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 <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         // Should be called before start().
  35         void set_header(const std::string &data)
  36         {
  37                 header = data;
  38         }
  39
  40         // Should be called before start() (due to threading issues).
  41         enum CORSPolicy {
  42                 NO_CORS_POLICY,
  43                 ALLOW_ALL_ORIGINS
  44         };
  45         void add_endpoint(const std::string &url, const EndpointCallback &callback, CORSPolicy cors_policy)
  46         {
  47                 endpoints[url] = Endpoint{ callback, cors_policy };
  48         }
  49
  50         void start(int port);
  51         void stop();
  52         void add_data(const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase);
  53         int64_t get_num_connected_clients() const
  54         {
  55                 return metric_num_connected_clients.load();
  56         }
  57
  58 private:
  59         static int answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  60                                               const char *url, const char *method,
  61                                               const char *version, const char *upload_data,
  62                                               size_t *upload_data_size, void **con_cls);
  63
  64         int answer_to_connection(MHD_Connection *connection,
  65                                  const char *url, const char *method,
  66                                  const char *version, const char *upload_data,
  67                                  size_t *upload_data_size, void **con_cls);
  68
  69         static void free_stream(void *cls);
  70
  71
  72         class Stream {
  73         public:
  74                 enum Framing {
  75                         FRAMING_RAW,
  76                         FRAMING_METACUBE
  77                 };
  78                 Stream(HTTPD *parent, Framing framing) : parent(parent), framing(framing) {}
  79
  80                 static ssize_t reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max);
  81                 ssize_t reader_callback(uint64_t pos, char *buf, size_t max);
  82
  83                 enum DataType {
  84                         DATA_TYPE_HEADER,
  85                         DATA_TYPE_KEYFRAME,
  86                         DATA_TYPE_OTHER
  87                 };
  88                 void add_data(const char *buf, size_t size, DataType data_type, int64_t time, AVRational timebase);
  89                 void stop();
  90                 HTTPD *get_parent() const { return parent; }
  91
  92         private:
  93                 HTTPD *parent;
  94                 Framing framing;
  95
  96                 std::mutex buffer_mutex;
  97                 bool should_quit = false;  // Under <buffer_mutex>.
  98                 std::condition_variable has_buffered_data;
  99                 std::deque<std::string> buffered_data;  // Protected by <buffer_mutex>.
 100                 size_t used_of_buffered_data = 0;  // How many bytes of the first element of <buffered_data> that is already used. Protected by <mutex>.
 101                 size_t seen_keyframe = false;
 102         };
 103
 104         MHD_Daemon *mhd = nullptr;
 105         std::mutex streams_mutex;
 106         std::set<Stream *> streams;  // Not owned.
 107         struct Endpoint {
 108                 EndpointCallback callback;
 109                 CORSPolicy cors_policy;
 110         };
 111         std::unordered_map<std::string, Endpoint> endpoints;
 112         std::string header;
 113
 114         // Metrics.
 115         std::atomic<int64_t> metric_num_connected_clients{0};
 116 };
 117
 118 #endif  // !defined(_HTTPD_H)