Megatest

;;  start-server-find-port  ;; gotta have a server port ready from the very begining

;; udata    - all the connection info, captain, server, ulex db etc. MUST BE PASSED IN
;; dbpath   - full path and filename of the db to talk to or a symbol naming the db?
;; callname - the remote call to execute
;; params   - parameters to pass to the remote call
;;
(define (remote-call udata dbpath dbtype callname params)
  (start-server-find-port udata) ;; ensure we have a local server
  (find-or-setup-captain udata)
  ;; look at connect, process-request, send, send-receive
  (let-values (((cookie-key host-port)(get-db-owner udata dbpath dbtype)))
    (if (and cookie-key host-port)
	(send-receive udata host-port callname cookie-key params)
	#f)))

;;======================================================================
;; KEY FUNCTIONS - THESE ARE TOO BE EXPOSED AND USED
;;======================================================================

;; connection setup and management functions

;; This is the basic setup command. Must always be
;; called before connecting to a db using connect.
;;
;; find or become the captain
;; setup and return a ulex object
;;
(define (find-or-setup-captain udata #!optional (tries 0))
  ;; see if we already have a captain and if the lease is ok
  (if (and (udat-captain-address udata)
	   (udat-captain-port    udata)
	   (< (current-seconds) (udat-captain-lease udata)))
      udata
      (let* ((cpkts (get-all-captain-pkts udata)) ;; read captain pkts
	     (captn (get-winning-pkt cpkts)))

	      (udat-captain-lease-set!   udata (+ (current-seconds) 10))
	      (let-values (((success pingtime)(ping udata (conc ipaddr ":" port))))
		(if success
		    udata
		    (begin
		      (print "Found unreachable captain at " ipaddr ":" port ", removing pkt")
		      (remove-captain-pkt udata captn)
		      (if (< tries 20)
			  (find-or-setup-captain udata (+ tries 1))
			  #f)))))
	    (begin
	      (setup-as-captain udata)  ;; this saves the thread to captain-thread and starts the thread
	      (if (< tries 20)
		  (find-or-setup-captain udata (+ tries 1))
		  #f))))))

;; connect to a specific dbfile
;;   - if already connected - return the dbowner host-port
;;   - ask the captain who to talk to for this db
;;   - put the entry in the dbowners hash as dbfile => host-port
;;
(define (connect udata dbfname dbtype)

  (let* ((host-port (udat-captain-host-port udata)))
    (if host-port
	(let* ((cookie (make-cookie udata))
	       (msg    #f) ;; (conc dbname " " dbtype))
	       (params `(,dbname ,dbtype))
	       (res    (send udata host-port 'db-owner cookie msg
			     params: params retval: #t)))
	  (match (and res (string-split res))
	    ((retcookie owner-host-port)
	     (values (equal? retcookie cookie) owner-host-port))
	    (else (values #f #f))))
	(values #f -1))))

;; called in ulex-handler to dispatch work, called on the workers side
;;     calls (proc params data)
;;     returns result with cookie
;;
;; pdat is the info of the caller, used to send the result data

      (let* ((my-addr (udat-my-address udata))
	     (my-port (udat-my-port    udata))
	     (th (make-thread (lambda ()
				(ulex-handler-loop udata)) "Captain handler")))
	(udat-handler-thread-set! udata th)
	(udat-captain-address-set! udata my-addr)
	(udat-captain-port-set!    udata my-port)
	(thread-start! th)
	(print "Captain setup complete and thread started. Address: " my-addr ", port: " my-port))
      (begin
	(print "ERROR: failed to create captain pkt")
	#f)))

;; given a pkts dir read 
;;
(define (get-all-captain-pkts udata)

	  (udat-my-pid     udata) "-"
	  newcnum)))

;; create a tcp listener and return a populated udat struct with
;; my port, address, hostname, pid etc.
;; return #f if fail to find a port to allocate.
;;
;;  does not actually start a server thread
;;
;;  if udata-in is #f create the record
;;  if there is already a serv-listener return the udata
;;
(define (start-server-find-port udata-in #!optional (port 4242)(tries 0))
  (let ((udata (or udata-in (make-udat))))
    (if (udat-serv-listener udata) ;; TODO - add check that the listener is alive and ready?
	udata
	(let ((res (connect-server udata port)))
	  (if res
	      res
	      (begin
		;; (print "Could not connect to " port)
		(if (and (< port  65535)
			 (< tries 10000)) ;; make this number bigger when things are working
		    (start-server-find-port udata (+ port 1)(+ tries 1))
		    #f)))))))


(define (connect-server udata port)
  ;; (tcp-listener-socket LISTENER)(socket-name so)
  ;; sockaddr-address, sockaddr-port, sockaddr->string
  (let* ((tlsn (handle-exceptions
		   exn
		   #f ;; NB// NEED BETTER HANDLING HERE ASAP
		 (tcp-listen port 1000 #f))) ;; (tcp-listen TCPPORT [BACKLOG [HOST]])
	 (addr (get-my-best-address))) ;; (hostinfo-addresses (host-information (current-hostname)))
    (if tlsn
	(begin
	  (udat-my-address-set!    udata addr)
	  (udat-my-port-set!       udata port)
	  (udat-my-hostname-set!   udata (get-host-name))
	  (udat-serv-listener-set! udata tlsn)
	  udata)
	#f)))

(define (get-peer-dat udata host-port #!optional (hostname #f)(pid #f))
  (let* ((pdat (or (udat-get-peer udata host-port)
		   (handle-exceptions ;; ERROR - MAKE THIS EXCEPTION HANDLER MORE SPECIFIC
		    exn
		    #f
		    (let ((npdat (make-peer addr-port: host-port)))