;;======================================================================
;; Copyright 2017, Matthew Welland.
;; 
;; This file is part of Megatest.
;; 
;;     Megatest is free software: you can redistribute it and/or modify
;;     it under the terms of the GNU General Public License as published by
;;     the Free Software Foundation, either version 3 of the License, or
;;     (at your option) any later version.
;; 
;;     Megatest is distributed in the hope that it will be useful,
;;     but WITHOUT ANY WARRANTY; without even the implied warranty of
;;     MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;;     GNU General Public License for more details.
;; 
;;     You should have received a copy of the GNU General Public License
;;     along with Megatest.  If not, see <http://www.gnu.org/licenses/>.

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

(use srfi-18)

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

(module dbfile
	*
	
  (import scheme
	  chicken
	  data-structures
	  extras
	  matchable
  
	  (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 .mtdb
(define dbfile:sync-method    (make-parameter 'attach)) ;; 'attach or 'original
(define dbfile:cache-method   (make-parameter 'inmem))  ;; 'direct
(define dbcache-mode (make-parameter 'tmp)) ;; 'inmem, 'tmp (changes what open inmem routine does)


;; '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) ;; .mtdb/1.db
  (mtdbfile    #f) ;; mtrah/.mtdb/1.db
  (mtdbdat     #f) ;; only need one of these for syncing
  ;; (dbdats      (make-hash-table))  ;; id => dbdat 
  (tmpdbfile   #f) ;; /tmp/.../.mtdb/1.db
  ;; (refndbfile  #f) ;; /tmp/.../.mtdb/1.db_ref
  (dbstack     (make-stack)) ;; stack for tmp dbr:dbdat,
  (homehost    #f) ;; not used yet
  (on-homehost #f) ;; not used yet
  (read-only   #f)
  (last-sync   0)
  (last-write  (current-seconds))
  )                ;; goal is to converge on one struct for an area but for now it is too confusing

;; need to keep dbhandles and cached statements together
(defstruct dbr:dbdat
  (dbfile      #f)
  (dbh         #f)    
  (stmt-cache  (make-hash-table))
  (read-only   #f)
  (birth-sec   (current-seconds)))

;; used in simple-get-runs (thanks Brandon!)
(define-record simple-run target id runname state status owner event_time)
(define-record-printer (simple-run x out)
  (fprintf out "#,(simple-run ~S ~S ~S ~S)"
	   (simple-run-target x) (simple-run-id x) (simple-run-runname x) (time->string (seconds->local-time (simple-run-event_time x) ))))

(define *dbstruct-dbs* #f)
(define *db-open-mutex* (make-mutex))
(define *db-access-mutex* (make-mutex)) ;; used in common.scm
(define *no-sync-db*   #f)
(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)
    ", location: "  ((condition-property-accessor 'exn 'location)  exn)
    ))

(define (dbfile:run-id->key run-id)
  (or run-id 'main))

(define (db:safely-close-sqlite3-db db stmt-cache #!key (try-num 3))
  (if (<= try-num 0)
      #f
      (handle-exceptions
	  exn
	(begin
	  (print "Attempt to safely close sqlite3 db failed. Trying again. exn=" exn)
	  (thread-sleep! 3)
	  (sqlite3:interrupt! db)
	  (db:safely-close-sqlite3-db db stmt-cache try-num: (- try-num 1)))
	(if (sqlite3:database? db)
	    (let* ((stmts (and stmt-cache (hash-table-ref/default stmt-cache db #f))))
	      (if stmts (map sqlite3:finalize! (hash-table-values stmts)))
	      (sqlite3:finalize! db)
	      #t)
            (begin
             (dbfile:print-err "db:safely-close-sqlite3-db: " db " is not an sqlite3 db")
	     #f
            )
        ))))

