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 #include <string>
  10
  11 #include "base/basictypes.h"
  12 #include "base/files/file_path.h"
  13 #include "base/memory/ref_counted.h"
  14 #include "content/common/content_export.h"
  15 #include "url/gurl.h"
  16
  17 namespace content {
  18
  19 class DOMStorageArea;
  20 class DOMStorageTaskRunner;
  21 class SessionStorageDatabase;
  22
  23 // Container for the set of per-origin Areas.
  24 // See class comments for DOMStorageContextImpl for a larger overview.
  25 class CONTENT_EXPORT DOMStorageNamespace
  26     : public base::RefCountedThreadSafe<DOMStorageNamespace> {
  27  public:
  28   // Option for PurgeMemory.
  29   enum PurgeOption {
  30     // Purge unopened areas only.
  31     PURGE_UNOPENED,
  32
  33     // Purge aggressively, i.e. discard cache even for areas that have
  34     // non-zero open count.
  35     PURGE_AGGRESSIVE,
  36   };
  37
  38   // Constructor for a LocalStorage namespace with id of 0
  39   // and an optional backing directory on disk.
  40   DOMStorageNamespace(const base::FilePath& directory,  // may be empty
  41                       DOMStorageTaskRunner* task_runner);
  42
  43   // Constructor for a SessionStorage namespace with a non-zero id and an
  44   // optional backing on disk via |session_storage_database| (may be NULL).
  45   DOMStorageNamespace(int64 namespace_id,
  46                       const std::string& persistent_namespace_id,
  47                       SessionStorageDatabase* session_storage_database,
  48                       DOMStorageTaskRunner* task_runner);
  49
  50   int64 namespace_id() const { return namespace_id_; }
  51   const std::string& persistent_namespace_id() const {
  52     return persistent_namespace_id_;
  53   }
  54
  55   // Returns the storage area for the given origin,
  56   // creating instance if needed. Each call to open
  57   // must be balanced with a call to CloseStorageArea.
  58   DOMStorageArea* OpenStorageArea(const GURL& origin);
  59   void CloseStorageArea(DOMStorageArea* area);
  60
  61   // Returns the area for |origin| if it's open, otherwise NULL.
  62   DOMStorageArea* GetOpenStorageArea(const GURL& origin);
  63
  64   // Creates a clone of |this| namespace including
  65   // shallow copies of all contained areas.
  66   // Should only be called for session storage namespaces.
  67   DOMStorageNamespace* Clone(int64 clone_namespace_id,
  68                              const std::string& clone_persistent_namespace_id);
  69
  70   void DeleteLocalStorageOrigin(const GURL& origin);
  71   void DeleteSessionStorageOrigin(const GURL& origin);
  72   void PurgeMemory(PurgeOption purge);
  73   void Shutdown();
  74   void Flush();
  75
  76   unsigned int CountInMemoryAreas() const;
  77
  78  private:
  79   friend class base::RefCountedThreadSafe<DOMStorageNamespace>;
  80
  81   // Struct to hold references to our contained areas and
  82   // to keep track of how many tabs have a given area open.
  83   struct AreaHolder {
  84     scoped_refptr<DOMStorageArea> area_;
  85     int open_count_;
  86     AreaHolder();
  87     AreaHolder(DOMStorageArea* area, int count);
  88     ~AreaHolder();
  89   };
  90   typedef std::map<GURL, AreaHolder> AreaMap;
  91
  92   ~DOMStorageNamespace();
  93
  94   // Returns a pointer to the area holder in our map or NULL.
  95   AreaHolder* GetAreaHolder(const GURL& origin);
  96
  97   int64 namespace_id_;
  98   std::string persistent_namespace_id_;
  99   base::FilePath directory_;
 100   AreaMap areas_;
 101   scoped_refptr<DOMStorageTaskRunner> task_runner_;
 102   scoped_refptr<SessionStorageDatabase> session_storage_database_;
 103 };
 104
 105 }  // namespace content
 106
 107
 108 #endif  // CONTENT_BROWSER_DOM_STORAGE_DOM_STORAGE_NAMESPACE_H_