X-Git-Url: https://git.sesse.net/?p=cubemap;a=blobdiff_plain;f=server.h;h=ce9365d7a49cfb98d176d9a566358c2a5f98d937;hp=d8b9064f492f2ad12e333747b389bd1093b2564a;hb=c2c9f6441f9ae8091a39aea0340417d5915e1ac9;hpb=97bdb597d4847308ce9d6982505b56a3a09e930b diff --git a/server.h b/server.h index d8b9064..ce9365d 100644 --- a/server.h +++ b/server.h @@ -3,71 +3,203 @@ #include #include +#include #include #include +#include #define BACKLOG_SIZE 1048576 +#define EPOLL_MAX_EVENTS 8192 +#define EPOLL_TIMEOUT_MS 20 +#define MAX_CLIENT_REQUEST 16384 + +class ClientProto; +class CubemapStateProto; +class Stream; +class StreamProto; struct Client { - enum State { READING_REQUEST, SENDING_HEADER, SENDING_DATA }; + Client() {} + Client(int sock); + + // Serialization/deserialization. + Client(const ClientProto &serialized, Stream *stream); + ClientProto serialize() const; + + // The file descriptor associated with this socket. + int sock; + + enum State { READING_REQUEST, SENDING_HEADER, SENDING_DATA, SENDING_ERROR }; State state; // The HTTP request, as sent by the client. If we are in READING_REQUEST, // this might not be finished. - std::string client_request; + std::string request; -#if 0 - // What stream we're connecting to; parsed from client_request. + // What stream we're connecting to; parsed from . // Not relevant for READING_REQUEST. - string stream_id; -#endif + std::string stream_id; + Stream *stream; - // Number of bytes we've sent of the header. Only relevant for SENDING_HEADER. - size_t header_bytes_sent; + // The header we want to send. This is nominally a copy of Stream::header, + // but since that might change on reconnects etc., we keep a local copy here. + // Only relevant for SENDING_HEADER or SENDING_ERROR; blank otherwise. + std::string header_or_error; + + // Number of bytes we've sent of the header. Only relevant for SENDING_HEADER + // or SENDING_ERROR. + size_t header_or_error_bytes_sent; // Number of bytes we've sent of data. Only relevant for SENDING_DATA. size_t bytes_sent; }; struct Stream { + Stream(const std::string &stream_id); + ~Stream(); + + // Serialization/deserialization. + Stream(const StreamProto &serialized); + StreamProto serialize() const; + + std::string stream_id; + // The HTTP response header, plus the video stream header (if any). std::string header; // The stream data itself, stored in a circular buffer. - char data[BACKLOG_SIZE]; + char *data; // How many bytes contains. Can very well be larger than BACKLOG_SIZE, // since the buffer wraps. size_t data_size; + + // Clients that are in SENDING_DATA, but that we don't listen on, + // because we currently don't have any data for them. + // See put_client_to_sleep() and wake_up_all_clients(). + std::vector sleeping_clients; + + // Clients that we recently got data for (when they were in + // ). + std::vector to_process; + + // Put client to sleep, since there is no more data for it; we will on + // longer listen on POLLOUT until we get more data. Also, it will be put + // in the list of clients to wake up when we do. + void put_client_to_sleep(Client *client); + + // We have more data, so mark all clients that are sleeping as ready to go. + void wake_up_all_clients(); + +private: + Stream(const Stream& other); }; class Server { public: Server(); + ~Server(); // Start a new thread that handles clients. void run(); - void add_client(int sock); - void add_stream(const std::string &stream_id); + + // Stop the thread. + void stop(); + void set_header(const std::string &stream_id, const std::string &header); - void add_data(const std::string &stream_id, const char *data, size_t bytes); + + // These will be deferred until the next time an iteration in do_work() happens, + // and the order between them are undefined. + // XXX: header should ideally be ordered with respect to data. + void add_client_deferred(int sock); + void add_data_deferred(const std::string &stream_id, const char *data, size_t bytes); + + // These should not be called while running, since that would violate + // threading assumptions (ie., that epoll is only called from one thread + // at the same time). + CubemapStateProto serialize(); + void add_client_from_serialized(const ClientProto &client); + void add_stream(const std::string &stream_id); + void add_stream_from_serialized(const StreamProto &stream); private: + pthread_t worker_thread; + + // Mutex protecting queued_data only. Note that if you want to hold both this + // and below, you will need to take before this one. + pthread_mutex_t queued_data_mutex; + + // Deferred commands that should be run from the do_work() thread as soon as possible. + // We defer these for two reasons: + // + // - We only want to fiddle with epoll from one thread at any given time, + // and doing add_client() from the acceptor thread would violate that. + // - We don't want the input thread(s) hanging on when doing + // add_data(), since they want to do add_data() rather often, and + // can be taken a lot of the time. + // + // Protected by . + std::vector queued_add_clients; + std::map queued_data; + + // All variables below this line are protected by the mutex. pthread_mutex_t mutex; + // If the thread should stop or not. + bool should_stop; + // Map from stream ID to stream. - std::map streams; + std::map streams; // Map from file descriptor to client. std::map clients; + // Used for epoll implementation (obviously). int epoll_fd; + epoll_event events[EPOLL_MAX_EVENTS]; // Recover the this pointer, and call do_work(). static void *do_work_thunk(void *arg); // The actual worker thread. void do_work(); + + // Process a client; read and write data as far as we can. + // After this call, one of these four is true: + // + // 1. The socket is closed, and the client deleted. + // 2. We are still waiting for more data from the client. + // 3. We've sent all the data we have to the client, + // and put it in . + // 4. The socket buffer is full (which means we still have + // data outstanding). + // + // For #2, we listen for EPOLLIN events. For #3 and #4, we listen + // for EPOLLOUT in edge-triggered mode; it will never fire for #3, + // but it's cheaper than taking it in and out all the time. + void process_client(Client *client); + + // Close a given client socket, and clean up after it. + void close_client(Client *client); + + // Parse the HTTP request. Returns a HTTP status code (200/400/404). + int parse_request(Client *client); + + // Construct the HTTP header, and set the client into + // the SENDING_HEADER state. + void construct_header(Client *client); + + // Construct a generic error with the given line, and set the client into + // the SENDING_ERROR state. + void construct_error(Client *client, int error_code); + + // TODO: This function should probably die. + Stream *find_stream(const std::string &stream_id); + + void process_queued_data(); + + void add_client(int sock); + void add_data(const std::string &stream_id, const char *data, size_t bytes); }; #endif // !defined(_SERVER_H)