Megatest

;; 
;;     You should have received a copy of the GNU General Public License
;;     along with Megatest.  If not, see <http://www.gnu.org/licenses/>.

;;======================================================================

(declare (unit dbfile))
(declare (uses debugprint))
(declare (uses commonmod))

(module dbfile
	*
	
  (import scheme
	  chicken
	  data-structures
	  extras
	  matchable)
  
(import (prefix sqlite3 sqlite3:)
	posix typed-records srfi-18 srfi-1
	srfi-69
	stack
	files
	ports

	commonmod
	debugprint
	)

;; parameters
;;
(define dbfile:testsuite-name (make-parameter #f))

(define keep-age-param        (make-parameter 10))      ;; qif file age, if over move to attic
(define num-run-dbs           (make-parameter 10))      ;; number of db's in .megatest
(define dbfile:sync-method    (make-parameter 'attach)) ;; 'attach or 'original
(define dbfile:cache-method   (make-parameter 'inmem))  ;; 'direct

;; 'original     - use old condition code
;; 'suicide-mode - create mtrah/stop-the-train with info on what went wrong
;; else use no condition code (should be production mode)
;;
(define no-condition-db-with-db (make-parameter 'suicide-mode))

;;======================================================================
;;  R E C O R D S
;;======================================================================

;; a single Megatest area with it's multiple dbs is
;; managed in a dbstruct
;;
(defstruct dbr:dbstruct
  (areapath  #f)
  (homehost  #f)
  (tmppath   #f)
  (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 ...
;;
(defstruct dbr:subdb
  (dbname      #f) ;; .megatest/1.db
  (mtdbfile    #f) ;; mtrah/.megatest/1.db

(define *db-sync-in-progress* #f)
(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)

	   subdbs)
           #t
          )
          #f
  )
)






























(define (dbfile:run-id->path apath run-id)
  (conc apath"/"(dbfile:run-id->dbname run-id)))

(define (db:dbname->path apath dbname)
  (conc apath"/"dbname))

(define (dbfile:run-id->dbnum run-id)
  (cond
   ((number? run-id)
    (modulo run-id (num-run-dbs)))
   ((not run-id) "main")   ;; 0 or main?
   (else run-id)))

;; POTENTIAL BUG: this implementation could produce a db file if run-id is neither #f or a number
(define (dbfile:run-id->dbname run-id)


  (conc ".megatest/"(dbfile:run-id->dbnum run-id)".db"))


;; Make the dbstruct, setup up auxillary db's and call for main db at least once
;;
;; called in http-transport and replicated in rmt.scm for *local* access. 
;;
(define (dbfile:setup do-sync areapath tmppath)
  (cond
   (*dbstruct-dbs*
    (dbfile:print-err "WARNING: dbfile:setup called when *dbstruct-dbs* is already initialized")
    *dbstruct-dbs*) ;; TODO: when multiple areas are supported, this optimization will be a hazard
   (else
    (let* ((dbstruct (make-dbr:dbstruct areapath: areapath tmppath: tmppath)))
      (set! *dbstruct-dbs* dbstruct)


      dbstruct))))

(define (dbfile:get-subdb dbstruct run-id)
  (let* ((dbfname (dbfile:run-id->dbname run-id)))
    (hash-table-ref/default (dbr:dbstruct-subdbs dbstruct) dbfname #f)))

(define (dbfile:set-subdb dbstruct run-id subdb)
  (hash-table-set! (dbr:dbstruct-subdbs dbstruct) (dbfile:run-id->dbname run-id) subdb))

;; (define *dbfile:num-handles-in-use* 0)

;; Get/open a database.
;;
;;    NOTE: most usage should call dbfile:open-db to get a dbdat
;;
;;    if run-id => get run specific db
;;    if #f     => get main db
;;    if run-id is a string treat it as a filename - DON'T use this - we'll get rid of it.
;;    if db already open - return inmem
;;    if db not open, open inmem, rundb and sync then return inmem
;;    inuse gets set automatically for rundb's
;;
(define (dbfile:get-dbdat dbstruct run-id)
  (let* ((subdb (dbfile:get-subdb dbstruct run-id)))
    (if (stack-empty? (dbr:subdb-dbstack subdb))
	#f
	(begin
	  (stack-pop! (dbr:subdb-dbstack subdb))))))

