Remove //net (except for Android test stuff) and sdch

net/quic/quic_sent_packet_manager.h

-// Copyright 2013 The Chromium Authors. All rights reserved.
-// Use of this source code is governed by a BSD-style license that can be
-// found in the LICENSE file.
-
-#ifndef NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_
-#define NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_
-
-#include <map>
-#include <set>
-#include <utility>
-#include <vector>
-
-#include "base/containers/hash_tables.h"
-#include "base/memory/scoped_ptr.h"
-#include "net/base/linked_hash_map.h"
-#include "net/quic/congestion_control/loss_detection_interface.h"
-#include "net/quic/congestion_control/rtt_stats.h"
-#include "net/quic/congestion_control/send_algorithm_interface.h"
-#include "net/quic/crypto/cached_network_parameters.h"
-#include "net/quic/quic_ack_notifier_manager.h"
-#include "net/quic/quic_protocol.h"
-#include "net/quic/quic_sustained_bandwidth_recorder.h"
-#include "net/quic/quic_unacked_packet_map.h"
-
-namespace net {
-
-namespace test {
-class QuicConnectionPeer;
-class QuicSentPacketManagerPeer;
-}  // namespace test
-
-class QuicClock;
-class QuicConfig;
-struct QuicConnectionStats;
-
-// Class which tracks the set of packets sent on a QUIC connection and contains
-// a send algorithm to decide when to send new packets.  It keeps track of any
-// retransmittable data associated with each packet. If a packet is
-// retransmitted, it will keep track of each version of a packet so that if a
-// previous transmission is acked, the data will not be retransmitted.
-class NET_EXPORT_PRIVATE QuicSentPacketManager {
- public:
-  // Interface which gets callbacks from the QuicSentPacketManager at
-  // interesting points.  Implementations must not mutate the state of
-  // the packet manager or connection as a result of these callbacks.
-  class NET_EXPORT_PRIVATE DebugDelegate {
-   public:
-    virtual ~DebugDelegate() {}
-
-    // Called when a spurious retransmission is detected.
-    virtual void OnSpuriousPacketRetransmission(
-        TransmissionType transmission_type,
-        QuicByteCount byte_size) {}
-
-    virtual void OnIncomingAck(
-        const QuicAckFrame& ack_frame,
-        QuicTime ack_receive_time,
-        QuicPacketSequenceNumber largest_observed,
-        bool rtt_updated,
-        QuicPacketSequenceNumber least_unacked_sent_packet) {}
-  };
-
-  // Interface which gets callbacks from the QuicSentPacketManager when
-  // network-related state changes. Implementations must not mutate the
-  // state of the packet manager as a result of these callbacks.
-  class NET_EXPORT_PRIVATE NetworkChangeVisitor {
-   public:
-    virtual ~NetworkChangeVisitor() {}
-
-    // Called when congestion window may have changed.
-    virtual void OnCongestionWindowChange() = 0;
-
-    // Called when RTT may have changed, including when an RTT is read from
-    // the config.
-    virtual void OnRttChange() = 0;
-  };
-
-  // Struct to store the pending retransmission information.
-  struct PendingRetransmission {
-    PendingRetransmission(QuicPacketSequenceNumber sequence_number,
-                          TransmissionType transmission_type,
-                          const RetransmittableFrames& retransmittable_frames,
-                          QuicSequenceNumberLength sequence_number_length)
-            : sequence_number(sequence_number),
-              transmission_type(transmission_type),
-              retransmittable_frames(retransmittable_frames),
-              sequence_number_length(sequence_number_length) {
-        }
-
-        QuicPacketSequenceNumber sequence_number;
-        TransmissionType transmission_type;
-        const RetransmittableFrames& retransmittable_frames;
-        QuicSequenceNumberLength sequence_number_length;
-  };
-
-  QuicSentPacketManager(bool is_server,
-                        const QuicClock* clock,
-                        QuicConnectionStats* stats,
-                        CongestionControlType congestion_control_type,
-                        LossDetectionType loss_type,
-                        bool is_secure);
-  virtual ~QuicSentPacketManager();
-
-  virtual void SetFromConfig(const QuicConfig& config);
-
-  // Pass the CachedNetworkParameters to the send algorithm.
-  // Returns true if this changes the initial connection state.
-  bool ResumeConnectionState(
-      const CachedNetworkParameters& cached_network_params);
-
-  void SetNumOpenStreams(size_t num_streams);
-
-  void SetHandshakeConfirmed() { handshake_confirmed_ = true; }
-
-  // Processes the incoming ack.
