Megatest

;;      *transport-type* and *runremote* from the monitor.db
;;
;; client:setup
;;
;; lookup_server, need to remove *runremote* stuff
;;

(define (client:setup-http areapath #!key (remaining-tries 100) (failed-connects 0)(area-dat #f))
  (debug:print-info 2 *default-log-port* "client:setup remaining-tries=" remaining-tries)
  (server:start-and-wait areapath)
  (if (<= remaining-tries 0)
      (begin
	(debug:print-error 0 *default-log-port* "failed to start or connect to server")
	(exit 1))
      ;;
      ;; Alternatively here, we can get the list of candidate servers and work our way
      ;; through them searching for a good one.
      ;;
      (let* ((server-dat (server:get-first-best areapath))
	     (runremote  (or area-dat *runremote*)))
	(if (not server-dat) ;; no server found
	    (client:setup-http areapath remaining-tries: (- remaining-tries 1))
	    (let ((host  (cadr  server-dat))
		  (port  (caddr server-dat)))
	      (debug:print-info 4 *default-log-port* "client:setup server-dat=" server-dat ", remaining-tries=" remaining-tries)
	      (if (and (not area-dat)
		       (not *runremote*))
		  (set! *runremote* (make-remote)))
	      (if (and host port)
		  (let* ((start-res (case *transport-type*
				      ((http)(http-transport:client-connect host port))))
			 (ping-res  (case *transport-type* 
				      ((http)(rmt:login-no-auto-client-setup start-res)))))
		    (if (and start-res
			     ping-res)
			(begin
			  (remote-conndat-set! runremote start-res) ;; (hash-table-set! runremote run-id start-res)
			  (debug:print-info 2 *default-log-port* "connected to " (http-transport:server-dat-make-url start-res))
			  start-res)
			(begin    ;; login failed but have a server record, clean out the record and try again
			  (debug:print-info 0 *default-log-port* "client:setup, login failed, will attempt to start server ... start-res=" start-res ", run-id=" run-id ", server-dat=" server-dat)
			  (case *transport-type* 
			    ((http)(http-transport:close-connections)))
			  (remote-conndat-set! runremote #f)  ;; (hash-table-delete! runremote run-id)
			  (thread-sleep! 1)
			  (client:setup-http areapath remaining-tries: (- remaining-tries 1))
			  )))
		  (begin    ;; no server registered
		    (server:kind-run areapath)
		    (debug:print-info 0 *default-log-port* "client:setup, no server registered, remaining-tries=" remaining-tries)
		    (thread-sleep! 1) ;; (+ 5 (random (- 20 remaining-tries))))  ;; give server a little time to start up, randomize a little to avoid start storms.

(define (http-transport:inc-requests-and-prep-to-close-all-connections)
  (mutex-lock! *http-mutex*)
  (set! *http-requests-in-progress* (+ 1 *http-requests-in-progress*)))

;; Send "cmd" with json payload "params" to serverdat and receive result
;;
(define (http-transport:client-api-send-receive run-id serverdat cmd params #!key (numretries 3)(area-dat #f))
  (let* ((fullurl    (if (vector? serverdat)
			 (http-transport:server-dat-get-api-req serverdat)
			 (begin
			   (debug:print 0 *default-log-port* "FATAL ERROR: http-transport:client-api-send-receive called with no server info")
			   (exit 1))))
	 (res        (vector #f "uninitialized"))
	 (success    #t)
	 (sparams    (db:obj->string params transport: 'http))
	 (runremote  (or area-dat *runremote*)))
       (debug:print-info 11 *default-log-port* "fullurl=" fullurl ", cmd=" cmd ", params=" params ", run-id=" run-id "\n")
       ;; set up the http-client here
       (max-retry-attempts 1)
       ;; consider all requests indempotent
       (retry-request? (lambda (request)
			 #f))
       ;; send the data and get the response

