Megatest

  (read-only #f)
  (subdbs (make-hash-table))
  ;;
  ;; for the inmem approach (see dbmod.scm)
  ;; this is one db per server
  (inmem     #f)  ;; handle for the in memory copy
  (dbfile    #f)  ;; path to the db file on disk
  (dbfname   #f)  ;; short name of db file on disk (used to validate accessing correct db)
  (ondiskdb  #f)  ;; handle for the on-disk file
  (dbdat     #f)  ;; create a dbdat for the downstream calls such as db:with-db
  (last-update 0)
  (sync-proc #f)
  )

;; NOTE: Need one dbr:subdb per main.db, 1.db ...

(define *db-with-db-mutex*    (make-mutex))
(define *max-api-process-requests* 0)
(define *api-process-request-count* 0)
(define *db-write-access*     #t)
(define *db-last-sync*        0)                 ;; last time the sync to megatest.db happened
(define *db-multi-sync-mutex* (make-mutex))      ;; protect access to *db-sync-in-progress*, *db-last-sync*
(define *db-last-access*      (current-seconds))

(define *db-transaction-mutex* (make-mutex))

(define (db:generic-error-printout exn . message)
  (print-call-chain (current-error-port))
  (apply dbfile:print-err message)
  (dbfile:print-err
    ", error: "     ((condition-property-accessor 'exn 'message)   exn)
    ", arguments: " ((condition-property-accessor 'exn 'arguments) exn)

(define (dbfile:with-simple-file-lock fname proc #!key (expire-time 300))
  (let ((gotlock (dbfile:simple-file-lock-and-wait fname expire-time: expire-time)))
    (if gotlock
	(let ((res (proc)))
	  (dbfile:simple-file-release-lock fname)
	  res)
	(assert #t "FATAL: simple file lock never got a lock."))))
  

(define *get-cache-stmth-mutex* (make-mutex))

(define (db:get-cache-stmth dbdat db stmt)
  (mutex-lock! *get-cache-stmth-mutex*)
  (let* (;; (dbdat       (dbfile:get-dbdat dbstruct run-id))
	 (stmt-cache  (dbr:dbdat-stmt-cache dbdat))
	 ;; (stmth       (db:hoh-get stmt-cache db stmt))
	 (stmth       (hash-table-ref/default stmt-cache stmt #f)))
    (or stmth
	(let* ((newstmth (sqlite3:prepare db stmt)))
	  ;; (db:hoh-set! stmt-cache db stmt newstmth)
	  (hash-table-set! stmt-cache stmt newstmth)
	  newstmth))))


	 (stmth       (hash-table-ref/default stmt-cache stmt #f))
	 (result      (or stmth
			  (let* ((newstmth (sqlite3:prepare db stmt)))
			    ;; (db:hoh-set! stmt-cache db stmt newstmth)
			    (hash-table-set! stmt-cache stmt newstmth)
			    newstmth))))
    (mutex-unlock! *get-cache-stmth-mutex*)
    result))

)