From: "Ludovic Courtès" <ludo@gnu.org>
To: 36351@debbugs.gnu.org
Subject: [bug#36351] [PATCH 06/10] derivations: 'derivation' preserves pointer equality.
Date: Mon, 24 Jun 2019 14:22:08 +0200 [thread overview]
Message-ID: <20190624122212.5932-6-ludo@gnu.org> (raw)
In-Reply-To: <20190624122212.5932-1-ludo@gnu.org>
* guix/derivations.scm (derivation): Check if FILE is already in
%DERIVATION-CACHE and return it if it is.
---
guix/derivations.scm | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/guix/derivations.scm b/guix/derivations.scm
index 5c568f223b..403e86749b 100644
--- a/guix/derivations.scm
+++ b/guix/derivations.scm
@@ -873,8 +873,12 @@ derivation. It is kept as-is, uninterpreted, in the derivation."
(append (map derivation-input-path inputs)
sources)))
(drv* (set-field drv (derivation-file-name) file)))
- (hash-set! %derivation-cache file drv*)
- drv*)))
+ ;; Preserve pointer equality. This improves the performance of
+ ;; 'eq?'-memoization on derivations.
+ (or (hash-ref %derivation-cache file)
+ (begin
+ (hash-set! %derivation-cache file drv*)
+ drv*)))))
(define (invalidate-derivation-caches!)
"Invalidate internal derivation caches. This is mostly useful for
--
2.22.0
next prev parent reply other threads:[~2019-06-24 12:23 UTC|newest]
Thread overview: 12+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-06-24 12:18 [bug#36351] [PATCH 00/10] Add 'derivation-build-plan', improve (guix derivations) Ludovic Courtès
2019-06-24 12:22 ` [bug#36351] [PATCH 01/10] derivations: Add 'derivation-input' Ludovic Courtès
2019-06-24 12:22 ` [bug#36351] [PATCH 02/10] derivations: Rewrite and replace 'derivations-prerequisites-to-build' Ludovic Courtès
2019-06-24 12:22 ` [bug#36351] [PATCH 03/10] ui: 'show-what-to-build' uses 'derivation-build-plan' Ludovic Courtès
2019-06-24 12:22 ` [bug#36351] [PATCH 04/10] graph: Use 'derivation-input-derivation' Ludovic Courtès
2019-06-24 12:22 ` [bug#36351] [PATCH 05/10] derivations: <derivation-input> now aggregates a <derivation> Ludovic Courtès
2019-06-24 12:22 ` Ludovic Courtès [this message]
2019-06-24 12:22 ` [bug#36351] [PATCH 07/10] derivations: 'build-derivations' can be passed derivation inputs Ludovic Courtès
2019-06-24 12:22 ` [bug#36351] [PATCH 08/10] packages: 'specification->package+output' distinguishes "no output specified" Ludovic Courtès
2019-06-24 12:22 ` [bug#36351] [PATCH 09/10] ui: 'show-what-to-build' accepts derivation inputs Ludovic Courtès
2019-06-24 12:22 ` [bug#36351] [PATCH 10/10] ui: 'show-derivation-outputs' accepts <derivation-input> records Ludovic Courtès
2019-06-27 9:17 ` bug#36351: [PATCH 00/10] Add 'derivation-build-plan', improve (guix derivations) Ludovic Courtès
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