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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_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, including those packets which are
// currently pending, and the relationship between packets which
// contain the same data (via retransmissions)
class NET_EXPORT_PRIVATE QuicUnackedPacketMap {
public:
QuicUnackedPacketMap();
~QuicUnackedPacketMap();
// Adds |serialized_packet| to the map. Does not mark it pending.
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);
// 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 pending.
void SetNotPending(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 the bytes in all pending packets.
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 pending and tracks the |bytes_sent| if |set_pending| is true.
// Packets marked as pending 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_pending);
// 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 pending.
bool HasPendingPackets() 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 pending packet was sent.
QuicTime GetFirstPendingPacketSentTime() const;
// Returns the number of unacked packets.
size_t GetNumUnackedPackets() const;
// Returns true if there are multiple packet pending.
bool HasMultiplePendingPackets() const;
// Returns true if there are any pending crypto packets.
bool HasPendingCryptoPackets() const;
// Removes entries from the unacked packet map, and deletes
// the retransmittable frames associated with the packet.
// Does not remove any previous or subsequent transmissions of this packet.
void RemovePacket(QuicPacketSequenceNumber sequence_number);
// Neuters the specified packet. Deletes any retransmittable
// frames, and sets all_transmissions to only include itself.
void NeuterPacket(QuicPacketSequenceNumber sequence_number);
// Returns true if the packet's only purpose is to measure RTT. It must not
// be pending, have retransmittable frames, or be linked to transmissions
// with retransmittable frames.
static bool IsForRttOnly(const TransmissionInfo& transmission_info);
private:
void MaybeRemoveRetransmittableFrames(TransmissionInfo* transmission_info);
QuicPacketSequenceNumber largest_sent_packet_;
// 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 outstanding crypto handshake packets.
size_t pending_crypto_packet_count_;
DISALLOW_COPY_AND_ASSIGN(QuicUnackedPacketMap);
};
} // namespace net
#endif // NET_QUIC_QUIC_UNACKED_PACKET_MAP_H_
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