;; close all opened run-id dbs
(define (db:close-all dbstruct)
  (if (dbr:dbstruct? dbstruct)
;; (handle-exceptions
;; 	  exn
;; 	  (begin
;; 	    (debug:print 0 *default-log-port* "WARNING: Finalizing failed, "  ((condition-property-accessor 'exn 'message) exn) ", note - exn=" exn)
;; 	    (print-call-chain *default-log-port*))
	;; (db:sync-touched dbstruct 0 force-sync: #t) ;; NO. Do not do this here. Instead we rely on a server to be started when there are writes, even if the server itself is not going to be used as a server.
        (let* ((subdbs     (hash-table-values (dbr:dbstruct-subdbs dbstruct))))
	  (for-each
	   (lambda (subdb)
	     (let* ((tdbs       (stack->list (dbr:subdb-dbstack subdb)))
		    (mtdbdat    (dbr:dbdat-dbh (dbr:subdb-mtdbdat subdb)))
		    #;(rdb        (dbr:dbdat-dbh (dbr:subdb-refndb subdb))))
		    
	       (map (lambda (dbdat)
		      (let* ((stmt-cache (dbr:dbdat-stmt-cache dbdat))
			     (dbh        (dbr:dbdat-dbh        dbdat)))
			(db:safely-close-sqlite3-db dbh stmt-cache)))
		    tdbs)
	       (db:safely-close-sqlite3-db mtdbdat (dbr:dbdat-stmt-cache  (dbr:subdb-mtdbdat subdb))) 
               ;; (if (sqlite3:database? mdb) (sqlite3:finalize! mdb))
	       #;(db:safely-close-sqlite3-db rdb #f))) ;; stmt-cache))))) ;; (if (sqlite3:database? rdb) (sqlite3:finalize! rdb))))))
	   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? No, not 0. 
   (else
    (assert #f "FATAL: run-id is required to be a number or #f"))))

;; just the filename
(define (dbfile:run-id->dbfname run-id)
  (conc (dbfile:run-id->dbnum run-id)".db"))

;; the path in MTRAH with the filename
(define (dbfile:run-id->dbname run-id)
  (conc ".mtdb/"(dbfile:run-id->dbfname run-id)))


;; 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))
	 (tmppath   (dbr:dbstruct-tmppath  dbstruct))
	 (mtdbpath  (dbfile:run-id->path areapath run-id))
	 (tmpdbpath (dbfile:run-id->path tmppath run-id))
	 (mtdbdat   (dbfile:open-sqlite3-db mtdbpath init-proc sync-mode: 0 journal-mode: #f)) ;; "WAL"))
	 (newsubdb  (make-dbr:subdb dbname:    dbname
				    mtdbfile:  mtdbpath
				    tmpdbfile: tmpdbpath
				    mtdbdat:   mtdbdat)))
    (dbfile:set-subdb dbstruct run-id newsubdb)
    newsubdb)) ;; return the new subdb - but shouldn't really use it

;; returns dbdat with dbh and dbfilepath
;;
;; NOTE: the handle is on /tmp db file!
;;
;;  1. if needed setup the subdb for the given run-id
;;  2. if there is no existing db handle in the stack
;;     create a new handle and return it (do NOT add
;;     it to the stack).
;;
(define (dbfile:open-db dbstruct run-id init-proc)
  (let* ((subdb (dbfile:get-subdb dbstruct run-id)))
    (if (not subdb) ;; not yet defined
	(begin
	  (dbfile:init-subdb dbstruct run-id init-proc)
	  (dbfile:open-db dbstruct run-id init-proc))
	(let* ((dbdat (dbfile:get-dbdat dbstruct run-id)))
	  (if dbdat
	      dbdat
	      (let* ((tmppath   (dbr:dbstruct-tmppath  dbstruct))
		     (tmpdbpath (dbfile:run-id->path tmppath run-id))
		     (dbdat     (dbfile:open-sqlite3-db tmpdbpath init-proc sync-mode: 0 journal-mode: "WAL")))
		;; the following line short-circuits the "one db handle per thread" model
		;; 
		;; (dbfile:add-dbdat dbstruct run-id dbdat)
		;;
		dbdat))))))
    
;; COMBINE dbfile:open-sqlite-db and dbfile:lock-create-open
;;

;; this stuff is for initial debugging, please remove it when
;; this code stabilizes
(define *dbopens* (make-hash-table))
(define (dbfile:inc-db-open dbfile)
  (let* ((curr-opens-count (+ (hash-table-ref/default *dbopens* dbfile 0) 1)))
    (if (and (> curr-opens-count 1) ;; this should NOT be happening
	     (common:low-noise-print 15 "db-opens"))
	(dbfile:print-err "INFO: db "dbfile" has been opened "curr-opens-count" times!"))
    (hash-table-set! *dbopens* dbfile curr-opens-count)
    curr-opens-count))

