SyncedWindowMap synced_window_map_;
219 // Per client mapping synced session objects.
221 // Value: SyncedSession object pointer.
222 SyncedSessionMap synced_session_map_;
224 // The set of tabs that we have seen, and created SessionTab objects for, but
225 // have not yet mapped to SyncedSessions. These are temporarily orphaned
226 // tabs, and won't be deleted if we delete synced_session_map_, but are still
227 // owned by the SyncedSessionTracker itself (and deleted on Clear()).
228 std::set<SessionTab*> unmapped_tabs_;
230 // The tag for this machine's local session, so we can distinguish the foreign
232 std::string local_session_tag_;
234 DISALLOW_COPY_AND_ASSIGN(SyncedSessionTracker);
237 } // namespace browser_sync
239 #endif // CHROME_BROWSER_SYNC_GLUE_SYNCED_SESSION_TRACKER_H_