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

   1 #ifndef _HTTPD_H
   2 #define _HTTPD_H
   3
   4 // A class dealing with stream output to HTTP.
   5
   6 #include <stddef.h>
   7 #include <stdint.h>
   8 #include <sys/types.h>
   9 #include <atomic>
  10 #include <condition_variable>
  11 #include <deque>
  12 #include <mutex>
  13 #include <set>
  14 #include <string>
  15
  16 struct MHD_Connection;
  17 struct MHD_Daemon;
  18
  19 class HTTPD {
  20 public:
  21         HTTPD();
  22         ~HTTPD();
  23
  24         // Should be called before start().
  25         void set_header(const std::string &data) {
  26                 header = data;
  27         }
  28
  29         void start(int port);
  30         void add_data(const char *buf, size_t size, bool keyframe);
  31         int64_t get_num_connected_clients() const {
  32                 return metric_num_connected_clients.load();
  33         }
  34
  35 private:
  36         static int answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  37                                               const char *url, const char *method,
  38                                               const char *version, const char *upload_data,
  39                                               size_t *upload_data_size, void **con_cls);
  40
  41         int answer_to_connection(MHD_Connection *connection,
  42                                  const char *url, const char *method,
  43                                  const char *version, const char *upload_data,
  44                                  size_t *upload_data_size, void **con_cls);
  45
  46         static void free_stream(void *cls);
  47
  48
  49         class Stream {
  50         public:
  51                 enum Framing {
  52                         FRAMING_RAW,
  53                         FRAMING_METACUBE
  54                 };
  55                 Stream(HTTPD *parent, Framing framing) : parent(parent), framing(framing) {}
  56
  57                 static ssize_t reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max);
  58                 ssize_t reader_callback(uint64_t pos, char *buf, size_t max);
  59
  60                 enum DataType {
  61                         DATA_TYPE_HEADER,
  62                         DATA_TYPE_KEYFRAME,
  63                         DATA_TYPE_OTHER
  64                 };
  65                 void add_data(const char *buf, size_t size, DataType data_type);
  66                 void stop();
  67                 HTTPD *get_parent() const { return parent; }
  68
  69         private:
  70                 HTTPD *parent;
  71                 Framing framing;
  72
  73                 std::mutex buffer_mutex;
  74                 bool should_quit = false;  // Under <buffer_mutex>.
  75                 std::condition_variable has_buffered_data;
  76                 std::deque<std::string> buffered_data;  // Protected by <buffer_mutex>.
  77                 size_t used_of_buffered_data = 0;  // How many bytes of the first element of <buffered_data> that is already used. Protected by <mutex>.
  78                 size_t seen_keyframe = false;
  79         };
  80
  81         MHD_Daemon *mhd = nullptr;
  82         std::mutex streams_mutex;
  83         std::set<Stream *> streams;  // Not owned.
  84         std::string header;
  85
  86         // Metrics.
  87         std::atomic<int64_t> metric_num_connected_clients{0};
  88 };
  89
  90 #endif  // !defined(_HTTPD_H)