net/tools/quic/test_tools/packet_dropping_test_writer.h

   1 // Copyright 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_TOOLS_QUIC_TEST_TOOLS_PACKET_DROPPING_TEST_WRITER_H_
   6 #define NET_TOOLS_QUIC_TEST_TOOLS_PACKET_DROPPING_TEST_WRITER_H_
   7
   8 #include <list>
   9
  10 #include "base/basictypes.h"
  11 #include "base/logging.h"
  12 #include "base/memory/scoped_ptr.h"
  13 #include "base/synchronization/lock.h"
  14 #include "net/quic/quic_alarm.h"
  15 #include "net/quic/test_tools/quic_test_utils.h"
  16 #include "net/tools/quic/quic_epoll_clock.h"
  17 #include "net/tools/quic/quic_packet_writer_wrapper.h"
  18 #include "net/tools/quic/test_tools/quic_test_client.h"
  19 #include "net/tools/quic/test_tools/quic_test_utils.h"
  20
  21 namespace net {
  22 namespace tools {
  23 namespace test {
  24
  25 // Simulates a connection that drops packets a configured percentage of the time
  26 // and has a blocked socket a configured percentage of the time.  Also provides
  27 // the options to delay packets and reorder packets if delay is enabled.
  28 class PacketDroppingTestWriter : public QuicPacketWriterWrapper {
  29  public:
  30   class Delegate {
  31    public:
  32     virtual ~Delegate() {}
  33     virtual void OnPacketSent(WriteResult result) = 0;
  34     virtual void OnCanWrite() = 0;
  35   };
  36
  37   PacketDroppingTestWriter();
  38
  39   virtual ~PacketDroppingTestWriter();
  40
  41   // Must be called before blocking, reordering or delaying (loss is OK). May be
  42   // called after connecting if the helper is not available before.
  43   // |on_can_write| will be triggered when fake-unblocking; ownership will be
  44   // assumed.
  45   void Initialize(QuicEpollConnectionHelper* helper, Delegate* on_can_write);
  46
  47   // QuicPacketWriter methods:
  48   virtual WriteResult WritePacket(
  49       const char* buffer,
  50       size_t buf_len,
  51       const IPAddressNumber& self_address,
  52       const IPEndPoint& peer_address) OVERRIDE;
  53
  54   virtual bool IsWriteBlocked() const OVERRIDE;
  55
  56   virtual void SetWritable() OVERRIDE;
  57
  58   // Writes out any packet which should have been sent by now
  59   // to the contained writer and returns the time
  60   // for the next delayed packet to be written.
  61   QuicTime ReleaseOldPackets();
  62
  63   void OnCanWrite();
  64
  65   // The percent of time a packet is simulated as being lost.
  66   void set_fake_packet_loss_percentage(int32 fake_packet_loss_percentage) {
  67     base::AutoLock locked(config_mutex_);
  68     fake_packet_loss_percentage_ = fake_packet_loss_percentage;
  69   }
  70
  71   // The percent of time WritePacket will block and set WriteResult's status
  72   // to WRITE_STATUS_BLOCKED.
  73   void set_fake_blocked_socket_percentage(
  74       int32 fake_blocked_socket_percentage) {
  75     DCHECK(clock_);
  76     base::AutoLock locked(config_mutex_);
  77     fake_blocked_socket_percentage_  = fake_blocked_socket_percentage;
  78   }
  79
  80   // The percent of time a packet is simulated as being reordered.
  81   void set_fake_reorder_percentage(int32 fake_packet_reorder_percentage) {
  82     DCHECK(clock_);
  83     base::AutoLock locked(config_mutex_);
  84     DCHECK(!fake_packet_delay_.IsZero());
  85     fake_packet_reorder_percentage_ = fake_packet_reorder_percentage;
  86   }
  87
  88   // The percent of time WritePacket will block and set WriteResult's status
  89   // to WRITE_STATUS_BLOCKED.
  90   void set_fake_packet_delay(QuicTime::Delta fake_packet_delay) {
  91     DCHECK(clock_);
  92     base::AutoLock locked(config_mutex_);
  93     fake_packet_delay_  = fake_packet_delay;
  94   }
  95
  96   // The maximum bandwidth and buffer size of the connection.  When these are
  97   // set, packets will be delayed until a connection with that bandwidth would
  98   // transmit it.  Once the |buffer_size| is reached, all new packets are
  99   // dropped.
 100   void set_max_bandwidth_and_buffer_size(QuicBandwidth fake_bandwidth,
 101                                          QuicByteCount buffer_size) {
 102     DCHECK(clock_);
 103     base::AutoLock locked(config_mutex_);
 104     fake_bandwidth_ = fake_bandwidth;
 105     buffer_size_ = buffer_size;
 106   }
 107
 108   void set_seed(uint64 seed) {
 109     simple_random_.set_seed(seed);
 110   }
 111
 112  private:
 113   // Writes out the next packet to the contained writer and returns the time
 114   // for the next delayed packet to be written.
 115   QuicTime ReleaseNextPacket();
 116
 117   // A single packet which will be sent at the supplied send_time.
 118   struct DelayedWrite {
 119    public:
 120     DelayedWrite(const char* buffer,
 121                  size_t buf_len,
 122                  const IPAddressNumber& self_address,
 123                  const IPEndPoint& peer_address,
 124                  QuicTime send_time);
 125     ~DelayedWrite();
 126
 127     string buffer;
 128     const IPAddressNumber self_address;
 129     const IPEndPoint peer_address;
 130     QuicTime send_time;
 131   };
 132
 133   typedef std::list<DelayedWrite> DelayedPacketList;
 134
 135   const QuicClock* clock_;
 136   scoped_ptr<QuicAlarm> write_unblocked_alarm_;
 137   scoped_ptr<QuicAlarm> delay_alarm_;
 138   scoped_ptr<Delegate> on_can_write_;
 139   net::test::SimpleRandom simple_random_;
 140   // Stored packets delayed by fake packet delay or bandwidth restrictions.
 141   DelayedPacketList delayed_packets_;
 142   QuicByteCount cur_buffer_size_;
 143
 144   base::Lock config_mutex_;
 145   int32 fake_packet_loss_percentage_;
 146   int32 fake_blocked_socket_percentage_;
 147   int32 fake_packet_reorder_percentage_;
 148   QuicTime::Delta fake_packet_delay_;
 149   QuicBandwidth fake_bandwidth_;
 150   QuicByteCount buffer_size_;
 151
 152   DISALLOW_COPY_AND_ASSIGN(PacketDroppingTestWriter);
 153 };
 154
 155 }  // namespace test
 156 }  // namespace tools
 157 }  // namespace net
 158
 159 #endif  // NET_TOOLS_QUIC_TEST_TOOLS_PACKET_DROPPING_TEST_WRITER_H_