| // 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 CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_IMPL_H_ |
| #define CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_IMPL_H_ |
| |
| #include <map> |
| #include <set> |
| #include <vector> |
| |
| #include "base/atomic_sequence_num.h" |
| #include "base/basictypes.h" |
| #include "base/files/file_path.h" |
| #include "base/gtest_prod_util.h" |
| #include "base/memory/ref_counted.h" |
| #include "base/observer_list.h" |
| #include "base/time/time.h" |
| #include "content/common/content_export.h" |
| #include "url/gurl.h" |
| |
| namespace base { |
| class FilePath; |
| class NullableString16; |
| class Time; |
| } |
| |
| namespace quota { |
| class SpecialStoragePolicy; |
| } |
| |
| namespace content { |
| |
| class DOMStorageArea; |
| class DOMStorageNamespace; |
| class DOMStorageSession; |
| class DOMStorageTaskRunner; |
| class SessionStorageDatabase; |
| struct LocalStorageUsageInfo; |
| struct SessionStorageUsageInfo; |
| |
| // The Context is the root of an object containment hierachy for |
| // Namespaces and Areas related to the owning profile. |
| // One instance is allocated in the main process for each profile, |
| // instance methods should be called serially in the background as |
| // determined by the task_runner. Specifcally not on chrome's non-blocking |
| // IO thread since these methods can result in blocking file io. |
| // |
| // In general terms, the DOMStorage object relationships are... |
| // Contexts (per-profile) own Namespaces which own Areas which share Maps. |
| // Hosts(per-renderer) refer to Namespaces and Areas open in its renderer. |
| // Sessions (per-tab) cause the creation and deletion of session Namespaces. |
| // |
| // Session Namespaces are cloned by initially making a shallow copy of |
| // all contained Areas, the shallow copies refer to the same refcounted Map, |
| // and does a deep copy-on-write if needed. |
| // |
| // Classes intended to be used by an embedder are DOMStorageContextImpl, |
| // DOMStorageHost, and DOMStorageSession. The other classes are for |
| // internal consumption. |
| class CONTENT_EXPORT DOMStorageContextImpl |
| : public base::RefCountedThreadSafe<DOMStorageContextImpl> { |
| public: |
| // An interface for observing Local and Session Storage events on the |
| // background thread. |
| class EventObserver { |
| public: |
| // |old_value| may be null on initial insert. |
| virtual void OnDOMStorageItemSet( |
| const DOMStorageArea* area, |
| const base::string16& key, |
| const base::string16& new_value, |
| const base::NullableString16& old_value, |
| const GURL& page_url) = 0; |
| virtual void OnDOMStorageItemRemoved( |
| const DOMStorageArea* area, |
| const base::string16& key, |
| const base::string16& old_value, |
| const GURL& page_url) = 0; |
| virtual void OnDOMStorageAreaCleared( |
| const DOMStorageArea* area, |
| const GURL& page_url) = 0; |
| |
| protected: |
| virtual ~EventObserver() {} |
| }; |
| |
| // |localstorage_directory| and |sessionstorage_directory| may be empty |
| // for incognito browser contexts. |
| DOMStorageContextImpl( |
| const base::FilePath& localstorage_directory, |
| const base::FilePath& sessionstorage_directory, |
| quota::SpecialStoragePolicy* special_storage_policy, |
| DOMStorageTaskRunner* task_runner); |
| |
| // Returns the directory path for localStorage, or an empty directory, if |
| // there is no backing on disk. |
| const base::FilePath& localstorage_directory() { |
| return localstorage_directory_; |
| } |
| |
| // Returns the directory path for sessionStorage, or an empty directory, if |
| // there is no backing on disk. |
| const base::FilePath& sessionstorage_directory() { |
| return sessionstorage_directory_; |
| } |
| |
| DOMStorageTaskRunner* task_runner() const { return task_runner_.get(); } |
| DOMStorageNamespace* GetStorageNamespace(int64 namespace_id); |
| |
| void GetLocalStorageUsage(std::vector<LocalStorageUsageInfo>* infos, |
| bool include_file_info); |
| void GetSessionStorageUsage(std::vector<SessionStorageUsageInfo>* infos); |
| void DeleteLocalStorage(const GURL& origin); |
| void DeleteSessionStorage(const SessionStorageUsageInfo& usage_info); |
| void PurgeMemory(); |
| |
| // Used by content settings to alter the behavior around |
| // what data to keep and what data to discard at shutdown. |