-  void OnIncomingAck(const QuicAckFrame& ack_frame,
-                     QuicTime ack_receive_time);
-
-  // Returns true if the non-FEC packet |sequence_number| is unacked.
-  bool IsUnacked(QuicPacketSequenceNumber sequence_number) const;
-
-  // Requests retransmission of all unacked packets of |retransmission_type|.
-  // The behavior of this method depends on the value of |retransmission_type|:
-  // ALL_UNACKED_RETRANSMISSION - All unacked packets will be retransmitted.
-  // This can happen, for example, after a version negotiation packet has been
-  // received and all packets needs to be retransmitted with the new version.
-  // ALL_INITIAL_RETRANSMISSION - Only initially encrypted packets will be
-  // retransmitted. This can happen, for example, when a CHLO has been rejected
-  // and the previously encrypted data needs to be encrypted with a new key.
-  void RetransmitUnackedPackets(TransmissionType retransmission_type);
-
-  // Retransmits the oldest pending packet there is still a tail loss probe
-  // pending.  Invoked after OnRetransmissionTimeout.
-  bool MaybeRetransmitTailLossProbe();
-
-  // Removes the retransmittable frames from all unencrypted packets to ensure
-  // they don't get retransmitted.
-  void NeuterUnencryptedPackets();
-
-  // Returns true if the unacked packet |sequence_number| has retransmittable
-  // frames.  This will only return false if the packet has been acked, if a
-  // previous transmission of this packet was ACK'd, or if this packet has been
-  // retransmitted as with different sequence number.
-  bool HasRetransmittableFrames(QuicPacketSequenceNumber sequence_number) const;
-
-  // Returns true if there are pending retransmissions.
-  bool HasPendingRetransmissions() const;
-
-  // Retrieves the next pending retransmission.  You must ensure that
-  // there are pending retransmissions prior to calling this function.
-  PendingRetransmission NextPendingRetransmission();
-
-  bool HasUnackedPackets() const;
-
-  // Returns the smallest sequence number of a serialized packet which has not
-  // been acked by the peer.
-  QuicPacketSequenceNumber GetLeastUnacked() const;
-
-  // Called when we have sent bytes to the peer.  This informs the manager both
-  // the number of bytes sent and if they were retransmitted.  Returns true if
-  // the sender should reset the retransmission timer.
-  virtual bool OnPacketSent(SerializedPacket* serialized_packet,
-                            QuicPacketSequenceNumber original_sequence_number,
-                            QuicTime sent_time,
-                            QuicByteCount bytes,
-                            TransmissionType transmission_type,
-                            HasRetransmittableData has_retransmittable_data);
-
-  // Called when the retransmission timer expires.
-  virtual void OnRetransmissionTimeout();
-
-  // Calculate the time until we can send the next packet to the wire.
-  // Note 1: When kUnknownWaitTime is returned, there is no need to poll
-  // TimeUntilSend again until we receive an OnIncomingAckFrame event.
-  // Note 2: Send algorithms may or may not use |retransmit| in their
-  // calculations.
-  virtual QuicTime::Delta TimeUntilSend(QuicTime now,
-                                        HasRetransmittableData retransmittable);
-
-  // Returns amount of time for delayed ack timer.
-  const QuicTime::Delta DelayedAckTime() const;
-
-  // Returns the current delay for the retransmission timer, which may send
-  // either a tail loss probe or do a full RTO.  Returns QuicTime::Zero() if
-  // there are no retransmittable packets.
-  const QuicTime GetRetransmissionTime() const;
-
-  const RttStats* GetRttStats() const;
-
-  // Returns the estimated bandwidth calculated by the congestion algorithm.
-  QuicBandwidth BandwidthEstimate() const;
-
-  // Returns true if the current instantaneous bandwidth estimate is reliable.
-  bool HasReliableBandwidthEstimate() const;
-
-  const QuicSustainedBandwidthRecorder& SustainedBandwidthRecorder() const;
-
-  // Returns the size of the current congestion window in number of
-  // kDefaultTCPMSS-sized segments. Note, this is not the *available* window.
-  // Some send algorithms may not use a congestion window and will return 0.
-  QuicPacketCount GetCongestionWindowInTcpMss() const;
-
-  // Returns the number of packets of length |max_packet_length| which fit in
-  // the current congestion window. More packets may end up in flight if the
-  // congestion window has been recently reduced, of if non-full packets are
-  // sent.
-  QuicPacketCount EstimateMaxPacketsInFlight(
-      QuicByteCount max_packet_length) const;
-
-  // Returns the size of the slow start congestion window in nume of 1460 byte
-  // TCP segments, aka ssthresh.  Some send algorithms do not define a slow
-  // start threshold and will return 0.
