Megatest

(define (dbfile:brute-force-salvage-db fname)
  (let* ((backupfname (conc fname"-"(current-process-id)".bak"))
	 (cmd (conc "cp "fname" "backupfname";mv "fname" "(conc fname ".delme;")
		    "cp "backupfname" "fname)))
    (dbfile:print-err "WARNING: attempting recovery of file "fname" by running commands:\n"
		      "  "cmd)
    (system cmd)))

;; opens and returns handle and nothing else
;;
(define (dbfile:raw-open-no-sync-db dbpath)



  (if (not (file-exists? dbpath))
      (create-directory dbpath #t))
  (let* ((dbname    (conc dbpath "/no-sync.db"))
	 (db-exists (file-exists? dbname))
	 (init-proc (lambda (db)
		      (if (not db-exists)
			  (begin
			    (sqlite3:execute db "CREATE TABLE IF NOT EXISTS no_sync_metadat (var TEXT,val TEXT, CONSTRAINT no_sync_metadat_constraint UNIQUE (var));"))
			  )))
	 (on-tmp      (equal? (car (string-split dbpath "/")) "tmp"))
	 (db        (if on-tmp
			(dbfile:cautious-open-database dbname init-proc 0 "WAL")
			(dbfile:cautious-open-database dbname init-proc 0 #f)
			;; (sqlite3:open-database dbname)
			)))
    (if on-tmp	      ;; done in cautious-open-database
	(begin
	  (sqlite3:execute db "PRAGMA synchronous = 0;")
	  (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))))
    db))

(define (dbfile:with-no-sync-db dbpath proc)
  (let* ((db  (dbfile:raw-open-no-sync-db dbpath))
	 (res (proc db)))
    (sqlite3:finalize! db)
    res))

(define (dbfile:open-no-sync-db dbpath)
  (if *no-sync-db*
      *no-sync-db*
      (let* ((db (dbfile:raw-open-no-sync-db dbpath)))
	(set! *no-sync-db* db)
	db)))

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

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