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 <assert.h>
   7 #include <atomic>
   8 #include <condition_variable>
   9 #include <deque>
  10 #include <functional>
  11 #include <mutex>
  12 #include <set>
  13 #include <stddef.h>
  14 #include <stdint.h>
  15 #include <string>
  16 #include <sys/types.h>
  17 #include <map>
  18 #include <unordered_map>
  19 #include <utility>
  20
  21 extern "C" {
  22 #include <libavutil/rational.h>
  23 }
  24
  25 #include <microhttpd.h>
  26
  27 #include "shared/shared_defs.h"
  28
  29 struct MHD_Connection;
  30 struct MHD_Daemon;
  31
  32 class HTTPD {
  33 public:
  34         // Returns a pair of content and content-type.
  35         using EndpointCallback = std::function<std::pair<std::string, std::string>()>;
  36
  37         HTTPD();
  38         ~HTTPD();
  39
  40         enum StreamType {
  41                 MAIN_STREAM,
  42                 MULTICAM_STREAM,
  43                 SIPHON_STREAM   // The only one that can have stream_index != 0.
  44         };
  45         struct StreamID {
  46                 StreamType type;
  47                 unsigned index;
  48
  49                 bool operator< (const StreamID &other) const {
  50                         if (type != other.type)
  51                                 return type < other.type;
  52                         return index < other.index;
  53                 }
  54                 bool operator== (const StreamID &other) const {
  55                         return (type == other.type && index == other.index);
  56                 }
  57         };
  58
  59         // Should be called before start() (due to threading issues).
  60         enum CORSPolicy {
  61                 NO_CORS_POLICY,
  62                 ALLOW_ALL_ORIGINS
  63         };
  64         void add_endpoint(const std::string &url, const EndpointCallback &callback, CORSPolicy cors_policy)
  65         {
  66                 endpoints[url] = Endpoint{ callback, cors_policy };
  67         }
  68
  69         void start(int port);
  70         void stop();
  71         void set_header(StreamID stream_id, const std::string &data);
  72         void add_data(StreamID stream_id, const char *buf, size_t size, bool keyframe, int64_t time, AVRational timebase);
  73         int64_t get_num_connected_clients() const
  74         {
  75                 return metric_num_connected_clients.load();
  76         }
  77         int64_t get_num_connected_multicam_clients() const {
  78                 return metric_num_connected_multicam_clients.load();
  79         }
  80         int64_t get_num_connected_siphon_clients(unsigned stream_idx) const {
  81                 assert(stream_idx < MAX_VIDEO_CARDS);
  82                 return metric_num_connected_siphon_clients[stream_idx].load();
  83         }
  84
  85 private:
  86         // libmicrohttpd 0.9.71 broke the type of MHD_YES/MHD_NO, causing
  87         // compilation errors for C++ and undefined behavior for C.
  88 #if MHD_VERSION >= 0x00097002
  89         using MHD_Result = ::MHD_Result;
  90 #else
  91         using MHD_Result = int;
  92 #endif
  93
  94         static MHD_Result answer_to_connection_thunk(void *cls, MHD_Connection *connection,
  95                                                      const char *url, const char *method,
  96                                                      const char *version, const char *upload_data,
  97                                                      size_t *upload_data_size, void **con_cls);
  98
  99         MHD_Result answer_to_connection(MHD_Connection *connection,
 100                                         const char *url, const char *method,
 101                                         const char *version, const char *upload_data,
 102                                         size_t *upload_data_size, void **con_cls);
 103
 104         static void free_stream(void *cls);
 105
 106         class Stream {
 107         public:
 108                 enum Framing {
 109                         FRAMING_RAW,
 110                         FRAMING_METACUBE
 111                 };
 112                 Stream(HTTPD *parent, Framing framing, StreamID stream_id)
 113                         : parent(parent), framing(framing), stream_id(stream_id) {}
 114
 115                 static ssize_t reader_callback_thunk(void *cls, uint64_t pos, char *buf, size_t max);
 116                 ssize_t reader_callback(uint64_t pos, char *buf, size_t max);
 117
 118                 enum DataType {
 119                         DATA_TYPE_HEADER,
 120                         DATA_TYPE_KEYFRAME,
 121                         DATA_TYPE_OTHER
 122                 };
 123                 void add_data(const char *buf, size_t size, DataType data_type, int64_t time, AVRational timebase);
 124                 void stop();
 125                 HTTPD *get_parent() const { return parent; }
 126                 StreamID get_stream_id() const { return stream_id; }
 127
 128         private:
 129                 HTTPD *parent;
 130                 Framing framing;
 131
 132                 std::mutex buffer_mutex;
 133                 bool should_quit = false;  // Under <buffer_mutex>.
 134                 std::condition_variable has_buffered_data;
 135                 std::deque<std::string> buffered_data;  // Protected by <buffer_mutex>.
 136                 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>.
 137                 size_t buffered_data_bytes = 0;  // The sum of all size() in buffered_data. Protected by <buffer_mutex>.
 138                 size_t seen_keyframe = false;
 139                 StreamID stream_id;
 140         };
 141
 142         void add_data_locked(StreamID stream_id, const char *buf, size_t size, Stream::DataType data_type, int64_t time, AVRational timebase);
 143
 144         MHD_Daemon *mhd = nullptr;
 145         std::mutex streams_mutex;
 146         std::set<Stream *> streams;  // Not owned.
 147         struct Endpoint {
 148                 EndpointCallback callback;
 149                 CORSPolicy cors_policy;
 150         };
 151         std::unordered_map<std::string, Endpoint> endpoints;
 152         std::map<StreamID, std::string> header;
 153
 154         // Metrics.
 155         std::atomic<int64_t> metric_num_connected_clients{0};
 156         std::atomic<int64_t> metric_num_connected_multicam_clients{0};
 157         std::atomic<int64_t> metric_num_connected_siphon_clients[MAX_VIDEO_CARDS] {{0}};
 158 };
 159
 160 #endif  // !defined(_HTTPD_H)