Megatest

(define (cdb:use-non-blocking-mode proc)
  (set! *client-non-blocking-mode* #t)
  (let ((res (proc)))
    (set! *client-non-blocking-mode* #f)
    res))
  
;; params = 'target cached remparams
(define (cdb:client-call zmq-sockets . params)
  (debug:print-info 11 "cdb:client-call zmq-sockets=" zmq-sockets " params=" params)
  (let* ((push-socket (vector-ref zmq-sockets 0))
	 (sub-socket  (vector-ref zmq-sockets 1))
	 (query-id (conc (server:get-client-signature) "-" (message-digest-string (md5-primitive) (conc params))))
	 (zdat (db:obj->string (vector query-id params))) ;; (with-output-to-string (lambda ()(serialize params))))
	 (res  #f)

	 (get-res (lambda ()


		    (db:string->obj (if *client-non-blocking-mode* 
					(receive-message* zmq-socket)
					(receive-message  zmq-socket))))))
    (send-message zmq-socket zdat)
    (let loop ((res (get-res)))
      (if res res
	  (begin 
	    (thread-sleep! 0.5)
	    (get-res))))))
  
(define (cdb:set-verbosity zmq-socket val)
  (cdb:client-call zmq-socket 'set-verbosity #f val))

(define (cdb:login zmq-sockets keyval signature)
  (cdb:client-call zmq-sockets 'login #t keyval megatest-version signature))

(define (cdb:logout zmq-socket keyval signature)
  (cdb:client-call zmq-socket 'logout #t keyval signature))

(define (cdb:num-clients zmq-socket)
  (cdb:client-call zmq-socket 'numclients #t))

;;   1. client sends request to server via push to the pull port
;;   2. server puts request in queue or processes immediately as appropriate
;;   3. server puts responses from completed requests into pub port 
;;
;; TODO
;;
;; Done Tested
;; [x]  [ ]    1. Add columns pullport pubport to servers table
;; [x]  [ ]    2. Add rm of monitor.db if older than 11/12/2012 
;; [x]  [ ]    3. Add create of pullport and pubport with finding of available ports
;; [ ]  [ ]    4. Add client compose of request
;; [ ]  [ ]        - name of client: testname/itempath-test_id-hostname 
;; [ ]  [ ]        - name of request: callname, params
;; [ ]  [ ]        - request key: f(clientname, callname, params)
;; [ ]  [ ]    5. Add processing of subscription hits
;; [ ]  [ ]        - done when get key 

(define (server:get-client-signature)
  (if *my-client-signature* *my-client-signature*
      (let ((sig (server:mk-signature)))
	(set! *my-client-signature* sig)
	*my-client-signature*)))

;; 
(define (server:client-connect iface port #!key (context #f)(type 'req))
  (debug:print-info 3 "client-connect " iface ":" port)
  (let ((connect-ok #f)
	(zmq-socket (if context 
			(make-socket type context)
			(make-socket type)))
	(conurl     (server:make-server-url (list iface port))))
    (if (socket? zmq-socket)
	(begin
	  (connect-socket zmq-socket conurl)
	  zmq-socket)
	#f)))
  

(define (server:client-login zmq-sockets)
  (cdb:login zmq-sockets *toppath* (server:get-client-signature)))

(define (server:client-logout zmq-socket)
  (let ((ok (and (socket? zmq-socket)
		 (cdb:logout zmq-socket *toppath* (server:get-client-signature)))))
    ;; (close-socket zmq-socket)
    ok))

;; Do all the connection work, start a server if not already running
(define (server:client-setup #!key (numtries 50))
  (if (not *toppath*)
      (if (not (setup-for-run))
	  (begin
	    (debug:print 0 "ERROR: failed to find megatest.config, exiting")
	    (exit))))
  (let ((hostinfo   (open-run-close tasks:get-best-server tasks:open-db)))
    (if hostinfo
	(let ((host     (list-ref hostinfo 0))
	      (iface    (list-ref hostinfo 1))
	      (pullport (list-ref hostinfo 2))
	      (pubport  (list-ref hostinfo 3)))
	  (debug:print-info 2 "Setting up to connect to " hostinfo)
	  (handle-exceptions
	   exn
	   (begin
	     ;; something went wrong in connecting to the server. In this scenario it is ok
	     ;; to try again
	     (debug:print 0 "ERROR: Failed to open a connection to the server at: " hostinfo)
	     (debug:print 0 "   EXCEPTION: " ((condition-property-accessor 'exn 'message) exn))
	     (debug:print 0 "   perhaps jobs killed with -9? Removing server records")
	     (open-run-close tasks:server-deregister tasks:open-db host port: port)
	     (server:client-setup (- numtries 1))
	     #f)
	   (let* ((push-socket (server:client-connect iface pullport 'push))
		  (sub-socket  (server:client-connect iface pubport  'sub))
		  (zmq-sockets (vector push-socket sub-socket))
		  (login-res   #f)
		  ;; (connect-ok 
		  (conurl     (server:make-server-url (list iface port))))
	     (socket-option-set! sub-socket 'subscribe  (server:get-client-signature))
	     (set! login-res (server:client-login zmq-sockets))
	     (if (and (not (null? login-res))
		      (car login-res))
		 (begin
		   (debug:print-info 2 "Logged in and connected to " conurl)
		   (set! *runremote* zmq-socket)
		   #t)
		 (begin
		   (debug:print-info 2 "Failed to login or connect to " conurl)
		   (set! *runremote* #f)