-  QuicPacketCount GetSlowStartThresholdInTcpMss() const;
-
-  // Called by the connection every time it receives a serialized packet.
-  void OnSerializedPacket(const SerializedPacket& serialized_packet);
-
-  // Enables pacing if it has not already been enabled.
-  void EnablePacing();
-
-  bool using_pacing() const { return using_pacing_; }
-
-  void set_debug_delegate(DebugDelegate* debug_delegate) {
-    debug_delegate_ = debug_delegate;
-  }
-
-  QuicPacketSequenceNumber largest_observed() const {
-    return unacked_packets_.largest_observed();
-  }
-
-  QuicPacketSequenceNumber least_packet_awaited_by_peer() {
-    return least_packet_awaited_by_peer_;
-  }
-
-  void set_network_change_visitor(NetworkChangeVisitor* visitor) {
-    DCHECK(!network_change_visitor_);
-    DCHECK(visitor);
-    network_change_visitor_ = visitor;
-  }
-
-  size_t consecutive_rto_count() const {
-    return consecutive_rto_count_;
-  }
-
-  size_t consecutive_tlp_count() const {
-    return consecutive_tlp_count_;
-  }
-
- private:
-  friend class test::QuicConnectionPeer;
-  friend class test::QuicSentPacketManagerPeer;
-
-  // The retransmission timer is a single timer which switches modes depending
-  // upon connection state.
-  enum RetransmissionTimeoutMode {
-    // A conventional TCP style RTO.
-    RTO_MODE,
-    // A tail loss probe.  By default, QUIC sends up to two before RTOing.
-    TLP_MODE,
-    // Retransmission of handshake packets prior to handshake completion.
-    HANDSHAKE_MODE,
-    // Re-invoke the loss detection when a packet is not acked before the
-    // loss detection algorithm expects.
-    LOSS_MODE,
-  };
-
-  typedef linked_hash_map<QuicPacketSequenceNumber,
-                          TransmissionType> PendingRetransmissionMap;
-
-  // Called when a packet is retransmitted with a new sequence number.
-  // Replaces the old entry in the unacked packet map with the new
-  // sequence number.
-  void OnRetransmittedPacket(QuicPacketSequenceNumber old_sequence_number,
-                             QuicPacketSequenceNumber new_sequence_number);
-
-  // Updates the least_packet_awaited_by_peer.
-  void UpdatePacketInformationReceivedByPeer(const QuicAckFrame& ack_frame);
-
-  // Process the incoming ack looking for newly ack'd data packets.
-  void HandleAckForSentPackets(const QuicAckFrame& ack_frame);
-
-  // Returns the current retransmission mode.
-  RetransmissionTimeoutMode GetRetransmissionMode() const;
-
-  // Retransmits all crypto stream packets.
-  void RetransmitCryptoPackets();
-
-  // Retransmits two packets for an RTO and removes any non-retransmittable
-  // packets from flight.
-  void RetransmitRtoPackets();
-
-  // Retransmits all the packets and abandons by invoking a full RTO.
-  void RetransmitAllPackets();
-
-  // Returns the timer for retransmitting crypto handshake packets.
-  const QuicTime::Delta GetCryptoRetransmissionDelay() const;
-
-  // Returns the timer for a new tail loss probe.
-  const QuicTime::Delta GetTailLossProbeDelay() const;
-
-  // Returns the retransmission timeout, after which a full RTO occurs.
-  const QuicTime::Delta GetRetransmissionDelay() const;
-
-  // Update the RTT if the ack is for the largest acked sequence number.
-  // Returns true if the rtt was updated.
-  bool MaybeUpdateRTT(const QuicAckFrame& ack_frame,
-                      const QuicTime& ack_receive_time);
-
-  // Invokes the loss detection algorithm and loses and retransmits packets if
-  // necessary.
-  void InvokeLossDetection(QuicTime time);
-
-  // Invokes OnCongestionEvent if |rtt_updated| is true, there are pending acks,
-  // or pending losses.  Clears pending acks and pending losses afterwards.
-  // |bytes_in_flight| is the number of bytes in flight before the losses or
-  // acks.
-  void MaybeInvokeCongestionEvent(bool rtt_updated,
-                                  QuicByteCount bytes_in_flight);
-
-  // Marks |sequence_number| as having been revived by the peer, but not
-  // received, so the packet remains pending if it is and the congestion control
-  // does not consider the packet acked.
