Megatest

  (subdbs (make-hash-table))
  )

;; NOTE: Need one dbr:subdb per main.db, 1.db ...
;;
(defstruct dbr:subdb
  (dbname      #f) ;; .db/1.db
  (mtdbfile    #f) ;; mtrah/.db/1.db
  (mtdbdat     #f) ;; only need one of these for syncing
  ;; (dbdats      (make-hash-table))  ;; id => dbdat 
  (tmpdbfile   #f) ;; /tmp/.../.db/1.db
  ;; (refndbfile  #f) ;; /tmp/.../.db/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

   ((not run-id)     (conc ".db/main.db"))
   (else             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* *dbstruct-dbs*);; TODO: when multiple areas are supported, this optimization will be a hazard
   (else ;;(common:on-homehost?)
    (let* ((dbstruct (make-dbr:dbstruct)))
      #;(when (not *toppath*)
        (debug:print-info 0 *default-log-port* "in db:setup, *toppath* not set; calling launch:setup")
        (launch:setup areapath: areapath))
      (set! *dbstruct-dbs* dbstruct)
      (dbr:dbstruct-areapath-set! dbstruct areapath)
      (dbr:dbstruct-tmppath-set!  dbstruct tmppath)
      dbstruct))))

#;(define (dbfile:get-subdb dbstruct run-id)
  (let* ((res (hash-table-ref/default (dbr:dbstruct-subdbs dbstruct) (dbfile:run-id->key run-id) #f)))
    (if res
	res
	(let* ((newsubdb (make-dbr:subdb)))
	  (db:open-db newsubdb run-id areapath: (dbr:dbstruct-areapath dbstruct) do-sync: #t)

;;    if run-id => get run specific db
;;    if #f     => get main db
;;    if run-id is a string treat it as a filename
;;    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
	(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)))
    (stack-push! (dbr:subdb-dbstack subdb) dbdat)))

;; returns the dbstruct with needed data populated
;;  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
	(let* ((dbname    (db:run-id->dbname run-id))
	       (areapath  (dbr:dbstruct-areapath dbstruct))
	       (tmppath   (dbr:dbstruct-tmppath  dbstruct))
	       (mtdbpath  (db:run-id->path areapath run-id))
	       (tmpdbpath (db:run-id->path tmppath run-id))
	       (mtdbdat   (dbfile:open-sqlite3-db mtdbpath init-proc))
	       (tmpdbdat  (dbfile:open-sqlite3-db tmpdbpath init-proc)) ;; push this on the stack
	       (newsubdb  (make-dbr:subdb dbname:    dbname
					  mtdbfile:  mtdbpath
					  tmpdbfile: tmpdbpath
					  mtdbdat:   mtdbdat)))
	  (dbfile:add-dbdat dbstruct run-id tmpdbdat)
	  (dbfile:set-subdb dbstruct run-id newsubdb)
	  (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 (db:run-id->path tmppath run-id)))
		(dbfile:open-sqlite3-db tmpdbpath init-proc)))))))

;; COMBINE dbfile:open-sqlite-db and dbfile:lock-create-open
;;

;; Open the classic megatest.db file (defaults to open in toppath)
;;
;;   NOTE: returns a dbdat not a dbstruct!
;;
(define (dbfile:open-sqlite-db dbpath init-proc)
  (let* ((dbexists     (file-exists? dbpath))
	 (db           (dbfile:lock-create-open dbpath
					    (lambda (db)
                                              (db:initialize-main-db db))))
	 (write-access (file-write-access? dbpath)))
    (dbfile:print-err  "db:open-megatest-db "dbpath)
    (if (and dbexists (not write-access))
	(set! *db-write-access* #f))
    ;; (cons db dbpath)))
    (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))))
    
