Megatest

;; return the target db handle so it can be used
;;
(define (db:cache-for-read-only source target #!key (use-last-update #f))
  (if (and (hash-table-ref/default *global-db-store* target #f)
	   (>= (file-modification-time target)(file-modification-time source)))
      (hash-table-ref *global-db-store* target)
      (let* ((toppath   (launch:setup))
	     (targ-db-last-mod (db:get-sqlite3-mod-time target))
;;	      (if (common:file-exists? target)
;; BUG: This needs to include wal mode stuff .shm etc.
;;				   (file-modification-time target)
;;				   0))
	     (cache-db  (or (hash-table-ref/default *global-db-store* target #f)
			    (db:open-megatest-db path: target)))
	     (source-db (db:open-megatest-db path: source))
	     (curr-time (current-seconds))
	     (res      '())
	     (last-update (if use-last-update (cons "last_update" targ-db-last-mod) #f)))
	(db:sync-tables (db:sync-main-list source-db) last-update source-db cache-db)

;; 			  megatest-db
;; 			  (conc cache-dir "/" fname)
;; 			  use-last-update: #t)))
;; 	  (thread-start! th1)
;; 	  (apply proc cache-db params)
;; 	  ))))

(define (db:get-sqlite3-mod-time fname)
  (let* ((wal-file (conc fname "-wal"))
	 (shm-file (conc fname "-shm"))
	 (get-mtime (lambda (f)
		      (if (and (file-exists? f)
			       (file-read-access? f))
			  (file-modification-time f)
			  0))))
    (max (get-mtime fname)
	 (get-mtime wal-file)
	 (get-mtime shm-file))))
	 
(define (db:all-db-sync dbstruct)
  (let* ((dbdat (db:open-db dbstruct #f db:initialize-main-db))
	 (data-synced       0) ;; count of changed records
    (tmp-area       (common:get-db-tmp-area))
    (dbfiles        (glob (conc tmp-area"/.megatest/*.db")))
    (sync-durations (make-hash-table))
    (no-sync-db        (db:open-no-sync-db)))
    (for-each
     (lambda (file) ;; tmp db file
       (debug:print-info 3 *default-log-port* "file: " file)
       (let* ((fname       (conc (pathname-file file) ".db")) ;; fname is tmp db file
              (wal-file (conc fname "-wal"))
              (shm-file (conc fname "-shm"))
	      (fulln       (conc *toppath*"/.megatest/"fname)) ;; fulln is nfs db name
              (wal-time     (if (file-exists? wal-file)             
			       (file-modification-time wal-file)
                               0))
              (shm-time     (if (file-exists? shm-file)             
			       (file-modification-time shm-file)
                               0))
	      (time1        (db:get-sqlite3-mod-time file))
;;	       (if (file-exists? file)              ;; time1 is the max itime of the tmp db, -wal and -shm files.
;;			       (max (file-modification-time file) wal-time shm-time)
;;			       (begin
;;				 (debug:print-info 2 *default-log-port* "Sync - I do not see file "file)
;;			   1)))
	      (time2       (db:get-sqlite3-mod-time fulln))
;;	      (if (file-exists? fulln)             ;; time2 is nfs file time
;;			       (file-modification-time fulln)
;;			       (begin
;;				 (debug:print-info 2 *default-log-port* "Sync - I do not see file "fulln)
;;				 0)))
	      (changed      (> (- time1 time2) (+ (random 5) 1)))  ;; it has been at some few seconds since last synced
	      (changed10    (> (- time1 time2) 10)) ;; it has been at least ten seconds since sync'd
	      (jfile-exists (file-exists? (conc file"-journal"))) ;; i.e. are we busy?
	      (do-cp        (cond
			     ((not (file-exists? fulln)) ;; shouldn't happen, but this might recover
			      (cons #t (conc "File "fulln" not found! Copying "fname" to "fulln)))
			     ((and (not jfile-exists) changed)