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;; Make the dbstruct, call for main db at least once
;; sync disk db to inmem
;;
;; called in http-transport and replicated in rmt.scm for *local* access.
;;
(define (db:setup run-id)
(assert *toppath* "FATAL: db:setup called before toppath is available.")
(let* ((dbstruct (make-dbr:dbstruct)))
(db:get-dbdat dbstruct *toppath* run-id)
(set! *dbstruct-db* dbstruct)
dbstruct))
;;======================================================================
;; setting/getting a lock on the db for only one server per db
;;
;; NOTE:
;; These operate directly on the disk file, NOT on the inmemory db
;; The lockname is the filename (can have many to one, run-id to fname
;;======================================================================
(define (db:get-iam-server-lock dbstruct apath run-id)
(let* ((dbh (db:get-ddb apath dbstruct run-id))
(dbfname (db:run-id->path run-id)))
(sqlite3:with-transaction
dbh
(lambda ()
(let* ((locked (db:get-locker dbh dbfname)))
(if (not locked)
(db:take-lock dbh dbfname)))))))
;; (exn sqlite3)
(define (db:get-locker dbh dbfname)
(condition-case
(sqlite3:first-row dbh "SELECT owner_id,owner_host,event_time FROM locks WHERE lockname=%;" dbfname)
(exn (sqlite3) #f)))
(define (db:take-lock dbh dbfname)
(condition-case
(sqlite3:first-row dbh "INSERT INTO locks lockname,owner_id,owner_host VALUES (?,?,?);" dbfname (current-process-id) (get-host-name))
(exn (sqlite3) #f)))
(define (db:release-lock dbh dbfname)
(sqlite3:execute dbh "DELETE FROM locks WHERE lockname=?;" dbfname))
;;======================================================================
;; SQLITE3 HELPERS
;;======================================================================
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;; Make the dbstruct, call for main db at least once
;; sync disk db to inmem
;;
;; called in http-transport and replicated in rmt.scm for *local* access.
;;
(define (db:setup run-id)
(assert *toppath* "FATAL: db:setup called before toppath is available.")
(let* ((dbstruct (make-dbr:dbstruct))
(db-file (db:run-id->path *toppath* run-id)))
(db:get-dbdat dbstruct *toppath* db-file)
(set! *dbstruct-db* dbstruct)
dbstruct))
;;======================================================================
;; setting/getting a lock on the db for only one server per db
;;
;; NOTE:
;; These operate directly on the disk file, NOT on the inmemory db
;; The lockname is the filename (can have many to one, run-id to fname
;;======================================================================
;; called before db is open?
;;
(define (db:get-iam-server-lock dbh dbfname)
(sqlite3:with-transaction
dbh
(lambda ()
(let* ((locked (db:get-locker dbh dbfname)))
(if (not locked)
(db:take-lock dbh dbfname)
#f)))))
;; (exn sqlite3)
(define (db:get-locker dbh dbfname)
(condition-case
(sqlite3:first-row dbh "SELECT owner_pid,owner_host,event_time FROM locks WHERE lockname=%;" dbfname)
(exn (sqlite3) #f)))
;; should never fail because it is run in a transaction with a test for the lock
;;
(define (db:take-lock dbh dbfname)
;; (condition-case
;; (begin
(sqlite3:execute dbh "INSERT INTO locks (lockname,owner_pid,owner_host) VALUES (?,?,?);" dbfname (current-process-id) (get-host-name))
;; #t)
;; (exn (sqlite3) #f)))
#t)
(define (db:release-lock dbh dbfname)
(sqlite3:execute dbh "DELETE FROM locks WHERE lockname=?;" dbfname))
;;======================================================================
;; SQLITE3 HELPERS
;;======================================================================
|