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// Copyright 2014 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_THIRD_PARTY_QUIC_CORE_QUIC_UNACKED_PACKET_MAP_H_
#define NET_THIRD_PARTY_QUIC_CORE_QUIC_UNACKED_PACKET_MAP_H_
#include <cstddef>
#include <deque>
#include "base/macros.h"
#include "net/third_party/quic/core/quic_packets.h"
#include "net/third_party/quic/core/quic_transmission_info.h"
#include "net/third_party/quic/core/session_notifier_interface.h"
#include "net/third_party/quic/platform/api/quic_export.h"
namespace quic {
namespace test {
class QuicUnackedPacketMapPeer;
} // namespace test
// Class which tracks unacked packets for three purposes:
// 1) Track retransmittable data, including multiple transmissions of frames.
// 2) Track packets and bytes in flight for congestion control.
// 3) Track sent time of packets to provide RTT measurements from acks.
class QUIC_EXPORT_PRIVATE QuicUnackedPacketMap {
public:
QuicUnackedPacketMap(Perspective perspective);
QuicUnackedPacketMap(const QuicUnackedPacketMap&) = delete;
QuicUnackedPacketMap& operator=(const QuicUnackedPacketMap&) = delete;
~QuicUnackedPacketMap();
// Adds |serialized_packet| to the map and marks it as sent at |sent_time|.
// Marks the packet as in flight if |set_in_flight| is true.
// Packets marked as in flight are expected to be marked as missing when they
// don't arrive, indicating the need for retransmission.
// |old_packet_number| is the packet number of the previous transmission,
// or 0 if there was none.
// Any AckNotifierWrappers in |serialized_packet| are swapped from the
// serialized packet into the QuicTransmissionInfo.
void AddSentPacket(SerializedPacket* serialized_packet,
QuicPacketNumber old_packet_number,
TransmissionType transmission_type,
QuicTime sent_time,
bool set_in_flight);
// Returns true if the packet |packet_number| is unacked.
bool IsUnacked(QuicPacketNumber packet_number) const;
// Notifies session_notifier that frames have been acked. Returns true if any
// new data gets acked, returns false otherwise.
bool NotifyFramesAcked(const QuicTransmissionInfo& info,
QuicTime::Delta ack_delay);
// Notifies session_notifier that frames in |info| are considered as lost.
void NotifyFramesLost(const QuicTransmissionInfo& info,
TransmissionType type);
// Notifies session_notifier to retransmit frames in |info| with
// |transmission_type|.
void RetransmitFrames(const QuicTransmissionInfo& info,
TransmissionType type);
// Marks |info| as no longer in flight.
void RemoveFromInFlight(QuicTransmissionInfo* info);
// Marks |packet_number| as no longer in flight.
void RemoveFromInFlight(QuicPacketNumber packet_number);
// No longer retransmit data for |stream_id|.
void CancelRetransmissionsForStream(QuicStreamId stream_id);
// Returns true if |packet_number| has retransmittable frames. This will
// return false if all frames of this packet are either non-retransmittable or
// have been acked.
bool HasRetransmittableFrames(QuicPacketNumber packet_number) const;
// Returns true if |info| has retransmittable frames. This will return false
// if all frames of this packet are either non-retransmittable or have been
// acked.
bool HasRetransmittableFrames(const QuicTransmissionInfo& info) const;
// Returns true if there are any unacked packets which have retransmittable
// frames.
bool HasUnackedRetransmittableFrames() const;
// Returns true if there are no packets present in the unacked packet map.
bool empty() const { return unacked_packets_.empty(); }
// Returns the largest packet number that has been sent.
QuicPacketNumber largest_sent_packet() const { return largest_sent_packet_; }
// Returns the largest retransmittable packet number that has been sent.
QuicPacketNumber largest_sent_retransmittable_packet() const {
DCHECK(!use_uber_loss_algorithm_);
return largest_sent_retransmittable_packet_;
}
QuicPacketNumber largest_sent_largest_acked() const {
return largest_sent_largest_acked_;
}
// Returns the largest packet number that has been acked.
