Megatest

(declare (uses commonmod))
(declare (uses configfmod))
(declare (uses mtargs))
(declare (uses mtver))
(declare (uses dbmod))
(declare (uses stml2))
(declare (uses portloggermod))
(declare (uses pkts))

(module http-transportmod
	*
	
(import scheme
	(prefix sqlite3 sqlite3:)
	chicken.base

	commonmod
	configfmod
	debugprint
	mtver
	dbmod
	stml2
	portloggermod
	pkts
	
	)

;; (require-extension (srfi 18) extras tcp s11n)
;; 
;; 
;; (use  srfi-1 posix regex regex-case srfi-69 hostinfo md5 message-digest posix-extras)
;; 
;; (use spiffy uri-common intarweb http-client spiffy-request-vars intarweb spiffy-directory-listing)
;; 
;; Configurations for server
(tcp-buffer-size 2048)
(max-connections 2048) 

















(define (http-transport:make-server-url hostport)
  (if (not hostport)
      #f
      (conc "http://" (car hostport) ":" (cadr hostport))))

;;======================================================================
;; S E R V E R
;; ======================================================================

;; NOTE: http-transport:launch is the entry point
;;          -> http-transport:run
;;             -> http-transport:try-start-server -> http-transport:try-start-server (until success)

(define (http-get-function fnkey)
  (hash-table-ref/default *http-functions* fnkey (lambda () "nothing here yet")))

(define (http-transport:run hostn)
  ;; Configurations for server
  (tcp-buffer-size 2048)

				   (send-response body: ((http-get-function 'http-transport:html-test-log) $) 
						  headers: '((content-type text/HTML))))    
                                  ((equal? (uri-path (request-uri (current-request))) 
					   '(/ "dashboard"))
				   (send-response body: ((http-get-function 'http-transport:html-dboard) $)
						  headers: '((content-type text/HTML)))) 
				  (else (continue))))))))
    #;(handle-exceptions
	exn
      (debug:print 0 *default-log-port* "Failed to create file " start-file ", exn=" exn)
      (with-output-to-file start-file (lambda ()(print (current-process-id)))))
    (http-transport:try-start-server ipaddrstr start-port)))

;; This is recursively run by http-transport:run until sucessful
;;

;;
(define (http-transport:client-connect iface port server-id) 
  (let* ((api-url      (conc "http://" iface ":" port "/api"))
	 (api-uri      (uri-reference (conc "http://" iface ":" port "/api")))
	 (api-req      (make-request method: 'POST uri: api-uri))
	 (server-dat   (vector iface port api-uri api-url api-req (current-seconds) server-id)))
    server-dat))

;;======================================================================
;; NEW SERVER METHOD
;;======================================================================

(define *srvpktspec*
  `((server (host    . h)
	    (port    . p)
	    (servkey . k)
	    (pid     . i)
	    (ipaddr  . a)
	    (dbpath  . d))))

(define (register-server pkts-dir pkt-spec host port servkey ipaddr dbpath)
  (let* ((pkt-dat `((host    . ,host)
		    (port    . ,port)
		    (servkey . ,servkey)
		    (pid     . ,(current-process-id))
		    (ipaddr  . ,ipaddr)
		    (dbpath  . ,dbpath))))
    (write-alist->pkt
     pkts-dir
     pkt-dat
     pktspec: pkt-spec
     ptype: 'server)))

;; ya, fake it for now
;;
(define (register-server-in-db db-file)
  #t)

;; load up the db into inmem
;;
(define (load-up-database db-file)
  (let* ((db (db:open-db db-file)))
    db))

(define (get-pkts-dir)
  (assert *toppath* "ERROR: get-pkts-dir called without *toppath* set. Exiting.")
  (let* ((pdir (conc *toppath* "/.meta/srvpkts")))
     (if (file-exists? pdir)
	 pdir
	 (begin
	   (create-directory pdir #t)
	   pdir))))

;; given a pkts dir read 
;;
(define (get-all-server-pkts pktsdir-in pktspec)
  (let* ((pktsdir  (if (file-exists? pktsdir-in)
		       pktsdir-in
		       (begin
			 (create-directory pktsdir-in #t)
			 pktsdir-in)))
	 (all-pkt-files (glob (conc pktsdir "/*.pkt"))))
    (map (lambda (pkt-file)
	   (read-pkt->alist pkt-file pktspec: pktspec))
	 all-pkt-files)))

(define (server-address srv-pkt)
  (conc (alist-ref 'host srv-pkt) ":"
	(alist-ref 'port srv-pkt)))
	
(define (server-ready? server-address)
  ;; ping the server and ask it
  ;; if it ready
  #f)

