content/browser/dom_storage/dom_storage_namespace.h

   1 // Copyright 2013 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 CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_
   6 #define CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_
   7
   8 #include <map>
   9
  10 #include "base/basictypes.h"
  11 #include "base/files/file_path.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "content/common/content_export.h"
  14 #include "url/gurl.h"
  15
  16 namespace content {
  17
  18 class DOMStorageArea;
  19 class DOMStorageTaskRunner;
  20 class SessionStorageDatabase;
  21
  22 // Container for the set of per-origin Areas.
  23 // See class comments for DOMStorageContextImpl for a larger overview.
  24 class CONTENT_EXPORT DOMStorageNamespace
  25     : public base::RefCountedThreadSafe<DOMStorageNamespace> {
  26  public:
  27   // Option for PurgeMemory.
  28   enum PurgeOption {
  29     // Purge unopened areas only.
  30     PURGE_UNOPENED,
  31
  32     // Purge aggressively, i.e. discard cache even for areas that have
  33     // non-zero open count.
  34     PURGE_AGGRESSIVE,
  35   };
  36
  37   // Constructor for a LocalStorage namespace with id of 0
  38   // and an optional backing directory on disk.
  39   DOMStorageNamespace(const base::FilePath& directory,  // may be empty
  40                       DOMStorageTaskRunner* task_runner);
  41
  42   // Constructor for a SessionStorage namespace with a non-zero id and an
  43   // optional backing on disk via |session_storage_database| (may be NULL).
  44   DOMStorageNamespace(int64 namespace_id,
  45                       const std::string& persistent_namespace_id,
  46                       SessionStorageDatabase* session_storage_database,
  47                       DOMStorageTaskRunner* task_runner);
  48
  49   int64 namespace_id() const { return namespace_id_; }
  50   const std::string& persistent_namespace_id() const {
  51     return persistent_namespace_id_;
  52   }
  53
  54   // Returns the storage area for the given origin,
  55   // creating instance if needed. Each call to open
  56   // must be balanced with a call to CloseStorageArea.
  57   DOMStorageArea* OpenStorageArea(const GURL& origin);
  58   void CloseStorageArea(DOMStorageArea* area);
  59
  60   // Returns the area for |origin| if it's open, otherwise NULL.
  61   DOMStorageArea* GetOpenStorageArea(const GURL& origin);
  62
  63   // Creates a clone of |this| namespace including
  64   // shallow copies of all contained areas.
  65   // Should only be called for session storage namespaces.
  66   DOMStorageNamespace* Clone(int64 clone_namespace_id,
  67                              const std::string& clone_persistent_namespace_id);
  68
  69   void DeleteLocalStorageOrigin(const GURL& origin);
  70   void DeleteSessionStorageOrigin(const GURL& origin);
  71   void PurgeMemory(PurgeOption purge);
  72   void Shutdown();
  73
  74   unsigned int CountInMemoryAreas() const;
  75
  76  private:
  77   friend class base::RefCountedThreadSafe<DOMStorageNamespace>;
  78
  79   // Struct to hold references to our contained areas and
  80   // to keep track of how many tabs have a given area open.
  81   struct AreaHolder {
  82     scoped_refptr<DOMStorageArea> area_;
  83     int open_count_;
  84     AreaHolder();
  85     AreaHolder(DOMStorageArea* area, int count);
  86     ~AreaHolder();
  87   };
  88   typedef std::map<GURL, AreaHolder> AreaMap;
  89
  90   ~DOMStorageNamespace();
  91
  92   // Returns a pointer to the area holder in our map or NULL.
  93   AreaHolder* GetAreaHolder(const GURL& origin);
  94
  95   int64 namespace_id_;
  96   std::string persistent_namespace_id_;
  97   base::FilePath directory_;
  98   AreaMap areas_;
  99   scoped_refptr<DOMStorageTaskRunner> task_runner_;
 100   scoped_refptr<SessionStorageDatabase> session_storage_database_;
 101 };
 102
 103 }  // namespace content
 104
 105
 106 #endif  // CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_