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 void set_header(const std::string &stream_id, const std::string &header);
111 // These will be deferred until the next time an iteration in do_work() happens,
112 // and the order between them are undefined.
113 // XXX: header should ideally be ordered with respect to data.
114 void add_client_deferred(int sock);
115 void add_data_deferred(const std::string &stream_id, const char *data, size_t bytes);
117 // These should not be called while running, since that would violate
118 // threading assumptions (ie., that epoll is only called from one thread
119 // at the same time).
120 CubemapStateProto serialize();
121 void add_client_from_serialized(const ClientProto &client);
122 void add_stream(const std::string &stream_id);
123 void add_stream_from_serialized(const StreamProto &stream);
126 pthread_t worker_thread;
128 // Mutex protecting queued_data only. Note that if you want to hold both this
129 // and <mutex> below, you will need to take <mutex> before this one.
130 pthread_mutex_t queued_data_mutex;
132 // Deferred commands that should be run from the do_work() thread as soon as possible.
133 // We defer these for two reasons:
135 // - We only want to fiddle with epoll from one thread at any given time,
136 // and doing add_client() from the acceptor thread would violate that.
137 // - We don't want the input thread(s) hanging on <mutex> when doing
138 // add_data(), since they want to do add_data() rather often, and <mutex>
139 // can be taken a lot of the time.
141 // Protected by <queued_data_mutex>.
142 std::vector<int> queued_add_clients;
143 std::map<std::string, std::string> queued_data;
145 // All variables below this line are protected by the mutex.
146 pthread_mutex_t mutex;
148 // If the thread should stop or not.
151 // Map from stream ID to stream.
152 std::map<std::string, Stream *> streams;
154 // Map from file descriptor to client.
155 std::map<int, Client> clients;
157 // Used for epoll implementation (obviously).
159 epoll_event events[EPOLL_MAX_EVENTS];
161 // Recover the this pointer, and call do_work().
162 static void *do_work_thunk(void *arg);
164 // The actual worker thread.
167 // Process a client; read and write data as far as we can.
168 // After this call, one of these four is true:
170 // 1. The socket is closed, and the client deleted.
171 // 2. We are still waiting for more data from the client.
172 // 3. We've sent all the data we have to the client,
173 // and put it in <sleeping_clients>.
174 // 4. The socket buffer is full (which means we still have
175 // data outstanding).
177 // For #2, we listen for EPOLLIN events. For #3 and #4, we listen
178 // for EPOLLOUT in edge-triggered mode; it will never fire for #3,
179 // but it's cheaper than taking it in and out all the time.
180 void process_client(Client *client);
182 // Close a given client socket, and clean up after it.
183 void close_client(Client *client);
185 // Parse the HTTP request. Returns a HTTP status code (200/400/404).
186 int parse_request(Client *client);
188 // Construct the HTTP header, and set the client into
189 // the SENDING_HEADER state.
190 void construct_header(Client *client);
192 // Construct a generic error with the given line, and set the client into
193 // the SENDING_ERROR state.
194 void construct_error(Client *client, int error_code);
196 // TODO: This function should probably die.
197 Stream *find_stream(const std::string &stream_id);
199 void process_queued_data();
201 void add_client(int sock);
202 void add_data(const std::string &stream_id, const char *data, size_t bytes);
205 #endif // !defined(_SERVER_H)