;; Open the classic megatest.db file (defaults to open in toppath)
;;
;;   NOTE: returns a dbdat not a dbstruct!
;;
(define (dbfile:open-sqlite3-db dbpath init-proc #!key (sync-mode 0)(journal-mode #f))
  (let* ((dbexists     (file-exists? dbpath))
	 (write-access (file-write-access? dbpath))
	 (db           (dbfile:cautious-open-database dbpath init-proc sync-mode journal-mode)))
    (dbfile:inc-db-open dbpath)
    ;; (init-proc db)
    (make-dbr:dbdat dbfile: dbpath dbh: db read-only: (not write-access))))

(define (dbfile:print-and-exit . params)
  (with-output-to-port
      (current-error-port)
    (lambda ()
      (apply print params)))
  (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))
				      (db        (sqlite3:open-database fname))) ;; creates an empty db if it did not already exist.
                                 (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 30000))
				 (if sync-mode
				     (sqlite3:execute db (conc "PRAGMA synchronous = "sync-mode";")))
				 (if journal-mode
				     (sqlite3:execute db (conc "PRAGMA journal_mode = "journal-mode";")))
				 (if (and init-proc (not db-exists))
				     (init-proc db))
				 db)))
                            (begin
			      (if (file-exists? fname )
                                  (let ((db (sqlite3:open-database fname)))
				    ;; pragmas synchronous not needed because this db is used read-only
				    ;; (sqlite3:execute db (conc "PRAGMA synchronous = "mode";")
				    (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 30000)) ;; read-only but still need timeout
				    db )
                                  (print "file doesn't exist: " fname))))
			(exn (io-error)
			     (dbfile:print-err exn "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again.")
			     (retry))
			(exn (corrupt)
			     (dbfile:print-err exn "ERROR: database " fname " is corrupt. Repair it to proceed.")
			     (retry))
			(exn (busy)
			     (dbfile:print-err exn "ERROR: database " fname
					       " is locked. Try copying to another location, remove original and copy back.")
			     (retry))
			(exn (permission)(dbfile:print-err exn "ERROR: database " fname " has some permissions problem.")
			     (retry))
			(exn ()
			     (dbfile:print-err exn "ERROR: Unknown error with database " fname " message: "
					       ((condition-property-accessor 'exn 'message) exn))
			     (retry)))))
	  result))))

(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
;;
;; 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))

(define (db:no-sync-get/default db var default)
  (assert (sqlite3:database? db) "FATAL: db:no-sync-get/default called with a bad db handle:" db)
  (let ((res default))
    (sqlite3:for-each-row
     (lambda (val)
       (set! res val))
     db
     "SELECT val FROM no_sync_metadat WHERE var=?;"
     var)
    (if res
        (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
;;
(define (db:no-sync-get-lock db keyname)
  (sqlite3:with-transaction
   db
   (lambda ()
     (condition-case
	 (let* ((curr-val (db:no-sync-get/default db keyname #f)))
	   (if curr-val
	       `(#f . ,curr-val)   ;; (sqlite3:first-result db "SELECT val FROM no_sync_metadat WHERE var=?;" keyname))
	       (let ((lock-time (current-seconds)))
		 (sqlite3:execute db "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES(?,?);" keyname lock-time)
		 `(#t . ,lock-time))))
       (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 . ,(current-seconds)))))))

(define (db:no-sync-get-lock-timeout db keyname timeout)
  (let* ((lockdat (db:no-sync-get-lock db keyname)))
    (match lockdat
      ((#f . lock-time)
       (if (> (- (current-seconds) (if (string? lock-time)(string->number lock-time)lock-time)) timeout)
	   (let ((lock-time (current-seconds)))
	     ;; (debug:print-info 2 *default-log-port* "db:no-sync-get-lock keyname=" keyname ", lock-time=" lock-time ", exn=" exn)
	     (sqlite3:execute db "INSERT OR REPLACE INTO no_sync_metadat (var,val) VALUES(?,?);" keyname lock-time)
	     `(#t . ,lock-time))
	   lockdat))
      (else lockdat))))

