zoneminder/src/zm_packetqueue.h

//ZoneMinder Packet Queue Interface Class
//Copyright 2016 Steve Gilvarry
//
//This file is part of ZoneMinder.
//
//ZoneMinder is free software: you can redistribute it and/or modify
//it under the terms of the GNU General Public License as published by
//the Free Software Foundation, either version 3 of the License, or
//(at your option) any later version.
//
//ZoneMinder is distributed in the hope that it will be useful,
//but WITHOUT ANY WARRANTY; without even the implied warranty of
//MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
//GNU General Public License for more details.
//
//You should have received a copy of the GNU General Public License
//along with ZoneMinder.  If not, see <http://www.gnu.org/licenses/>.

#ifndef ZM_PACKETQUEUE_H
#define ZM_PACKETQUEUE_H

#include <condition_variable>
#include <list>
#include <mutex>
#include <memory>

class ZMPacket;
class ZMLockedPacket;

typedef std::list<std::shared_ptr<ZMPacket>>::iterator packetqueue_iterator;

class PacketQueue {
  public: // For now just to ease development
    std::list<std::shared_ptr<ZMPacket>>    pktQueue;
    std::list<std::shared_ptr<ZMPacket>>::iterator analysis_it;

    int video_stream_id;
    int max_video_packet_count; // allow a negative value to someday mean unlimited
                                // This is now a hard limit on the # of video packets to keep in the queue so that we can limit ram
    int pre_event_video_packet_count; // Was max_video_packet_count
    int max_stream_id;
    int *packet_counts;     /* packet count for each stream_id, to keep track of how many video vs audio packets are in the queue */
    bool deleting;
    bool keep_keyframes;
    std::list<packetqueue_iterator *> iterators;

    std::mutex mutex;
    std::condition_variable condition;

  public:
    PacketQueue();
    virtual ~PacketQueue();
    std::list<std::shared_ptr<ZMPacket>>::const_iterator end() const { return pktQueue.end(); }
    std::list<std::shared_ptr<ZMPacket>>::const_iterator begin() const { return pktQueue.begin(); }

    int addStream();
    void setMaxVideoPackets(int p);
    void setPreEventVideoPackets(int p);
    void setKeepKeyframes(bool k) { keep_keyframes = k; };

    bool queuePacket(std::shared_ptr<ZMPacket> packet);
    void clear();
    void dumpQueue();
    unsigned int size();
    unsigned int get_packet_count(int stream_id) const { return packet_counts[stream_id]; };

    void clearPackets(const std::shared_ptr<ZMPacket> &packet);
    int packet_count(int stream_id);

    bool increment_it(packetqueue_iterator *it);
    bool increment_it(packetqueue_iterator *it, int stream_id);
    ZMLockedPacket *get_packet(packetqueue_iterator *);
    ZMLockedPacket *get_packet_and_increment_it(packetqueue_iterator *);
    packetqueue_iterator *get_video_it(bool wait);
    packetqueue_iterator *get_stream_it(int stream_id);
    void free_it(packetqueue_iterator *);

    packetqueue_iterator *get_event_start_packet_it(
        packetqueue_iterator snapshot_it,
        unsigned int pre_event_count
    );
    bool is_there_an_iterator_pointing_to_packet(const std::shared_ptr<ZMPacket> &zm_packet);
    void unlock(ZMLockedPacket *lp);
};

#endif /* ZM_PACKETQUEUE_H */