| // 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_QUIC_QUIC_UNACKED_PACKET_MAP_H_ |
| #define NET_QUIC_QUIC_UNACKED_PACKET_MAP_H_ |
| |
| #include "net/base/linked_hash_map.h" |
| #include "net/quic/quic_protocol.h" |
| |
| namespace net { |
| |
| // 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 NET_EXPORT_PRIVATE QuicUnackedPacketMap { |
| public: |
| QuicUnackedPacketMap(); |
| ~QuicUnackedPacketMap(); |
| |
| // Adds |serialized_packet| to the map. Does not mark it in flight. |
| void AddPacket(const SerializedPacket& serialized_packet); |
| |
| // Called when a packet is retransmitted with a new sequence number. |
| // |old_sequence_number| will remain unacked, but will have no |
| // retransmittable data associated with it. |new_sequence_number| will |
| // be both unacked and associated with retransmittable data. |
| void OnRetransmittedPacket(QuicPacketSequenceNumber old_sequence_number, |
| QuicPacketSequenceNumber new_sequence_number, |
| TransmissionType transmission_type); |
| |
| // Returns true if the packet |sequence_number| is unacked. |
| bool IsUnacked(QuicPacketSequenceNumber sequence_number) const; |
| |
| // Sets the nack count to the max of the current nack count and |min_nacks|. |
| void NackPacket(QuicPacketSequenceNumber sequence_number, |
| size_t min_nacks); |
| |
| // Marks |sequence_number| as no longer in flight. |
| void RemoveFromInFlight(QuicPacketSequenceNumber sequence_number); |
| |
| // Returns true if the unacked packet |sequence_number| has retransmittable |
| // frames. This will 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, or if the packet never |
| // had any retransmittable packets in the first place. |
| bool HasRetransmittableFrames(QuicPacketSequenceNumber sequence_number) const; |
| |
| // Returns true if there are any unacked packets. |
| bool HasUnackedPackets() const; |
| |
| // Returns true if there are any unacked packets which have retransmittable |
| // frames. |
| bool HasUnackedRetransmittableFrames() const; |
| |
| // Returns the largest sequence number that has been sent. |
| QuicPacketSequenceNumber largest_sent_packet() const { |
| return largest_sent_packet_; |
| } |
| |
| // Returns the sum of bytes from all packets in flight. |
| QuicByteCount bytes_in_flight() const { |
| return bytes_in_flight_; |
| } |
| |
| // Returns the smallest sequence number of a serialized packet which has not |
| // been acked by the peer. If there are no unacked packets, returns 0. |
| QuicPacketSequenceNumber GetLeastUnackedSentPacket() const; |
| |
| // Sets a packet as sent with the sent time |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. |
| void SetSent(QuicPacketSequenceNumber sequence_number, |
| QuicTime sent_time, |
| QuicByteCount bytes_sent, |
| bool set_in_flight); |
| |
| // Clears up to |num_to_clear| previous transmissions in order to make room |
| // in the ack frame for new acks. |
| void ClearPreviousRetransmissions(size_t num_to_clear); |
| |
| typedef linked_hash_map<QuicPacketSequenceNumber, |
| TransmissionInfo> UnackedPacketMap; |
| |
| typedef UnackedPacketMap::const_iterator const_iterator; |
| |
| const_iterator begin() const { return unacked_packets_.begin(); } |
| const_iterator end() const { return unacked_packets_.end(); } |
| |
| // Returns true if there are unacked packets that are in flight. |
| bool HasInFlightPackets() const; |
| |
| // Returns the TransmissionInfo associated with |sequence_number|, which |
| // must be unacked. |
| const TransmissionInfo& GetTransmissionInfo( |
| QuicPacketSequenceNumber sequence_number) const; |
| |
| // Returns the time that the last unacked packet was sent. |
| QuicTime GetLastPacketSentTime() const; |
| |
| // Returns the time that the first in flight packet was sent. |
| QuicTime GetFirstInFlightPacketSentTime() const; |
| |
| // Returns the number of unacked packets. |
| size_t GetNumUnackedPackets() const; |
| |
| // Returns true if there are multiple packets in flight. |
| bool HasMultipleInFlightPackets() const; |
| |
| // Returns true if there are any pending crypto packets. |
| 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(QuicPacketSequenceNumber sequence_number); |
| |
| // Increases the largest observed. Any packets less or equal to |
| // |largest_acked_packet| are discarded if they are only for the RTT purposes. |
| void IncreaseLargestObserved(QuicPacketSequenceNumber largest_observed); |
| |
| private: |
| void MaybeRemoveRetransmittableFrames(TransmissionInfo* transmission_info); |
| |
| // Returns true if the packet no longer has a purpose in the map. |
| bool IsPacketUseless(UnackedPacketMap::const_iterator it) const; |
| |
| QuicPacketSequenceNumber largest_sent_packet_; |
| QuicPacketSequenceNumber largest_observed_; |
| |
| // 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 NULL, 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 NULL. |
| UnackedPacketMap unacked_packets_; |
| |
| size_t bytes_in_flight_; |
| // Number of retransmittable crypto handshake packets. |
| size_t pending_crypto_packet_count_; |
| |
| DISALLOW_COPY_AND_ASSIGN(QuicUnackedPacketMap); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_QUIC_QUIC_UNACKED_PACKET_MAP_H_ |