;; NOTE: This will steal the lock after timeout of waiting.
;;
(define (db:with-no-sync-lock db keyname timeout proc)
  (let* ((lockdat  (db:no-sync-get-lock-timeout db keyname))
	 (gotlock  (car lockdat))
	 (locktime (cdr lockdat)))
    (if gotlock
	(let ((res (proc)))
	  (db:no-sync-del! db keyname)
	  res))))
  
;;======================================================================
;; sync back functions pulled from db.scm
;;======================================================================

;; 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 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.")
  ;; (dbfile:print-err *default-log-port* "db:lock-and-delta-sync")
  (let* ((lock-file (conc from-db-file ".lock")))
    (if (common:simple-file-lock lock-file)
	(begin
	  (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.")
;;   ;; (dbfile:print-err *default-log-port* "db:lock-and-delta-sync")
;;   (let* ((lockdat  (db:no-sync-get-lock-timeout no-sync-db from-db-file 60))
;; 	 (gotlock  (car lockdat))
;; 	 (locktime (cdr lockdat)))
;;     ;; (debug:print-info 3 *default-log-port* "db:lock-and-delta-sync: got lock?")
;;     
;;     (if gotlock
;; 	(begin
;;           (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)
;; 	  (db:no-sync-del! no-sync-db from-db-file)
;; 	  #t)
;;         (begin
;;           (dbfile:print-err "ERROR: could not get lock for " from-db-file " from no-sync-db")
;; 	  #f
;;         ))))

;; sync run from tmp disk to nfs disk if touched
;;
;; call with dbinit=db:initialize-main-db
;;
(define (db:sync-touched dbstruct run-id keys #!key dbinit (force-sync #f))
  (dbfile:print-err "db:sync-touched Syncing: " (conc (if run-id run-id "main") ".db"))
  (let* (;; the subdb is needed to access the mtdbdat
	 (subdb     (or (dbfile:get-subdb dbstruct run-id)
			(dbfile:init-subdb dbstruct run-id dbinit)))
         (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))

;; just tests, test_steps and test_data tables
(define db:sync-tests-only
  (list
   ;; (list "strs"
   ;;       '("id"             #f)
   ;;       '("str"            #f))
   (list "tests" 
	 '("id"             #f)
	 '("run_id"         #f)
	 '("testname"       #f)
	 '("host"           #f)
	 '("cpuload"        #f)
	 '("diskfree"       #f)
	 '("uname"          #f)
	 '("rundir"         #f)
	 '("shortdir"       #f)
	 '("item_path"      #f)
	 '("state"          #f)
	 '("status"         #f)
	 '("attemptnum"     #f)
	 '("final_logf"     #f)
	 '("logdat"         #f)
	 '("run_duration"   #f)
	 '("comment"        #f)
	 '("event_time"     #f)
	 '("fail_count"     #f)
	 '("pass_count"     #f)
	 '("archived"       #f)
         '("last_update"    #f))
  (list "test_steps"
	 '("id"             #f)
	 '("test_id"        #f)
	 '("stepname"       #f)
	 '("state"          #f)
	 '("status"         #f)
	 '("event_time"     #f)
	 '("comment"        #f)
	 '("logfile"        #f)
         '("last_update"    #f))
   (list "test_data"
	 '("id"             #f)
	 '("test_id"        #f)
	 '("category"       #f)
	 '("variable"       #f)
	 '("value"          #f)
	 '("expected"       #f)
	 '("tol"            #f)
	 '("units"          #f)
	 '("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" 
		   '("id"  #f))
	     (map (lambda (k)(list k #f))
		  (append keys
			  (list "runname" "state" "status" "owner" "event_time" "comment" "fail_count" "pass_count" "contour" "last_update"))))
     (list "archive_disks"
           '("id" #f)
           '("archive_area_name" #f) 
           '("disk_path" #f)
           '("last_df" #f)
           '("last_df_time" #f)
           '("creation_time" #f)) 

     (list "archive_blocks"
           '("id" #f)
           '("archive_disk_id" #f) 
           '("disk_path" #f)
           '("last_du" #f)
           '("last_du_time" #f)
           '("creation_time" #f)) 