;; return a previously opened db handle to the stack of available handles
(define (dbfile:add-dbdat dbstruct run-id dbdat)
  (let* ((subdb (dbfile:get-subdb dbstruct run-id))
	 (dbstk (dbr:subdb-dbstack subdb))
	 (count (stack-count dbstk)))
    (if (> count 15)
	(dbfile:print-err "WARNING: stack for "run-id".db is "count"."))
    (stack-push! dbstk dbdat)
    dbdat))

;; set up a subdb
;;
(define (dbfile:init-subdb dbstruct run-id init-proc)
  (let* ((dbname    (dbfile:run-id->dbname run-id))
	 (areapath  (dbr:dbstruct-areapath dbstruct))

  (exit 1))
    
(define (dbfile:print-err . params)
  (with-output-to-port
      (current-error-port)
    (lambda ()
      (apply print params))))

(define (dbfile:cautious-open-database fname init-proc sync-mode journal-mode #!optional (tries-left 500))
  (let* ((busy-file  (conc fname "-journal"))
	 (delay-time (* (- 51 tries-left) 1.1))
      	 (write-access (file-write-access? fname))
         (dir-access (file-write-access? (pathname-directory fname)))
         (retry      (lambda ()
		       (thread-sleep! delay-time)
		       (if (> tries-left 0)
			   (dbfile:cautious-open-database fname init-proc
							  sync-mode journal-mode
							  (- tries-left 1))))))
    (assert (>= tries-left 0) (conc "FATAL: too many attempts in dbfile:cautious-open-database of "fname", giving up."))
    
    (if (and (file-write-access? fname)
	     (file-exists? busy-file))
	(begin
	  (if (common:low-noise-print 120 busy-file)
	      (dbfile:print-err "INFO: dbfile:cautious-open-database: journal file "
				busy-file" exists, trying again in few seconds."))
	  (thread-sleep! 1)
	  (if (eq? tries-left 2)
	      (begin
	  	(dbfile:print-err "INFO: forcing journal rollup "busy-file)
	  	(dbfile:brute-force-salvage-db fname)))
	  (dbfile:cautious-open-database fname init-proc sync-mode journal-mode (- tries-left 1)))
	
	(let* ((result (condition-case
		        (if dir-access
			    (dbfile:with-simple-file-lock
			     (conc fname ".lock")
			     (lambda ()
			       (let* ((db-exists (file-exists? 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

;;
;; NOTE: this is already protected by mutex *no-sync-db-mutex*
;;
(define (dbfile:raw-open-no-sync-db dbpath)

  (if (not (file-exists? dbpath))
      (create-directory dbpath #t))
  (debug:print-info 0 *default-log-port* "Opening "dbpath"/no-sync.db")
  (let* ((dbname    (conc dbpath "/no-sync.db"))
	 (db-exists (file-exists? dbname))
	 (init-proc (lambda (db)
		      (sqlite3:with-transaction
		       db
		       (lambda ()
			 ;; I have been having trouble with init of no-sync.db so
			 ;; doing the init in a transaction every time (no gating
			 ;; on file existance.
			  (for-each
			   (lambda (stmt)
			     (sqlite3:execute db stmt))
			   (list
			    "CREATE TABLE IF NOT EXISTS no_sync_metadat
                                (var TEXT,
                                 val TEXT,
                                   CONSTRAINT no_sync_metadat_constraint UNIQUE (var));"
			    "CREATE TABLE IF NOT EXISTS no_sync_locks 
                                (key TEXT,
                                 val TEXT,
                                   CONSTRAINT no_sync_metadat_constraint UNIQUE (key));"))))))
	 (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)
  (mutex-lock! *no-sync-db-mutex*)
  (let* ((already-open *no-sync-db*)
	 (db  (or already-open (dbfile:raw-open-no-sync-db dbpath)))
	 (res (proc db)))
    (if (not already-open)
	(sqlite3:finalize! db))
    (mutex-unlock! *no-sync-db-mutex*)
    res))

(define *no-sync-db-mutex* (make-mutex))

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

(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))

        (let ((newres (if (string? res)
			  (string->number res)
			  #f)))
          (if newres
              newres
              res))
        res)))

