Add support for forced prebuffering.

[cubemap] / stream.h

diff --git a/stream.h b/stream.h
index a57c6d88e7ff0955a68e0d02fceeb0910bd7491f..4947c3fbd7fdf11a43b8456a78f4a0c80812c58f 100644 (file)
--- a/stream.h
+++ b/stream.h
@@ -6,25 +6,49 @@
 
 #include <stddef.h>
 #include <stdint.h>
+#include <sys/types.h>
+#include <sys/uio.h>
 #include <string>
 #include <vector>
 
-class MarkPool;
 class StreamProto;
 struct Client;
 
+enum StreamStartSuitability {
+       NOT_SUITABLE_FOR_STREAM_START,
+       SUITABLE_FOR_STREAM_START,
+};
+
 struct Stream {
-       Stream(const std::string &stream_id, size_t backlog_size);
+       // Must be in sync with StreamConfig::Encoding.
+       enum Encoding { STREAM_ENCODING_RAW = 0, STREAM_ENCODING_METACUBE };
+
+       Stream(const std::string &stream_id, size_t backlog_size, size_t prebuffering_bytes, Encoding encoding);
        ~Stream();
 
        // Serialization/deserialization.
-       Stream(const StreamProto &serialized);
+       Stream(const StreamProto &serialized, int data_fd);
        StreamProto serialize();
 
-       std::string stream_id;
+       // Changes the backlog size, restructuring the data as needed.
+       void set_backlog_size(size_t new_size);
+
+       // Mutex protecting <queued_data> and <queued_data_last_starting_point>.
+       // Note that if you want to hold both this and the owning server's
+       // <mutex> you will need to take <mutex> before this one.
+       mutable pthread_mutex_t queued_data_mutex;
+
+       std::string url;
+
+       // The HTTP response header, without the trailing double newline.
+       std::string http_header;
 
-       // The HTTP response header, plus the video stream header (if any).
-       std::string header;
+       // The video stream header (if any).
+       std::string stream_header;
+
+       // What encoding we apply to the outgoing data (usually raw, but can also
+       // be Metacube, for reflecting to another Cubemap instance).
+       Encoding encoding;
 
        // The stream data itself, stored in a circular buffer.
        //
@@ -39,9 +63,21 @@ struct Stream {
        // How many bytes <data_fd> can hold (the buffer size).
        size_t backlog_size;
 
+       // How many bytes we need to have in the backlog before we start
+       // sending (in practice, we will then send all of them at once,
+       // and then start sending at the normal rate thereafter).
+       // This is basically to force a buffer on the client, which can help
+       // if the client expects us to be able to fill up the buffer much
+       // faster than realtime (ie., it expects a static file).
+       size_t prebuffering_bytes;
+
        // How many bytes this stream have received. Can very well be larger
        // than <backlog_size>, since the buffer wraps.
        size_t bytes_received;
+
+       // The last point in the stream that is suitable to start new clients at
+       // (after having sent the header). -1 if no such point exists yet.
+       ssize_t last_suitable_starting_point;
        
        // Clients that are in SENDING_DATA, but that we don't listen on,
        // because we currently don't have any data for them.
@@ -52,22 +88,37 @@ struct Stream {
        // <sleeping_clients>).
        std::vector<Client *> to_process;
 
-       // What pool to fetch marks from, or NULL.
-       MarkPool *mark_pool;
+       // Maximum pacing rate for the stream.
+       uint32_t pacing_rate;
+
+       // Queued data, if any. Protected by <queued_data_mutex>.
+       // The data pointers in the iovec are owned by us.
+       std::vector<iovec> queued_data;
+
+       // Index of the last element in queued_data that is suitable to start streaming at.
+       // -1 if none. Protected by <queued_data_mutex>.
+       int queued_data_last_starting_point;
 
        // 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);
 
-       // Add more input data to the stream, and wake up all clients that are sleeping.
-       void add_data(const char *data, ssize_t bytes);
+       // Add more data to <queued_data>, adding Metacube headers if needed.
+       // Does not take ownership of <data>.
+       void add_data_deferred(const char *data, size_t bytes, StreamStartSuitability suitable_for_stream_start);
+
+       // Add queued data to the stream, if any.
+       // You should hold the owning Server's <mutex>.
+       void process_queued_data();
 
 private:
        Stream(const Stream& other);
 
-       // We have more data, so mark all clients that are sleeping as ready to go.
-       void wake_up_all_clients();
+       // Adds data directly to the stream file descriptor, without adding headers or
+       // going through <queued_data>.
+       // You should hold the owning Server's <mutex>.
+       void add_data_raw(const std::vector<iovec> &data);
 };
 
 #endif  // !defined(_STREAM_H)