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