git.sesse.net Git - nageru/blob - shared/httpd.h

   1 #ifndef _HTTPD_H
   2 #define _HTTPD_H
   3
   4 // A class dealing with stream output to HTTP.
   5
   6 #include <assert.h>
   7 #include <atomic>
   8 #include <condition_variable>
   9 #include <deque>
  10 #include <functional>
  11 #include <mutex>
  12 #include <set>
  13 #include <stddef.h>
  14 #include <stdint.h>
  15 #include <string>
  16 #include <sys/types.h>
  17 #include <map>
  18 #include <unordered_map>
  19 #include <utility>
  20
  21 extern "C" {
  22 #include <libavutil/rational.h>
  23 }
  24
  25 #include "shared/shared_defs.h"
  26
  27 struct MHD_Connection;
  28 struct MHD_Daemon;
  29
  30 class HTTPD {
  31 public:
  32         // Returns a pair of content and content-type.
  33         using EndpointCallback = std::function<std::pair<std::string, std::string>()>;
  34
  35         HTTPD();
  36         ~HTTPD();
  37
  38         enum StreamType {
  39                 MAIN_STREAM,
  40                 MULTICAM_STREAM,
  41                 SIPHON_STREAM   // The only one that can have stream_index != 0.
  42         };
  43         struct StreamID {
  44                 StreamType type;
  45                 unsigned index;
  46
  47                 bool operator< (const StreamID &other) const {
  48                         if (type != other.type)
  49                                 return type < other.type;
  50                         return index < other.index;
  51                 }
  52                 bool operator== (const StreamID &other) const {
  53                         return (type == other.type && index == other.index);
  54                 }
  55         };
  56
  57         // Should be called before start() (due to threading issues).
  58         enum CORSPolicy {
  59                 NO_CORS_POLICY,
  60                 ALLOW_ALL_ORIGINS
  61         };
  62         void add_endpoint(const std::string &url, const EndpointCallback &callback, CORSPolicy cors_policy)
  63         {
  64                 endpoints[url] = Endpoint{ callback, cors_policy };
  65         }
  66
  67         void start(int port);
  68         void stop();
  69         void set_header(StreamID stream_id, const std::string &data);
  70         void add_data(StreamID stream_id, const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase);
  71         int64_t get_num_connected_clients() const
  72         {
  73                 return metric_num_connected_clients.load();
  74         }
  75         int64_t get_num_connected_multicam_clients() const {
  76                 return metric_num_connected_multicam_clients.load();
  77         }
  78         int64_t get_num_connected_siphon_clients(unsigned stream_idx) const {
  79                 assert(stream_idx < MAX_VIDEO_CARDS);
  80                 return metric_num_connected_siphon_clients[stream_idx].load();
  81         }
  82
  83 private:
  84         static int answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  85                                               const char *url, const char *method,
  86                                               const char *version, const char *upload_data,
  87                                               size_t *upload_data_size, void **con_cls);
  88
  89         int answer_to_connection(MHD_Connection *connection,
  90                                  const char *url, const char *method,
  91                                  const char *version, const char *upload_data,
  92                                  size_t *upload_data_size, void **con_cls);
  93
  94         static void free_stream(void *cls);
  95
  96         class Stream {
  97         public:
  98                 enum Framing {
  99                         FRAMING_RAW,
 100                         FRAMING_METACUBE
 101                 };
 102                 Stream(HTTPD *parent, Framing framing, StreamID stream_id)
 103                         : parent(parent), framing(framing), stream_id(stream_id) {}
 104
 105                 static ssize_t reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max);
 106                 ssize_t reader_callback(uint64_t pos, char *buf, size_t max);
 107
 108                 enum DataType {
 109                         DATA_TYPE_HEADER,
 110                         DATA_TYPE_KEYFRAME,
 111                         DATA_TYPE_OTHER
 112                 };
 113                 void add_data(const char *buf, size_t size, DataType data_type, int64_t time, AVRational timebase);
 114                 void stop();
 115                 HTTPD *get_parent() const { return parent; }
 116                 StreamID get_stream_id() const { return stream_id; }
 117
 118         private:
 119                 HTTPD *parent;
 120                 Framing framing;
 121
 122                 std::mutex buffer_mutex;
 123                 bool should_quit = false;  // Under <buffer_mutex>.
 124                 std::condition_variable has_buffered_data;
 125                 std::deque<std::string> buffered_data;  // Protected by <buffer_mutex>.
 126                 size_t used_of_buffered_data = 0;  // How many bytes of the first element of <buffered_data> that is already used. Protected by <buffer_mutex>.
 127                 size_t buffered_data_bytes = 0;  // The sum of all size() in buffered_data. Protected by <buffer_mutex>.
 128                 size_t seen_keyframe = false;
 129                 StreamID stream_id;
 130         };
 131
 132         void add_data_locked(StreamID stream_id, const char *buf, size_t size, Stream::DataType data_type, int64_t time, AVRational timebase);
 133
 134         MHD_Daemon *mhd = nullptr;
 135         std::mutex streams_mutex;
 136         std::set<Stream *> streams;  // Not owned.
 137         struct Endpoint {
 138                 EndpointCallback callback;
 139                 CORSPolicy cors_policy;
 140         };
 141         std::unordered_map<std::string, Endpoint> endpoints;
 142         std::map<StreamID, std::string> header;
 143
 144         // Metrics.
 145         std::atomic<int64_t> metric_num_connected_clients{0};
 146         std::atomic<int64_t> metric_num_connected_multicam_clients{0};
 147         std::atomic<int64_t> metric_num_connected_siphon_clients[MAX_VIDEO_CARDS] {{0}};
 148 };
 149
 150 #endif  // !defined(_HTTPD_H)