civodul pushed a commit to branch master
in repository guix.
commit 97e7e47d6f1e036e1ed6bd3f428e40d9794a3353
Author: Ludovic Courtès <l...@gnu.org>
AuthorDate: Mon Dec 2 17:06:52 2024 +0100
packages: Optimize ‘all-packages’.
On my laptop, wall-clock time for (all-packages) goes from 27s to 1s.
* gnu/packages.scm (all-packages): Use a hash table to remember visited
packages instead of calling ‘delete-duplicates’ on the final list.
Change-Id: I4aae804656b56ef2095993e91f0572a5891f419f
---
gnu/packages.scm | 32 ++++++++++++++++++++------------
1 file changed, 20 insertions(+), 12 deletions(-)
diff --git a/gnu/packages.scm b/gnu/packages.scm
index 1af3b8d440..bdd5d21940 100644
--- a/gnu/packages.scm
+++ b/gnu/packages.scm
@@ -258,18 +258,26 @@ is guaranteed to never traverse the same package twice."
(mlambda ()
"Return the list of all public packages, including replacements and hidden
packages, excluding superseded packages."
- (delete-duplicates
- (fold-packages (lambda (package result)
- (match (package-replacement package)
- ((? package? replacement)
- (cons* replacement package result))
- (#f
- (cons package result))))
- '()
-
- ;; Dismiss deprecated packages but keep hidden packages.
- #:select? (negate package-superseded))
- eq?)))
+ ;; Note: 'fold-packages' never traverses the same package twice but
+ ;; replacements break that (they may or may not be visible to
+ ;; 'fold-packages'), hence this hash table to track visited packages.
+ (define visited (make-hash-table))
+
+ (fold-packages (lambda (package result)
+ (if (hashq-ref visited package)
+ result
+ (begin
+ (hashq-set! visited package #t)
+ (match (package-replacement package)
+ ((? package? replacement)
+ (hashq-set! visited replacement #t)
+ (cons* replacement package result))
+ (#f
+ (cons package result))))))
+ '()
+
+ ;; Dismiss deprecated packages but keep hidden packages.
+ #:select? (negate package-superseded))))
(define %package-cache-file
;; Location of the package cache.
