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      1 // Copyright (c) 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 WEBKIT_BROWSER_BLOB_BLOB_STORAGE_CONTEXT_H_
      6 #define WEBKIT_BROWSER_BLOB_BLOB_STORAGE_CONTEXT_H_
      7 
      8 #include <map>
      9 #include <string>
     10 
     11 #include "base/memory/ref_counted.h"
     12 #include "base/memory/scoped_ptr.h"
     13 #include "base/memory/weak_ptr.h"
     14 #include "webkit/browser/blob/blob_data_handle.h"
     15 #include "webkit/browser/webkit_storage_browser_export.h"
     16 #include "webkit/common/blob/blob_data.h"
     17 
     18 class GURL;
     19 
     20 namespace base {
     21 class FilePath;
     22 class Time;
     23 }
     24 
     25 namespace webkit_blob {
     26 
     27 class BlobDataHandle;
     28 
     29 // This class handles the logistics of blob Storage within the browser process,
     30 // and maintains a mapping from blob uuid to the data. The class is single
     31 // threaded and should only be used on the IO thread.
     32 // In chromium, there is one instance per profile.
     33 class WEBKIT_STORAGE_BROWSER_EXPORT BlobStorageContext
     34     : public base::SupportsWeakPtr<BlobStorageContext> {
     35  public:
     36   BlobStorageContext();
     37   ~BlobStorageContext();
     38 
     39   scoped_ptr<BlobDataHandle> GetBlobDataFromUUID(const std::string& uuid);
     40   scoped_ptr<BlobDataHandle> GetBlobDataFromPublicURL(const GURL& url);
     41 
     42   // Useful for coining blobs from within the browser process. If the
     43   // blob cannot be added due to memory consumption, returns NULL.
     44   scoped_ptr<BlobDataHandle> AddFinishedBlob(const BlobData* blob_data);
     45 
     46   // Useful for coining blob urls from within the browser process.
     47   bool RegisterPublicBlobURL(const GURL& url, const std::string& uuid);
     48   void RevokePublicBlobURL(const GURL& url);
     49 
     50  private:
     51   friend class BlobDataHandle;
     52   friend class BlobStorageHost;
     53   friend class ViewBlobInternalsJob;
     54 
     55   enum EntryFlags {
     56     BEING_BUILT = 1 << 0,
     57     EXCEEDED_MEMORY = 1 << 1,
     58   };
     59 
     60   struct BlobMapEntry {
     61     int refcount;
     62     int flags;
     63     scoped_refptr<BlobData> data;
     64 
     65     BlobMapEntry();
     66     BlobMapEntry(int refcount, int flags, BlobData* data);
     67     ~BlobMapEntry();
     68   };
     69 
     70   typedef std::map<std::string, BlobMapEntry>
     71       BlobMap;
     72   typedef std::map<GURL, std::string> BlobURLMap;
     73 
     74   void StartBuildingBlob(const std::string& uuid);
     75   void AppendBlobDataItem(const std::string& uuid,
     76                           const BlobData::Item& data_item);
     77   void FinishBuildingBlob(const std::string& uuid, const std::string& type);
     78   void CancelBuildingBlob(const std::string& uuid);
     79   void IncrementBlobRefCount(const std::string& uuid);
     80   void DecrementBlobRefCount(const std::string& uuid);
     81 
     82   bool ExpandStorageItems(BlobData* target_blob_data,
     83                           BlobData* src_blob_data,
     84                           uint64 offset,
     85                           uint64 length);
     86   bool AppendBytesItem(BlobData* target_blob_data,
     87                        const char* data, int64 length);
     88   void AppendFileItem(BlobData* target_blob_data,
     89                       const base::FilePath& file_path,
     90                       uint64 offset, uint64 length,
     91                       const base::Time& expected_modification_time);
     92   void AppendFileSystemFileItem(
     93       BlobData* target_blob_data,
     94       const GURL& url, uint64 offset, uint64 length,
     95       const base::Time& expected_modification_time);
     96 
     97   bool IsInUse(const std::string& uuid);
     98   bool IsBeingBuilt(const std::string& uuid);
     99   bool IsUrlRegistered(const GURL& blob_url);
    100 
    101   BlobMap blob_map_;
    102   BlobURLMap public_blob_urls_;
    103 
    104   // Used to keep track of how much memory is being utitlized for blob data,
    105   // we count only the items of TYPE_DATA which are held in memory and not
    106   // items of TYPE_FILE.
    107   int64 memory_usage_;
    108 
    109   DISALLOW_COPY_AND_ASSIGN(BlobStorageContext);
    110 };
    111 
    112 }  // namespace webkit_blob
    113 
    114 #endif  // WEBKIT_BROWSER_BLOB_BLOB_STORAGE_CONTEXT_H_
    115