-  void MarkPacketRevived(QuicPacketSequenceNumber sequence_number,
-                         QuicTime::Delta delta_largest_observed);
-
-  // Removes the retransmittability and pending properties from the packet at
-  // |it| due to receipt by the peer.  Returns an iterator to the next remaining
-  // unacked packet.
-  void MarkPacketHandled(QuicPacketSequenceNumber sequence_number,
-                         const TransmissionInfo& info,
-                         QuicTime::Delta delta_largest_observed);
-
-  // Request that |sequence_number| be retransmitted after the other pending
-  // retransmissions.  Does not add it to the retransmissions if it's already
-  // a pending retransmission.
-  void MarkForRetransmission(QuicPacketSequenceNumber sequence_number,
-                             TransmissionType transmission_type);
-
-  // Notify observers about spurious retransmits.
-  void RecordSpuriousRetransmissions(
-      const SequenceNumberList& all_transmissions,
-      QuicPacketSequenceNumber acked_sequence_number);
-
-  // Returns true if the client is sending or the server has received a
-  // connection option.
-  bool HasClientSentConnectionOption(const QuicConfig& config,
-                                     QuicTag tag) const;
-
-  // Newly serialized retransmittable and fec packets are added to this map,
-  // which contains owning pointers to any contained frames.  If a packet is
-  // retransmitted, this map will contain entries for both the old and the new
-  // packet. The old packet's retransmittable frames entry will be nullptr,
-  // while the new packet's entry will contain the frames to retransmit.
-  // If the old packet is acked before the new packet, then the old entry will
-  // be removed from the map and the new entry's retransmittable frames will be
-  // set to nullptr.
-  QuicUnackedPacketMap unacked_packets_;
-
-  // Pending retransmissions which have not been packetized and sent yet.
-  PendingRetransmissionMap pending_retransmissions_;
-
-  // Tracks if the connection was created by the server.
-  bool is_server_;
-
-  // An AckNotifier can register to be informed when ACKs have been received for
-  // all packets that a given block of data was sent in. The AckNotifierManager
-  // maintains the currently active notifiers.
-  AckNotifierManager ack_notifier_manager_;
-
-  const QuicClock* clock_;
-  QuicConnectionStats* stats_;
-  DebugDelegate* debug_delegate_;
-  NetworkChangeVisitor* network_change_visitor_;
-  const QuicPacketCount initial_congestion_window_;
-  RttStats rtt_stats_;
-  scoped_ptr<SendAlgorithmInterface> send_algorithm_;
-  scoped_ptr<LossDetectionInterface> loss_algorithm_;
-  bool n_connection_simulation_;
-
-  // Receiver side buffer in bytes.
-  QuicByteCount receive_buffer_bytes_;
-
-  // Least sequence number which the peer is still waiting for.
-  QuicPacketSequenceNumber least_packet_awaited_by_peer_;
-
-  // Tracks the first RTO packet.  If any packet before that packet gets acked,
-  // it indicates the RTO was spurious and should be reversed(F-RTO).
-  QuicPacketSequenceNumber first_rto_transmission_;
-  // Number of times the RTO timer has fired in a row without receiving an ack.
-  size_t consecutive_rto_count_;
-  // Number of times the tail loss probe has been sent.
-  size_t consecutive_tlp_count_;
-  // Number of times the crypto handshake has been retransmitted.
-  size_t consecutive_crypto_retransmission_count_;
-  // Number of pending transmissions of TLP, RTO, or crypto packets.
-  size_t pending_timer_transmission_count_;
-  // Maximum number of tail loss probes to send before firing an RTO.
-  size_t max_tail_loss_probes_;
-  bool using_pacing_;
-  // If true, use the new RTO with loss based CWND reduction instead of the send
-  // algorithms's OnRetransmissionTimeout to reduce the congestion window.
-  bool use_new_rto_;
-
-  // Vectors packets acked and lost as a result of the last congestion event.
-  SendAlgorithmInterface::CongestionVector packets_acked_;
-  SendAlgorithmInterface::CongestionVector packets_lost_;
-
-  // Set to true after the crypto handshake has successfully completed. After
-  // this is true we no longer use HANDSHAKE_MODE, and further frames sent on
-  // the crypto stream (i.e. SCUP messages) are treated like normal
-  // retransmittable frames.
-  bool handshake_confirmed_;
-
-  // Records bandwidth from server to client in normal operation, over periods
-  // of time with no loss events.
-  QuicSustainedBandwidthRecorder sustained_bandwidth_recorder_;
-
-  DISALLOW_COPY_AND_ASSIGN(QuicSentPacketManager);
-};
-
-}  // namespace net
-
-#endif  // NET_QUIC_QUIC_SENT_PACKET_MANAGER_H_