;; from the pkts return servers associated with dbpath
;; NOTE: Only one can be alive - have to check on each
;;       in the list of pkts returned
;;
(define (get-viable-servers serv-pkts dbpath)
  (let loop ((tail serv-pkts)
	     (res  '()))
    (if (null? tail)
	res ;; NOTE: sort by age so oldest is considered first
	(let* ((spkt (car tail)))
	  (loop (cdr tail)
		(if (equal? dbpath (alist-ref 'dbpath spkt))
		    (cons spkt res)
		    res))))))

;; from viable servers get one that is alive and ready
;;
(define (get-the-server serv-pkts dbpath)
  (let loop ((tail serv-pkts))
    (if (null? tail)
	#f
	(let* ((spkt (car tail))
	       (addr (server-address spkt)))
	  (if (server-ready? addr)
	      spkt
	      (loop (cdr tail)))))))

;; am I the "first" in line server? I.e. my D card is smallest
;; use Z card as tie breaker
;;
(define (get-best-candidate serv-pkts dbpath)
  (if (null? serv-pkts)
      #f
      (let loop ((tail serv-pkts)
		 (best  (car serv-pkts)))
	(if (null? tail)
	    best
	    (let* ((candidate (car tail))
		   (candidate-bd (string->number (alist-ref 'D candidate)))
		   (best-bd      (string->number (alist-ref 'D best)))
		   ;; bigger number is younger
		   (candidate-z  (alist-ref 'Z candidate))
		   (best-z       (alist-ref 'Z best))
		   (new-best     (cond
				  ((> best-bd candidate-bd) ;; best is younger than candidate
				   candidate)
				  ((< best-bd candidate-bd) ;; candidate is younger than best
				   best)
				  (else
				   (if (string>=? best-z candidate-z)
				       best
				       candidate))))) ;; use Z card as tie breaker
	      (if (null? tail)
		  new-best
		  (loop (cdr tail) new-best)))))))
	  
	  

;;======================================================================
;; END NEW SERVER METHOD
;;======================================================================

;; run http-transport:keep-running in a parallel thread to monitor that the db is being 
;; used and to shutdown after sometime if it is not.
;;
(define (http-transport:keep-running) 
  ;; if none running or if > 20 seconds since 
  ;; server last used then start shutdown
  ;; This thread waits for the server to come alive
  (debug:print-info 0 *default-log-port* "Starting the sync-back, keep alive thread in server")
  (let* ((sdat              #f)
	 (tmp-area          (common:get-db-tmp-area))
	 (started-file      (conc tmp-area "/.server-started"))
	 (server-start-time (current-seconds))
	 (pkts-dir          (get-pkts-dir))
	 (server-key        (server:mk-signature))
	 (db-file           (conc *toppath* "/.db/" (or (args:get-arg "-db") "main.db")))
	 (server-info (let loop ((start-time (current-seconds))
				 (changed    #t)
				 (last-sdat  "not this"))
                        (begin ;; let ((sdat #f))
			  (thread-sleep! 0.01)
			  (debug:print-info 0 *default-log-port* "Waiting for server alive signature")
                          (mutex-lock! *heartbeat-mutex*)
                          (set! sdat *server-info*)
                          (mutex-unlock! *heartbeat-mutex*)
                          (if (and sdat
				   (not changed)
				   (> (- (current-seconds) start-time) 2))
			      (begin
				(debug:print-info 0 *default-log-port* "Received server alive signature, now attempting to lock in server")
				;; create a server pkt in *toppath*/.meta/srvpkts
				(register-server pkts-dir *srvpktspec* (get-host-name) (cadr sdat) server-key (car sdat) db-file)

				;; now read pkts and see if we are a contender
				(let* ((all-pkts     (get-all-server-pkts pkts-dir *srvpktspec*))
				       (viables      (get-viable-servers all-pkts db-file))
				       (best-srv     (get-best-candidate viables db-file))
				       (best-srv-key (if best-srv (alist-ref 'servkey best-srv) #f)))
				  ;; am I the best-srv, compare server-keys to know
				  (if (and (equal? best-srv-key server-key)
					   (register-server-in-db db-file))
				      (load-up-database db-file)          ;; ready to go!
				      (bdat-time-to-exit-set! *bdat* #t)) ;; nope, we are not needed, exit when can do
				  sdat))
                              (begin
				(debug:print-info 0 *default-log-port* "Still waiting, last-sdat=" last-sdat)
                                (sleep 4)
				(if (> (- (current-seconds) start-time) 120) ;; been waiting for two minutes
				    (begin
				      (debug:print-error 0 *default-log-port* "transport appears to have died, exiting server")
                                      #;(common:save-pkt `((action . died)
                                                         (T      . server)
                                                         (pid    . ,(current-process-id))
                                                         (ipaddr . ,(car sdat))
                                                         (port   . ,(cadr sdat))
                                                         (msg    . "Transport died?"))
						       *configdat* #t)
				      (exit))

