Megatest

	    (format   . f)  ;; sb=serialized-base64, t=text, sx=sexpr, j=json
	    (data     . d)  ;; base64 encoded slln data
	    )))

;; struct for keeping track of our world

(defstruct udat
  ;; captain info
  (captain-address #f)
  (captain-host    #f)
  (captain-port    #f)
  (captain-pid     #f)
  (ulex-dir        (conc (get-environment-variable "HOME") "/.ulex"))
  (cpkts-dir       (conc (get-environment-variable "HOME") "/.ulex/pkts"))
  (cpkt-spec       *captain-pktspec*)
  ;; this processes info
  (my-cpkt-key     #f)   ;; put Z card here when I create a pkt for myself as captain
  (my-address      #f)
  (my-hostname     #f)
  (my-port         #f)
  (my-pid          (current-process-id))
  ;; server and handler thread
  (serv-listener   #f)                 ;; this processes server info
  (handler-thread  #f)
  (handlers        (make-hash-table))
  (outgoing-conns  (make-hash-table))  ;; host:port -> conn
  ;; app info
  (appname         #f)
  (dbtypes         (make-hash-table))  ;; this should be an alist but hash is easier. dbtype => [ initproc syncproc ]
  )

;; struct for keeping track of others we are talking to

(defstruct peer
  (addr-port       #f)
  (hostname        #f)

;; add a proc to the handler list
(define (register-handler udata key proc)
  (hash-table-set! (udat-handlers udata) key proc))


;;======================================================================
;; Generic db handling
;;======================================================================

(defstruct dbconn
  (inmem  #f)
  (conn   #f)
  (sync   #f) ;; sync proc
  (init   #f) ;; init proc
  (lastsync (current-seconds))
  )

(defstruct dbinfo
  (initproc #f)
  (syncproc #f))

;; open inmem and disk database
;;   init with initproc
;;   return db struct
;;
;;   appname; megatest, ulex or something else.
;;
(define (setup-db-connection udata fname-in appname dbtype)
  (let* ((is-ulex (eq? appname 'ulex))
	 (dbinf   (if is-ulex ;; ulex is a built-in special case
		      (make-dbinfo initproc: ulexdb-init syncproc: ulexdb-sync)
		      (hash-table-ref/default (udat-dbtypes udata) dbtype #f)))
	 (initproc (dbinfo-initproc dbinf))
	 (syncproc (dbinfo-syncproc dbinf))
	 (fname   (if is-ulex
		      (conc (udat-ulex-dir udata) "/ulex.db")
		      fname-in))
	 (inmem-db (open-and-initdb udata #f 'inmem (dbinfo-initproc dbinf)))
	 (disk-db  (open-and-initdb udata fname 'disk (dbinfo-initproc dbinf))))
    (make-dbconn inmem: inmem-db conn: disk-db sync: syncproc init: initproc)))

;; dest='inmem or 'disk
;;
(define (open-and-initdb udata filename dest init-proc)
  (let* ((inmem    (eq? dest 'inmem))
	 (dbfile   (if inmem
		       ":INMEM:"
		       filename))
	 (dbexists (if inmem #t (file-exists? dbfile)))
	 (db       (sqlite3:open-database dbfile)))
    (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
    (if (not dbexists)
	(init-proc db))
    db))


;;======================================================================
;; Ulex db
;;======================================================================

(define (ulexdb-init db inmem)
  (sqlite3:with-transaction
   db
   (lambda ()
     (for-each
      (lambda (stmt)
	(if stmt (sqlite3:execute db stmt)))
      `("CREATE TABLE IF NOT EXISTS processes 
                 (id INTEGER PRIMARY KEY,
                  host  TEXT NOT NULL,
                  ipadr TEXT NOT NULL,
                  port  INTEGER NOT NULL,
                  pid   INTEGER NOT NULL,
                  regtime INTEGER DEFAULT (strftime('%s','now')),
                  last_update INTEGER DEFAULT (strftime('%s','now')));"
	(if inmem
	    "CREATE TRIGGER  IF NOT EXISTS update_proces_trigger AFTER UPDATE ON processes
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE processes SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;"
	    #f))))))


;; open databases, do initial sync
(define (ulexdb-sync dbconndat udata)
  #f)


;;======================================================================
;; connection setup and management functions
;;======================================================================

;; find or become the captain, return a ulex object