;; open an sql database inside a file lock
;; returns: db existed-prior-to-opening
;; RA => Returns a db handler; sets the lock if opened in writable mode
;;
;; (define *db-open-mutex* (make-mutex))
;;
(define (dbfile:lock-create-open fname initproc)
  (let* ((parent-dir   (or (pathname-directory fname)(current-directory))) ;; no parent? go local
         (raw-fname    (pathname-file fname))
	 (dir-writable (file-write-access? parent-dir))
	 (file-exists  (file-exists? fname))
	 (file-write   (if file-exists
			   (file-write-access? fname)
			   dir-writable )))
    ;; (mutex-lock! *db-open-mutex*) ;; tried this mutex, not clear it helped.
    (if file-write ;; dir-writable
	(condition-case
         (let* ((lockfname   (conc fname ".lock"))
                (readyfname  (conc parent-dir "/.ready-" raw-fname))
                (readyexists (common:file-exists? readyfname)))
           (if (not readyexists)
               (common:simple-file-lock-and-wait lockfname))
           (let ((db      (sqlite3:open-database fname)))
             (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
             (sqlite3:execute db "PRAGMA synchronous = 0;")
             (if (not file-exists)
                 (initproc db))
             (if (not readyexists)
                 (begin
                   (common:simple-file-release-lock lockfname)
                   (with-output-to-file
                       readyfname
                     (lambda ()
                       (print "Ready at " 
                              (seconds->year-work-week/day-time 
                               (current-seconds)))))))
             db))
         (exn (io-error)  (dbfile:print-and-exit "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again."))
         (exn (corrupt)   (dbfile:print-and-exit "ERROR: database " fname " is corrupt. Repair it to proceed."))
         (exn (busy)      (dbfile:print-and-exit "ERROR: database " fname " is locked. Try copying to another location, remove original and copy back."))
         (exn (permission)(dbfile:print-and-exit "ERROR: database " fname " has some permissions problem."))
         (exn () (dbfile:print-and-exit "ERROR: Unknown error with database " fname " message: " ((condition-property-accessor 'exn 'message) exn))))
        
	(condition-case
         (begin
           (dbfile:print-err "WARNING: opening db in non-writable dir " fname)
           (let ((db (sqlite3:open-database fname)))
             (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
             (sqlite3:execute db "PRAGMA synchronous = 0;")
	     ;; (mutex-unlock! *db-open-mutex*)
             db))
         (exn (io-error)
	      (dbfile:print-and-exit
	       "ERROR: i/o error with " fname ". Check permissions, disk space etc. and try again."))
         (exn (corrupt)
	      (dbfile:print-and-exit
	       "ERROR: database " fname " is corrupt. Repair it to proceed."))
         (exn (busy)
	      (dbfile:print-and-exit
	       "ERROR: database " fname " is locked. Try copying to another location, remove original and copy back."))
         (exn (permission)
	      (dbfile:print-and-exit
	       "ERROR: database " fname " has some permissions problem."))
         (exn ()
	      (dbfile:print-and-exit
	       "ERROR: Unknown error with database " fname " message: " ((condition-property-accessor 'exn 'message) exn))))
	)))


;; This routine creates the db if not already present. It is only called if the db is not already opened
;;
(define (db:init-dbstruct dbstruct run-id init-proc #!key (do-sync #t))
  (let* ((subdb          (dbfile:get-subdb dbstruct run-id))
	 (tmpdb-stack    (dbr:subdb-dbstack subdb)) 
	 (max-stale-tmp  (dbr:dbstruct-max-stale-secs dbstruct));; (configf:lookup-number *configdat* "server" "filling-db-max-stale-seconds" default: 10))
	   (dbpath       (dbr:dbstruct-tmppath dbstruct)) ;;  (db:dbfile-path))      ;; path to tmp db area
	   (dbname       (db:run-id->dbname run-id))
	   (dbexists     (file-exists? dbpath))
	   (areapath     (dbr:dbstruct-areapath dbstruct))
	   (mtdbfname    (conc areapath "/"dbname))
	   (mtdbexists   (file-exists? mtdbfname))
	   (mtdbmodtime  (if mtdbexists (dbfile:lazy-sqlite-db-modification-time mtdbfname)  #f))
	   (mtdb         (db:open-sqlite-db mtdbfname init-proc))
	   ;; the reference db for syncing
	   (refdbfname   (conc dbpath "/"dbname"_ref"))
	   (refndb       (db:open-megatest-db refdbfname))
	   ;; (mtdbpath     (dbr:dbdat-dbfile mtdb))
	   ;; the tmpdb
	   (tmpdbfname   (conc dbpath"/"dbname)) ;; /tmp/<stuff>/.db/[main|1,2...].db 
	   (tmpdb        (db:open-megatest-db tmpdbfname)) ;; lock-create-open dbpath db:initialize-main-db))
	   (dbfexists    (common:file-exists? tmpdbfname))  ;; (conc dbpath "/megatest.db")))
	   (tmpdbmodtime (if dbfexists  (common:lazy-sqlite-db-modification-time tmpdbfname) #f))
	   
	   (write-access (file-write-access? mtdbfname))
	   
	   ;; (mtdbmodtime (if mtdbexists
	   ;; (common:lazy-sqlite-db-modification-time mtdbpath)
	   ;; #f)) ; moving this before db:open-megatest-db is
	   ;; called. if wal mode is on -WAL and -shm file get
	   ;; created with causing the tmpdbmodtime timestamp
	   ;; always greater than mtdbmodtime (tmpdbmodtime (if
	   ;; dbfexists (common:lazy-sqlite-db-modification-time
	   ;; tmpdbfname) #f)) if wal mode is on -WAL and -shm
	   ;; file get created when db:open-megatest-db is
	   ;; called. modtimedelta will always be < 10 so db in
	   ;; tmp not get synced (tmpdbmodtime (if dbfexists
	   ;; (db:get-last-update-time (car tmpdb)) #f)) (fmt
	   ;; (file-modification-time tmpdbfname))
	   
