Roc Toolkit internal modules
Roc Toolkit: real-time audio streaming
sorted_queue.h
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1 /*
2  * Copyright (c) 2015 Roc authors
3  *
4  * This Source Code Form is subject to the terms of the Mozilla Public
5  * License, v. 2.0. If a copy of the MPL was not distributed with this
6  * file, You can obtain one at http://mozilla.org/MPL/2.0/.
7  */
8 
9 //! @file roc_packet/sorted_queue.h
10 //! @brief Sorted packet queue.
11 
12 #ifndef ROC_PACKET_SORTED_QUEUE_H_
13 #define ROC_PACKET_SORTED_QUEUE_H_
14 
15 #include "roc_core/list.h"
16 #include "roc_core/noncopyable.h"
17 #include "roc_packet/ireader.h"
18 #include "roc_packet/iwriter.h"
19 #include "roc_packet/packet.h"
20 
21 namespace roc {
22 namespace packet {
23 
24 //! Sorted packet queue.
25 //! @remarks
26 //! Packets order is determined by Packet::compare() method.
27 class SortedQueue : public IWriter, public IReader, public core::NonCopyable<> {
28 public:
29  //! Construct empty queue.
30  //! @remarks
31  //! If @p max_size is non-zero, it specifies maximum number of packets in queue.
32  explicit SortedQueue(size_t max_size);
33 
34  //! Add packet to the queue.
35  //! @remarks
36  //! - if the maximum queue size is reached, packet is dropped
37  //! - if packet is equal to another packet in the queue, it is dropped
38  //! - otherwise, packet is inserted into the queue, keeping the queue sorted
39  virtual void write(const PacketPtr& packet);
40 
41  //! Read next packet.
42  //! @returns
43  //! the first packet in the queue or null if there are no packets
44  //! @remarks
45  //! Removes returned packet from the queue.
46  virtual PacketPtr read();
47 
48  //! Get number of packets in queue.
49  size_t size() const;
50 
51  //! Get first packet in the queue.
52  //! @returns
53  //! the first packet in the queue or null if there are no packets
54  //! @remarks
55  //! Returned packet is not removed from the queue.
56  PacketPtr head() const;
57 
58  //! Get last packet in the queue.
59  //! @returns
60  //! the last packet in the queue or null if there are no packets
61  //! @remarks
62  //! Returned packet is not removed from the queue.
63  PacketPtr tail() const;
64 
65  //! Get the latest packet that were ever added to the queue.
66  //! @remarks
67  //! Returns null if the queue never has any packets. Otherwise, returns
68  //! the latest ever added packet, even if that packet is not currently
69  //! in the queue. Returned packet is not removed from the queue.
70  PacketPtr latest() const;
71 
72 private:
73  core::List<Packet> list_;
74  PacketPtr latest_;
75  const size_t max_size_;
76 };
77 
78 } // namespace packet
79 } // namespace roc
80 
81 #endif // ROC_PACKET_SORTED_QUEUE_H_
Packet reader interface.
Packet reader interface.
Definition: ireader.h:21
PacketPtr head() const
Get first packet in the queue.
virtual PacketPtr read()
Read next packet.
Root namespace.
Intrusive doubly-linked list.
Definition: list.h:31
Packet writer interface.
Packet writer interface.
Definition: iwriter.h:21
Intrusive doubly-linked list.
SortedQueue(size_t max_size)
Construct empty queue.
Base class for non-copyable objects.
Definition: noncopyable.h:23
PacketPtr tail() const
Get last packet in the queue.
Packet.
Non-copyable object.
virtual void write(const PacketPtr &packet)
Add packet to the queue.
PacketPtr latest() const
Get the latest packet that were ever added to the queue.
size_t size() const
Get number of packets in queue.
Sorted packet queue.
Definition: sorted_queue.h:27