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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 #ifndef WEBKIT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_H_ | |
6 #define WEBKIT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_H_ | |
7 | |
8 #include <map> | |
9 #include <set> | |
10 #include <vector> | |
11 | |
12 #include "base/atomic_sequence_num.h" | |
13 #include "base/basictypes.h" | |
14 #include "base/files/file_path.h" | |
15 #include "base/gtest_prod_util.h" | |
16 #include "base/memory/ref_counted.h" | |
17 #include "base/observer_list.h" | |
18 #include "base/time/time.h" | |
19 #include "url/gurl.h" | |
20 #include "webkit/browser/webkit_storage_browser_export.h" | |
21 | |
22 namespace base { | |
23 class FilePath; | |
24 class NullableString16; | |
25 class Time; | |
26 } | |
27 | |
28 namespace quota { | |
29 class SpecialStoragePolicy; | |
30 } | |
31 | |
32 namespace dom_storage { | |
33 | |
34 class DomStorageArea; | |
35 class DomStorageNamespace; | |
36 class DomStorageSession; | |
37 class DomStorageTaskRunner; | |
38 class SessionStorageDatabase; | |
39 struct LocalStorageUsageInfo; | |
40 struct SessionStorageUsageInfo; | |
41 | |
42 // The Context is the root of an object containment hierachy for | |
43 // Namespaces and Areas related to the owning profile. | |
44 // One instance is allocated in the main process for each profile, | |
45 // instance methods should be called serially in the background as | |
46 // determined by the task_runner. Specifcally not on chrome's non-blocking | |
47 // IO thread since these methods can result in blocking file io. | |
48 // | |
49 // In general terms, the DomStorage object relationships are... | |
50 // Contexts (per-profile) own Namespaces which own Areas which share Maps. | |
51 // Hosts(per-renderer) refer to Namespaces and Areas open in its renderer. | |
52 // Sessions (per-tab) cause the creation and deletion of session Namespaces. | |
53 // | |
54 // Session Namespaces are cloned by initially making a shallow copy of | |
55 // all contained Areas, the shallow copies refer to the same refcounted Map, | |
56 // and does a deep copy-on-write if needed. | |
57 // | |
58 // Classes intended to be used by an embedder are DomStorageContext, | |
59 // DomStorageHost, and DomStorageSession. The other classes are for | |
60 // internal consumption. | |
61 class WEBKIT_STORAGE_BROWSER_EXPORT DomStorageContext | |
62 : public base::RefCountedThreadSafe<DomStorageContext> { | |
63 public: | |
64 // An interface for observing Local and Session Storage events on the | |
65 // background thread. | |
66 class EventObserver { | |
67 public: | |
68 virtual void OnDomStorageItemSet( | |
69 const DomStorageArea* area, | |
70 const base::string16& key, | |
71 const base::string16& new_value, | |
72 const base::NullableString16& old_value, // may be null on initial inse
rt | |
73 const GURL& page_url) = 0; | |
74 virtual void OnDomStorageItemRemoved( | |
75 const DomStorageArea* area, | |
76 const base::string16& key, | |
77 const base::string16& old_value, | |
78 const GURL& page_url) = 0; | |
79 virtual void OnDomStorageAreaCleared( | |
80 const DomStorageArea* area, | |
81 const GURL& page_url) = 0; | |
82 | |
83 protected: | |
84 virtual ~EventObserver() {} | |
85 }; | |
86 | |
87 DomStorageContext( | |
88 const base::FilePath& localstorage_directory, // empty for incognito prof
iles | |
89 const base::FilePath& sessionstorage_directory, // empty for incognito pr
ofiles | |
90 quota::SpecialStoragePolicy* special_storage_policy, | |
91 DomStorageTaskRunner* task_runner); | |
92 | |
93 // Returns the directory path for localStorage, or an empty directory, if | |
94 // there is no backing on disk. | |
95 const base::FilePath& localstorage_directory() { | |
96 return localstorage_directory_; | |
97 } | |
98 | |
99 // Returns the directory path for sessionStorage, or an empty directory, if | |
100 // there is no backing on disk. | |
101 const base::FilePath& sessionstorage_directory() { | |
102 return sessionstorage_directory_; | |
103 } | |
104 | |
105 DomStorageTaskRunner* task_runner() const { return task_runner_.get(); } | |
106 DomStorageNamespace* GetStorageNamespace(int64 namespace_id); | |
107 | |
108 void GetLocalStorageUsage(std::vector<LocalStorageUsageInfo>* infos, | |
109 bool include_file_info); | |
110 void GetSessionStorageUsage(std::vector<SessionStorageUsageInfo>* infos); | |
111 void DeleteLocalStorage(const GURL& origin); | |
112 void DeleteSessionStorage(const SessionStorageUsageInfo& usage_info); | |
113 void PurgeMemory(); | |
114 | |
115 // Used by content settings to alter the behavior around | |
116 // what data to keep and what data to discard at shutdown. | |
117 // The policy is not so straight forward to describe, see | |
118 // the implementation for details. | |
