summaryrefslogtreecommitdiff
path: root/guix/packages.scm
diff options
context:
space:
mode:
authorLudovic Courtès <ludo@gnu.org>2015-07-11 23:13:24 +0200
committerLudovic Courtès <ludo@gnu.org>2015-07-12 01:27:00 +0200
commit161094c8e2b46128544b85dae8e97d4fcb2818c0 (patch)
tree00f9eb24f608fd5b75ca8298ae6dc781f0a119fa /guix/packages.scm
parent686784d0b958478a0fd8a2fbf69755ceea2d27ec (diff)
packages: Rewrite 'transitive-inputs' to be linear and remove duplicates.
There were two issues: 1. Use of 'delete-duplicates', which is quadratic, was a serious problem for closures with lots of propagated inputs, such as that of the 'hydra' package (several minutes for 'guix build hydra -n'!). 2. The 'delete-duplicates' call essentially had no effect since duplicate inputs typically had a different label and were thus kept. For instance, (bag-transitive-inputs (package->bag inkscape)) would return 216 items whereas (delete-duplicates (map cdr THAT)) contains only 67 items. The new implementation returns 67 items in this case. For 'hydra', we're down from 42211 items to 361, and roughly 13s for 'guix build hydra'. * guix/packages.scm (transitive-inputs): Rewrite as a breadth-first traversal. Remove duplicate propagated inputs. * tests/packages.scm ("package-transitive-inputs", "package->bag, propagated inputs"): Adjust to use simple labels for propagated inputs, without "/". ("package-transitive-inputs, no duplicates"): New test.
Diffstat (limited to 'guix/packages.scm')
-rw-r--r--guix/packages.scm40
1 files changed, 28 insertions, 12 deletions
diff --git a/guix/packages.scm b/guix/packages.scm
index 5a280857ea..34222724c0 100644
--- a/guix/packages.scm
+++ b/guix/packages.scm
@@ -491,21 +491,37 @@ IMPORTED-MODULES specify modules to use/import for use by SNIPPET."
#:guile-for-build guile-for-build))))
(define (transitive-inputs inputs)
- (let loop ((inputs inputs)
- (result '()))
+ "Return the closure of INPUTS when considering the 'propagated-inputs'
+edges. Omit duplicate inputs, except for those already present in INPUTS
+itself.
+
+This is implemented as a breadth-first traversal such that INPUTS is
+preserved, and only duplicate propagated inputs are removed."
+ (define (seen? seen item outputs)
+ (match (vhash-assq item seen)
+ ((_ . o) (equal? o outputs))
+ (_ #f)))
+
+ (let loop ((inputs inputs)
+ (result '())
+ (propagated '())
+ (first? #t)
+ (seen vlist-null))
(match inputs
(()
- (delete-duplicates (reverse result))) ; XXX: efficiency
- (((and i (name (? package? p) sub ...)) rest ...)
- (let ((t (map (match-lambda
- ((dep-name derivation ...)
- (cons (string-append name "/" dep-name)
- derivation)))
- (package-propagated-inputs p))))
- (loop (append t rest)
- (append t (cons i result)))))
+ (if (null? propagated)
+ (reverse result)
+ (loop (reverse (concatenate propagated)) result '() #f seen)))
+ (((and input (label (? package? package) outputs ...)) rest ...)
+ (if (and (not first?) (seen? seen package outputs))
+ (loop rest result propagated first? seen)
+ (loop rest
+ (cons input result)
+ (cons (package-propagated-inputs package) propagated)
+ first?
+ (vhash-consq package outputs seen))))
((input rest ...)
- (loop rest (cons input result))))))
+ (loop rest (cons input result) propagated first? seen)))))
(define (package-direct-sources package)
"Return all source origins associated with PACKAGE; including origins in