net/quic/quic_write_blocked_list.h

   1 // Copyright 2014 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_WRITE_BLOCKED_LIST_H_
   6 #define NET_QUIC_QUIC_WRITE_BLOCKED_LIST_H_
   7
   8 #include <set>
   9
  10 #include "net/base/net_export.h"
  11 #include "net/quic/quic_protocol.h"
  12 #include "net/spdy/write_blocked_list.h"
  13
  14 namespace net {
  15
  16 // Keeps tracks of the QUIC streams that have data to write, sorted by
  17 // priority.  QUIC stream priority order is:
  18 // Crypto stream > Headers stream > Data streams by requested priority.
  19 class NET_EXPORT_PRIVATE QuicWriteBlockedList {
  20  private:
  21   typedef WriteBlockedList<QuicStreamId> QuicWriteBlockedListBase;
  22
  23  public:
  24   static const QuicPriority kHighestPriority;
  25   static const QuicPriority kLowestPriority;
  26
  27   QuicWriteBlockedList();
  28   ~QuicWriteBlockedList();
  29
  30   bool HasWriteBlockedDataStreams() const {
  31     return base_write_blocked_list_.HasWriteBlockedStreams();
  32   }
  33
  34   bool HasWriteBlockedCryptoOrHeadersStream() const {
  35     return crypto_stream_blocked_ || headers_stream_blocked_;
  36   }
  37
  38   size_t NumBlockedStreams() const {
  39     size_t num_blocked = base_write_blocked_list_.NumBlockedStreams();
  40     if (crypto_stream_blocked_) {
  41       ++num_blocked;
  42     }
  43     if (headers_stream_blocked_) {
  44       ++num_blocked;
  45     }
  46
  47     return num_blocked;
  48   }
  49
  50   QuicStreamId PopFront() {
  51     if (crypto_stream_blocked_) {
  52       crypto_stream_blocked_ = false;
  53       return kCryptoStreamId;
  54     }
  55
  56     if (headers_stream_blocked_) {
  57       headers_stream_blocked_ = false;
  58       return kHeadersStreamId;
  59     }
  60
  61     SpdyPriority priority =
  62         base_write_blocked_list_.GetHighestPriorityWriteBlockedList();
  63     QuicStreamId id = base_write_blocked_list_.PopFront(priority);
  64     return id;
  65   }
  66
  67   void PushBack(QuicStreamId stream_id, QuicPriority priority) {
  68     if (stream_id == kCryptoStreamId) {
  69       DCHECK_EQ(kHighestPriority, priority);
  70       // TODO(avd) Add DCHECK(!crypto_stream_blocked_)
  71       crypto_stream_blocked_ = true;
  72       return;
  73     }
  74
  75     if (stream_id == kHeadersStreamId) {
  76       DCHECK_EQ(kHighestPriority, priority);
  77       // TODO(avd) Add DCHECK(!headers_stream_blocked_);
  78       headers_stream_blocked_ = true;
  79       return;
  80     }
  81
  82     base_write_blocked_list_.PushBack(
  83         stream_id, static_cast<SpdyPriority>(priority));
  84     return;
  85   }
  86
  87   bool crypto_stream_blocked() const { return crypto_stream_blocked_; }
  88   bool headers_stream_blocked() const { return headers_stream_blocked_; }
  89
  90  private:
  91   QuicWriteBlockedListBase base_write_blocked_list_;
  92   bool crypto_stream_blocked_;
  93   bool headers_stream_blocked_;
  94
  95   DISALLOW_COPY_AND_ASSIGN(QuicWriteBlockedList);
  96 };
  97
  98 }  // namespace net
  99
 100
 101 #endif  // NET_QUIC_QUIC_WRITE_BLOCKED_LIST_H_