| // The policy is not so straight forward to describe, see |
| // the implementation for details. |
| void SetForceKeepSessionState() { |
| force_keep_session_state_ = true; |
| } |
| |
| // Called when the owning BrowserContext is ending. |
| // Schedules the commit of any unsaved changes and will delete |
| // and keep data on disk per the content settings and special storage |
| // policies. Contained areas and namespaces will stop functioning after |
| // this method has been called. |
| void Shutdown(); |
| |
| // Methods to add, remove, and notify EventObservers. |
| void AddEventObserver(EventObserver* observer); |
| void RemoveEventObserver(EventObserver* observer); |
| void NotifyItemSet( |
| const DOMStorageArea* area, |
| const base::string16& key, |
| const base::string16& new_value, |
| const base::NullableString16& old_value, |
| const GURL& page_url); |
| void NotifyItemRemoved( |
| const DOMStorageArea* area, |
| const base::string16& key, |
| const base::string16& old_value, |
| const GURL& page_url); |
| void NotifyAreaCleared( |
| const DOMStorageArea* area, |
| const GURL& page_url); |
| |
| // May be called on any thread. |
| int64 AllocateSessionId() { |
| return session_id_sequence_.GetNext(); |
| } |
| |
| std::string AllocatePersistentSessionId(); |
| |
| // Must be called on the background thread. |
| void CreateSessionNamespace(int64 namespace_id, |
| const std::string& persistent_namespace_id); |
| void DeleteSessionNamespace(int64 namespace_id, bool should_persist_data); |
| void CloneSessionNamespace(int64 existing_id, int64 new_id, |
| const std::string& new_persistent_id); |
| |
| // Starts backing sessionStorage on disk. This function must be called right |
| // after DOMStorageContextImpl is created, before it's used. |
| void SetSaveSessionStorageOnDisk(); |
| |
| // Deletes all namespaces which don't have an associated DOMStorageNamespace |
| // alive. This function is used for deleting possible leftover data after an |
| // unclean exit. |
| void StartScavengingUnusedSessionStorage(); |
| |
| private: |
| friend class DOMStorageContextImplTest; |
| FRIEND_TEST_ALL_PREFIXES(DOMStorageContextImplTest, Basics); |
| friend class base::RefCountedThreadSafe<DOMStorageContextImpl>; |
| typedef std::map<int64, scoped_refptr<DOMStorageNamespace> > |
| StorageNamespaceMap; |
| |
| ~DOMStorageContextImpl(); |
| |
| void ClearSessionOnlyOrigins(); |
| |
| // For scavenging unused sessionStorages. |
| void FindUnusedNamespaces(); |
| void FindUnusedNamespacesInCommitSequence( |
| const std::set<std::string>& namespace_ids_in_use, |
| const std::set<std::string>& protected_persistent_session_ids); |
| void DeleteNextUnusedNamespace(); |
| void DeleteNextUnusedNamespaceInCommitSequence(); |
| |
| // Collection of namespaces keyed by id. |
| StorageNamespaceMap namespaces_; |
| |
| // Where localstorage data is stored, maybe empty for the incognito use case. |
| base::FilePath localstorage_directory_; |
| |
| // Where sessionstorage data is stored, maybe empty for the incognito use |
| // case. Always empty until the file-backed session storage feature is |
| // implemented. |
| base::FilePath sessionstorage_directory_; |
| |
| // Used to schedule sequenced background tasks. |
| scoped_refptr<DOMStorageTaskRunner> task_runner_; |
| |
| // List of objects observing local storage events. |
| ObserverList<EventObserver> event_observers_; |
| |
| // We use a 32 bit identifier for per tab storage sessions. |
| // At a tab per second, this range is large enough for 68 years. |
| base::AtomicSequenceNumber session_id_sequence_; |
| |
| bool is_shutdown_; |
| bool force_keep_session_state_; |
| scoped_refptr<quota::SpecialStoragePolicy> special_storage_policy_; |
| scoped_refptr<SessionStorageDatabase> session_storage_database_; |
| |
| // For cleaning up unused namespaces gradually. |
| bool scavenging_started_; |
| std::vector<std::string> deletable_persistent_namespace_ids_; |
| |
| // Persistent namespace IDs to protect from gradual deletion (they will |
| // be needed for session restore). |
| std::set<std::string> protected_persistent_session_ids_; |
| |
| // Mapping between persistent namespace IDs and namespace IDs for |
| // sessionStorage. |
| std::map<std::string, int64> persistent_namespace_id_to_namespace_id_; |
| }; |
| |
| } // namespace content |
| |
| #endif // CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_CONTEXT_IMPL_H_ |