#include <map>
#include <vector>
+#include "thread.h"
+
#define BACKLOG_SIZE 1048576
#define EPOLL_MAX_EVENTS 8192
#define EPOLL_TIMEOUT_MS 20
// Serialization/deserialization.
Stream(const StreamProto &serialized);
- StreamProto serialize() const;
+ StreamProto serialize();
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;
+ // The stream data itself, stored in a circular buffer.q
+ //
+ // We store our data in a file, so that we can send the data to the
+ // kernel only once (with write()). We then use sendfile() for each
+ // client, which effectively zero-copies it out of the kernel's buffer
+ // cache. This is significantly more efficient than doing write() from
+ // a userspace memory buffer, since the latter makes the kernel copy
+ // the same data from userspace many times.
+ int data_fd;
// How many bytes <data> contains. Can very well be larger than BACKLOG_SIZE,
// since the buffer wraps.
Stream(const Stream& other);
};
-class Server {
+class Server : public Thread {
public:
Server();
~Server();
- // Start a new thread that handles clients.
- void run();
-
- // Stop the thread.
- void stop();
-
// Get the list of all currently connected clients.
std::vector<ClientStats> get_client_stats() const;
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 <mutex> below, you will need to take <mutex> before this one.
mutable pthread_mutex_t queued_data_mutex;
// All variables below this line are protected by the mutex.
mutable pthread_mutex_t mutex;
- // If the thread should stop or not.
- bool should_stop;
-
// Map from stream ID to stream.
std::map<std::string, Stream *> streams;
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();
+ virtual void do_work();
// Process a client; read and write data as far as we can.
// After this call, one of these four is true:
void process_queued_data();
void add_client(int sock);
- void add_data(const std::string &stream_id, const char *data, size_t bytes);
+ void add_data(const std::string &stream_id, const char *data, ssize_t bytes);
};
#endif // !defined(_SERVER_H)