content/browser/streams/stream_registry.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 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
  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_