(define (db:extract-time-identifier instr)
  (let ((tokens (string-split instr "+")))
    (match tokens
      ((t i)(cons (string->number t) i))
      ((t)  (cons (string->number t) #f))
      (else
       (assert #f "FATAL: db:extract-time-identifier handed bad data "instr)))))

;; 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-with-id db keyname identifier)
  (sqlite3:with-transaction
   db
   (lambda ()
     (condition-case
      (let* ((curr-val (db:no-sync-get/default db keyname #f)))
	(if curr-val
	    (match (db:extract-time-identifier curr-val)
	       ((timestamp ident)
		(if (equal? ident identifier)
		    #t     ;; this *is* my lock
		    #f))   ;; nope, not my lock
	       (else #f))  ;; nope, not my lock
	    (let ((lock-value (if identifier
				  (conc (current-seconds)"+"identifier)
				  (current-seconds))))
	      (sqlite3:execute db "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES(?,?);" keyname lock-value)
	      #t)))
      (exn (io-error)  (dbfile:print-err "ERROR: i/o error with no-sync db. Check permissions, disk space etc. and try again."))
      (exn (corrupt)   (dbfile:print-err "ERROR: database no-sync db is corrupt. Repair it to proceed."))
      (exn (busy)      (dbfile:print-err "ERROR: database no-sync db is locked. Try copying to another location, remove original and copy back."))
      (exn (permission)(dbfile:print-err "ERROR: database no-sync db has some permissions problem."))
      (exn () ;; (status done) ;; I don't know how to detect status done but no data!
	   (dbfile:print-err "ERROR: Unknown error with database no-sync db message: exn="(condition->list exn)", \n"
			     ((condition-property-accessor 'exn 'message) exn))
	   #f)))))

;; 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
;;

	  (dbfile:print-err "INFO: db:lock-and-delta-sync copying db "runid" at "(current-seconds))
	  (set! *db-sync-in-progress* #t)
	  (db:sync-touched dbstruct runid keys dbinit)
	  (set! *db-sync-in-progress* #f)
	  (delete-file* lock-file)
	  #t)
        (begin
	  (if (common:low-noise-print 120 (conc "no lock "from-db-file))
	      (dbfile:print-err "INFO: could not get lock for " from-db-file ", sync likely in progress."))
	  #f
	  ))))

;; ;; Get a lock from the no-sync-db for the from-db, then delta sync the from-db to the to-db, otherwise return #f
;; ;;
;; (define (db:lock-and-delta-sync-orig no-sync-db dbstruct from-db-file runid keys dbinit)
;;   (assert (not *db-sync-in-progress*) "FATAL: db:lock-and-sync called while a sync is in progress.")

         (tmpdbfile (dbr:subdb-tmpdbfile subdb))
	 (mtdb      (dbr:subdb-mtdbdat subdb))
         (tmpdb     (db:open-db dbstruct run-id dbinit)) ;; sqlite3-db tmpdbfile #f))
	 (start-t   (current-seconds)))
    (mutex-lock! *db-multi-sync-mutex*)
    (let ((update_info (cons "last_update" (if force-sync 0 *db-last-sync*) )))
      (mutex-unlock! *db-multi-sync-mutex*)
      (db:sync-tables (db:sync-all-tables-list keys) update_info tmpdb mtdb))
    (mutex-lock! *db-multi-sync-mutex*)
    (set! *db-last-sync* start-t)
    (set! *db-last-access* start-t)
    (mutex-unlock! *db-multi-sync-mutex*)
    (dbfile:add-dbdat dbstruct run-id tmpdb)
  #t))

	 '("comment"        #f)
	 '("status"         #f)
	 '("type"           #f)
         '("last_update"    #f))))

;; needs db to get keys, this is for syncing all tables
;;
(define (db:sync-main-list keys)
  (let ((keys  keys))
    (list
     (list "keys"
	   '("id"        #f)
	   '("fieldname" #f)
	   '("fieldtype" #f))
     (list "metadat" '("var" #f) '("val" #f))
     (append (list "runs" 

	   '("owner"          #f)
	   '("description"    #f)
	   '("reviewed"       #f)
	   '("iterated"       #f)
	   '("avg_runtime"    #f)
	   '("avg_disk"       #f)
	   '("tags"           #f)
	   '("jobgroup"       #f))