;;======================================================================
;; Tasks db
;;======================================================================

(define (tasks:open-db)
  (let* ((dbpath  (conc *toppath* "/monitor.db"))
	 (exists  (if (file-exists? dbpath)
		      ;; BUGGISHNESS: Remove this code in six months. Today is 11/13/2012
		      (if (< (file-change-time dbpath) 1352851396.0)
			  (begin (delete-file dbpath) #f)
			  #t) #t))
	 (mdb     (sqlite3:open-database dbpath)) ;; (never-give-up-open-db dbpath))
	 (handler (make-busy-timeout 36000)))
    (sqlite3:set-busy-handler! mdb handler)
    (sqlite3:execute mdb (conc "PRAGMA synchronous = 0;"))
    (if (not exists)
	(begin
	  (sqlite3:execute mdb "CREATE TABLE IF NOT EXISTS tasks_queue (id INTEGER PRIMARY KEY,

                                hostname TEXT,
                                username TEXT,
                               CONSTRAINT monitors_constraint UNIQUE (pid,hostname));")
	  (sqlite3:execute mdb "CREATE TABLE IF NOT EXISTS servers (id INTEGER PRIMARY KEY,
                                  pid INTEGER,
                                  interface TEXT,
                                  hostname TEXT,
                                  pullport INTEGER,
                                  pubport  INTEGER,
                                  start_time TIMESTAMP,
                                  priority INTEGER,
                                  state TEXT,
                                  mt_version TEXT,
                                  heartbeat TIMESTAMP,
                               CONSTRAINT servers_constraint UNIQUE (pid,hostname,port));")
	  (sqlite3:execute mdb "CREATE TABLE IF NOT EXISTS clients (id INTEGER PRIMARY KEY,

  (let ((res '())
	(best #f))
    (sqlite3:for-each-row
     (lambda (id hostname interface port pid)
       (set! res (cons (list hostname interface port pid) res))
       (debug:print-info 2 "Found existing server " hostname ":" port " registered in db"))
     mdb
     "SELECT id,hostname,interface,pullport,pubport,pid FROM servers WHERE state='live' AND mt_version=? ORDER BY start_time ASC LIMIT 1;" megatest-version)
    ;; (print "res=" res)
    (if (null? res) #f
	(let loop ((hed (car res))
		   (tal (cdr res)))
	  ;; (print "hed=" hed ", tal=" tal)
	  (let* ((host     (list-ref hed 0))
		 (iface    (list-ref hed 1))
		 (pullport (list-ref hed 2))
		 (pubport  (list-ref hed 3))
		 (pid      (list-ref hed 4))
		 (alive    (open-run-close tasks:server-alive? tasks:open-db #f hostname: host pullport: pullport)))
	    (if alive
		(begin
		  (debug:print-info 2 "Found an existing, alive, server " host ", " pullport " and " pubport ".")
		  (list host iface pullport pubport))
		(begin
		  (debug:print-info 1 "Marking " host ":" pullport " as dead in server registry.")
		  (if port
		      (open-run-close tasks:server-deregister tasks:open-db host pullport: pullport)
		      (open-run-close tasks:server-deregister tasks:open-db host pid:  pid))
		  (if (null? tal)
		      #f
		      (loop (car tal)(cdr tal))))))))))

(define (tasks:mark-server hostname pullport pid state)
  (if port
      (open-run-close tasks:server-deregister tasks:open-db hostname port: port)
      (open-run-close tasks:server-deregister tasks:open-db hostname pid:  pid)))


;; NOTE: NOT PORTED TO WORK WITH pullport/pubport
(define (tasks:kill-server status hostname port pid)
  (debug:print-info 1 "Removing defunct server record for " hostname ":" port)
  (if port
      (open-run-close tasks:server-deregister tasks:open-db hostname port: port)
      (open-run-close tasks:server-deregister tasks:open-db hostname pid:  pid))
  (if status ;; #t means alive
      (begin