	   (modtimedelta (and mtdbmodtime tmpdbmodtime (- mtdbmodtime tmpdbmodtime))))

    (when write-access
      (sqlite3:execute (dbr:dbdat-dbh mtdb) "drop trigger if exists update_tests_trigger")
      (sqlite3:execute (dbr:dbdat-dbh mtdb) "drop trigger if exists update_runs_trigger"))
    
    ;; (print "mtdbmodtime " mtdbmodtime " tmpdbmodtime " tmpdbmodtime " mtdbpath " mtdbpath " " (conc *toppath* "/megatest.db"))
    ;; (debug:print-info 13 *default-log-port* "db:open-db>> mtdbpath="mtdbpath" mtdbexists="mtdbexists" and write-access="write-access)
    (if (and dbexists (not write-access))
	(begin
	  (set! *db-write-access* #f)
	  (dbr:subdb-read-only-set! subdb #t)))
    (dbr:subdb-mtdb-set!   subdb mtdb)
    (dbr:subdb-tmpdb-set!  subdb tmpdb)
    (dbr:subdb-dbstack-set! subdb (make-stack)) ;; BB: why a stack?  Why would the number of db's be indeterminate?  Is this a legacy of 1.db 2.db .. ?
    (stack-push! (dbr:subdb-dbstack subdb) tmpdb) ;; olddb is already a (cons db path)
    (dbr:subdb-refndb-set! subdb refndb)
    (if (and  (or (not dbfexists)
		  (and modtimedelta
		       (> modtimedelta max-stale-tmp))) ;; if db in tmp is over ten seconds older than the file in MTRA then do a sync back
	      do-sync)
	(begin
	  (dbfile:print-err "filling db " (dbr:dbdat-dbfile tmpdb) " with data \n    from " (dbr:dbdat-dbfile mtdb) " mod time delta: " modtimedelta)
	  (db:sync-tables (db:sync-all-tables-list subdb) #f mtdb refndb tmpdb)
	  ;; touch tmp db to avoid wal mode wierdness  
	  (set! (file-modification-time tmpdbfname) (current-seconds))  
	  (dbfile:print-err "INFO: db:sync-all-tables-list done.")
	  )
	(dbfile:print-err " db, " (dbr:dbdat-dbfile tmpdb) " already exists or fresh enough, not propogating data from\n     " (dbr:dbdat-dbfile mtdb) " mod time delta: " modtimedelta) )
    ;; (db:multi-db-sync subdb 'old2new))  ;; migrate data from megatest.db automatically
    tmpdb))
		
;;======================================================================
;; no-sync.db - small bits of data to be shared between servers
;;======================================================================

(define (dbfile:open-no-sync-db dbpath)
  (let* (;; (dbpath (db:dbfile-path))
	 (dbname (conc dbpath "/no-sync.db"))
	 (db-exists (file-exists? dbname))
	 (db     (sqlite3:open-database dbname)))
    (sqlite3:set-busy-handler! db (sqlite3:make-busy-timeout 136000))
    (if (not db-exists)
	(begin
	  (sqlite3:execute db "PRAGMA synchronous = 0;")
	  (sqlite3:execute db "CREATE TABLE IF NOT EXISTS no_sync_metadat (var TEXT,val TEXT, CONSTRAINT no_sync_metadat_constraint UNIQUE (var));")
	  (sqlite3:execute db "PRAGMA journal_mode=WAL;")))
    db))

;;======================================================================
;; 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 modifcation 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 (common:simple-file-lock fname #!key (expire-time 300))
  (let ((fmod-time (handle-exceptions
		       ext
		     (current-seconds)
		     (file-modification-time fname))))
    (if (file-exists? fname)
	(if (> (- (current-seconds) fmod-time) expire-time)
	    (begin
	      (handle-exceptions exn #f (delete-file* fname))	
	      (common:simple-file-lock fname expire-time: expire-time))
	    #f)
	(let ((key-string (conc (get-host-name) "-" (current-process-id))))
	  (with-output-to-file fname
	    (lambda ()
	      (print key-string)))
	  (thread-sleep! 0.25)
	  (if (file-exists? fname)
	      (handle-exceptions exn
                #f 
                (with-input-from-file fname
	  	  (lambda ()
		    (equal? key-string (read-line)))))
	      #f)))))

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

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


)