     (list "tasks_queue"
           '("id"            #f)
           '("action"        #f)
           '("owner"         #f) 
           '("state"         #f)
           '("target"        #f)
           '("name"          #f)
           '("testpatt"      #f)
           '("keylock"       #f)
           '("params"        #f)
           '("creation_time" #f)
           '("execution_time" #f))
     )))

(define (db:sync-all-tables-list keys)
  (append (db:sync-main-list keys)
	  db:sync-tests-only))

;; tbls is ( ("tablename" ( "field1" [#f|proc1] ) ( "field2" [#f|proc2] ) .... ) )
;; db's are dbdat's
;;
;; if last-update specified ("field-name" . time-in-seconds)
;;    then sync only records where field-name >= time-in-seconds

	     (append (list todb) slave-dbs)
           )
          )
        )
	tbls)
       (let* ((runtime      (- (current-milliseconds) start-time))
	      (should-print (or ;; (debug:debug-mode 12)
			     (common:low-noise-print 120 "db sync")
			     (> runtime 500)))) ;; low and high sync times treated as separate.
	 (for-each 
	  (lambda (dat)
	    (let ((tblname (car dat))
		  (count   (cdr dat)))
	      (set! tot-count (+ tot-count count))
              )) 
	  (sort (hash-table->alist numrecs)(lambda (a b)(> (cdr a)(cdr b))))))

                               END;" )
	   (list "update_test_data_trigger"  "CREATE TRIGGER  IF NOT EXISTS update_test_data_trigger AFTER UPDATE ON test_data
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE test_data SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;" )))




















(define (db:is-trigger-dropped db tbl-name)
  (let* ((trigger-name (if (equal? tbl-name "test_steps")
			   "update_teststeps_trigger" 
                           (conc "update_" tbl-name "_trigger")))
	 (res          #f))
    (sqlite3:for-each-row
     (lambda (name)

;;======================================================================

;; call with dbinit=db:initialize-main-db
;;
(define (db:open-db dbstruct run-id dbinit)
  ;; (mutex-lock! *db-open-mutex*)
  (let* ((dbdat (dbfile:open-db dbstruct run-id dbinit)))
              #;(case (rmt:transport-mode)
		  ((http) (dbfile:open-db dbstruct run-id dbinit))
		  ((tcp)  (dbmod:open-db  dbstruct run-id dbinit))
		  (else (assert #f "FATAL: rmt:transport-node not correct value"(rmt:transport-mode))))
    (set! *db-write-access* (not (dbr:dbdat-read-only dbdat)))
    ;; (mutex-unlock! *db-open-mutex*)
    dbdat))

(define dbfile:db-init-proc (make-parameter #f))

;; in xmaxima this gives a curve close to what I want:
;;    plot2d ((exp(x/1.2)-1)/300, [x, 0, 10])$
;;    plot2d ((exp(x/1.5)-1)/40, [x, 0, 10])$
;;    plot2d ((exp(x/5)-1)/40, [x, 0, 20])$
(define (dbfile:droop x)
  (/ (- (exp (/ x 5)) 1) 40))
  ;; (* numqrys (/ 1 (qif-slope))))

;; create a dropping near the db file in a qif dir
;; use count of such files to gate queries (queries in flight)
;;
(define (dbfile:wait-for-qif fname run-id params)
  (let* ((thedir  (pathname-directory fname))
	 (dbnum   (dbfile:run-id->dbnum run-id))
	 (destdir (conc thedir"/qif-"dbnum))
	 (uniqn   (get-area-path-signature (conc dbnum params)))
	 (crumbn  (conc destdir"/"(current-seconds)"-"uniqn"."(current-process-id))))
    (if (not (file-exists? destdir))(create-directory (conc destdir"/attic") #t))
    (let loop ((count 0))
      (let* ((currlks (glob (conc destdir"/*")))
	     (numqrys (length currlks))
	     (delayval (cond ;; do a droopish curve
			((> numqrys 25)
			 (for-each
			  (lambda (f)
			    (if (> (- (current-seconds)
				      (handle-exceptions
					  exn
					(current-seconds) ;; file is likely gone, just fake out
					(file-modification-time f)))
				   (keep-age-param))
				(let* ((basedir (pathname-directory f))
				       (filen   (pathname-file f))
				       (destf   (conc basedir"/attic/"filen)))
				  (dbfile:print-err "Moving qif file "f" older than 10 seconds to "destf)
				  ;; (delete-file* f)
				  (handle-exceptions
				      exn
				    #t
				    (file-move f destf #t)))))
			  currlks)
			 4)
			((> numqrys 0)  (dbfile:droop numqrys)) ;; slope of 1/100
			(else #f))))
	(if (and delayval
		 (< count 5))
	    (begin
	      (thread-sleep! delayval)
	      (loop (+ count 1))))))
    (with-output-to-file crumbn
      (lambda ()
	(print fname" run-id="run-id" params="params)
	))
    crumbn))

