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 NET_SPDY_SPDY_WRITE_QUEUE_H_
6 #define NET_SPDY_SPDY_WRITE_QUEUE_H_
7 
8 #include <memory>
9 
10 #include "base/containers/circular_deque.h"
11 #include "base/macros.h"
12 #include "base/memory/weak_ptr.h"
13 #include "net/base/net_export.h"
14 #include "net/base/request_priority.h"
15 #include "net/third_party/quiche/src/spdy/core/spdy_protocol.h"
16 #include "net/traffic_annotation/network_traffic_annotation.h"
17 
18 namespace net {
19 
20 // Returns whether this frame type is subject to caps on how many
21 // frames can be queued at any given time.
22 NET_EXPORT_PRIVATE bool IsSpdyFrameTypeWriteCapped(
23     spdy::SpdyFrameType frame_type);
24 
25 class SpdyBufferProducer;
26 class SpdyStream;
27 
28 // A queue of SpdyBufferProducers to produce frames to write. Ordered
29 // by priority, and then FIFO.
30 class NET_EXPORT_PRIVATE SpdyWriteQueue {
31  public:
32   SpdyWriteQueue();
33   ~SpdyWriteQueue();
34 
35   // Returns whether there is anything in the write queue,
36   // i.e. whether the next call to Dequeue will return true.
37   bool IsEmpty() const;
38 
39   // Enqueues the given frame producer of the given type at the given
40   // priority associated with the given stream, which may be NULL if
41   // the frame producer is not associated with a stream. If |stream|
42   // is non-NULL, its priority must be equal to |priority|, and it
43   // must remain non-NULL until the write is dequeued or removed.
44   void Enqueue(RequestPriority priority,
45                spdy::SpdyFrameType frame_type,
46                std::unique_ptr<SpdyBufferProducer> frame_producer,
47                const base::WeakPtr<SpdyStream>& stream,
48                const NetworkTrafficAnnotationTag& traffic_annotation);
49 
50   // Dequeues the frame producer with the highest priority that was
51   // enqueued the earliest and its associated stream. Returns true and
52   // fills in |frame_type|, |frame_producer|, and |stream| if
53   // successful -- otherwise, just returns false.
54   bool Dequeue(spdy::SpdyFrameType* frame_type,
55                std::unique_ptr<SpdyBufferProducer>* frame_producer,
56                base::WeakPtr<SpdyStream>* stream,
57                MutableNetworkTrafficAnnotationTag* traffic_annotation);
58 
59   // Removes all pending writes for the given stream, which must be
60   // non-NULL.
61   void RemovePendingWritesForStream(SpdyStream* stream);
62 
63   // Removes all pending writes for streams after |last_good_stream_id|
64   // and streams with no stream id.
65   void RemovePendingWritesForStreamsAfter(
66       spdy::SpdyStreamId last_good_stream_id);
67 
68   // Change priority of all pending writes for the given stream.  Frames will be
69   // queued after other writes with |new_priority|.
70   void ChangePriorityOfWritesForStream(SpdyStream* stream,
71                                        RequestPriority old_priority,
72                                        RequestPriority new_priority);
73 
74   // Removes all pending writes.
75   void Clear();
76 
77   // Returns the estimate of dynamically allocated memory in bytes.
78   size_t EstimateMemoryUsage() const;
79 
80   // Returns the number of currently queued capped frames including all
81   // priorities.
num_queued_capped_frames()82   int num_queued_capped_frames() const { return num_queued_capped_frames_; }
83 
84  private:
85   // A struct holding a frame producer and its associated stream.
86   struct PendingWrite {
87     spdy::SpdyFrameType frame_type;
88     std::unique_ptr<SpdyBufferProducer> frame_producer;
89     base::WeakPtr<SpdyStream> stream;
90     MutableNetworkTrafficAnnotationTag traffic_annotation;
91     // Whether |stream| was non-NULL when enqueued.
92     bool has_stream;
93 
94     PendingWrite();
95     PendingWrite(spdy::SpdyFrameType frame_type,
96                  std::unique_ptr<SpdyBufferProducer> frame_producer,
97                  const base::WeakPtr<SpdyStream>& stream,
98                  const MutableNetworkTrafficAnnotationTag& traffic_annotation);
99     ~PendingWrite();
100     PendingWrite(PendingWrite&& other);
101     PendingWrite& operator=(PendingWrite&& other);
102 
103     size_t EstimateMemoryUsage() const;
104 
105    private:
106     DISALLOW_COPY_AND_ASSIGN(PendingWrite);
107   };
108 
109   bool removing_writes_;
110 
111   // Number of currently queued capped frames including all priorities.
112   int num_queued_capped_frames_ = 0;
113 
114   // The actual write queue, binned by priority.
115   base::circular_deque<PendingWrite> queue_[NUM_PRIORITIES];
116 
117   DISALLOW_COPY_AND_ASSIGN(SpdyWriteQueue);
118 };
119 
120 }  // namespace net
121 
122 #endif  // NET_SPDY_SPDY_WRITE_QUEUE_H_
123