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 <atomic>
   7 #include <condition_variable>
   8 #include <deque>
   9 #include <functional>
  10 #include <mutex>
  11 #include <set>
  12 #include <stddef.h>
  13 #include <stdint.h>
  14 #include <string>
  15 #include <sys/types.h>
  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         {
  52                 endpoints[url] = Endpoint{ callback, cors_policy };
  53         }
  54
  55         void start(int port);
  56         void stop();
  57         void add_data(StreamType stream_type, const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase);
  58         int64_t get_num_connected_clients() const
  59         {
  60                 return metric_num_connected_clients.load();
  61         }
  62         int64_t get_num_connected_multicam_clients() const {
  63                 return metric_num_connected_multicam_clients.load();
  64         }
  65
  66 private:
  67         static int answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  68                                               const char *url, const char *method,
  69                                               const char *version, const char *upload_data,
  70                                               size_t *upload_data_size, void **con_cls);
  71
  72         int answer_to_connection(MHD_Connection *connection,
  73                                  const char *url, const char *method,
  74                                  const char *version, const char *upload_data,
  75                                  size_t *upload_data_size, void **con_cls);
  76
  77         static void free_stream(void *cls);
  78
  79         class Stream {
  80         public:
  81                 enum Framing {
  82                         FRAMING_RAW,
  83                         FRAMING_METACUBE
  84                 };
  85                 Stream(HTTPD *parent, Framing framing, StreamType stream_type)
  86                         : parent(parent), framing(framing), stream_type(stream_type) {}
  87
  88                 static ssize_t reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max);
  89                 ssize_t reader_callback(uint64_t pos, char *buf, size_t max);
  90
  91                 enum DataType {
  92                         DATA_TYPE_HEADER,
  93                         DATA_TYPE_KEYFRAME,
  94                         DATA_TYPE_OTHER
  95                 };
  96                 void add_data(const char *buf, size_t size, DataType data_type, int64_t time, AVRational timebase);
  97                 void stop();
  98                 HTTPD *get_parent() const { return parent; }
  99                 StreamType get_stream_type() const { return stream_type; }
 100
 101         private:
 102                 HTTPD *parent;
 103                 Framing framing;
 104
 105                 std::mutex buffer_mutex;
 106                 bool should_quit = false;  // Under <buffer_mutex>.
 107                 std::condition_variable has_buffered_data;
 108                 std::deque<std::string> buffered_data;  // Protected by <buffer_mutex>.
 109                 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>.
 110                 size_t buffered_data_bytes = 0;  // The sum of all size() in buffered_data. Protected by <buffer_mutex>.
 111                 size_t seen_keyframe = false;
 112                 StreamType stream_type;
 113         };
 114
 115         MHD_Daemon *mhd = nullptr;
 116         std::mutex streams_mutex;
 117         std::set<Stream *> streams;  // Not owned.
 118         struct Endpoint {
 119                 EndpointCallback callback;
 120                 CORSPolicy cors_policy;
 121         };
 122         std::unordered_map<std::string, Endpoint> endpoints;
 123         std::string header[NUM_STREAM_TYPES];
 124
 125         // Metrics.
 126         std::atomic<int64_t> metric_num_connected_clients{0};
 127         std::atomic<int64_t> metric_num_connected_multicam_clients{0};
 128 };
 129
 130 #endif  // !defined(_HTTPD_H)