Megatest

;;======================================================================

(use format typed-records) ;; RADT => purpose of json format??

(declare (unit rmt))
(declare (uses debugprint))
(declare (uses api))
(declare (uses http-transport))
(declare (uses commonmod))
(declare (uses dbfile))
;; (declare (uses dbmemmod))
(declare (uses dbmod))
(declare (uses tcp-transportmod))
(include "common_records.scm")
(declare (uses rmtmod))

;; used by http-transport
(import dbfile

;;
;;  grep define ../rmt.scm | grep rmt: |perl -pi -e 's/\(define\s+\((\S+)\W.*$/\1/'|sort -u

;;======================================================================
;;  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 runremote) ;; TODO: push areapath down.
  (let* ((cinfo     (if (and (remote? runremote)
			     (remote-api-url runremote)) ;; we have a connection
			runremote
			#f)))
    (if cinfo
	cinfo
	(if (server:check-if-running areapath)
	    (client:setup areapath runremote)
	    #f))))

(define (rmt:on-homehost? runremote)
  (let* ((hh-dat (remote-hh-dat runremote)))
    (if (pair? hh-dat)
	(cdr hh-dat)
	(begin
	  (debug:print-info 0 *default-log-port* "hh-dat="hh-dat)
	  #f))))

  (if (not runremote)
      (let* ((newremote  (make-and-init-remote areapath)))
	(set! *runremote* newremote)
	(set! runremote newremote)))
  (let* ((dbfname (conc (dbfile:run-id->dbnum run-id)".db"))) ;;(dbfile:run-id->path areapath run-id)))
    (tt:handler runremote cmd run-id params attemptnum area-dat areapath readonly-mode dbfname testsuite mtexe)))
	
(define (http-transport-handler runremote cmd rid params attemptnum area-dat areapath readonly-mode)
    ;; do all the prep locked under the rmt-mutex
  (mutex-lock! *rmt-mutex*)
  
  ;; ensure we have a record for our connection for given area
  (if (not runremote)                   ;; can remove this one. should never get here.         
      (begin
	(set! *runremote* (make-and-init-remote areapath))
        (let* ((server-info (remote-server-info *runremote*))) 
          (if server-info
	      (begin
		(remote-server-url-set! *runremote* (server:record->url server-info))
		(remote-server-id-set! *runremote* (server:record->id server-info)))))  
	(set! runremote   *runremote*))) ;; new runremote will come from this on next iteration

  ;; ensure we have a homehost record
  (if (or (not (pair? (remote-hh-dat runremote)))  ;; not on homehost
	  (not (cdr (remote-hh-dat runremote))))   ;; not on homehost
      (thread-sleep! 0.1) ;; since we shouldn't get here, delay a little
      (let ((hh-data (server:choose-server areapath 'homehost)))
	(remote-hh-dat-set! runremote (or hh-data (cons #f #f)))))
  
  (cond
   ;; give up if more than 150 attempts
   ((> attemptnum 150)
    (debug:print 0 *default-log-port* "ERROR: 150 tries to start/connect to server. Giving up.")
    (exit 1))

   ;; readonly mode, read request-  handle it - case 2
   ((and readonly-mode
         (member cmd api:read-only-queries)) 
    (mutex-unlock! *rmt-mutex*)
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case 2")
    (rmt:open-qry-close-locally cmd 0 params)
    )

   ;; readonly mode, write request.  Do nothing, return #f
   (readonly-mode (extras-readonly-mode *rmt-mutex* *default-log-port* cmd params))

   ;; This block was for pre-emptively resetting the connection if there had been no communication for some time.
   ;; I don't think it adds any value. If the server is not there, just fail and start a new connection.
   ;; also, the expire-time calculation might not be correct. We want, time-since-last-server-access > (server:get-timeout)
   ;;
   ;; reset the connection if it has been unused too long
   ((and runremote
         (remote-api-url runremote)
	 (> (current-seconds) ;; if it has been more than server-timeout seconds since last contact, close this connection and start a new on
	    (+ (remote-last-access runremote)
	       (remote-server-timeout runremote))))
    (debug:print-info 0 *default-log-port* "Connection to " (remote-server-url runremote) " expired due to no accesses in " (remote-server-timeout runremote) " seconds, forcing new connection.")
    (http-transport:close-connections runremote)
    ;; moving this setting of runremote conndat to #f to inside the http-transport:close-connections
    ;; (remote-conndat-set! runremote #f) ;; invalidate the connection, thus forcing a new connection.
    (mutex-unlock! *rmt-mutex*)
    (rmt:send-receive cmd rid params attemptnum: attemptnum))
   
   ;; on homehost and this is a read
   ((and (not (remote-force-server runremote)) ;; honor forced use of server, i.e. server NOT required
	 (rmt:on-homehost? runremote)
         (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  5")
    (rmt:open-qry-close-locally cmd 0 params))

   ;; on homehost and this is a write, we already have a server
   ((and (not (remote-force-server runremote))     ;; honor forced use of server, i.e. server NOT required
	 (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 (needed to sync written data back)
    (mutex-unlock! *rmt-mutex*)
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case  4.1")
    (rmt:open-qry-close-locally cmd 0 params))