     (list "test_meta"
	   '("id"             #f)
	   '("testname"       #f)
	   '("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
;;    IFF field-name exists
;;
(define (db:sync-tables tbls last-update fromdb todb . slave-dbs)
  (handle-exceptions
   exn
   (begin
     (dbfile:print-err  "EXCEPTION: database probably overloaded or unreadable in db:sync-tables.")
     (print-call-chain (current-error-port))
     (dbfile:print-err  " message: " ((condition-property-accessor 'exn 'message) exn))
     (dbfile:print-err  "exn=" (condition->list exn))
     (dbfile:print-err  " status:  " ((condition-property-accessor 'sqlite3 'status) exn))
     (dbfile:print-err  " src db:  " (dbr:dbdat-dbfile fromdb))
     (for-each (lambda (dbdat)
		 (let ((dbpath (dbr:dbdat-dbfile dbdat)))
		   (dbfile:print-err  " dbpath:  " dbpath)
		   (if #t ;; (not (db:repair-db dbdat))
		       (begin
			 (dbfile:print-err "Failed to rebuild (repair is turned off) " dbpath ", exiting now.")
			 (exit)))))
	       (cons todb slave-dbs))
     
     0)

   ;; this is the work to be done")
   (cond
    ((not fromdb) (dbfile:print-err  "WARNING: db:sync-tables called with fromdb missing")
     -1)
    ((not todb)   (dbfile:print-err  "WARNING: db:sync-tables called with todb missing")
     -2)
    ((not (sqlite3:database? (dbr:dbdat-dbh fromdb)))
     (dbfile:print-err "db:sync-tables called with fromdb not a database " fromdb)
   -3)
    ((not (sqlite3:database? (dbr:dbdat-dbh todb)))
     (dbfile:print-err "db:sync-tables called with todb not a database " todb)
   -4)

    ((not (file-write-access? (dbr:dbdat-dbfile todb)))
     (dbfile:print-err "db:sync-tables called with todb not a read-only database " todb)
     -5)
    ((not (null? (let ((readonly-slave-dbs
                        (filter
                         (lambda (dbdat)
                           (not (file-write-access? (dbr:dbdat-dbfile todb))))
                         slave-dbs)))
                   (for-each
                    (lambda (bad-dbdat)
                      (dbfile:print-err "db:sync-tables called with todb not a read-only database " bad-dbdat))
                    readonly-slave-dbs)
                   readonly-slave-dbs))) -6)
    (else
     ;; (dbfile:print-err "db:sync-tables: args are good")

     (let ((stmts       (make-hash-table)) ;; table-field => stmt
	   (all-stmts   '())              ;; ( ( stmt1 value1 ) ( stml2 value2 ))
	   (numrecs     (make-hash-table))
	   (start-time  (current-milliseconds))
	   (tot-count   0))
       (for-each ;; table
	(lambda (tabledat)
	  (let* ((tablename        (car tabledat))
		 (fields           (cdr tabledat))
		 (has-last-update  (member "last_update" fields))
		 (use-last-update  (cond
				    ((and has-last-update
					  (member "last_update" fields))
				     #t) ;; if given a number, just use it for all fields
				    ((number? last-update) #f) ;; if not matched first entry then ignore last-update for this table
				    ((and (pair? last-update)
					  (member (car last-update)    ;; last-update field name
						  (map car fields)))
                                        #t)
				    ((and last-update (not (pair? last-update)) (not (number? last-update)))
				     (dbfile:print-err  "ERROR: parameter last-update for db:sync-tables must be a pair or a number, received: " last-update);; found in fields
				     #f)
				    (else
				     #f)))
		 (last-update-value (if use-last-update ;; no need to check for has-last-update - it is already accounted for
					(if (number? last-update)
					    last-update
					    (cdr last-update))
					#f))
		 (last-update-field (if use-last-update
					(if (number? last-update)
					    "last_update"
					    (car last-update))
					#f))
		 (num-fields (length fields))
		 (field->num (make-hash-table))
		 (num->field (apply vector (map car fields))) ;; BBHERE
		 (full-sel   (conc "SELECT " (string-intersperse (map car fields) ",") 
				   " FROM " tablename (if use-last-update ;; apply last-update criteria
							  (conc " WHERE " last-update-field " >= " last-update-value)
							  "")
				   ";"))
		 (full-ins   (conc "INSERT OR REPLACE INTO " tablename " ( " (string-intersperse (map car fields) ",") " ) "
				   " VALUES ( " (string-intersperse (make-list num-fields "?") ",") " );"))
		 (fromdat    '())
		 (fromdats   '())
		 (totrecords 0)
		 (batch-len  100) ;; (string->number (or (configf:lookup *configdat* "sync" "batchsize") "100")))
		 (todat      (make-hash-table))
		 (count      0)
                 (field-names (map car fields))
                 (delay-handicap  0) ;; (string->number (or (configf:lookup *configdat* "sync" "delay-handicap") "0")))
                 )

