database: Make 'register-items' transactional.

* guix/store/database.scm (SQLITE_BUSY, register-output-sql): New variables.
(add-references): Don't try finalizing after each use, only after all the
uses (otherwise a finalized statement would be used if #:cache? was #f).
(call-with-transaction): New procedure.
(register-items): Use call-with-transaction to prevent broken intermediate
states from being visible.

* .dir-locals.el (call-with-transaction): indent it.

Signed-off-by: Ludovic Courtès <ludo@gnu.org>
This commit is contained in:
Caleb Ristvedt 2019-01-30 17:03:38 -06:00 committed by Ludovic Courtès
parent 274fa49100
commit a4678c6ba1
No known key found for this signature in database
GPG Key ID: 090B11993D9AEBB5
2 changed files with 41 additions and 12 deletions

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@ -79,6 +79,7 @@
(eval . (put 'with-extensions 'scheme-indent-function 1))
(eval . (put 'with-database 'scheme-indent-function 2))
(eval . (put 'call-with-transaction 'scheme-indent-function 2))
(eval . (put 'call-with-container 'scheme-indent-function 1))
(eval . (put 'container-excursion 'scheme-indent-function 1))

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@ -1,5 +1,5 @@
;;; GNU Guix --- Functional package management for GNU
;;; Copyright © 2017 Caleb Ristvedt <caleb.ristvedt@cune.org>
;;; Copyright © 2017, 2019 Caleb Ristvedt <caleb.ristvedt@cune.org>
;;; Copyright © 2018 Ludovic Courtès <ludo@gnu.org>
;;;
;;; This file is part of GNU Guix.
@ -96,6 +96,31 @@ create it and initialize it as a new database."
(lambda ()
(sqlite-close db)))))
;; XXX: missing in guile-sqlite3@0.1.0
(define SQLITE_BUSY 5)
(define (call-with-transaction db proc)
"Start a transaction with DB (make as many attempts as necessary) and run
PROC. If PROC exits abnormally, abort the transaction, otherwise commit the
transaction after it finishes."
(catch 'sqlite-error
(lambda ()
;; We use begin immediate here so that if we need to retry, we
;; figure that out immediately rather than because some SQLITE_BUSY
;; exception gets thrown partway through PROC - in which case the
;; part already executed (which may contain side-effects!) would be
;; executed again for every retry.
(sqlite-exec db "begin immediate;")
(let ((result (proc)))
(sqlite-exec db "commit;")
result))
(lambda (key who error description)
(if (= error SQLITE_BUSY)
(call-with-transaction db proc)
(begin
(sqlite-exec db "rollback;")
(throw 'sqlite-error who error description))))))
(define %default-database-file
;; Default location of the store database.
(string-append %store-database-directory "/db.sqlite"))
@ -172,9 +197,9 @@ ids of items referred to."
(sqlite-bind-arguments stmt #:referrer referrer
#:reference reference)
(sqlite-fold cons '() stmt) ;execute it
(sqlite-finalize stmt)
(last-insert-row-id db))
references)))
references)
(sqlite-finalize stmt)))
(define* (sqlite-register db #:key path (references '())
deriver hash nar-size time)
@ -305,6 +330,7 @@ Write a progress report to LOG-PORT."
(define real-file-name
(string-append store-dir "/" (basename (store-info-item item))))
;; When TO-REGISTER is already registered, skip it. This makes a
;; significant differences when 'register-closures' is called
;; consecutively for overlapping closures such as 'system' and 'bootcfg'.
@ -325,6 +351,8 @@ Write a progress report to LOG-PORT."
(mkdir-p db-dir)
(parameterize ((sql-schema schema))
(with-database (string-append db-dir "/db.sqlite") db
(call-with-transaction db
(lambda ()
(let* ((prefix (format #f "registering ~a items" (length items)))
(progress (progress-reporter/bar (length items)
prefix log-port)))
@ -333,4 +361,4 @@ Write a progress report to LOG-PORT."
(for-each (lambda (item)
(register db item)
(report))
items)))))))
items)))))))))