					 (db:string->obj 
					  (handle-exceptions
					   exn
					   (begin
					     (set! success #f)
					     (debug:print 0 *default-log-port* "WARNING: failure in with-input-from-request to " fullurl ".")
					     (debug:print 0 *default-log-port* " message: " ((condition-property-accessor 'exn 'message) exn))
					     (if runremote
                                                 (remote-conndat-set! runremote #f))
					     ;; Killing associated server to allow clean retry.")
					     ;; (tasks:kill-server-run-id run-id)  ;; better to kill the server in the logic that called this routine?
					     (mutex-unlock! *http-mutex*)
					     ;;; (signal (make-composite-condition
					     ;;;          (make-property-condition 'commfail 'message "failed to connect to server")))
					     ;;; "communications failed"
					     (db:obj->string #f))

	     (signal (make-composite-condition
		      (make-property-condition 
		       'timeout
		       'message "nmsg-transport:client-api-send-receive-raw timed out talking to server")))))))

;; careful closing of connections stored in *runremote*
;;
(define (http-transport:close-connections #!key (area-dat #f))
  (let* ((runremote  (or area-dat *runremote*))
	 (server-dat (if runremote
                         (remote-conndat runremote)
                         #f))) ;; (hash-table-ref/default *runremote* run-id #f)))
    (if (vector? server-dat)
	(let ((api-dat (http-transport:server-dat-get-api-uri server-dat)))
	  (close-connection! api-dat)
	  #t)
	#f)))

;;======================================================================
;;  S U P P O R T   F U N C T I O N S
;;======================================================================

;; if a server is either running or in the process of starting call client:setup
;; else return #f to let the calling proc know that there is no server available
;;
(define (rmt:get-connection-info areapath #!key (area-dat #f)) ;; TODO: push areapath down.
  (let* ((runremote (or area-dat *runremote*))
	 (cinfo     (remote-conndat runremote))
        (run-id 0))
    (if cinfo
	cinfo
	(if (server:check-if-running areapath)
	    (client:setup areapath)
	    #f))))

(define *send-receive-mutex* (make-mutex)) ;; should have separate mutex per run-id

;; RA => e.g. usage (rmt:send-receive 'get-var #f (list varname))
;;
(define (rmt:send-receive cmd rid params #!key (attemptnum 1)(area-dat #f)) ;; start attemptnum at 1 so the modulo below works as expected

  ;; do all the prep locked under the rmt-mutex
  (mutex-lock! *rmt-mutex*)

  ;; 1. check if server is started IFF cmd is a write OR if we are not on the homehost, store in runremote
  ;; 2. check the age of the connections. refresh the connection if it is older than timeout-20 seconds.
  ;; 3. do the query, if on homehost use local access
  ;;
  (let* ((start-time (current-seconds)) ;; snapshot time so all use cases get same value
	 (runremote  (or area-dat *runremote*)))
    (cond
     ;; give up if more than 15 attempts
     ((> attemptnum 15)
      (debug:print 0 *default-log-port* "ERROR: 15 tries to start/connect to server. Giving up.")
      (exit 1))
     ;; reset the connection if it has been unused too long
     ((and runremote
           (remote-conndat runremote)
	   (let ((expire-time (+ (- start-time (remote-server-timeout runremote))(random 30)))) ;; add 30 seconds of noise so that not all running tests expire at the same time causing a storm of server starts
	     (< (http-transport:server-dat-get-last-access (remote-conndat runremote)) expire-time)))
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  8")
      (remote-conndat-set! runremote #f)
      (mutex-unlock! *rmt-mutex*)
      (rmt:send-receive cmd rid params attemptnum: attemptnum))
     ;; ensure we have a record for our connection for given area
     ((not runremote)                     
      (set! *runremote* (make-remote))
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  1")
      (rmt:send-receive cmd rid params attemptnum: attemptnum))
     ;; ensure we have a homehost record
     ((not (pair? (remote-hh-dat runremote)))  ;; not on homehost
      (thread-sleep! 0.1) ;; since we shouldn't get here, delay a little
      (remote-hh-dat-set! runremote (common:get-homehost))
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  2")
      (rmt:send-receive cmd rid params attemptnum: attemptnum))
     ;; on homehost and this is a read
     ((and (cdr (remote-hh-dat runremote))   ;; on homehost
           (member cmd api:read-only-queries)) ;; this is a read
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  3")
      (rmt:open-qry-close-locally cmd 0 params))