   ;;  on homehost, no server contact made and this is a write, passively start a server 
   ((and (not (remote-force-server runremote))     ;; honor forced use of server, i.e. server NOT required
	 (cdr (remote-hh-dat runremote))           ;; have homehost
         (not (remote-server-url runremote))       ;; no connection yet
	 (not (member cmd api:read-only-queries))) ;; not a read-only query
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case  8")
    (let ((server-info  (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-info
	  (begin
            (remote-server-url-set! runremote (server:record->url server-info)) ;; the string can be consumed by the client setup if needed
            (remote-server-id-set! runremote (server:record->id server-info)))  
	  (if (common:force-server?)
	      (server:start-and-wait *toppath*)
	      (server:kind-run *toppath*)))
      (remote-force-server-set! runremote (common:force-server?))
      (mutex-unlock! *rmt-mutex*)
      (debug:print-info 12 *default-log-port* "rmt:send-receive, case  8.1")
      (rmt:open-qry-close-locally cmd 0 params)))

   ;;DOT CASE9 [label="force server\nnot on homehost"];
   ;;DOT MUTEXLOCK -> CASE9 [label="no connection\nand either require server\nor not on homehost"]; {rank=same "case 9" CASE9};
   ;;DOT CASE9 -> "start\nserver" -> "rmt:send-receive";
   ((or (and (remote-force-server runremote)              ;; we are forcing a server and don't yet have a connection to one
	     (not (remote-api-url runremote)))
	(and (not (cdr (remote-hh-dat runremote)))        ;; not on a homehost 
	     (not (remote-api-url runremote))))           ;; and no connection
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case 9, hh-dat: " (remote-hh-dat runremote) " runremote: " (remote->alist runremote))
    (mutex-unlock! *rmt-mutex*)
    (if (not (server:check-if-running *toppath*)) ;; who knows, maybe one has started up?
	(server:start-and-wait *toppath*))
    ;; was: (remote-conndat-set! runremote (rmt:get-connection-info *toppath* runremote)) ;; calls client:setup which calls client:setup-http
    (set! runremote (rmt:get-connection-info *toppath* runremote)) ;; calls client:setup which calls client:setup-http
    (rmt:send-receive cmd rid params attemptnum: attemptnum)) ;; TODO: add back-off timeout as

   ;;DOT CASE10 [label="on homehost"];
   ;;DOT MUTEXLOCK -> CASE10 [label="server not required,\non homehost"]; {rank=same "case 10" CASE10};
   ;;DOT CASE10 -> "rmt:open-qry-close-locally";
   ;; all set up if get this far, dispatch the query
   ((and (not (remote-force-server runremote))
	 (cdr (remote-hh-dat runremote))) ;; we are on homehost
    (mutex-unlock! *rmt-mutex*)
    (debug:print-info 12 *default-log-port* "rmt:send-receive, case 10")
    (rmt:open-qry-close-locally cmd (if rid rid 0) params))

   ;;DOT CASE11 [label="send_receive"];
   ;;DOT MUTEXLOCK -> CASE11 [label="else"]; {rank=same "case 11" CASE11};
   ;;DOT CASE11 -> "rmt:send-receive" [label="call failed"];
   ;;DOT CASE11 -> "RESULT" [label="call succeeded"];
   ;; not on homehost, do server query
   (else (extras-case-11 *default-log-port* runremote cmd params attemptnum rid))))

;; bunch of small functions factored out of send-receive to make debug easier
;;

(define (extras-case-11 *default-log-port* runremote cmd params attemptnum rid)
  ;; (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-in  (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 runremote cmd params)
			     ;; (http-transport:client-api-send-receive 0 conninfo cmd params runremote)
			     ((servermismatch)  (vector #f "Server id mismatch" ))
			     ((commfail)(vector #f "communications fail"))
			     ((exn)(vector #f "other fail" (print-call-chain)))))
	 (dat      (if (and (vector? dat-in) ;; ... check it is a correct size
			    (> (vector-length dat-in) 1))
		       dat-in
		       (vector #f (conc "communications fail (type 2), dat-in=" dat-in))))
	 (success  (if (vector? dat) (vector-ref dat 0) #f))
	 (res      (if (vector? dat) (vector-ref dat 1) #f)))
    (if (and (remote? runremote)
	     (remote-api-url runremote)) ;; (and (vector? conninfo) (< 5 (vector-length conninfo)))
	(remote-last-access-set! runremote (current-seconds)) ;; refresh access time
	(begin
	  (debug:print 0 *default-log-port* "INFO: Should not get here! runremote="(remote->alist runremote))
	  ;; (set! conninfo #f)
	  (http-transport:close-connections runremote)))
    (debug:print-info 13 *default-log-port* "rmt:send-receive, case  9. runremote=" (remote->alist runremote) " dat=" dat " runremote = " runremote)
    (mutex-unlock! *rmt-mutex*)
    (if success ;; success only tells us that the transport was
	;; successful, have to examine the data to see if
	;; there was a detected issue at the other end
	(extras-transport-succeded *default-log-port* *rmt-mutex* attemptnum runremote res params rid cmd)
	(begin
           (debug:print-error 0 *default-log-port* " dat=" dat) 
           (extras-transport-failed *default-log-port* *rmt-mutex* attemptnum runremote cmd rid params))
	)))