	    ;; set up the field->num table
	    (for-each
	     (lambda (field)
	       (hash-table-set! field->num field count)
	       (set! count (+ count 1)))
	     fields)

	    ;; read the source table
            ;; store a list of all rows in the table in fromdat, up to batch-len.
            ;; Then add fromdat to the fromdats list, clear fromdat and repeat.
            (sqlite3:with-transaction 
              (dbr:dbdat-dbh fromdb)
              (lambda ()
	        (sqlite3:for-each-row
	          (lambda (a . b)
	            (set! fromdat (cons (apply vector a b) fromdat))
	            (if (> (length fromdat) batch-len)
		      (begin
		        (set! fromdats (cons fromdat fromdats))
		        (set! fromdat  '())
		        (set! totrecords (+ totrecords 1)))
                    )
                 )
	         (dbr:dbdat-dbh fromdb)
	         full-sel)
              )
            )

             ;; Count less than batch-len as a record
             (if (> (length fromdat) 0)
                 (set! totrecords (+ totrecords 1)))

	    ;; tack on remaining records in fromdat
	    (if (not (null? fromdat))
		(set! fromdats (cons fromdat fromdats)))

	    (sqlite3:for-each-row
	     (lambda (a . b)
	       (hash-table-set! todat a (apply vector a b)))
	     (dbr:dbdat-dbh todb)
	     full-sel)

            (when (and delay-handicap (> delay-handicap 0))
              (dbfile:print-err "imposing synthetic sync delay of "delay-handicap" seconds since sync/delay-handicap is configured")
              (thread-sleep! delay-handicap)
              (dbfile:print-err "synthetic sync delay of "delay-handicap" seconds completed")
              )
            
	    ;; first pass implementation, just insert all changed rows

	    (for-each 
	     (lambda (targdb)
	       (let* ((db                 (dbr:dbdat-dbh targdb))
                      (drp-trigger        (if (member "last_update" field-names)
					      (db:drop-trigger db tablename) 
					      #f))
		      (has-last-update    (member "last_update" field-names))
                      (is-trigger-dropped (if has-last-update
                                              (db:is-trigger-dropped db tablename)
					      #f)) 
		      (stmth  (sqlite3:prepare db full-ins))
                      (changed-rows 0))
		 (for-each
		  (lambda (fromdat-lst)
		    (sqlite3:with-transaction
		     db
		     (lambda ()
		       (for-each ;; 
			(lambda (fromrow)
			  (let* ((a    (vector-ref fromrow 0))
				 (curr (hash-table-ref/default todat a #f))
				 (same #t))
			    (let loop ((i 0))
			      (if (or (not curr)
				      (not (equal? (vector-ref fromrow i)(vector-ref curr i))))
				  (set! same #f))
			      (if (and same
				       (< i (- num-fields 1)))
				  (loop (+ i 1))))
			    (if (not same)
				(begin
				  (apply sqlite3:execute stmth (vector->list fromrow))
				  (hash-table-set! numrecs tablename (+ 1 (hash-table-ref/default numrecs tablename 0)))
                                  (set! changed-rows (+ changed-rows 1))
                                )
                            )
                            ))
			fromdat-lst))))
		  fromdats)

		 (sqlite3:finalize! stmth)
                 (if (member "last_update" field-names)
                    (db:create-trigger db tablename))))
	     (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))))))
       tot-count)))))

;;======================================================================
;; trigger setup/takedown
;;======================================================================

