Megatest

;;======================================================================
;; 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 inmem one-db file per server method goes in here
;;======================================================================

(define (dbmod:with-db dbstruct run-id r/w proc params)
  (let* ((dbdat  (dbmod:open-db dbstruct run-id (dbfile:db-init-proc)))
	 (dbh    (dbr:dbdat-dbh dbdat)) ;; this will be the inmem handle
	 (dbfile (dbr:dbdat-dbfile dbdat)))
    (apply proc dbdat dbh params)))

(define (dbmod:open-inmem-db initproc)
  (let* ((db      (sqlite3:open-database ":memory:"))
	 (handler (sqlite3:make-busy-timeout 3600)))
    (sqlite3:set-busy-handler! db handler)

			  (lambda ()
			    (let* ((db      (sqlite3:open-database dbfullname))
				   (handler (sqlite3:make-busy-timeout 136000)))
			      (sqlite3:set-busy-handler! db handler)
			      (if write-access
				  (init-proc db))
			      db)))))
	 (db            ;; (if (dbmod:need-on-disk-db-handle)
			    (open-the-db))
;;			    #f))
	 (tables       (db:sync-all-tables-list keys)))
    (dbr:dbstruct-inmem-set!     dbstruct inmem)
    (dbr:dbstruct-ondiskdb-set!  dbstruct db)
    (dbr:dbstruct-dbfile-set!    dbstruct dbfullname)
    (dbr:dbstruct-dbfname-set!   dbstruct dbfname)
    (dbr:dbstruct-sync-proc-set! dbstruct
				 (lambda (last-update)
				   ;; (if db
				       (dbmod:sync-gasket tables last-update inmem db
						    dbfullname syncdir))) ;; )
    ;; (dbmod:sync-tables tables #f db inmem)
    ;; (if db
    (dbmod:sync-gasket tables #f inmem db dbfullname 'fromdest) ;; ) ;; load into inmem
    (dbr:dbstruct-last-update-set! dbstruct (current-seconds)) ;; should this be offset back in time by one second?
    dbstruct))

;;    (if (eq? syncdir 'todisk) ;; sync to disk normally, sync from in dashboard
;;        (dbmod:sync-tables tables last-update inmem db)
;;        (dbmod:sync-tables tables last-update db inmem))))

;; direction: 'fromdest 'todest
;;
(define (dbmod:sync-gasket tables last-update inmem dbh dbfname direction)
  (case (dbfile:sync-method)
    ((none) #f)
    ((attach)
     (dbmod:attach-sync tables inmem dbfname direction))
    ((newsync)
     (dbmod:new-sync tables inmem dbh dbfname direction))
    (else
     (case direction
       ((todisk)
	(dbmod:sync-tables tables last-update inmem dbh)
	)
       (else
	(dbmod:sync-tables tables last-update dbh inmem))))))


(define (dbmod:close-db dbstruct)
  ;; do final sync to disk file
  ;; (do-sync ...)

	 (sqlite3:for-each-row
	  (lambda (a . b)
	    (hash-table-set! todat a (apply vector a b)))
	  todb
	  full-sel)
	 
	 ;; first pass implementation, just insert all changed rows
	 
	 (let* ((db                 todb)
                (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)
	      (mutex-lock! *db-transaction-mutex*)
	      (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)))
	      (mutex-unlock! *db-transaction-mutex*))
	    fromdats)
	   
	   (sqlite3:finalize! stmth)
           (if (member "last_update" field-names)
               (db:create-trigger db tablename)))
	 ))
     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)

			       " SELECT * FROM "fromdb table";"))
		  (stmt8 (conc "UPDATE "todb table" SET ("no-id-fields-str") = (SELECT "no-id-fields-str" FROM "fromdb table" WHERE "todb table".id="fromdb table".id"
			       (if (member "last_update" fields)
				   (conc " AND "fromdb table".last_update > "todb table".last_update);")
				   ");")))
		  (start-ms (current-milliseconds)))
	     ;; (debug:print 0 *default-log-port* "stmt8="stmt8)
	     ;; (if (sqlite3:auto-committing? dbh)
	     ;; (begin
	     (mutex-lock! *db-transaction-mutex*)
	     (sqlite3:with-transaction
	      dbh
	      (lambda ()
		(debug:print-info 0 *default-log-port* "Sync from "fromdb table" to "todb table" using "stmt1)
		(sqlite3:execute dbh stmt1)    ;; get all new rows
		
		#;(if (member "last_update" fields)
		(sqlite3:execute dbh stmt8))    ;; get all updated rows
		;; (sqlite3:execute dbh stmt5)
		;; (sqlite3:execute dbh stmt4) ;; if it worked this would be better for incremental up
		;; (sqlite3:execute dbh stmt6)
		))
	     (debug:print 0 *default-log-port* "Synced table "table
			  " in "(- (current-milliseconds) start-ms)"ms") ;; )
	     (mutex-unlock! *db-transaction-mutex*)))
	     
	 ;; (debug:print 0 *default-log-port* "Skipping sync of table "table" due to transaction in flight."))))
	 table-names)
	(sqlite3:execute dbh "DETACH auxdb;"))))

;; FAILED ATTEMPTS

	     ;; (if (not (has-last-update dbh table))
	     ;;     (sqlite3:execute dbh (conc "ALTER TABLE "table" ADD COLUMN last_update INTEGER;")))