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1 // Copyright (c) 2012 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_QUIC_QUIC_STREAM_SEQUENCER_H_ | |
6 #define NET_QUIC_QUIC_STREAM_SEQUENCER_H_ | |
7 | |
8 #include <map> | |
9 #include <string> | |
10 | |
11 #include "base/basictypes.h" | |
12 #include "net/base/iovec.h" | |
13 #include "net/quic/quic_protocol.h" | |
14 | |
15 namespace net { | |
16 | |
17 namespace test { | |
18 class QuicStreamSequencerPeer; | |
19 } // namespace test | |
20 | |
21 class QuicSession; | |
22 class ReliableQuicStream; | |
23 | |
24 // Buffers frames until we have something which can be passed | |
25 // up to the next layer. | |
26 class NET_EXPORT_PRIVATE QuicStreamSequencer { | |
27 public: | |
28 explicit QuicStreamSequencer(ReliableQuicStream* quic_stream); | |
29 virtual ~QuicStreamSequencer(); | |
30 | |
31 // If the frame is the next one we need in order to process in-order data, | |
32 // ProcessData will be immediately called on the stream until all buffered | |
33 // data is processed or the stream fails to consume data. Any unconsumed | |
34 // data will be buffered. If the frame is not the next in line, it will be | |
35 // buffered. | |
36 void OnStreamFrame(const QuicStreamFrame& frame); | |
37 | |
38 // Once data is buffered, it's up to the stream to read it when the stream | |
39 // can handle more data. The following three functions make that possible. | |
40 | |
41 // Fills in up to iov_len iovecs with the next readable regions. Returns the | |
42 // number of iovs used. Non-destructive of the underlying data. | |
43 int GetReadableRegions(iovec* iov, size_t iov_len); | |
44 | |
45 // Copies the data into the iov_len buffers provided. Returns the number of | |
46 // bytes read. Any buffered data no longer in use will be released. | |
47 int Readv(const struct iovec* iov, size_t iov_len); | |
48 | |
49 // Returns true if the sequncer has bytes available for reading. | |
50 bool HasBytesToRead() const; | |
51 | |
52 // Returns true if the sequencer has delivered the fin. | |
53 bool IsClosed() const; | |
54 | |
55 // Returns true if the sequencer has received this frame before. | |
56 bool IsDuplicate(const QuicStreamFrame& frame) const; | |
57 | |
58 // Returns true if |frame| contains data which overlaps buffered data | |
59 // (indicating an invalid stream frame has been received). | |
60 bool FrameOverlapsBufferedData(const QuicStreamFrame& frame) const; | |
61 | |
62 // Calls |ProcessRawData| on |stream_| for each buffered frame that may | |
63 // be processed. | |
64 void FlushBufferedFrames(); | |
65 | |
66 // Blocks processing of frames until |FlushBufferedFrames| is called. | |
67 void SetBlockedUntilFlush(); | |
68 | |
69 size_t num_bytes_buffered() const { return num_bytes_buffered_; } | |
70 QuicStreamOffset num_bytes_consumed() const { return num_bytes_consumed_; } | |
71 | |
72 int num_frames_received() const { return num_frames_received_; } | |
73 | |
74 int num_duplicate_frames_received() const { | |
75 return num_duplicate_frames_received_; | |
76 } | |
77 | |
78 int num_early_frames_received() const { return num_early_frames_received_; } | |
79 | |
80 private: | |
81 friend class test::QuicStreamSequencerPeer; | |
82 | |
83 // Wait until we've seen 'offset' bytes, and then terminate the stream. | |
84 void CloseStreamAtOffset(QuicStreamOffset offset); | |
85 | |
86 // If we've received a FIN and have processed all remaining data, then inform | |
87 // the stream of FIN, and clear buffers. | |
88 bool MaybeCloseStream(); | |
89 | |
90 // Called whenever bytes are consumed by the stream. Updates | |
91 // num_bytes_consumed_ and num_bytes_buffered_. | |
92 void RecordBytesConsumed(size_t bytes_consumed); | |
93 | |
94 // The stream which owns this sequencer. | |
95 ReliableQuicStream* stream_; | |
96 | |
97 // The last data consumed by the stream. | |
98 QuicStreamOffset num_bytes_consumed_; | |
99 | |
100 // TODO(alyssar) use something better than strings. | |
101 // TODO(rjshade): In future we may support retransmission of partial stream | |
102 // frames, in which case we will have to allow receipt of overlapping frames. | |
103 // Maybe write new frames into a ring buffer, and keep track of consumed | |
104 // bytes, and gaps. | |
105 typedef std::map<QuicStreamOffset, std::string> FrameMap; | |
106 | |
107 // Stores buffered frames (maps from sequence number -> frame data as string). | |
108 FrameMap buffered_frames_; | |
109 | |
110 // The offset, if any, we got a stream termination for. When this many bytes | |
111 // have been processed, the sequencer will be closed. | |
112 QuicStreamOffset close_offset_; | |
113 | |
114 // If true, the sequencer is blocked from passing data to the stream and will | |
115 // buffer all new incoming data until FlushBufferedFrames is called. | |
116 bool blocked_; | |
117 | |
118 // Tracks how many bytes the sequencer has buffered. | |
119 size_t num_bytes_buffered_; | |
120 | |
121 // Count of the number of frames received. | |
122 int num_frames_received_; | |
123 | |
124 // Count of the number of duplicate frames received. | |
125 int num_duplicate_frames_received_; | |
126 | |
127 // Count of the number of frames received before all previous frames were | |
128 // received. | |
129 int num_early_frames_received_; | |
130 | |
131 DISALLOW_COPY_AND_ASSIGN(QuicStreamSequencer); | |
132 }; | |
133 | |
134 } // namespace net | |
135 | |
136 #endif // NET_QUIC_QUIC_STREAM_SEQUENCER_H_ | |
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