;; (db:with-db dbstruct run-id sqlite3:exec "select blah fgrom blaz;")
;; r/w is a flag to indicate if the db is modified by this query #t = yes, #f = no
;;
(define (dbfile:with-db dbstruct run-id r/w proc params)
  (assert dbstruct "FATAL: db:with-db called with dbstruct "#f)
  (assert (dbr:dbstruct? dbstruct) "FATAL: dbstruct is "dbstruct)
  (let* ((use-mutex (> *api-process-request-count* 25)) ;; risk of db corruption
	 (have-struct (dbr:dbstruct? dbstruct))
         (dbdat     (if have-struct                ;; this stuff just allows us to call with a db handle directly
			(db:open-db dbstruct run-id (dbfile:db-init-proc)) ;; (dbfile:get-subdb dbstruct run-id)
			#f))
	 (db        (if have-struct                ;; this stuff just allows us to call with a db handle directly
			(dbr:dbdat-dbh dbdat)
			dbstruct))
	 (fname     (if dbdat
			(dbr:dbdat-dbfile dbdat)
			"nofilenameavailable"))
	 (jfile     (conc fname"-journal"))
	 (qryproc   (lambda ()
		      (if use-mutex (mutex-lock! *db-with-db-mutex*))
		      (let ((res (apply proc dbdat db params))) ;; the actual call is here.
			(if use-mutex (mutex-unlock! *db-with-db-mutex*))
			;; (if (vector? dbstruct)(db:done-with dbstruct run-id r/w))
			(if dbdat
			    (dbfile:add-dbdat dbstruct run-id dbdat))
			;; (delete-file* crumbfile)
			res)))
	 (stop-train (conc (dbr:dbstruct-areapath dbstruct)"/stop-the-train")))

    (assert (sqlite3:database? db) "FATAL: db:with-db, db is not a database, db="db
	    ", fname="fname)
    (if (file-exists? jfile)
	(begin
	  (dbfile:print-err "INFO: "jfile" exists, delaying to reduce database load")
	  (thread-sleep! 0.2)))
    (if (and use-mutex
	     (common:low-noise-print 120 "over-50-parallel-api-requests"))
	(dbfile:print-err *api-process-request-count*
			  " parallel api requests being processed in process "
			  (current-process-id))) ;;  ", throttling access"))
    (case (no-condition-db-with-db)
      ((production)(qryproc))
      ((suicide-mode)
       (handle-exceptions
	exn
	(with-output-to-file stop-train



	  (lambda ()

	    (db:generic-error-printout exn "Stop train mode, run-id: "run-id
				       " params: "params" proc: "proc)))
	(qryproc)))
      (else
       (condition-case
	(qryproc)
	(exn (io-error)
	     (db:generic-error-printout exn "ERROR: i/o error with "fname
					". Check permissions, disk space etc. and try again."))
	(exn (corrupt)
	     (db:generic-error-printout exn "ERROR: database "fname
					" is corrupt. Repair it to proceed."))
	(exn (busy)
	     (db:generic-error-printout exn "ERROR: database "fname
					" is locked. Try copying to another location,"
					" remove original and copy back."))
	(exn (permission)(db:generic-error-printout exn "ERROR: database "fname
						    " has some permissions problem."))
	(exn ()
	     (db:generic-error-printout exn "ERROR: Unknown error with database "fname
					" message: "
					((condition-property-accessor 'exn 'message) exn))))))))

;;======================================================================
;; another attempt at a transactionized queue
;;======================================================================

;; ;; ;; (define *transaction-queues* (make-hash-table))
;; ;; ;; 

(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))
	 (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))

)