11 #define BACKLOG_SIZE 1048576
12 #define EPOLL_MAX_EVENTS 8192
13 #define EPOLL_TIMEOUT_MS 20
14 #define MAX_CLIENT_REQUEST 16384
17 class CubemapStateProto;
25 // Serialization/deserialization.
26 Client(const ClientProto &serialized, Stream *stream);
27 ClientProto serialize() const;
29 // The file descriptor associated with this socket.
32 enum State { READING_REQUEST, SENDING_HEADER, SENDING_DATA, SENDING_ERROR };
35 // The HTTP request, as sent by the client. If we are in READING_REQUEST,
36 // this might not be finished.
39 // What stream we're connecting to; parsed from <request>.
40 // Not relevant for READING_REQUEST.
41 std::string stream_id;
44 // The header we want to send. This is nominally a copy of Stream::header,
45 // but since that might change on reconnects etc., we keep a local copy here.
46 // Only relevant for SENDING_HEADER or SENDING_ERROR; blank otherwise.
47 std::string header_or_error;
49 // Number of bytes we've sent of the header. Only relevant for SENDING_HEADER
51 size_t header_or_error_bytes_sent;
53 // Number of bytes we've sent of data. Only relevant for SENDING_DATA.
58 Stream(const std::string &stream_id);
61 // Serialization/deserialization.
62 Stream(const StreamProto &serialized);
63 StreamProto serialize() const;
65 std::string stream_id;
67 // The HTTP response header, plus the video stream header (if any).
70 // The stream data itself, stored in a circular buffer.
73 // How many bytes <data> contains. Can very well be larger than BACKLOG_SIZE,
74 // since the buffer wraps.
77 // Clients that are in SENDING_DATA, but that we don't listen on,
78 // because we currently don't have any data for them.
79 // See put_client_to_sleep() and wake_up_all_clients().
80 std::vector<Client *> sleeping_clients;
82 // Clients that we recently got data for (when they were in
83 // <sleeping_clients>).
84 std::vector<Client *> to_process;
86 // Put client to sleep, since there is no more data for it; we will on
87 // longer listen on POLLOUT until we get more data. Also, it will be put
88 // in the list of clients to wake up when we do.
89 void put_client_to_sleep(Client *client);
91 // We have more data, so mark all clients that are sleeping as ready to go.
92 void wake_up_all_clients();
95 Stream(const Stream& other);
103 // Start a new thread that handles clients.
109 // Set header (both HTTP header and any stream headers) for the given stream.
110 void set_header(const std::string &stream_id, const std::string &header);
112 // These will be deferred until the next time an iteration in do_work() happens,
113 // and the order between them are undefined.
114 // XXX: header should ideally be ordered with respect to data.
115 void add_client_deferred(int sock);
116 void add_data_deferred(const std::string &stream_id, const char *data, size_t bytes);
118 // These should not be called while running, since that would violate
119 // threading assumptions (ie., that epoll is only called from one thread
120 // at the same time).
121 CubemapStateProto serialize();
122 void add_client_from_serialized(const ClientProto &client);
123 void add_stream(const std::string &stream_id);
124 void add_stream_from_serialized(const StreamProto &stream);
127 pthread_t worker_thread;
129 // Mutex protecting queued_data only. Note that if you want to hold both this
130 // and <mutex> below, you will need to take <mutex> before this one.
131 pthread_mutex_t queued_data_mutex;
133 // Deferred commands that should be run from the do_work() thread as soon as possible.
134 // We defer these for two reasons:
136 // - We only want to fiddle with epoll from one thread at any given time,
137 // and doing add_client() from the acceptor thread would violate that.
138 // - We don't want the input thread(s) hanging on <mutex> when doing
139 // add_data(), since they want to do add_data() rather often, and <mutex>
140 // can be taken a lot of the time.
142 // Protected by <queued_data_mutex>.
143 std::vector<int> queued_add_clients;
144 std::map<std::string, std::string> queued_data;
146 // All variables below this line are protected by the mutex.
147 pthread_mutex_t mutex;
149 // If the thread should stop or not.
152 // Map from stream ID to stream.
153 std::map<std::string, Stream *> streams;
155 // Map from file descriptor to client.
156 std::map<int, Client> clients;
158 // Used for epoll implementation (obviously).
160 epoll_event events[EPOLL_MAX_EVENTS];
162 // Recover the this pointer, and call do_work().
163 static void *do_work_thunk(void *arg);
165 // The actual worker thread.
168 // Process a client; read and write data as far as we can.
169 // After this call, one of these four is true:
171 // 1. The socket is closed, and the client deleted.
172 // 2. We are still waiting for more data from the client.
173 // 3. We've sent all the data we have to the client,
174 // and put it in <sleeping_clients>.
175 // 4. The socket buffer is full (which means we still have
176 // data outstanding).
178 // For #2, we listen for EPOLLIN events. For #3 and #4, we listen
179 // for EPOLLOUT in edge-triggered mode; it will never fire for #3,
180 // but it's cheaper than taking it in and out all the time.
181 void process_client(Client *client);
183 // Close a given client socket, and clean up after it.
184 void close_client(Client *client);
186 // Parse the HTTP request. Returns a HTTP status code (200/400/404).
187 int parse_request(Client *client);
189 // Construct the HTTP header, and set the client into
190 // the SENDING_HEADER state.
191 void construct_header(Client *client);
193 // Construct a generic error with the given line, and set the client into
194 // the SENDING_ERROR state.
195 void construct_error(Client *client, int error_code);
197 // TODO: This function should probably die.
198 Stream *find_stream(const std::string &stream_id);
200 void process_queued_data();
202 void add_client(int sock);
203 void add_data(const std::string &stream_id, const char *data, size_t bytes);
206 #endif // !defined(_SERVER_H)