- added random bias to search and tunnel request maximum depth

- added random (and biased) re-routing of tunnel request to improve tunnel length.


git-svn-id: http://svn.code.sf.net/p/retroshare/code/trunk@4130 b45a01b8-16f6-495d-af2f-9b41ad6348cc

libretroshare/src/turtle/p3turtle.h

@@ -164,6 +164,7 @@ class TurtleRequestInfo
 	public:
 		TurtlePeerId origin ;			// where the request came from.
 		uint32_t	time_stamp ;			// last time the tunnel was actually used. Used for cleaning old tunnels.
+		int depth ;							// depth of the request. Used to optimize tunnel length.
 };
 
 class TurtleTunnel
@@ -402,6 +403,11 @@ class p3turtle: public p3Service, /*public pqiMonitor,*/ public RsTurtle,/* publ
 		/// used to force digging new tunnels
 		bool _force_digg_new_tunnels ;			
 
+		/// used as a bias to introduce randomness in a consistent way, for
+		/// altering tunnel request depths, and tunnel re-routing actions.
+		///
+		uint32_t _random_bias ;
+
 #ifdef P3TURTLE_DEBUG
 		// debug function
 		void dumpState() ;