X-Git-Url: https://git.sesse.net/?p=cubemap;a=blobdiff_plain;f=server.h;h=e9b74315f1b3d5fdd6227d67c2c4160ccf89be58;hp=8d5261f6ca9b42fb84bab11776486cd44a67f125;hb=c5cdeee3a4c99abbf7303b47634b0a748e50bcb4;hpb=109af5c530539fd614d7d61dc33a4811ff631932

diff --git a/server.h b/server.h
index 8d5261f..e9b7431 100644
--- a/server.h
+++ b/server.h
@@ -81,15 +81,22 @@ struct Stream {
 
 	// 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.
@@ -217,7 +224,7 @@ private:
 	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)