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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 CONTENT_BROWSER_STREAMS_STREAM_REGISTRY_H_
6 #define CONTENT_BROWSER_STREAMS_STREAM_REGISTRY_H_
7 
8 #include <map>
9 
10 #include "base/basictypes.h"
11 #include "base/memory/ref_counted.h"
12 #include "base/threading/non_thread_safe.h"
13 #include "content/common/content_export.h"
14 #include "url/gurl.h"
15 
16 namespace content {
17 
18 class Stream;
19 
20 // Maintains a mapping of blob: URLs to active streams.
21 class CONTENT_EXPORT StreamRegistry : public base::NonThreadSafe {
22  public:
23   StreamRegistry();
24   virtual ~StreamRegistry();
25 
26   // Registers a stream, and sets its URL.
27   void RegisterStream(scoped_refptr<Stream> stream);
28 
29   // Clones a stream.  Returns true on success, or false if |src_url| doesn't
30   // exist.
31   bool CloneStream(const GURL& url, const GURL& src_url);
32 
33   void UnregisterStream(const GURL& url);
34 
35   // Called by Stream instances to request increase of memory usage. If the
36   // total memory usage for this registry is going to exceed the limit,
37   // returns false. Otherwise, updates |total_memory_usage_| and returns true.
38   //
39   // |current_size| is the up-to-date size of ByteStream of the Stream instance
40   // and |increase| must be the amount of data going to be added to the Stream
41   // instance.
42   bool UpdateMemoryUsage(const GURL& url, size_t current_size, size_t increase);
43 
44   // Gets the stream associated with |url|.  Returns NULL if there is no such
45   // stream.
46   scoped_refptr<Stream> GetStream(const GURL& url);
47 
set_max_memory_usage_for_testing(size_t size)48   void set_max_memory_usage_for_testing(size_t size) {
49     max_memory_usage_ = size;
50   }
51 
52  private:
53   typedef std::map<GURL, scoped_refptr<Stream> > StreamMap;
54 
55   StreamMap streams_;
56 
57   size_t total_memory_usage_;
58 
59   // Maximum amount of memory allowed to use for Stream instances registered
60   // with this registry.
61   size_t max_memory_usage_;
62 
63   DISALLOW_COPY_AND_ASSIGN(StreamRegistry);
64 };
65 
66 }  // namespace content
67 
68 #endif  // CONTENT_BROWSER_STREAMS_STREAM_REGISTRY_H_
69