Megatest

  (let* ((parent-dir (pathname-directory dbfile)))
    (if (not (directory-exists? parent-dir))
	(create-directory parent-dir #t))
    (let* ((exists  (file-exists? dbfile))
	   (db      (sqlite3:open-database dbfile))
	   (handler (sqlite3:make-busy-timeout 3600)))
      (sqlite3:set-busy-handler! db handler)
      ;; (db:set-sync db) ;; we don't mind that this is slow?
      (if (not exists)
	  (dbinit-proc db))
      db)))
    
;; open and initialize the inmem db
;; NOTE: Does NOT sync in the data from the disk db
;;

  (db:with-lock-db dbfile
		(lambda (dbh dbfile)
		  (db:get-iam-server-lock dbh dbfile))))

(define (db:with-lock-db dbfile proc)
  (let* ((dbh (db:open-run-db dbfile db:initialize-db))
	 (res (proc dbh dbfile)))
    ;; (sqlite3:finalize! dbh)
    res))

;; called before db is open?
;;
(define (db:get-iam-server-lock dbh dbfname)
  (sqlite3:with-transaction
   dbh

(define (db:sync-inmem->disk dbstruct apath dbfile #!key (force-sync #f))
  (let* ((dbdat       (db:get-dbdat dbstruct apath dbfile))
	 (db          (dbr:dbdat-db dbdat))
	 (inmem       (dbr:dbdat-inmem dbdat))
	 (start-t     (current-seconds))
	 (last-update (dbr:dbdat-last-write dbdat))
	 (last-sync   (dbr:dbdat-last-sync dbdat)))
    (debug:print-info 0 *default-log-port* "Syncing for dbfile: "dbfile", last-update: "last-update", last-sync: "last-sync)
    (mutex-lock! *db-multi-sync-mutex*)
    (let* ((update_info (cons "last_update" (if force-sync 0 last-update))) ;;  "last_update"))
    	   (need-sync   (or force-sync (>= last-update last-sync))))
       (if need-sync
	   (begin
	     (db:sync-tables (db:sync-all-tables-list) update_info inmem db)
	     (dbr:dbdat-last-sync-set! dbdat start-t))
	  (debug:print 0 *default-log-port* "Skipping sync as nothing touched.")))

    (mutex-unlock! *db-multi-sync-mutex*)))

;; TODO: Add final sync to this
;;
(define (db:safely-close-sqlite3-db db stmt-cache #!key (try-num 3))
  (if (<= try-num 0)
      #f

(define (db:sync-one-table fromdb todb tabledat last-update numrecs)
  (let* ((tablename        (car tabledat))
	 (fields           (cdr tabledat))
	 (has-last-update  (member "last_update" fields))
	 (use-last-update  (cond
			    ((and has-last-update
				  (number? last-update))
			     #t) ;; if given a number, just use it for all fields

			    ((and (pair? last-update)
				  (member (car last-update)    ;; last-update field name
					  (map car fields)))
			     #t)
			    ((and (pair? last-update)
				  (not (number? (cdr last-update))))
			     (debug:print 0 *default-log-port* "ERROR: parameter last-update malformed. last-update="last-update)
			     #f)
			    ((and (pair? last-update)
				  (string? (car last-update))) ;; valid format, field not recognised
			     #f)
			    ((number? last-update) #f) ;; if not matched first entry then ignore last-update for this table
			    (last-update
			     (debug:print 0 *default-log-port* "ERROR: parameter last-update for db:sync-tables must be a pair or a number, received: " last-update);; found in fields
			     #f)
			    (else
			     #f)))
	 (last-update-value (if use-last-update ;; no need to check for has-last-update - it is already accounted for
				(if (number? last-update)

      (if should-print (debug:print 3 *default-log-port* "INFO: db sync, total run time " runtime " ms"))
      (for-each 
       (lambda (dat)
	 (let ((tblname (car dat))
	       (count   (cdr dat)))
	   (set! tot-count (+ tot-count count))
	   (if (> count 0)
	       (if should-print (debug:print 0 *default-log-port* "   "tblname" "count))))) ;; (format #f "    ~10a ~5a" tblname count))))))
       (sort (hash-table->alist numrecs)(lambda (a b)(> (cdr a)(cdr b))))))
    tot-count))

(define (db:patch-schema-rundb frundb)
  ;;
  ;; remove this some time after September 2016 (added in version v1.6031
  ;;

		(debug:print-info 0 *default-log-port* "Server already running at "sinfo ", while trying to register server " host":"port)
		#f) ;; server already registered
	      (begin
		(sqlite3:execute db "INSERT INTO servers (host,port,servkey,pid,ipaddr,apath,dbname) VALUES (?,?,?,?,?,?,?);"
				 host port servkey pid ipaddr apath dbname)
		(db:get-server-info dbstruct apath dbname)))))))))
  
;; run this one in a transaction where first check if host:port is taken
(define (db:deregister-server dbstruct host port servkey pid ipaddr apath dbname)
  (db:with-db
   dbstruct
   #f #f
   (lambda (db)
     (sqlite3:with-transaction
      db
      (lambda ()
	(let* ((sinfo      (db:get-server-info dbstruct apath dbname)))
	  (if (not sinfo)
	      (begin
		(debug:print-info 0 *default-log-port* "Server already removed for "apath", "dbname) ;; at "sinfo ", while trying to register server " host":"port)
		#f) ;; server already deregistered
	      (begin
		(sqlite3:execute db "DELETE FROM servers WHERE apath=? AND dbname=?;" ;; (host,port,servkey,pid,ipaddr,apath,dbname) VALUES (?,?,?,?,?,?,?);"
				 ;; host port servkey pid ipaddr
				 apath dbname)
		#;(db:get-server-info dbstruct apath dbname)))))))))

(define (db:get-server-info dbstruct apath dbname)
  (db:with-db
   dbstruct
   #f #f
   (lambda (db)
     (sqlite3:fold-row
      (lambda (res host port servkey pid ipaddr apath dbpath)
	(list host port servkey pid ipaddr apath dbpath))
      #f
      db
      "SELECT host,port,servkey,pid,ipaddr,apath,dbname FROM servers WHERE apath=? AND dbname=?;"
      apath dbname))))

(define (db:get-count-servers dbstruct apath)
  (db:with-db
   dbstruct
   #f #f
   (lambda (db)
     (sqlite3:fold-row
      (lambda (res count)
	(max res count))
      0
      db
      "SELECT count(*) FROM servers WHERE apath=?;"
      apath))))

)