(define (rmt:print-db-stats)
  (let ((fmtstr "~40a~7-d~9-d~20,2-f")) ;; "~20,2-f"
    (debug:print 18 *default-log-port* "DB Stats\n========")
    (debug:print 18 *default-log-port* (format #f "~40a~8a~10a~10a" "Cmd" "Count" "TotTime" "Avg"))
    (for-each (lambda (cmd)
		(let ((cmd-dat (hash-table-ref *db-stats* cmd)))

	  (if qry-is-write
	      (let ((start-time (current-seconds)))
		(mutex-lock! *db-multi-sync-mutex*)
/		(set! *db-last-access* start-time)  ;; THIS IS PROBABLY USELESS? (we are on a client)
                (mutex-unlock! *db-multi-sync-mutex*)))))
    res))

(define (rmt:send-receive-no-auto-client-setup runremote cmd run-id params)
  (let* ((run-id   (if run-id run-id 0))
	 (res  	   (http-transport:client-api-send-receive run-id runremote cmd params)))
    (if (and res (vector-ref res 0))
	(vector-ref res 1) ;;; YES!! THIS IS CORRECT!! CHANGE IT HERE, THEN CHANGE rmt:send-receive ALSO!!!
	#f)))

;;======================================================================
;;
;; A C T U A L   A P I   C A L L S  
;;
;;======================================================================

;;======================================================================

(define (rmt:login run-id)
  (rmt:send-receive 'login run-id (list *toppath* megatest-version (client:get-signature))))

;; This login does no retries under the hood - it acts a bit like a ping.
;; Deprecated for nmsg-transport.
;;
(define (rmt:login-no-auto-client-setup runremote)
  (rmt:send-receive-no-auto-client-setup runremote 'login 0 (list *toppath* megatest-version (client:get-signature))))

;; hand off a call to one of the db:queries statements
;; added run-id to make looking up the correct db possible 
;;
(define (rmt:general-call stmtname run-id . params)
  (rmt:send-receive 'general-call run-id (append (list stmtname run-id) params)))

	   (if runremote
	       (begin
		 (tt-ro-mode-set! runremote ro-mode)
		 (tt-ro-mode-checked-set! runremote #t)
		 ro-mode)
	       ro-mode))))))

(define (extras-readonly-mode rmt-mutex log-port cmd params)
  (mutex-unlock! rmt-mutex)
  (debug:print-info 12 log-port "rmt:send-receive, case 3")
  (debug:print 0 log-port "WARNING: write transaction requested on a readonly area.  cmd="cmd" params="params)
  #f)

(define (extras-transport-failed *default-log-port* *rmt-mutex* attemptnum runremote cmd rid params)
  (debug:print 0 *default-log-port* "WARNING: communication failed. Trying again, try num: " attemptnum)
  (mutex-lock! *rmt-mutex*)
  (http-transport:close-connections runremote)
  ;; (remote-server-url-set! runremote #f)
  (mutex-unlock! *rmt-mutex*)
  (debug:print-info 12 *default-log-port* "rmt:send-receive, case  9.1")
  (rmt:send-receive cmd rid params attemptnum: (+ attemptnum 1)))
  
(define (extras-transport-succeded *default-log-port* *rmt-mutex* attemptnum runremote res params rid cmd)
  (if (and (vector? res)
	   (eq? (vector-length res) 2)
	   (eq? (vector-ref res 1) 'overloaded)) ;; since we are
						 ;; looking at the
						 ;; data to carry the
						 ;; error we'll use a
						 ;; fairly obtuse
						 ;; combo to minimise
						 ;; the chances of
						 ;; some sort of
						 ;; collision.  this
						 ;; is the case where
						 ;; the returned data
						 ;; is bad or the
						 ;; server is
						 ;; overloaded and we
						 ;; want to ease off
						 ;; the queries
      (let ((wait-delay (+ attemptnum (* attemptnum 10))))
	(debug:print 0 *default-log-port* "WARNING: server is overloaded. Delaying " wait-delay " seconds and trying call again.")
	(mutex-lock! *rmt-mutex*)
	(http-transport:close-connections runremote)
	(set! *runremote* #f) ;; force starting over
	(mutex-unlock! *rmt-mutex*)
	(thread-sleep! wait-delay)
	(rmt:send-receive cmd rid params attemptnum: (+ attemptnum 1)))
      res)) ;; All good, return res

#;(set-functions rmt:send-receive                       remote-server-url-set!
	       http-transport:close-connections	      remote-conndat-set!
	       debug:print                            debug:print-info
	       remote-ro-mode                         remote-ro-mode-set!
	       remote-ro-mode-checked-set!            remote-ro-mode-checked)