(define db:trigger-list 
     (list (list "update_runs_trigger"  "CREATE TRIGGER IF NOT EXISTS update_runs_trigger AFTER UPDATE ON runs
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE runs SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;" ) 
	   (list "update_run_stats_trigger"  "CREATE TRIGGER  IF NOT EXISTS update_run_stats_trigger AFTER UPDATE ON run_stats
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE run_stats SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;" )
	   (list "update_tests_trigger"  "CREATE TRIGGER  IF NOT EXISTS update_tests_trigger AFTER UPDATE ON tests
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE tests SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               END;" )
	   (list "update_teststeps_trigger"  "CREATE TRIGGER  IF NOT EXISTS update_teststeps_trigger AFTER UPDATE ON test_steps
                             FOR EACH ROW
                               BEGIN 
                                 UPDATE test_steps SET last_update=(strftime('%s','now'))
                                   WHERE id=old.id;
                               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)
       (if (equal? name trigger-name)
	   (set! res #t)))
     db 
     "SELECT name FROM sqlite_master WHERE type = 'trigger' ;")
    res))

(define (db:drop-triggers db)
  (for-each
   (lambda (key) 
     (sqlite3:execute db (conc "drop trigger if exists " (car key))))
   db:trigger-list))

(define  (db:drop-trigger db tbl-name)
  (let* ((trigger-name (if (equal? tbl-name "test_steps")
			   "update_teststeps_trigger" 
                           (conc "update_" tbl-name "_trigger"))))
    (for-each
     (lambda (key) 
       (if (equal? (car key) trigger-name)
           (sqlite3:execute db (conc "drop trigger if exists " trigger-name))))
     db:trigger-list)))

(define  (db:create-trigger db tbl-name)
      (let* ((trigger-name (if (equal? tbl-name "test_steps")
                              "update_teststeps_trigger" 
                              (conc "update_" tbl-name "_trigger"))))
       (for-each (lambda (key) 
             (if (equal? (car key) trigger-name)
             (sqlite3:execute db (cadr key))))
      db:trigger-list))) 

;;======================================================================
;; db access stuff
;;======================================================================

;; 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)))
    (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
;; ;;
;; ;; Used only with http - to be removed
;; ;;
;; (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)
;;   ;; Testing 2023, March 14th. I went from full time use of the mutext to no use at all and
;;   ;; didn't see much change in the frequency of the messages:
;;   ;; Warning (#<thread: thread14974>): in thread: (bind!) bad parameter or other API misuse
;;   ;; allowing request count to go up to 1000 and other crashes showed up:
;;   ;; Warning (#<thread: thread1889>): in thread: (deserialize) unexpected end of input: #<input port "(tcp)">
;;   ;;
;;   ;; leave it fully on for now, test later if there is a performance issue
;;   ;;
;;   (let* ((use-mutex   #t) ;;(> *api-process-request-count* 50)) ;; 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 (db:get-queue run-id)
;; ;; ;;   (let* ((res (hash-table-ref/default *transaction-queues* run-id #f)))
;; ;; ;;     (if res
;; ;; ;; 	res
;; ;; ;; 	(let* ((newq (make-queue)))
;; ;; ;; 	  (hash-table-set! *transaction-queues* run-id newq)
;; ;; ;; 	  newq))))
;; ;; ;; 
;; ;; ;; (define (db:add-to-transaction-queue dbstruct proc params)
;; ;; ;;   (let* ((mbox (make-mailbox))
;; ;; ;; 	 (q    (db:get-queue run-id)))
;; ;; ;;     (queue-add! *transaction-queue* (list dbstruct proc mbox))
;; ;; ;;     (mailbox-receive mbox)))
;; ;; ;; 
;; ;; ;; (define (db:process-transaction-queue *dbstruct-dbs*)
;; ;; ;;   (for-each
;; ;; ;;    (lambda (run-id)
;; ;; ;;      (let* ((q (hash-table-ref *transaction-queue* run-id)))
;; ;; ;;        ;; with-transaction
;; ;; ;;        ;;     dbstruct
;; ;; ;;        ;; pop items from queue and execute them, return results via mailbox
;; ;; ;;        q
;; ;; ;;        ;; pop 
;; ;; ;;        ))
;; ;; ;;    (hash-table-keys *transaction-queues*)))

