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