1 /*
2  *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
3  *
4  *  Use of this source code is governed by a BSD-style license
5  *  that can be found in the LICENSE file in the root of the source
6  *  tree. An additional intellectual property rights grant can be found
7  *  in the file PATENTS.  All contributing project authors may
8  *  be found in the AUTHORS file in the root of the source tree.
9  *
10  *  Class for storing RTP packets.
11  */
12 
13 #ifndef WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_HISTORY_H_
14 #define WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_HISTORY_H_
15 
16 #include <vector>
17 
18 #include "webrtc/base/thread_annotations.h"
19 #include "webrtc/modules/include/module_common_types.h"
20 #include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
21 #include "webrtc/typedefs.h"
22 
23 namespace webrtc {
24 
25 class Clock;
26 class CriticalSectionWrapper;
27 
28 static const size_t kMaxHistoryCapacity = 9600;
29 
30 class RTPPacketHistory {
31  public:
32   explicit RTPPacketHistory(Clock* clock);
33   ~RTPPacketHistory();
34 
35   void SetStorePacketsStatus(bool enable, uint16_t number_to_store);
36 
37   bool StorePackets() const;
38 
39   // Stores RTP packet.
40   int32_t PutRTPPacket(const uint8_t* packet,
41                        size_t packet_length,
42                        int64_t capture_time_ms,
43                        StorageType type);
44 
45   // Gets stored RTP packet corresponding to the input sequence number.
46   // The packet is copied to the buffer pointed to by ptr_rtp_packet.
47   // The rtp_packet_length should show the available buffer size.
48   // Returns true if packet is found.
49   // packet_length: returns the copied packet length on success.
50   // min_elapsed_time_ms: the minimum time that must have elapsed since the last
51   // time the packet was resent (parameter is ignored if set to zero).
52   // If the packet is found but the minimum time has not elapsed, no bytes are
53   // copied.
54   // stored_time_ms: returns the time when the packet was stored.
55   bool GetPacketAndSetSendTime(uint16_t sequence_number,
56                                int64_t min_elapsed_time_ms,
57                                bool retransmit,
58                                uint8_t* packet,
59                                size_t* packet_length,
60                                int64_t* stored_time_ms);
61 
62   bool GetBestFittingPacket(uint8_t* packet, size_t* packet_length,
63                             int64_t* stored_time_ms);
64 
65   bool HasRTPPacket(uint16_t sequence_number) const;
66 
67   bool SetSent(uint16_t sequence_number);
68 
69  private:
70   void GetPacket(int index,
71                  uint8_t* packet,
72                  size_t* packet_length,
73                  int64_t* stored_time_ms) const
74       EXCLUSIVE_LOCKS_REQUIRED(*critsect_);
75   void Allocate(size_t number_to_store) EXCLUSIVE_LOCKS_REQUIRED(*critsect_);
76   void Free() EXCLUSIVE_LOCKS_REQUIRED(*critsect_);
77   void VerifyAndAllocatePacketLength(size_t packet_length, uint32_t start_index)
78       EXCLUSIVE_LOCKS_REQUIRED(*critsect_);
79   bool FindSeqNum(uint16_t sequence_number, int32_t* index) const
80       EXCLUSIVE_LOCKS_REQUIRED(*critsect_);
81   int FindBestFittingPacket(size_t size) const
82       EXCLUSIVE_LOCKS_REQUIRED(*critsect_);
83 
84  private:
85   Clock* clock_;
86   rtc::scoped_ptr<CriticalSectionWrapper> critsect_;
87   bool store_ GUARDED_BY(critsect_);
88   uint32_t prev_index_ GUARDED_BY(critsect_);
89 
90   struct StoredPacket {
91     StoredPacket();
92     uint16_t sequence_number = 0;
93     int64_t time_ms = 0;
94     int64_t send_time = 0;
95     StorageType storage_type = kDontRetransmit;
96     bool has_been_retransmitted = false;
97 
98     uint8_t data[IP_PACKET_SIZE];
99     size_t length = 0;
100   };
101   std::vector<StoredPacket> stored_packets_ GUARDED_BY(critsect_);
102 };
103 }  // namespace webrtc
104 #endif  // WEBRTC_MODULES_RTP_RTCP_SOURCE_RTP_PACKET_HISTORY_H_
105