QuicPacketNumber largest_acked() const { return largest_acked_; }
// Returns the sum of bytes from all packets in flight.
QuicByteCount bytes_in_flight() const { return bytes_in_flight_; }
// Returns the smallest packet number of a serialized packet which has not
// been acked by the peer. If there are no unacked packets, returns 0.
QuicPacketNumber GetLeastUnacked() const;
// This can not be a QuicDeque since pointers into this are
// assumed to be stable.
typedef std::deque<QuicTransmissionInfo> UnackedPacketMap;
typedef UnackedPacketMap::const_iterator const_iterator;
typedef UnackedPacketMap::iterator iterator;
const_iterator begin() const { return unacked_packets_.begin(); }
const_iterator end() const { return unacked_packets_.end(); }
iterator begin() { return unacked_packets_.begin(); }
iterator end() { return unacked_packets_.end(); }
// Returns true if there are unacked packets that are in flight.
bool HasInFlightPackets() const;
// Returns the QuicTransmissionInfo associated with |packet_number|, which
// must be unacked.
const QuicTransmissionInfo& GetTransmissionInfo(
QuicPacketNumber packet_number) const;
// Returns mutable QuicTransmissionInfo associated with |packet_number|, which
// must be unacked.
QuicTransmissionInfo* GetMutableTransmissionInfo(
QuicPacketNumber packet_number);
// Returns the time that the last unacked packet was sent.
QuicTime GetLastPacketSentTime() const;
// Returns the time that the last unacked crypto packet was sent.
QuicTime GetLastCryptoPacketSentTime() const;
// Returns the number of unacked packets.
size_t GetNumUnackedPacketsDebugOnly() const;
// Returns true if there are multiple packets in flight.
bool HasMultipleInFlightPackets() const;
// Returns true if there are any pending crypto packets.
// TODO(fayang): Remove this method and call session_notifier_'s
// HasUnackedCryptoData() when session_decides_what_to_write_ is default true.
bool HasPendingCryptoPackets() const;
// Removes any retransmittable frames from this transmission or an associated
// transmission. It removes now useless transmissions, and disconnects any
// other packets from other transmissions.
void RemoveRetransmittability(QuicTransmissionInfo* info);
// Looks up the QuicTransmissionInfo by |packet_number| and calls
// RemoveRetransmittability.
void RemoveRetransmittability(QuicPacketNumber packet_number);
// Increases the largest acked. Any packets less or equal to
// |largest_acked| are discarded if they are only for the RTT purposes.
void IncreaseLargestAcked(QuicPacketNumber largest_acked);
// Called when |packet_number| gets acked. Maybe increase the largest acked of
// corresponding packet number space of |encryption_level|.
void MaybeUpdateLargestAckedOfPacketNumberSpace(
EncryptionLevel encryption_level,
QuicPacketNumber packet_number);
// Remove any packets no longer needed for retransmission, congestion, or
// RTT measurement purposes.
void RemoveObsoletePackets();
// Try to aggregate acked contiguous stream frames. For noncontiguous stream
// frames or control frames, notify the session notifier they get acked
// immediately.
void MaybeAggregateAckedStreamFrame(const QuicTransmissionInfo& info,
QuicTime::Delta ack_delay);
// Notify the session notifier of any stream data aggregated in
// aggregated_stream_frame_. No effect if the stream frame has an invalid
// stream id.
void NotifyAggregatedStreamFrameAcked(QuicTime::Delta ack_delay);
// Returns packet number space that |packet_number| belongs to. Please use
// GetPacketNumberSpace(EncryptionLevel) whenever encryption level is
// available.
PacketNumberSpace GetPacketNumberSpace(QuicPacketNumber packet_number) const;
// Returns packet number space of |encryption_level|.
PacketNumberSpace GetPacketNumberSpace(
EncryptionLevel encryption_level) const;
// Returns largest acked packet number of |packet_number_space|.
