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 <memory>
10 #include <string>
11 #include <vector>
12 
13 #include "base/macros.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(std::unique_ptr<content::BlobHandle> blob);
37 
38  private:
39   using BlobHandleMultimap =
40       std::multimap<std::string, std::unique_ptr<content::BlobHandle>>;
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_
63