#include <stddef.h>
#include <stdint.h>
#include <sys/types.h>
+#include <sys/uio.h>
+#include <deque>
#include <string>
#include <vector>
-class MarkPool;
class StreamProto;
struct Client;
+enum StreamStartSuitability {
+ NOT_SUITABLE_FOR_STREAM_START,
+ SUITABLE_FOR_STREAM_START,
+};
+
struct Stream {
// 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, Encoding encoding);
+ Stream(const std::string &stream_id, size_t backlog_size, size_t prebuffering_bytes, Encoding encoding);
~Stream();
// Serialization/deserialization.
// Changes the backlog size, restructuring the data as needed.
void set_backlog_size(size_t new_size);
- std::string stream_id;
+ // 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;
// 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;
+
+ // A list of points in the stream that is suitable to start new clients at
+ // (after having sent the header). Empty if no such point exists yet.
+ std::deque<size_t> suitable_starting_points;
// Clients that are in SENDING_DATA, but that we don't listen on,
// because we currently don't have any data for them.
// <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 the owning Server's <queued_data_mutex>.
- std::string queued_data;
+ // Queued data, if any. Protected by <queued_data_mutex>.
+ // The data pointers in the iovec are owned by us.
+ struct DataElement {
+ iovec data;
+ StreamStartSuitability suitable_for_stream_start;
+ };
+ std::vector<DataElement> queued_data;
// 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
void put_client_to_sleep(Client *client);
// Add more data to <queued_data>, adding Metacube headers if needed.
- // You should hold the owning Server's <queued_data_mutex>.
- void add_data_deferred(const char *data, size_t bytes);
+ // 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> _and_ <queued_data_mutex>.
+ // You should hold the owning Server's <mutex>.
void process_queued_data();
private:
Stream(const Stream& other);
// 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 char *data, ssize_t bytes);
+ // going through <queued_data>.
+ // You should hold the owning Server's <mutex>, and probably call
+ // remove_obsolete_starting_points() afterwards.
+ void add_data_raw(const std::vector<DataElement> &data);
+
+ // Remove points from <suitable_starting_points> that are no longer
+ // in the backlog.
+ // You should hold the owning Server's <mutex>.
+ void remove_obsolete_starting_points();
};
#endif // !defined(_STREAM_H)