QuicPacketNumber GetLargestAckedOfPacketNumberSpace(
PacketNumberSpace packet_number_space) const;
// Returns largest sent retransmittable packet number of
// |packet_number_space|.
QuicPacketNumber GetLargestSentRetransmittableOfPacketNumberSpace(
PacketNumberSpace packet_number_space) const;
// Called to start/stop letting session decide what to write.
void SetSessionDecideWhatToWrite(bool session_decides_what_to_write);
void SetSessionNotifier(SessionNotifierInterface* session_notifier);
bool session_decides_what_to_write() const {
return session_decides_what_to_write_;
}
bool use_uber_loss_algorithm() const { return use_uber_loss_algorithm_; }
Perspective perspective() const { return perspective_; }
private:
friend class test::QuicUnackedPacketMapPeer;
// Called when a packet is retransmitted with a new packet number.
// |old_packet_number| will remain unacked, but will have no
// retransmittable data associated with it. Retransmittable frames will be
// transferred to |info| and all_transmissions will be populated.
void TransferRetransmissionInfo(QuicPacketNumber old_packet_number,
QuicPacketNumber new_packet_number,
TransmissionType transmission_type,
QuicTransmissionInfo* info);
// Returns true if packet may be useful for an RTT measurement.
bool IsPacketUsefulForMeasuringRtt(QuicPacketNumber packet_number,
const QuicTransmissionInfo& info) const;
// Returns true if packet may be useful for congestion control purposes.
bool IsPacketUsefulForCongestionControl(
const QuicTransmissionInfo& info) const;
// Returns true if packet may be associated with retransmittable data
// directly or through retransmissions.
bool IsPacketUsefulForRetransmittableData(
const QuicTransmissionInfo& info) const;
// Returns true if the packet no longer has a purpose in the map.
bool IsPacketUseless(QuicPacketNumber packet_number,
const QuicTransmissionInfo& info) const;
const Perspective perspective_;
QuicPacketNumber largest_sent_packet_;
// The largest sent packet we expect to receive an ack for.
// TODO(fayang): Remove largest_sent_retransmittable_packet_ when deprecating
// quic_use_uber_loss_algorithm.
QuicPacketNumber largest_sent_retransmittable_packet_;
// The largest sent packet we expect to receive an ack for per packet number
// space. Only used if use_uber_loss_algorithm_ is true.
QuicPacketNumber
largest_sent_retransmittable_packets_[NUM_PACKET_NUMBER_SPACES];
// The largest sent largest_acked in an ACK frame.
QuicPacketNumber largest_sent_largest_acked_;
// The largest received largest_acked from an ACK frame.
QuicPacketNumber largest_acked_;
// The largest received largest_acked from ACK frame per packet number space.
// Only used if use_uber_loss_algorithm_ is true.
QuicPacketNumber largest_acked_packets_[NUM_PACKET_NUMBER_SPACES];
// Newly serialized retransmittable 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.
UnackedPacketMap unacked_packets_;
// The packet at the 0th index of unacked_packets_.
QuicPacketNumber least_unacked_;
QuicByteCount bytes_in_flight_;
// Number of retransmittable crypto handshake packets.
size_t pending_crypto_packet_count_;
// Time that the last unacked crypto packet was sent.
QuicTime last_crypto_packet_sent_time_;
// Aggregates acked stream data across multiple acked sent packets to save CPU
// by reducing the number of calls to the session notifier.
QuicStreamFrame aggregated_stream_frame_;
// Receives notifications of frames being retransmitted or acknowledged.
SessionNotifierInterface* session_notifier_;
// If true, let session decides what to write.
bool session_decides_what_to_write_;
// Latched value of quic_use_uber_loss_algorithm.
const bool use_uber_loss_algorithm_;
};
} // namespace quic
#endif // NET_THIRD_PARTY_QUIC_CORE_QUIC_UNACKED_PACKET_MAP_H_