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| author | Ludovic Courtès <ludo@gnu.org> | 2015-10-14 18:40:33 +0200 |
|---|---|---|
| committer | Ludovic Courtès <ludo@gnu.org> | 2015-10-14 21:39:06 +0200 |
| commit | 80a67734834a0981ca65cf1757a7d8408d02f1fd (patch) | |
| tree | 4f622b3c5a725544736a75eaee52c6b4db6b29e0 /gnu/services | |
| parent | c5d735f798e0e58774b9ce0c6197695bc6f0daa9 (diff) | |
| download | guix-80a67734834a0981ca65cf1757a7d8408d02f1fd.tar guix-80a67734834a0981ca65cf1757a7d8408d02f1fd.tar.gz | |
services: Add 'dmd-service-back-edges'.
* gnu/services/dmd.scm (dmd-service-back-edges): New procedure.
* tests/services.scm ("dmd-service-back-edges"): New test.
Diffstat (limited to 'gnu/services')
| -rw-r--r-- | gnu/services/dmd.scm | 34 |
1 files changed, 33 insertions, 1 deletions
diff --git a/gnu/services/dmd.scm b/gnu/services/dmd.scm index 7b6434a0ae..e87b9e4415 100644 --- a/gnu/services/dmd.scm +++ b/gnu/services/dmd.scm @@ -27,7 +27,9 @@ #:use-module (gnu services) #:use-module (gnu packages admin) #:use-module (ice-9 match) + #:use-module (ice-9 vlist) #:use-module (srfi srfi-1) + #:use-module (srfi srfi-26) #:use-module (srfi srfi-34) #:use-module (srfi srfi-35) #:export (dmd-root-service-type @@ -42,7 +44,9 @@ dmd-service-respawn? dmd-service-start dmd-service-stop - dmd-service-auto-start?)) + dmd-service-auto-start? + + dmd-service-back-edges)) ;;; Commentary: ;;; @@ -179,4 +183,32 @@ failure." (gexp->file "dmd.conf" config))) +(define (dmd-service-back-edges services) + "Return a procedure that, when given a <dmd-service> from SERVICES, returns +the list of <dmd-service> that depend on it." + (define provision->service + (let ((services (fold (lambda (service result) + (fold (cut vhash-consq <> service <>) + result + (dmd-service-provision service))) + vlist-null + services))) + (lambda (name) + (match (vhash-assq name services) + ((_ . service) service) + (#f #f))))) + + (define edges + (fold (lambda (service edges) + (fold (lambda (requirement edges) + (vhash-consq (provision->service requirement) service + edges)) + edges + (dmd-service-requirement service))) + vlist-null + services)) + + (lambda (service) + (vhash-foldq* cons '() service edges))) + ;;; dmd.scm ends here |