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 #include <set>
  10
  11 #include "base/basictypes.h"
  12 #include "base/memory/ref_counted.h"
  13 #include "base/threading/non_thread_safe.h"
  14 #include "content/browser/streams/stream_register_observer.h"
  15 #include "content/common/content_export.h"
  16 #include "url/gurl.h"
  17
  18 namespace content {
  19
  20 class Stream;
  21
  22 // Maintains a mapping of blob: URLs to active streams.
  23 class CONTENT_EXPORT StreamRegistry : public base::NonThreadSafe {
  24  public:
  25   StreamRegistry();
  26   virtual ~StreamRegistry();
  27
  28   // Registers a stream, and sets its URL.
  29   void RegisterStream(Stream* stream);
  30
  31   // Clones a stream.  Returns true on success, or false if |src_url| doesn't
  32   // exist.
  33   bool CloneStream(const GURL& url, const GURL& src_url);
  34
  35   void UnregisterStream(const GURL& url);
  36
  37   // Called by Stream instances to request increase of memory usage. If the
  38   // total memory usage for this registry is going to exceed the limit,
  39   // returns false. Otherwise, updates |total_memory_usage_| and returns true.
  40   //
  41   // |current_size| is the up-to-date size of ByteStream of the Stream instance
  42   // and |increase| must be the amount of data going to be added to the Stream
  43   // instance.
  44   bool UpdateMemoryUsage(const GURL& url, size_t current_size, size_t increase);
  45
  46   // Gets the stream associated with |url|.  Returns NULL if there is no such
  47   // stream.
  48   scoped_refptr<Stream> GetStream(const GURL& url);
  49
  50   void set_max_memory_usage_for_testing(size_t size) {
  51     max_memory_usage_ = size;
  52   }
  53
  54   void SetRegisterObserver(const GURL& url, StreamRegisterObserver* observer);
  55   void RemoveRegisterObserver(const GURL& url);
  56
  57   // If the reader is aborted before the stream is registered, call this method
  58   // to reduce the memory consumption. After this method is called,
  59   // RegisterStream doesn't register the stream of the URL.
  60   void AbortPendingStream(const GURL& url);
  61
  62  private:
  63   typedef std::map<GURL, scoped_refptr<Stream> > StreamMap;
  64
  65   StreamMap streams_;
  66   std::map<GURL, StreamRegisterObserver*> register_observers_;
  67   std::set<GURL> reader_aborted_urls_;
  68
  69   size_t total_memory_usage_;
  70
  71   // Maximum amount of memory allowed to use for Stream instances registered
  72   // with this registry.
  73   size_t max_memory_usage_;
  74
  75   DISALLOW_COPY_AND_ASSIGN(StreamRegistry);
  76 };
  77
  78 }  // namespace content
  79
  80 #endif  // CONTENT_BROWSER_STREAMS_STREAM_REGISTRY_H_