      (if (not server-going) ;; *dbstruct-db* 
	  (let ((watchdog (bdat-watchdog *bdat*)))
	    (debug:print 0 *default-log-port* "SERVER: dbprep")
	    (set! *dbstruct-db*  (db:setup #t)) ;;  run-id))
	    (set! server-going #t)
	    (debug:print 0 *default-log-port* "SERVER: running, megatest version: " (common:get-full-version)) ;; NOTE: the server is NOT yet marked as running in the log. We do that in the keep-running routine.
	    (if watchdog
		(if (not (member (thread-state watchdog) '(ready running blocked sleeping dead)))
		    (begin
		      (debug:print-info 0 "Starting watchdog thread (in state "(thread-state watchdog)")")
		      (thread-start! watchdog)))
		(debug:print 0 *default-log-port* "ERROR: *watchdog* not setup, cannot start it."))))
      
      ;; when things go wrong we don't want to be doing the various queries too often
      ;; so we strive to run this stuff only every four seconds or so.
      (let* ((sync-time (- (current-milliseconds) start-time))
	    (rem-time  (quotient (- 4000 sync-time) 1000)))
	(if (and (<= rem-time 4)

		  (current-seconds)))
          (if (common:low-noise-print 120 "server continuing")
              (debug:print-info 0 *default-log-port* "Server continuing, seconds since last db access: " (- (current-seconds) last-access))
	      (let ((curr-time (current-seconds)))
		(handle-exceptions
		    exn
		    (debug:print 0 *default-log-port* "ERROR: Failed to change timestamp on log file " server-log-file ". Are you out of space on that disk? exn=" exn)
		  (if (and server-log-file (not *server-overloaded*))
		      (set-file-times! server-log-file curr-time curr-time)))))
          (loop 0 server-state bad-sync-count (current-milliseconds)))
         (else
          (debug:print-info 0 *default-log-port* "Server timed out. seconds since last db access: " (- (current-seconds) last-access))
          (http-transport:server-shutdown port)))))))

(define (http-transport:server-shutdown port)

    (db:print-current-query-stats)
    (common:save-pkt `((action . exit)
                       (T      . server)
                       (pid    . ,(current-process-id)))
                     *configdat* #t)
    (debug:print-info 0 *default-log-port* "Server shutdown complete. Exiting")
    (exit)))

;; Call this to start the actual server
;;

;; all routes though here end in exit ...
;;
;; start_server? 
;;
(define (http-transport:launch)

  (let* ((tmp-area            (common:get-db-tmp-area))
	 (server-start        (conc tmp-area "/.server-start"))
	 (server-started      (conc tmp-area "/.server-started"))
	 (start-time          (common:lazy-modification-time server-start))
	 (started-time        (common:lazy-modification-time server-started))
	 (server-starting     (< start-time started-time)) ;; if start-time is less than started-time then a server is still starting
	 (start-time-old      (> (- (current-seconds) start-time) 5))
         (cleanup-proc        (lambda (msg)
                                (let* ((serv-fname      (conc "server-" (current-process-id) "-" (get-host-name) ".log"))
                                       (full-serv-fname (conc *toppath* "/logs/" serv-fname))
                                       (new-serv-fname  (conc *toppath* "/logs/" "defunct-" serv-fname)))
                                  (debug:print 0 *default-log-port* msg)
                                  (if (common:file-exists? full-serv-fname)
                                      (system (conc "sleep 1;mv -f " full-serv-fname " " new-serv-fname))
                                      (debug:print 0 *default-log-port* "INFO: cannot move " full-serv-fname " to " new-serv-fname))
                                  (exit)))))











    (common:save-pkt `((action . start)
		       (T      . server)
		       (pid    . ,(current-process-id)))
		     *configdat* #t)
    (let* ((th2 (make-thread (lambda ()
                               (debug:print-info 0 *default-log-port* "Server run thread started")
                               (http-transport:run 
                                (if (args:get-arg "-server")
                                    (args:get-arg "-server")
                                    "-")
                                )) "Server run"))

;; 			     (debug:print 0 *default-log-port* "       Done.")
;; 			     (exit 4))
;; 			   "exit on ^C timer")))
;;      (thread-start! th2)
;;      (thread-start! th1)
;;      (thread-join! th2))))













	    
;; Generate a unique signature for this server
(define (server:mk-signature)
  (message-digest-string (md5-primitive) 
			 (with-output-to-string
			   (lambda ()
			     (write (list (current-directory)