Megatest

	 (tmpdb       (db:get-db dbstruct))
	 (refndb      (dbr:dbstruct-refndb dbstruct)))
    (db:sync-tables (db:sync-all-tables-list dbstruct) last-update tmpdb refndb mtdb)))

;;;; run-ids
;;    if #f use *db-local-sync* : or 'local-sync-flags
;;    if #t use timestamps      : or 'timestamps
;;
;;  NB// no-sync-db is the db handle, not a flag!
;;
(define (db:sync-to-megatest.db dbstruct #!key (no-sync-db #f)) 
  (let* ((start-time         (current-seconds))
	 (last-full-update   (if no-sync-db
				 (db:no-sync-get/default no-sync-db "LAST_FULL_UPDATE" 0)
				 0))
	 (full-sync-needed   (> (- start-time last-full-update) 3600)) ;; every hour do a full sync
	 (last-update        (if full-sync-needed
				 0
				 (if no-sync-db
				     (db:no-sync-get/default no-sync-db "LAST_UPDATE" 0)
				     0))) ;; (or (db:get-var dbstruct "LAST_UPDATE") 0))
	 (sync-needed        (> (- start-time last-update) 6))
	 (res                (if (or sync-needed ;; don't sync if a sync already occurred in the past 6 seconds
				     full-sync-needed)
				 (begin
				   (if no-sync-db
				       (begin
					 (if full-sync-needed (db:no-sync-set no-sync-db "LAST_FULL_UPDATE" start-time))
					 (db:no-sync-set no-sync-db "LAST_UPDATE" start-time)))
				   (db:tmp->megatest.db-sync dbstruct last-update))
				 0))
	 (sync-time           (- (current-seconds) start-time)))
      (debug:print-info 3 *default-log-port* "Sync of newdb to olddb completed in " sync-time " seconds pid="(current-process-id))
      (if (common:low-noise-print 30 "sync new to old")
          (if sync-needed
              (debug:print-info 0 *default-log-port* "Sync of " res " records from newdb to olddb completed in " sync-time " seconds pid="(current-process-id))

;;======================================================================
;; no-sync.db - small bits of data to be shared between servers
;;======================================================================

(define (db:open-no-sync-db)
  (let* ((dbpath (db:dbfile-path))
	 (dbname (conc dbpath "/no-sync.db"))
	 (db-exists (common:file-exists? dbname))
	 (db     (sqlite3:open-database dbname)))
    (sqlite3:set-busy-handler! db (make-busy-timeout 136000))
    (if (not db-exists)
	(begin
	  (sqlite3:execute db "PRAGMA synchronous = 0;")
	  (sqlite3:execute db "CREATE TABLE IF NOT EXISTS no_sync_metadat (var TEXT,val TEXT, CONSTRAINT no_sync_metadat_constraint UNIQUE (var));")
	  (sqlite3:execute db "PRAGMA journal_mode=WAL;")))
    db))

;; if we are not a server create a db handle. this is not finalized
;; so watch for problems. I'm still not clear if it is needed to manually
;; finalize sqlite3 dbs with the sqlite3 egg.
;;
(define (db:no-sync-db db-in)
  (mutex-lock! *db-access-mutex*)
  (let ((res (if db-in
                 db-in
                 (let ((db (db:open-no-sync-db)))
                   (set! *no-sync-db* db)
                   db))))
    (mutex-unlock! *db-access-mutex*)
    res))

(define (db:no-sync-set db var val)
  (sqlite3:execute (db:no-sync-db db) "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES (?,?);" var val))

(define (db:no-sync-del! db var)
  (sqlite3:execute (db:no-sync-db db) "DELETE FROM no_sync_metadat WHERE var=?;" var))

          (if newres
              newres
              res))
        res)))

(define (db:no-sync-close-db db)
  (db:safely-close-sqlite3-db db))

;; transaction protected lock aquisition
;; either:
;;    fails    returns  (#f . lock-creation-time)
;;    succeeds (returns (#t . lock-creation-time)
;; use (db:no-sync-del! db keyname) to release the lock
;;
(define (db:no-sync-get-lock db-in keyname)
  (let ((db (db:no-sync-db db-in)))
    (sqlite3:with-transaction
     db
     (lambda ()
       (handle-exceptions
	   exn
	   (let ((lock-time (current-seconds)))
	     (sqlite3:execute db "INSERT INTO no_sync_metadat (var,val) VALUES(?,?);" keyname lock-time)
	     `(#t . ,lock-time))
	 `(#f . ,(sqlite3:first-result db "SELECT val FROM no_sync_metadat WHERE var=?;" keyname)))))))



;; use a global for some primitive caching, it is just silly to
;; re-read the db over and over again for the keys since they never
;; change

;; why get the keys from the db? why not get from the *configdat*
;; using keys:config-get-fields?