| // Copyright (c) 2012 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. |
| // |
| // Tracks information about an FEC group, including the packets |
| // that have been seen, and the running parity. Provides the ability |
| // to revive a dropped packet. |
| |
| #ifndef NET_QUIC_QUIC_FEC_GROUP_INTERFACE_H_ |
| #define NET_QUIC_QUIC_FEC_GROUP_INTERFACE_H_ |
| |
| #include <stddef.h> |
| |
| #include "base/macros.h" |
| #include "base/strings/string_piece.h" |
| #include "net/base/net_export.h" |
| #include "net/quic/quic_protocol.h" |
| |
| namespace net { |
| |
| class NET_EXPORT_PRIVATE QuicFecGroupInterface { |
| public: |
| ~QuicFecGroupInterface() {} |
| |
| // Updates the FEC group based on the delivery of a data packet decrypted at |
| // |encryption_level|. Returns false if this packet has already been seen, |
| // true otherwise. |
| virtual bool Update(EncryptionLevel encryption_level, |
| const QuicPacketHeader& header, |
| base::StringPiece decrypted_payload) = 0; |
| |
| // Updates the FEC group based on the delivery of an FEC packet decrypted at |
| // |encryption_level|. Returns false if this packet has already been seen or |
| // if it does not claim to protect all the packets previously seen in this |
| // group. |
| virtual bool UpdateFec(EncryptionLevel encryption_level, |
| const QuicPacketHeader& header, |
| base::StringPiece redundancy) = 0; |
| |
| // Returns true if a packet can be revived from this FEC group. |
| virtual bool CanRevive() const = 0; |
| |
| // Returns true if all packets (FEC and data) from this FEC group have been |
| // seen or revived. |
| virtual bool IsFinished() const = 0; |
| |
| // Revives the missing packet from this FEC group. This may return a packet |
| // that is null padded to a greater length than the original packet, but |
| // the framer will handle it correctly. Returns the length of the data |
| // written to |decrypted_payload|, or 0 if the packet could not be revived. |
| virtual size_t Revive(QuicPacketHeader* header, |
| char* decrypted_payload, |
| size_t decrypted_payload_len) = 0; |
| |
| // Returns true if the group is waiting for any packets with sequence numbers |
| // less than |num|. |
| virtual bool IsWaitingForPacketBefore(QuicPacketNumber num) const = 0; |
| |
| // The FEC data in the FEC packet. |
| virtual const base::StringPiece PayloadParity() const = 0; |
| |
| // Number of packets in the group. |
| virtual QuicPacketCount NumReceivedPackets() const = 0; |
| |
| // Returns the effective encryption level of the FEC group. |
| virtual EncryptionLevel EffectiveEncryptionLevel() const = 0; |
| |
| // Return the FEC group number of this group. |
| virtual QuicFecGroupNumber FecGroupNumber() const = 0; |
| |
| // An optimized version of running |output| ^= |input|, where ^ is |
| // byte-by-byte XOR and both |output| and |input| are of size |size_in_bytes|. |
| static void XorBuffers(const char* input, size_t size_in_bytes, char* output); |
| |
| protected: |
| QuicFecGroupInterface() {} |
| |
| private: |
| DISALLOW_COPY_AND_ASSIGN(QuicFecGroupInterface); |
| }; |
| |
| } // namespace net |
| |
| #endif // NET_QUIC_QUIC_FEC_GROUP_INTERFACE_H_ |