webkit/browser/blob/blob_storage_context.h

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