     ;; on homehost and this is a write, we already have a server, but server has died
     ((and (cdr (remote-hh-dat runremote))         ;; on homehost
           (not (member cmd api:read-only-queries))  ;; this is a write
           (remote-server-url runremote)           ;; have a server
           (not (server:check-if-running *toppath*)))  ;; server has died.
      (set! *runremote* (make-remote))
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  4.1")
      (rmt:send-receive cmd rid params attemptnum: attemptnum))

     ;; on homehost and this is a write, we already have a server
     ((and (cdr (remote-hh-dat runremote))         ;; on homehost
           (not (member cmd api:read-only-queries))  ;; this is a write
           (remote-server-url runremote))          ;; have a server
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  4")
      (rmt:open-qry-close-locally cmd 0 params))

     ;;  on homehost, no server contact made and this is a write, passively start a server 
     ((and (cdr (remote-hh-dat runremote)) ; new
           (not (remote-server-url runremote))
	   (not (member cmd api:read-only-queries)))
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  5")
      (let ((server-url  (server:check-if-running *toppath*))) ;; (server:read-dotserver->url *toppath*))) ;; (server:check-if-running *toppath*))) ;; Do NOT want to run server:check-if-running - very expensive to do for every write call
	(if server-url
	    (remote-server-url-set! runremote server-url) ;; the string can be consumed by the client setup if needed
	    (server:kind-run *toppath*)))
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  5.1")
      (rmt:open-qry-close-locally cmd 0 params))

     ((and (not (cdr (remote-hh-dat runremote)))        ;; not on a homehost 
           (not (remote-conndat runremote)))            ;; and no connection
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  6  hh-dat: " (remote-hh-dat runremote) " conndat: " (remote-conndat runremote))
      (mutex-unlock! *rmt-mutex*)
      (server:start-and-wait *toppath*)
      (remote-conndat-set! runremote (rmt:get-connection-info *toppath*)) ;; calls client:setup which calls client:setup-http
      (rmt:send-receive cmd rid params attemptnum: attemptnum)) ;; TODO: add back-off timeout as
     ;; all set up if get this far, dispatch the query
     ((cdr (remote-hh-dat runremote)) ;; we are on homehost
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  7")
      (rmt:open-qry-close-locally cmd (if rid rid 0) params))

     ;; not on homehost, do server query
     (else
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  9")
      (mutex-lock! *rmt-mutex*)
      (let* ((conninfo (remote-conndat runremote))
	     (dat      (case (remote-transport runremote)
			 ((http) (condition-case ;; handling here has caused a lot of problems. However it is needed to deal with attemtped communication to servers that have gone away
                                  (http-transport:client-api-send-receive 0 conninfo cmd params)
                                  ((commfail)(vector #f "communications fail"))
                                  ((exn)(vector #f "other fail" (print-call-chain)))))
			 (else
			  (debug:print 0 *default-log-port* "ERROR: transport " (remote-transport runremote) " not supported")
			  (exit))))
	     (success  (if (vector? dat) (vector-ref dat 0) #f))
	     (res      (if (vector? dat) (vector-ref dat 1) #f)))
	(if (vector? conninfo)(http-transport:server-dat-update-last-access conninfo)) ;; refresh access time
	;; (mutex-unlock! *rmt-mutex*)
        (debug:print-info 12 *default-log-port* "rmt:send-receive, case  9. conninfo=" conninfo " dat=" dat " runremote = "runremote)
	(if success
	    (case (remote-transport runremote)
	      ((http)
	       (mutex-unlock! *rmt-mutex*)
	       res)
	      (else
	       (debug:print 0 *default-log-port* "ERROR: transport " (remote-transport runremote) " is unknown")
	       (mutex-unlock! *rmt-mutex*)
	       (exit 1)))
	    (begin
	      (debug:print 0 *default-log-port* "WARNING: communication failed. Trying again, try num: " attemptnum)
	      (remote-conndat-set!    runremote #f)
	      (remote-server-url-set! runremote #f)
              (debug:print-info 12 *default-log-port* "rmt:send-receive, case  9.1")
	      (mutex-unlock! *rmt-mutex*)
	      (server:start-and-wait *toppath*)
	      (rmt:send-receive cmd rid params attemptnum: (+ attemptnum 1)))))))))

;; (define (rmt:update-db-stats run-id rawcmd params duration)
;;   (mutex-lock! *db-stats-mutex*)