From f09aea1b58b3ef961d3cc712f116fe4617bc8f90 Mon Sep 17 00:00:00 2001 From: Ludovic Courtès Date: Mon, 14 Mar 2016 16:53:38 +0100 Subject: store: 'references/substitutes' caches its results. * guix/store.scm (%reference-cache): New variable. (references/substitutes): Use it. --- guix/store.scm | 18 +++++++++++++++--- 1 file changed, 15 insertions(+), 3 deletions(-) (limited to 'guix') diff --git a/guix/store.scm b/guix/store.scm index a220b6e6f9..01248738dc 100644 --- a/guix/store.scm +++ b/guix/store.scm @@ -726,14 +726,23 @@ (define references "Return the list of references of PATH." store-path-list)) +(define %reference-cache + ;; Brute-force cache mapping store items to their list of references. + ;; Caching matters because when building a profile in the presence of + ;; grafts, we keep calling 'graft-derivation', which in turn calls + ;; 'references/substitutes' many times with the same arguments. Ideally we + ;; would use a cache associated with the daemon connection instead (XXX). + (make-hash-table 100)) + (define (references/substitutes store items) "Return the list of list of references of ITEMS; the result has the same length as ITEMS. Query substitute information for any item missing from the store at once. Raise a '&nix-protocol-error' exception if reference information for one of ITEMS is missing." (let* ((local-refs (map (lambda (item) - (guard (c ((nix-protocol-error? c) #f)) - (references store item))) + (or (hash-ref %reference-cache item) + (guard (c ((nix-protocol-error? c) #f)) + (references store item)))) items)) (missing (fold-right (lambda (item local-ref result) (if local-ref @@ -757,7 +766,10 @@ (define (references/substitutes store items) (result '())) (match items (() - (reverse result)) + (let ((result (reverse result))) + (for-each (cut hash-set! %reference-cache <> <>) + items result) + result)) ((item items ...) (match local-refs ((#f tail ...) -- cgit v1.2.3