119 void SetForceKeepSessionState() { | |
120 force_keep_session_state_ = true; | |
121 } | |
122 | |
123 // Called when the owning BrowserContext is ending. | |
124 // Schedules the commit of any unsaved changes and will delete | |
125 // and keep data on disk per the content settings and special storage | |
126 // policies. Contained areas and namespaces will stop functioning after | |
127 // this method has been called. | |
128 void Shutdown(); | |
129 | |
130 // Methods to add, remove, and notify EventObservers. | |
131 void AddEventObserver(EventObserver* observer); | |
132 void RemoveEventObserver(EventObserver* observer); | |
133 void NotifyItemSet( | |
134 const DomStorageArea* area, | |
135 const base::string16& key, | |
136 const base::string16& new_value, | |
137 const base::NullableString16& old_value, | |
138 const GURL& page_url); | |
139 void NotifyItemRemoved( | |
140 const DomStorageArea* area, | |
141 const base::string16& key, | |
142 const base::string16& old_value, | |
143 const GURL& page_url); | |
144 void NotifyAreaCleared( | |
145 const DomStorageArea* area, | |
146 const GURL& page_url); | |
147 | |
148 // May be called on any thread. | |
149 int64 AllocateSessionId() { | |
150 return session_id_sequence_.GetNext(); | |
151 } | |
152 | |
153 std::string AllocatePersistentSessionId(); | |
154 | |
155 // Must be called on the background thread. | |
156 void CreateSessionNamespace(int64 namespace_id, | |
157 const std::string& persistent_namespace_id); | |
158 void DeleteSessionNamespace(int64 namespace_id, bool should_persist_data); | |
159 void CloneSessionNamespace(int64 existing_id, int64 new_id, | |
160 const std::string& new_persistent_id); | |
161 | |
162 // Starts backing sessionStorage on disk. This function must be called right | |
163 // after DomStorageContext is created, before it's used. | |
164 void SetSaveSessionStorageOnDisk(); | |
165 | |
166 // Deletes all namespaces which don't have an associated DomStorageNamespace | |
167 // alive. This function is used for deleting possible leftover data after an | |
168 // unclean exit. | |
169 void StartScavengingUnusedSessionStorage(); | |
170 | |
171 private: | |
172 friend class DomStorageContextTest; | |
173 FRIEND_TEST_ALL_PREFIXES(DomStorageContextTest, Basics); | |
174 friend class base::RefCountedThreadSafe<DomStorageContext>; | |
175 typedef std::map<int64, scoped_refptr<DomStorageNamespace> > | |
176 StorageNamespaceMap; | |
177 | |
178 ~DomStorageContext(); | |
179 | |
180 void ClearSessionOnlyOrigins(); | |
181 | |
182 // For scavenging unused sessionStorages. | |
183 void FindUnusedNamespaces(); | |
184 void FindUnusedNamespacesInCommitSequence( | |
185 const std::set<std::string>& namespace_ids_in_use, | |
186 const std::set<std::string>& protected_persistent_session_ids); | |
187 void DeleteNextUnusedNamespace(); | |
188 void DeleteNextUnusedNamespaceInCommitSequence(); | |
189 | |
190 // Collection of namespaces keyed by id. | |
191 StorageNamespaceMap namespaces_; | |
192 | |
193 // Where localstorage data is stored, maybe empty for the incognito use case. | |
194 base::FilePath localstorage_directory_; | |
195 | |
196 // Where sessionstorage data is stored, maybe empty for the incognito use | |
197 // case. Always empty until the file-backed session storage feature is | |
198 // implemented. | |
199 base::FilePath sessionstorage_directory_; | |
200 | |
201 // Used to schedule sequenced background tasks. | |
202 scoped_refptr<DomStorageTaskRunner> task_runner_; | |
203 | |
204 // List of objects observing local storage events. | |
205 ObserverList<EventObserver> event_observers_; | |
206 | |
207 // We use a 32 bit identifier for per tab storage sessions. | |
208 // At a tab per second, this range is large enough for 68 years. | |
209 base::AtomicSequenceNumber session_id_sequence_; | |
210 | |
211 bool is_shutdown_; | |
212 bool force_keep_session_state_; | |
213 scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy_; | |
214 scoped_refptr<SessionStorageDatabase> session_storage_database_; | |
215 | |
216 // For cleaning up unused namespaces gradually. | |
217 bool scavenging_started_; | |
218 std::vector<std::string> deletable_persistent_namespace_ids_; | |
219 | |
220 // Persistent namespace IDs to protect from gradual deletion (they will | |
221 // be needed for session restore). | |
222 std::set<std::string> protected_persistent_session_ids_; | |
223 | |
224 // Mapping between persistent namespace IDs and namespace IDs for | |
225 // sessionStorage. | |
226 std::map<std::string, int64> persistent_namespace_id_to_namespace_id_; | |
227 }; | |
228 | |
229 } // namespace dom_storage | |
230 | |
231 #endif // WEBKIT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_H_ | |
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