extensions/browser/blob_holder.h

   1 // Copyright 2014 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 EXTENSIONS_BROWSER_BLOB_HOLDER_H_
   6 #define EXTENSIONS_BROWSER_BLOB_HOLDER_H_
   7
   8 #include <map>
   9 #include <string>
  10 #include <vector>
  11
  12 #include "base/memory/linked_ptr.h"
  13 #include "base/memory/scoped_ptr.h"
  14 #include "base/supports_user_data.h"
  15
  16 namespace content {
  17 class BlobHandle;
  18 class RenderProcessHost;
  19 }
  20
  21 namespace extensions {
  22
  23 class ExtensionMessageFilter;
  24
  25 // Used for holding onto Blobs created into the browser process until a
  26 // renderer takes over ownership. This class operates on the UI thread.
  27 class BlobHolder : public base::SupportsUserData::Data {
  28  public:
  29   // Will create the BlobHolder if it doesn't already exist.
  30   static BlobHolder* FromRenderProcessHost(
  31       content::RenderProcessHost* render_process_host);
  32
  33   ~BlobHolder() override;
  34
  35   // Causes BlobHolder to take ownership of |blob|.
  36   void HoldBlobReference(scoped_ptr<content::BlobHandle> blob);
  37
  38  private:
  39   typedef std::multimap<std::string, linked_ptr<content::BlobHandle> >
  40       BlobHandleMultimap;
  41
  42   explicit BlobHolder(content::RenderProcessHost* render_process_host);
  43
  44   // BlobHolder will drop a blob handle for each element in blob_uuids.
  45   // If caller wishes to drop multiple references to the same blob,
  46   // |blob_uuids| may contain duplicate UUIDs.
  47   void DropBlobs(const std::vector<std::string>& blob_uuids);
  48   friend class ExtensionMessageFilter;
  49
  50   bool ContainsBlobHandle(content::BlobHandle* handle) const;
  51
  52   // A reference to the owner of this class.
  53   content::RenderProcessHost* render_process_host_;
  54
  55   BlobHandleMultimap held_blobs_;
  56
  57   DISALLOW_COPY_AND_ASSIGN(BlobHolder);
  58 };
  59
  60 }  // namespace extensions
  61
  62 #endif  // EXTENSIONS_BROWSER_BLOB_HOLDER_H_