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 <functional>
  13 #include <mutex>
  14 #include <set>
  15 #include <string>
  16 #include <unordered_map>
  17 #include <utility>
  18
  19 extern "C" {
  20 #include <libavutil/rational.h>
  21 }
  22
  23 struct MHD_Connection;
  24 struct MHD_Daemon;
  25
  26 class HTTPD {
  27 public:
  28         // Returns a pair of content and content-type.
  29         using EndpointCallback = std::function<std::pair<std::string, std::string>()>;
  30
  31         HTTPD();
  32         ~HTTPD();
  33
  34         enum StreamType {
  35                 MAIN_STREAM,
  36                 MULTICAM_STREAM,
  37                 NUM_STREAM_TYPES
  38         };
  39
  40         // Should be called before start().
  41         void set_header(StreamType stream_type, const std::string &data) {
  42                 header[stream_type] = data;
  43         }
  44
  45         // Should be called before start() (due to threading issues).
  46         enum CORSPolicy {
  47                 NO_CORS_POLICY,
  48                 ALLOW_ALL_ORIGINS
  49         };
  50         void add_endpoint(const std::string &url, const EndpointCallback &callback, CORSPolicy cors_policy) {
  51                 endpoints[url] = Endpoint{ callback, cors_policy };
  52         }
  53
  54         void start(int port);
  55         void stop();
  56         void add_data(StreamType stream_type, const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase);
  57         int64_t get_num_connected_clients() const {
  58                 return metric_num_connected_clients.load();
  59         }
  60         int64_t get_num_connected_multicam_clients() const {
  61                 return metric_num_connected_multicam_clients.load();
  62         }
  63
  64 private:
  65         static int answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  66                                               const char *url, const char *method,
  67                                               const char *version, const char *upload_data,
  68                                               size_t *upload_data_size, void **con_cls);
  69
  70         int answer_to_connection(MHD_Connection *connection,
  71                                  const char *url, const char *method,
  72                                  const char *version, const char *upload_data,
  73                                  size_t *upload_data_size, void **con_cls);
  74
  75         static void free_stream(void *cls);
  76
  77
  78         class Stream {
  79         public:
  80                 enum Framing {
  81                         FRAMING_RAW,
  82                         FRAMING_METACUBE
  83                 };
  84                 Stream(HTTPD *parent, Framing framing, StreamType stream_type)
  85                         : parent(parent), framing(framing), stream_type(stream_type) {}
  86
  87                 static ssize_t reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max);
  88                 ssize_t reader_callback(uint64_t pos, char *buf, size_t max);
  89
  90                 enum DataType {
  91                         DATA_TYPE_HEADER,
  92                         DATA_TYPE_KEYFRAME,
  93                         DATA_TYPE_OTHER
  94                 };
  95                 void add_data(const char *buf, size_t size, DataType data_type, int64_t time, AVRational timebase);
  96                 void stop();
  97                 HTTPD *get_parent() const { return parent; }
  98                 StreamType get_stream_type() const { return stream_type; }
  99
 100         private:
 101                 HTTPD *parent;
 102                 Framing framing;
 103
 104                 std::mutex buffer_mutex;
 105                 bool should_quit = false;  // Under <buffer_mutex>.
 106                 std::condition_variable has_buffered_data;
 107                 std::deque<std::string> buffered_data;  // Protected by <buffer_mutex>.
 108                 size_t used_of_buffered_data = 0;  // How many bytes of the first element of <buffered_data> that is already used. Protected by <mutex>.
 109                 size_t seen_keyframe = false;
 110                 StreamType stream_type;
 111         };
 112
 113         MHD_Daemon *mhd = nullptr;
 114         std::mutex streams_mutex;
 115         std::set<Stream *> streams;  // Not owned.
 116         struct Endpoint {
 117                 EndpointCallback callback;
 118                 CORSPolicy cors_policy;
 119         };
 120         std::unordered_map<std::string, Endpoint> endpoints;
 121         std::string header[NUM_STREAM_TYPES];
 122
 123         // Metrics.
 124         std::atomic<int64_t> metric_num_connected_clients{0};
 125         std::atomic<int64_t> metric_num_connected_multicam_clients{0};
 126 };
 127
 128 #endif  // !defined(_HTTPD_H)