;;======================================================================
;; file utils
;;======================================================================

;;======================================================================
;; lazy-safe get file mod time. on any error (file not existing etc.) return 0
;;
(define (dbfile:lazy-modification-time fpath)
  (handle-exceptions
      exn
    (begin
      (dbfile:print-err "Failed to get modification time for " fpath ", treating it as zero. exn=" exn)
      0)
    (if (file-exists? fpath)
	(file-modification-time fpath)
	0)))

;;======================================================================
;; find timestamp of newest file associated with a sqlite db file
(define (dbfile:lazy-sqlite-db-modification-time fpath)
  (let* ((glob-list (handle-exceptions
			exn
		      (begin
			(dbfile:print-err "Failed to glob " fpath "*, exn=" exn)
			`(,(conc "/no/such/file, message: " ((condition-property-accessor 'exn 'message) exn))))
		      (glob (conc fpath "*"))))
         (file-list (if (eq? 0 (length glob-list))
			'("/no/such/file")
			glob-list)))
  (apply max
	 (map
	  dbfile:lazy-modification-time 
	  file-list))))

;; dot-locking egg seems not to work, using this for now
;; if lock is older than expire-time then remove it and try again
;; to get the lock
;;
(define (dbfile:simple-file-lock fname #!key (expire-time 300))
  (let ((fmod-time (handle-exceptions
		       ext
		     (current-seconds)
		     (file-modification-time fname))))

    ;; if the file exists, if it has expired, delete it and call this function recursively.
    (if (file-exists? fname)
	(if (> (- (current-seconds) fmod-time) expire-time)
	    (begin
              (dbfile:print-err "simple-file-lock: removing expired file: " fname)
	      (handle-exceptions exn #f (delete-file* fname))	
	      (dbfile:simple-file-lock fname expire-time: expire-time))
	    #f
        )

        ;; If it doesn't exist, write the host name and process id to the file
	(let ((key-string (conc (get-host-name) "-" (current-process-id) ": " (argv)))
	      (oup        (open-output-file fname)))
	  (with-output-to-port
	      oup
	    (lambda ()
	      (print key-string)))
	  (close-output-port oup)


          ;; sleep 3 seconds and make sure it still exists and contains the same host/process id.
          ;; if not, return #f
	  (thread-sleep! 0.25)
	  (if (file-exists? fname)
	      (handle-exceptions exn
                #f 
                (with-input-from-file fname
	  	  (lambda ()
		    (equal? key-string (read-line)))))
              (begin
                 (dbfile:print-err "dbfile:simple-file-lock created " fname " but it was gone 3 seconds later")
	         #f
              )
          )
       )
    )
  )
)

(define (dbfile:simple-file-lock-and-wait fname #!key (expire-time 300))
  (let ((end-time (+ expire-time (current-seconds))))
    (let loop ((got-lock (dbfile:simple-file-lock fname expire-time: expire-time)))
      (if got-lock
	  #t
	  (if (> end-time (current-seconds))
	      (begin
		(thread-sleep! 3)
		(loop (dbfile:simple-file-lock fname expire-time: expire-time)))
	      #f)))))

(define (dbfile:simple-file-release-lock fname)
  (handle-exceptions
      exn
      #f ;; I don't really care why this failed (at least for now)
    (delete-file* fname)))

(define (dbfile:with-simple-file-lock fname proc #!key (expire-time 300))
  (let ((start-time (current-seconds))
        (gotlock (dbfile:simple-file-lock-and-wait fname expire-time: expire-time))
        (end-time (current-seconds))
        )
    (if gotlock
	(let ((res (proc)))
	  (dbfile:simple-file-release-lock fname)
	  res)
        (begin
          (dbfile:print-err "dbfile:with-simple-file-lock: " fname " is locked by "
			    (with-input-from-file fname
			      (lambda ()
				(dbfile:print-err (read-line)))))
          (dbfile:print-err "wait time = " (- end-time start-time))
	  (dbfile:print-err "ERROR: simple file lock could not get a lock for " fname " in " expire-time " seconds")
          #f
        )
    )
  )
)


(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))

)
